Volume 16,Issue 5,2018 Table of Contents
2018, 16(5):1-8.
Abstract:
Because o f the complex terrain in the cold and dr y reg ion, ther e ar e few statio ns and little measur ed data. Remote sens2 ing precipitation pr oduct is a useful supplement to the measur ed data. Based on the observed pr ecipitatio n data from the surface met eo ro lo gical stations, taking Kaiko ng Riv er sub2basin of Tarim River basin as t he study area, w e ev aluated the accuracy of four r emo te sensing pr ecipitation products, TRMM 3B42RT , TRM M 3B42V7, CMORPH RAW and CMORPH CRT. Mean2 w hile, in the Yurungkash River sub2basin, based on the SRM model, w e evaluated the applicabilit y of t he abov e remo te sensing pr ecipitatio n pro ducts fo r runo ff simulation. The r esults showed that TRMM 3B42RT had low accur acy w hile the TRMM 3B42V7 had the highest accuracy. CMORPH had high accur acy in mo untaino us areas, but over est imated the precipitation in plain areas. Among the fo ur kinds of remo te sensing precipitat ion pr oducts, TRMM 3B42V7 was the most suitable for r unoff simulatio n, and could basically char acterize the pr ocess o f daily runoff.
Because o f the complex terrain in the cold and dr y reg ion, ther e ar e few statio ns and little measur ed data. Remote sens2 ing precipitation pr oduct is a useful supplement to the measur ed data. Based on the observed pr ecipitatio n data from the surface met eo ro lo gical stations, taking Kaiko ng Riv er sub2basin of Tarim River basin as t he study area, w e ev aluated the accuracy of four r emo te sensing pr ecipitation products, TRMM 3B42RT , TRM M 3B42V7, CMORPH RAW and CMORPH CRT. Mean2 w hile, in the Yurungkash River sub2basin, based on the SRM model, w e evaluated the applicabilit y of t he abov e remo te sensing pr ecipitatio n pro ducts fo r runo ff simulation. The r esults showed that TRMM 3B42RT had low accur acy w hile the TRMM 3B42V7 had the highest accuracy. CMORPH had high accur acy in mo untaino us areas, but over est imated the precipitation in plain areas. Among the fo ur kinds of remo te sensing precipitat ion pr oducts, TRMM 3B42V7 was the most suitable for r unoff simulatio n, and could basically char acterize the pr ocess o f daily runoff.
2018, 16(5):9-15.
Abstract:
The urban co ncave o verpass bridges can easily become " art ificial waterlog g ing zone" since the area beneath t he bridg e is usually lower than the surr ounding ar eas, which leads to frequent w aterlog g ing disasters, endang ering the safet y o f urban tr af2 fic, pedestrians, and vehicles. T her efor e, effective simulatio n o f r ainst orm waterlo gg ing pr ocesses in ur ban over pass bridg e ar ea will hav e important practical sig nificance fo r ur ban f loo d co nt ro l, disaster r eduction, and t raffic emer gency manag ement. It can pr ov ide impo rtant t echnical suppo rt for solv ing the ur ban w aterlog g ing pr oblems. I n this study, both M ike Urban and M ike21 FM mo dels w ere used to simulate the waterlo gg ing pro cesses o f the 3 h r ainstorm o bserv ed in July 18, 2007 at Huang tai Bridg e rain g aug e st ation and the design precipitatio n w ith different return periods at t he Lix ia ov erpass bridg e ar ea in Jicnan cit y. T he results of t his study showed that the depth of waterlo gg ing in the lowest area under the Lix ia over pass bridge co uld r each abo ut 11 95 m during the 2007. 07. 18 r ainsto rm ev ent, which was hig her than that in a 1002year rainstorm in Jicnan cit y.
The urban co ncave o verpass bridges can easily become " art ificial waterlog g ing zone" since the area beneath t he bridg e is usually lower than the surr ounding ar eas, which leads to frequent w aterlog g ing disasters, endang ering the safet y o f urban tr af2 fic, pedestrians, and vehicles. T her efor e, effective simulatio n o f r ainst orm waterlo gg ing pr ocesses in ur ban over pass bridg e ar ea will hav e important practical sig nificance fo r ur ban f loo d co nt ro l, disaster r eduction, and t raffic emer gency manag ement. It can pr ov ide impo rtant t echnical suppo rt for solv ing the ur ban w aterlog g ing pr oblems. I n this study, both M ike Urban and M ike21 FM mo dels w ere used to simulate the waterlo gg ing pro cesses o f the 3 h r ainstorm o bserv ed in July 18, 2007 at Huang tai Bridg e rain g aug e st ation and the design precipitatio n w ith different return periods at t he Lix ia ov erpass bridg e ar ea in Jicnan cit y. T he results of t his study showed that the depth of waterlo gg ing in the lowest area under the Lix ia over pass bridge co uld r each abo ut 11 95 m during the 2007. 07. 18 r ainsto rm ev ent, which was hig her than that in a 1002year rainstorm in Jicnan cit y.
2018, 16(5):16-20.
Abstract:
The ra infall in t he low er r eaches of the Tayang river is abundant and frequently causes flood disasters. It is urg ent to build a floo d r outing analysis model fo r the river to pr ovide suppo rt fo r the formulation o f scient ific floo d co ntr ol and disaster mitig atio n measures. Based on the measured sectio n data and hig h2precision DEM of the low er reaches of the Tayang river, w e established a 12D hydrodynamic model of the river section and a 22D hydro dy namic model o f the flo od t hr eat zo nes on bo th banks by M IKE FLOOD, and r ealized t he r eal2time dynamic coupling of the tw o. T hen w e analyzed the evo lution pro cess and inundat ion risk o f a 502year flood in the lower r eaches, calculated the inundatio n r ang e and w ater depth dist ribution in differ ent periods, and analyzed the rationalit y of t he calculat ion results using w ater balance analysis and flow field distributio n. The re2 sults show ed that the model can eff ectively simulate the pr ocess of flood routing and risk distributio n in the low er reaches of the Tayang River. T he calculat ion r esults w ere r easonable and reliable, and can pr ov ide important basic info rmation fo r reg ional floo d co ntr ol command, f loo d risk manag ement, and flood contro l plan formulatio n.
The ra infall in t he low er r eaches of the Tayang river is abundant and frequently causes flood disasters. It is urg ent to build a floo d r outing analysis model fo r the river to pr ovide suppo rt fo r the formulation o f scient ific floo d co ntr ol and disaster mitig atio n measures. Based on the measured sectio n data and hig h2precision DEM of the low er reaches of the Tayang river, w e established a 12D hydrodynamic model of the river section and a 22D hydro dy namic model o f the flo od t hr eat zo nes on bo th banks by M IKE FLOOD, and r ealized t he r eal2time dynamic coupling of the tw o. T hen w e analyzed the evo lution pro cess and inundat ion risk o f a 502year flood in the lower r eaches, calculated the inundatio n r ang e and w ater depth dist ribution in differ ent periods, and analyzed the rationalit y of t he calculat ion results using w ater balance analysis and flow field distributio n. The re2 sults show ed that the model can eff ectively simulate the pr ocess of flood routing and risk distributio n in the low er reaches of the Tayang River. T he calculat ion r esults w ere r easonable and reliable, and can pr ov ide important basic info rmation fo r reg ional floo d co ntr ol command, f loo d risk manag ement, and flood contro l plan formulatio n.
4 Study on multi-point joint correction method for real-time flood forecasting errors of river systems
2018, 16(5):21-26.
Abstract:
Real-time correction is an im po rtant w ay to improv e the accur acy o f r eal2time flood fo recasting. T her e are hig h2level hy dr aulic connect ions among the multiple st ations in a river sy st em, and the err ors betw een the mult iple stat ions ar e spat ially in2 ter connected as w ell. Based on the basic equatio ns of riv er floo d routing and the dynamic adaptive aut oreg ressive method, t his study pro posed a mult i2point jo int co rr ect ion metho d fo r real2time flo od fo recasting erro rs wit h consideratio n to the spat ial evo2 lut ion of erro rs. T he correctio n effect was evaluated in terms o f the flood vo lume erro r during flood peak period, f loo d peak dis2 charg e err or, Nash2Sutclif fe efficiency co efficient, and lag t ime of peak. This paper conducted a case study o n t he reg ion up the Wangjiaba section o f H ua ihe Riv er to demonstr ate the pro po sed met ho do log y . The results indicated that the effect of multi2point joint co rr ection was better than that of single2po int correctio n, and the ef fect w as even mo re prominent fo r the floo d peak peri2 o d. The pr oposed method can effectiv ely impro ve the accuracy o f flo od for ecasting of the river sy st em.
Real-time correction is an im po rtant w ay to improv e the accur acy o f r eal2time flood fo recasting. T her e are hig h2level hy dr aulic connect ions among the multiple st ations in a river sy st em, and the err ors betw een the mult iple stat ions ar e spat ially in2 ter connected as w ell. Based on the basic equatio ns of riv er floo d routing and the dynamic adaptive aut oreg ressive method, t his study pro posed a mult i2point jo int co rr ect ion metho d fo r real2time flo od fo recasting erro rs wit h consideratio n to the spat ial evo2 lut ion of erro rs. T he correctio n effect was evaluated in terms o f the flood vo lume erro r during flood peak period, f loo d peak dis2 charg e err or, Nash2Sutclif fe efficiency co efficient, and lag t ime of peak. This paper conducted a case study o n t he reg ion up the Wangjiaba section o f H ua ihe Riv er to demonstr ate the pro po sed met ho do log y . The results indicated that the effect of multi2point joint co rr ection was better than that of single2po int correctio n, and the ef fect w as even mo re prominent fo r the floo d peak peri2 o d. The pr oposed method can effectiv ely impro ve the accuracy o f flo od for ecasting of the river sy st em.
2018, 16(5):27-34.
Abstract:
Based on the data of dro ug hts and flo ods o ver the last 546 y ea rs in Beijing, we o btained different trends o f flo ods and dr oughts using Mann2Kendall test and mo ving t2test, and w e used Mar ko v chain to study the t ransfer pr obabilit y and recurrence of different states in each tr end. T he st udy show ed that the dro ug ht and flo od disasters in Beijing manifested o bv ious tenden2 cies. The over all trend was " f loo d2dro ug ht2flo od2dr ought " fluctuatio n, w ith rapid shifts betw een dro ug ht and floo d at some times. During 147021579, Beijing was pr one to f loo d and had the highest pro bability of t ransferring to a part ial floo d year ( 311 3% ) . During 158021768, Beijing w as pro ne to dr ought and had the highest probability o f transferring to a no rmal year ( 341 3% ) ; it w as also v ery likely to hav e co ntinuous dr oughts. During 176921898, Beijing w as pr one to floo d and had the hig hest pr obability o f t ransferring a normal year ( 411 5% ) ; t he occurrence pro babilities of droug ht and flo od disasters wer e basically the same. During 189921961, Beijing t ransf erred fr om flo od to droug ht and had the highest pr obability of transferring to a partial dr ought y ear ( 351 1% ) . During 196222015, Beijing w as pro ne to droug ht , and had the hig hest probability of tr ansferring to a partial dr ought y ea r ( 291 7% ) ; it w as also v ery likely to have continuo us dr oughts. The ov erall ana lysis of 546 years o f dro ug hts # 2 and flo ods show ed that the tr ansfer o f dr oughts and floo ds tended to be no rmal, but the o verall situation was partial dro ug ht.
Based on the data of dro ug hts and flo ods o ver the last 546 y ea rs in Beijing, we o btained different trends o f flo ods and dr oughts using Mann2Kendall test and mo ving t2test, and w e used Mar ko v chain to study the t ransfer pr obabilit y and recurrence of different states in each tr end. T he st udy show ed that the dro ug ht and flo od disasters in Beijing manifested o bv ious tenden2 cies. The over all trend was " f loo d2dro ug ht2flo od2dr ought " fluctuatio n, w ith rapid shifts betw een dro ug ht and floo d at some times. During 147021579, Beijing was pr one to f loo d and had the highest pro bability of t ransferring to a part ial floo d year ( 311 3% ) . During 158021768, Beijing w as pro ne to dr ought and had the highest probability o f transferring to a no rmal year ( 341 3% ) ; it w as also v ery likely to hav e co ntinuous dr oughts. During 176921898, Beijing w as pr one to floo d and had the hig hest pr obability o f t ransferring a normal year ( 411 5% ) ; t he occurrence pro babilities of droug ht and flo od disasters wer e basically the same. During 189921961, Beijing t ransf erred fr om flo od to droug ht and had the highest pr obability of transferring to a partial dr ought y ear ( 351 1% ) . During 196222015, Beijing w as pro ne to droug ht , and had the hig hest probability of tr ansferring to a partial dr ought y ea r ( 291 7% ) ; it w as also v ery likely to have continuo us dr oughts. The ov erall ana lysis of 546 years o f dro ug hts # 2 and flo ods show ed that the tr ansfer o f dr oughts and floo ds tended to be no rmal, but the o verall situation was partial dro ug ht.
2018, 16(5):35-40.
Abstract:
In the annual runoff fo recast, the auto correlat ion betw een meteo ro log ical facto rs w ill have an impact o n fo recast accu2 r acy. In o rder to so lv e this problem, w e added PCA and PSO to the SVR model and established a PCA2PSO2SVR model. We re2 mo ved the r edundant informat ion and no ise, ext racted the main features of the facto rs, and used the o ptimal parameter combina2 tion of the model as input to t he reg ression support v ecto r machine ( SVR) model. T aking Danjiangko u Reserv oir, the w ater so ur ce of the Middle Route of the South2to2No rth Water Div ersion Project , as the study area, we carried o ut model t ests using the data from 1981 to 2016 in Danjiang ko u. T he results show ed that t he qualificat ion r ate during the model v erificat ion period was 831 33% and the consistency rat e also r eached 831 33% , indicating hig h accuracy and stability. The model has certain r efer2 ence v alue for the annua l runoff fo recast of Danjiang ko u Reser vo ir.
In the annual runoff fo recast, the auto correlat ion betw een meteo ro log ical facto rs w ill have an impact o n fo recast accu2 r acy. In o rder to so lv e this problem, w e added PCA and PSO to the SVR model and established a PCA2PSO2SVR model. We re2 mo ved the r edundant informat ion and no ise, ext racted the main features of the facto rs, and used the o ptimal parameter combina2 tion of the model as input to t he reg ression support v ecto r machine ( SVR) model. T aking Danjiangko u Reserv oir, the w ater so ur ce of the Middle Route of the South2to2No rth Water Div ersion Project , as the study area, we carried o ut model t ests using the data from 1981 to 2016 in Danjiang ko u. T he results show ed that t he qualificat ion r ate during the model v erificat ion period was 831 33% and the consistency rat e also r eached 831 33% , indicating hig h accuracy and stability. The model has certain r efer2 ence v alue for the annua l runoff fo recast of Danjiang ko u Reser vo ir.
2018, 16(5):41-49.
Abstract:
Pond system in the hilly a rea is a result of the adaptat ion to water demand, embodying t he harmonio us relatio nship be2 tw een w ater resources and human being s. We took tw o small w atersheds ( ? : 11 14 km2 ; ò : 11 27 km2) as the st udy a reas, and developed terrain w eig ht index , pond and land use adaptability index , and w ater supply and demand balance index to quant ita2 tively illustrate the w ater adaptability mechanism o f t he pond system. T he data set included high2resolution remot e sensing ima2 g es, 1B 10000 DEM, and measured data ( depth and size) of the ponds. The results are as follow s. For est and g rassland ( mor e than 50% ) w as the dominant land use ty pe in the study areas. The cultiv ated land ( abo ut 351 5% ) came seco nd. Fa rm ponds co vered o nly 21 82% and 51 8% o f the study areas. The terr ain w eight index es indicated that the high2lying ponds were abso lute2 ly dominant. The land utilizatio n index indicated that study area ? had better adaptability than study area ò . Under the circum2 stance o f precipitation pr obability P= 85% , the water supply and demand balance index was 11 02 and 01 59 r espectiv ely. Ther e wer e restrictions and adaptatio ns betw een the po nds, farmland, and terrain in the study ar ea.
Pond system in the hilly a rea is a result of the adaptat ion to water demand, embodying t he harmonio us relatio nship be2 tw een w ater resources and human being s. We took tw o small w atersheds ( ? : 11 14 km2 ; ò : 11 27 km2) as the st udy a reas, and developed terrain w eig ht index , pond and land use adaptability index , and w ater supply and demand balance index to quant ita2 tively illustrate the w ater adaptability mechanism o f t he pond system. T he data set included high2resolution remot e sensing ima2 g es, 1B 10000 DEM, and measured data ( depth and size) of the ponds. The results are as follow s. For est and g rassland ( mor e than 50% ) w as the dominant land use ty pe in the study areas. The cultiv ated land ( abo ut 351 5% ) came seco nd. Fa rm ponds co vered o nly 21 82% and 51 8% o f the study areas. The terr ain w eight index es indicated that the high2lying ponds were abso lute2 ly dominant. The land utilizatio n index indicated that study area ? had better adaptability than study area ò . Under the circum2 stance o f precipitation pr obability P= 85% , the water supply and demand balance index was 11 02 and 01 59 r espectiv ely. Ther e wer e restrictions and adaptatio ns betw een the po nds, farmland, and terrain in the study ar ea.
2018, 16(5):50-56.
Abstract:
First, based o n t he conno tatio n of wat er resources security , w e built an ev aluatio n index system fo r water resources se2 curity of H unan pro vince, and determined the w ater resources security state during 200722015 with the integr al index of w ater resources security. Seco nd, w e built a multi2bucket model fo r the evaluation system based on the short2bo ard facto rs theo ry , and measured the length difference betw een bucket staves ( indexes) w ith the "equilibrium degr ee" index . The index es w ere divided into dominant fact ors, restrictive facto rs, and short2board facto rs. Then w e compar ed and analyzed the st atus quo and develop2 ment trend of w at er resour ces security o f H unan pr ovince f rom lo ng itudinal ( interannual) and later al ( index2 based) perspec2 tives. T he r esults indicated: ( 1) The w ater r eso urces security sy stem o f H unan prov ince w as in a somewhat unsafe state in 2011, and w as in a somew hat safe st at e in 2015, and was in a critically safe state in the other years. The water r eso ur ces security of H unan pr ov ince during 200722015 was in a sev ere situation in the earlier stag e and it eased up in the later stag e. ( 2) We drew a sho rt2boar d factors diagr am of w ater reso ur ces security of H unan pr ov ince, and found that the main sho rt2boar d facto rs wer e sev ere floo d contro l situation, lar ge amo unts of w aste w ater and org anic pollutants emissio ns, and larg e consum ption of w ater for industria l, ag ricultural, and domestic use.
First, based o n t he conno tatio n of wat er resources security , w e built an ev aluatio n index system fo r water resources se2 curity of H unan pro vince, and determined the w ater resources security state during 200722015 with the integr al index of w ater resources security. Seco nd, w e built a multi2bucket model fo r the evaluation system based on the short2bo ard facto rs theo ry , and measured the length difference betw een bucket staves ( indexes) w ith the "equilibrium degr ee" index . The index es w ere divided into dominant fact ors, restrictive facto rs, and short2board facto rs. Then w e compar ed and analyzed the st atus quo and develop2 ment trend of w at er resour ces security o f H unan pr ovince f rom lo ng itudinal ( interannual) and later al ( index2 based) perspec2 tives. T he r esults indicated: ( 1) The w ater r eso urces security sy stem o f H unan prov ince w as in a somewhat unsafe state in 2011, and w as in a somew hat safe st at e in 2015, and was in a critically safe state in the other years. The water r eso ur ces security of H unan pr ov ince during 200722015 was in a sev ere situation in the earlier stag e and it eased up in the later stag e. ( 2) We drew a sho rt2boar d factors diagr am of w ater reso ur ces security of H unan pr ov ince, and found that the main sho rt2boar d facto rs wer e sev ere floo d contro l situation, lar ge amo unts of w aste w ater and org anic pollutants emissio ns, and larg e consum ption of w ater for industria l, ag ricultural, and domestic use.
2018, 16(5):57-65.
Abstract:
The ut ilizat ion of flood r eso ur ces w ill pro duce benefits, but it w ill also bring risks. Ther efo re, it is necessary to study the risk assessment of flo od utilization so as to minimize the neg ativ e effects o f f loo d resour ces ut ilizat ion. We identified the risk facto rs of floo d r eso ur ces utilizatio n in a w ater div ersion pro ject, and co nstr ucted an index sy st em fo r risk assessment based o n three aspects: w ater stor age pro jects, w ater conveyance pr ojects, and water pumping pro jects. The subjective weight was calcu2 lated by the analytic hier archy pr ocess, and the objective w eig ht w as calculated by t he ent ropy w eight method and the pr ojectio n pursuit method. T he cloud model was ado pted to calculat e the membership degr ee of the risk index . Then, the risk gr ade of flo od resources utilization can be obtained. The abo ve metho d was applied to the Jiangsu Prov ince segment of t he East Route of the So ut h2to2Nort h Water T ransfer Pr oject. The risks of floo d resour ces utilizatio n in w et, norma l, and dr y years wer e evaluat ed, and the validity and applicability of the evaluation metho d w ere v erified.
The ut ilizat ion of flood r eso ur ces w ill pro duce benefits, but it w ill also bring risks. Ther efo re, it is necessary to study the risk assessment of flo od utilization so as to minimize the neg ativ e effects o f f loo d resour ces ut ilizat ion. We identified the risk facto rs of floo d r eso ur ces utilizatio n in a w ater div ersion pro ject, and co nstr ucted an index sy st em fo r risk assessment based o n three aspects: w ater stor age pro jects, w ater conveyance pr ojects, and water pumping pro jects. The subjective weight was calcu2 lated by the analytic hier archy pr ocess, and the objective w eig ht w as calculated by t he ent ropy w eight method and the pr ojectio n pursuit method. T he cloud model was ado pted to calculat e the membership degr ee of the risk index . Then, the risk gr ade of flo od resources utilization can be obtained. The abo ve metho d was applied to the Jiangsu Prov ince segment of t he East Route of the So ut h2to2Nort h Water T ransfer Pr oject. The risks of floo d resour ces utilizatio n in w et, norma l, and dr y years wer e evaluat ed, and the validity and applicability of the evaluation metho d w ere v erified.
2018, 16(5):66-76.
Abstract:
Tar geting the inhomog eneity of inflow pr ocess and uncertainty o f inflow fr equency o f transferred water and lo cal sur2 face w ater in the w ater r eceiv ing area of the Middle Route of the So uth2to2 No rth Water Tr ansfer Project as w ell as the complex2 ity of the wat er supply system ( multi2sour ce, multi2pro ject, multi2user) , we selected a w ater receiv ing area of t he South2t o2North Water Tr ansfer Pr oject in H ebei prov ince as the r esear ch object. Wit h the guidance of multi2tar get gr oup decisio n theory and lar ge system decompo sitio n coo rdinatio n theory , we constructed a 1+ 7 o pt imal allocation mo del o f w ater r eso ur ces based o n MIKE BASIN, and formulated an optimal allocatio n scheme fo r w ater resources in t he w ater receiv ing ar ea based o n differ ent years, different guarantee rates, differ ent w ater sav ing levels, and different water usersc demand co ndit ions. Under the conditio n of inflow frequency combinat ion in 2020 ( tr ansferred w ater P= 50% and local surface water P = 50% ) , we analy zed t he effects of the optimal allocatio n schemes for basic w ater saving and eff icient w ater saving , w ith a v iew to f inding the optimal w ater dis2 tribution scheme between multiple w ater so urces and multiple users under the pr emise o f utilizing w ater resources fully and sat2 isfy ing the w ater demand. Ex ploring the o pt imal water distribution scheme betw een multiple water sources and multiple users will maxim ize the comprehensive benefits o f the r egion and promo te reg ional sustainable dev elo pment.
Tar geting the inhomog eneity of inflow pr ocess and uncertainty o f inflow fr equency o f transferred water and lo cal sur2 face w ater in the w ater r eceiv ing area of the Middle Route of the So uth2to2 No rth Water Tr ansfer Project as w ell as the complex2 ity of the wat er supply system ( multi2sour ce, multi2pro ject, multi2user) , we selected a w ater receiv ing area of t he South2t o2North Water Tr ansfer Pr oject in H ebei prov ince as the r esear ch object. Wit h the guidance of multi2tar get gr oup decisio n theory and lar ge system decompo sitio n coo rdinatio n theory , we constructed a 1+ 7 o pt imal allocation mo del o f w ater r eso ur ces based o n MIKE BASIN, and formulated an optimal allocatio n scheme fo r w ater resources in t he w ater receiv ing ar ea based o n differ ent years, different guarantee rates, differ ent w ater sav ing levels, and different water usersc demand co ndit ions. Under the conditio n of inflow frequency combinat ion in 2020 ( tr ansferred w ater P= 50% and local surface water P = 50% ) , we analy zed t he effects of the optimal allocatio n schemes for basic w ater saving and eff icient w ater saving , w ith a v iew to f inding the optimal w ater dis2 tribution scheme between multiple w ater so urces and multiple users under the pr emise o f utilizing w ater resources fully and sat2 isfy ing the w ater demand. Ex ploring the o pt imal water distribution scheme betw een multiple water sources and multiple users will maxim ize the comprehensive benefits o f the r egion and promo te reg ional sustainable dev elo pment.
2018, 16(5):77-84.
Abstract:
In o rder to analyze the influence of Xiang jiaba hydro power pr oject on land use and landscape chang es in the peripheral reg ion, w e applied t he o bject2o riented classificatio n metho d to ex tract the land use ty pes fr om the Landsat images o f 2006 and 2017, and analyzed the landscape pattern changes a round Xiang jiaba hy dr opow er station. Then, we used CLUE2S model to simu2 late the land use and landscape changes in 2017 in the conditio n of natur al development w ithout the hy dr opow er pr oject. T he main co nclusio ns are as fo llows: from 2006 to 2017, the land types o f the st udy area wer e seriously affected by bo th social devel2 o pment and the hy dr opow er pr oject. The w ater area has increased sig nificant ly ; bare land has been ut ilized; constructio n area has ex panded; fo rest and farmland ar ea has decreased a lo t. Com par ed with the situation in t he natur al dev elo pment co ndition, under the influence of the hydro pow er pro ject, t he construction area is slightly smaller, and t he g arden/ gr ass land area is sma ller with more cr oss2dist ribution w ith fo rest land. The landscape patter n presented differ ent trends: enhancement of farmland and gar den/ gr assland, delay ed develo pment of co nstr uction and ba re land, and o pposite development o f forest land
In o rder to analyze the influence of Xiang jiaba hydro power pr oject on land use and landscape chang es in the peripheral reg ion, w e applied t he o bject2o riented classificatio n metho d to ex tract the land use ty pes fr om the Landsat images o f 2006 and 2017, and analyzed the landscape pattern changes a round Xiang jiaba hy dr opow er station. Then, we used CLUE2S model to simu2 late the land use and landscape changes in 2017 in the conditio n of natur al development w ithout the hy dr opow er pr oject. T he main co nclusio ns are as fo llows: from 2006 to 2017, the land types o f the st udy area wer e seriously affected by bo th social devel2 o pment and the hy dr opow er pr oject. The w ater area has increased sig nificant ly ; bare land has been ut ilized; constructio n area has ex panded; fo rest and farmland ar ea has decreased a lo t. Com par ed with the situation in t he natur al dev elo pment co ndition, under the influence of the hydro pow er pro ject, t he construction area is slightly smaller, and t he g arden/ gr ass land area is sma ller with more cr oss2dist ribution w ith fo rest land. The landscape patter n presented differ ent trends: enhancement of farmland and gar den/ gr assland, delay ed develo pment of co nstr uction and ba re land, and o pposite development o f forest land
2018, 16(5):85-92.
Abstract:
Based on the method of principal component analy sis, w e sam pled and analyzed the ro of r unoff at residential area and road surface runo ff at g rocer y market in T ianjin urban ar ea. We classified and analyzed t he characteristic indexes o f SS, COD, ammonia nitro gen, to tal nit rog en, and to tal phospho rus, attempted to find out the sources of r unoff po llut ants pr oduced on dif2 fer ent underly ing surfaces, and analy zed the first flush effect of each pollutant. Analy sis results show ed t hat the tot al nitr ogen, ammonia nitro gen, and COD among t he characterist ic po llutants of ro of rainw ater r unoff belo ng ed to the same class of indexes, which means that the first kind of potential main pollutio n sour ces wer e vehicle emissions, atmo spheric dry and wet deposition, and the roo fing material precipitat es. Tota l phosphorus and SS belonged to the other tw o classes, indicating that the second kind of potential main po llution so ur ces w ere const ruct ion site po llut ion and the spoilage of v ehicles. Among the char act eristic pollu2 tants of the r oad surface r unoff at g ro cery mar ket , SS, to tal phospho rus, and COD belonged to the same class o f index es, w hich means that the first kind of potential main pollutio n so ur ces w ere the spoilag e of mo tor vehicles and the po llut ion of domestic wastes. Ammonia nitr og en and t otal nitrog en belonged to another class, indicat ing that atmospheric dry and w et deposition and vehicle emissio n w ere the seco nd po tential main po llution sour ces. T he first flush effect w as mor e likely to o ccur o n ro ad surface than on the ro of. T here w as a co ntinuo us input of po llution source and the first flush effect o f ammo nia nitr og en was significant.
Based on the method of principal component analy sis, w e sam pled and analyzed the ro of r unoff at residential area and road surface runo ff at g rocer y market in T ianjin urban ar ea. We classified and analyzed t he characteristic indexes o f SS, COD, ammonia nitro gen, to tal nit rog en, and to tal phospho rus, attempted to find out the sources of r unoff po llut ants pr oduced on dif2 fer ent underly ing surfaces, and analy zed the first flush effect of each pollutant. Analy sis results show ed t hat the tot al nitr ogen, ammonia nitro gen, and COD among t he characterist ic po llutants of ro of rainw ater r unoff belo ng ed to the same class of indexes, which means that the first kind of potential main pollutio n sour ces wer e vehicle emissions, atmo spheric dry and wet deposition, and the roo fing material precipitat es. Tota l phosphorus and SS belonged to the other tw o classes, indicating that the second kind of potential main po llution so ur ces w ere const ruct ion site po llut ion and the spoilage of v ehicles. Among the char act eristic pollu2 tants of the r oad surface r unoff at g ro cery mar ket , SS, to tal phospho rus, and COD belonged to the same class o f index es, w hich means that the first kind of potential main pollutio n so ur ces w ere the spoilag e of mo tor vehicles and the po llut ion of domestic wastes. Ammonia nitr og en and t otal nitrog en belonged to another class, indicat ing that atmospheric dry and w et deposition and vehicle emissio n w ere the seco nd po tential main po llution sour ces. T he first flush effect w as mor e likely to o ccur o n ro ad surface than on the ro of. T here w as a co ntinuo us input of po llution source and the first flush effect o f ammo nia nitr og en was significant.
2018, 16(5):93-101.
Abstract:
Aiming at the fuzzy and uncertainty problems in ecolog ical wat erw ay assessment, w e built a five2element connectio n number model o n the basis of AHP ( Analy tic H ierar chy Pr ocess) method and the SPA ( Set Pa ir Analysis) . Accor ding to the co nnection between each index o f the eco log ical waterway assessment index sy st em and the g rade standard, we constr ucted the co nnection degr ee formula, and calculat ed the weight of each assessment index by AHP. The model w as applied t o assess the ec2 o lo gical waterway of Nanjing2Liuhekou reach in the low er r eaches of Yang tze River. T he r esults showed that the health condi2 tion of this ecolog ical w aterw ay w as in Gr ade " III" . The navig atio n functio n, self2purificat ion function, and landscape & enter2 tainment funct ion w ere in Grade " I", while the eco log ical function w as in Grade " IV". It is necessary to str eng then eco lo gical en2 v iro nmental pr otectio n o f the reach. A sensitivity ana lysis indicated that t he assessment results w ere not sensitive t o small2am2 plitude fluctuatio n o f the weig hts o f the function layer, sug g esting that the evaluation results of the Nanjing2Liuhekou reach wer e stable.
Aiming at the fuzzy and uncertainty problems in ecolog ical wat erw ay assessment, w e built a five2element connectio n number model o n the basis of AHP ( Analy tic H ierar chy Pr ocess) method and the SPA ( Set Pa ir Analysis) . Accor ding to the co nnection between each index o f the eco log ical waterway assessment index sy st em and the g rade standard, we constr ucted the co nnection degr ee formula, and calculat ed the weight of each assessment index by AHP. The model w as applied t o assess the ec2 o lo gical waterway of Nanjing2Liuhekou reach in the low er r eaches of Yang tze River. T he r esults showed that the health condi2 tion of this ecolog ical w aterw ay w as in Gr ade " III" . The navig atio n functio n, self2purificat ion function, and landscape & enter2 tainment funct ion w ere in Grade " I", while the eco log ical function w as in Grade " IV". It is necessary to str eng then eco lo gical en2 v iro nmental pr otectio n o f the reach. A sensitivity ana lysis indicated that t he assessment results w ere not sensitive t o small2am2 plitude fluctuatio n o f the weig hts o f the function layer, sug g esting that the evaluation results of the Nanjing2Liuhekou reach wer e stable.
2018, 16(5):102-107.
Abstract:
Taking co ntaminated sediment w ith a cadmium ( Cd) content of 2 mg / kg as the r esear ch object, we used electro kinetic remediation techno lo gy to r emo ve the Cd in the contaminated sediment. w e investig ated the inf luences of differ ent voltages be2 tw een elect rodes, ty pes of chemical enhancers, and electr ode mat erials on the curr ent, temperature, conductiv ity, sediment mo is2 tur e co ntent, and heav y metal co ntent. The ex perimental results show ed that: w ith catio nic polyacry lamide ( CPAM) as chemical enhancer, por ous car bo n as electr ode, electro de vo ltag e o f 30 V, and suctio n filtr ation at pr essure of 01 05 MPa, the sediment moisture content w as decreased fr om 75% to 341 17% in 5 ho urs, heavy metal cadmium content was decreased fr om 2 mg/ kg to 01 178 mg/ kg w ith a remo val rate of 911 12% , and t he content of cadmium in the r emediated sediment met t he first2lev el stand2 ar d fo r cadmium in GB 15618- 1995 So il Envir onment al Quality Standar d. It co uld r ea lize the pur po se of remo ving heavy metals during the dew atering pr ocess o f the co ntam inated sediment.
Taking co ntaminated sediment w ith a cadmium ( Cd) content of 2 mg / kg as the r esear ch object, we used electro kinetic remediation techno lo gy to r emo ve the Cd in the contaminated sediment. w e investig ated the inf luences of differ ent voltages be2 tw een elect rodes, ty pes of chemical enhancers, and electr ode mat erials on the curr ent, temperature, conductiv ity, sediment mo is2 tur e co ntent, and heav y metal co ntent. The ex perimental results show ed that: w ith catio nic polyacry lamide ( CPAM) as chemical enhancer, por ous car bo n as electr ode, electro de vo ltag e o f 30 V, and suctio n filtr ation at pr essure of 01 05 MPa, the sediment moisture content w as decreased fr om 75% to 341 17% in 5 ho urs, heavy metal cadmium content was decreased fr om 2 mg/ kg to 01 178 mg/ kg w ith a remo val rate of 911 12% , and t he content of cadmium in the r emediated sediment met t he first2lev el stand2 ar d fo r cadmium in GB 15618- 1995 So il Envir onment al Quality Standar d. It co uld r ea lize the pur po se of remo ving heavy metals during the dew atering pr ocess o f the co ntam inated sediment.
2018, 16(5):108-114.
Abstract:
The lar ge2scale promotion of w ater2saving irrig atio n technolo gy in arid ar eas has effect ively promoted the oasisizatio n pr ocess and expanded the scale of oasis. Reg arding the appr opriate scale of o asis on watershed sca le under w ater2sav ing condi2 tion, we conducted a case study on the Manas Riv er Basin, w here t he drip irrigat ion t echnolog y o riginates. We used the fiv e2 peri2 o d satellite r emote sensing imag es fr om 1976 to 2015 to analyze t he chang e pr ocess o f oasis area under w ater2saving condition. Based o n the theo ry o f water2heat balance, w e co nstr ucted a calculation model for the suitable sca le of oasis, and determ ined the suitable development scale o f t he basin o asis under w ater2sav ing condition. T he r esults show ed that: From 1976 to 2015, the to2 tal ar ea o f the o asis in the M anas Riv er Basin ex panded by 3881 3 km2; the ar ea o f the art ificial oasis ex panded by 3 8731 3 km2 ; and the area of the natural oasis diminished by 3 485. 0 km2. Calculatio n sugg ested that the suitable scale of the oasis in the Ma2 nas Riv er Basin is 4 0251 924 4991 8 km2. The actual sca le of the oasis ex ceeds the appro priate scale of the o asis by 31 4 times. The oasis stabilit y index H 0 is 01 46, indicating the oasis is in a metastable state. In o rder to ensure the stability o f the oasis, the suitable cultivated area of the Manas River Basin should be 1 8011 622 0131 7 km2 . The r esear ch results sug gested that unreasonable development o f oasis can thr eat en the safety and stability o f the oasis. Determining t he suitable scale of oasis can pro vide a basic scientific basis for the stability and sustainable develo pment of o asis.
The lar ge2scale promotion of w ater2saving irrig atio n technolo gy in arid ar eas has effect ively promoted the oasisizatio n pr ocess and expanded the scale of oasis. Reg arding the appr opriate scale of o asis on watershed sca le under w ater2sav ing condi2 tion, we conducted a case study on the Manas Riv er Basin, w here t he drip irrigat ion t echnolog y o riginates. We used the fiv e2 peri2 o d satellite r emote sensing imag es fr om 1976 to 2015 to analyze t he chang e pr ocess o f oasis area under w ater2saving condition. Based o n the theo ry o f water2heat balance, w e co nstr ucted a calculation model for the suitable sca le of oasis, and determ ined the suitable development scale o f t he basin o asis under w ater2sav ing condition. T he r esults show ed that: From 1976 to 2015, the to2 tal ar ea o f the o asis in the M anas Riv er Basin ex panded by 3881 3 km2; the ar ea o f the art ificial oasis ex panded by 3 8731 3 km2 ; and the area of the natural oasis diminished by 3 485. 0 km2. Calculatio n sugg ested that the suitable scale of the oasis in the Ma2 nas Riv er Basin is 4 0251 924 4991 8 km2. The actual sca le of the oasis ex ceeds the appro priate scale of the o asis by 31 4 times. The oasis stabilit y index H 0 is 01 46, indicating the oasis is in a metastable state. In o rder to ensure the stability o f the oasis, the suitable cultivated area of the Manas River Basin should be 1 8011 622 0131 7 km2 . The r esear ch results sug gested that unreasonable development o f oasis can thr eat en the safety and stability o f the oasis. Determining t he suitable scale of oasis can pro vide a basic scientific basis for the stability and sustainable develo pment of o asis.
2018, 16(5):115-121.
Abstract:
In this study , w e chose fiv e sam pling points in Gangnan reserv oir basin to m onitor nitro gen depo sitions. We analyzed the spatial and t em po ral distributio n characteristics o f dr y and w et depo sition fluxes o f atm ospheric nit rog en fr om July 2015 to June 2016. T he r esults show ed that dry and w et depositio n flux es of to tal nitr og en wer e 171 721341 7 kg/ ( km 2 # month) and 91 923861 8 kg/ ( km2 # m onth) r espectively. The nitr ate and or ganic nit rog en w ere the dominant contributors to atmo spheric dr y depositio n flux . Their amount w as hig her in spring and summer. The nitr og en form s in w et depositio n w ere m ainly amm onia nitro g en and nitr ate nitro g en, the am ount of w hich w as hig her in sum mer and spring and low er in fall and w inter. In t erms of spat ial dist ribution, ther e w as an increasing tr end f rom the northw est to the so utheast. Based o n the t otal amo unt o f atm os2 pheric nitro g en deposit ion, w at ershed ar ea, and r eserv oir surface area, w e calculated the tota l atmo spheric nitr og en depositio n into riv er fo r the w hole ba sin, w hich w as 3 674 t/ a. The dir ect nitr og en depo sition into the Gang nan reser vo ir w as 1 051 16 t/ a
In this study , w e chose fiv e sam pling points in Gangnan reserv oir basin to m onitor nitro gen depo sitions. We analyzed the spatial and t em po ral distributio n characteristics o f dr y and w et depo sition fluxes o f atm ospheric nit rog en fr om July 2015 to June 2016. T he r esults show ed that dry and w et depositio n flux es of to tal nitr og en wer e 171 721341 7 kg/ ( km 2 # month) and 91 923861 8 kg/ ( km2 # m onth) r espectively. The nitr ate and or ganic nit rog en w ere the dominant contributors to atmo spheric dr y depositio n flux . Their amount w as hig her in spring and summer. The nitr og en form s in w et depositio n w ere m ainly amm onia nitro g en and nitr ate nitro g en, the am ount of w hich w as hig her in sum mer and spring and low er in fall and w inter. In t erms of spat ial dist ribution, ther e w as an increasing tr end f rom the northw est to the so utheast. Based o n the t otal amo unt o f atm os2 pheric nitro g en deposit ion, w at ershed ar ea, and r eserv oir surface area, w e calculated the tota l atmo spheric nitr og en depositio n into riv er fo r the w hole ba sin, w hich w as 3 674 t/ a. The dir ect nitr og en depo sition into the Gang nan reser vo ir w as 1 051 16 t/ a
2018, 16(5):122-127.
Abstract:
The ro ot w ater upt ake mo del is essential to the study of v eg etatio n ev apo transpirat ion. I n arid and semi2arid reg io ns, the soil of ten has w ater str ess, which makes the ro ot w ater uptake pro cess even mo re complicat ed. I n o rder to describe t he r oot water uptake mor e accurately, the compensated roo t w ater uptake mo del w as co nceptualized in 1989 and became an important research directio n. There are many ex plo ratio ns abroad, but few in China. Although certain pr og ress has been made on the com2 pensated roo t water uptake mo del, it still has some physical defects. This paper summarizes and analyzes t he dev elo pment histo2 r y o f the compensat ed r oot w ater uptake mo del. It po ints out that the compensated water uptake mo del ov erlooks the physical mechanism of water str ess restr aining the r oot w ater uptake and that using plant stress index to judge w hether there is compen2 sated water uptake has certa in limitatio ns. Based on comprehensiv e analysis, this paper pro po ses that the compensated r oot w a2 ter uptake model should consider the g r ow ing env ir onment of plant ro ots and the supply2demand relationship betw een po tential transpiratio n and available soil moist ur e. The compensated model should co uple the plant stress function, the characteristics of so il moisture distribution, and the dynamic char acteristics of gr oundwater.
The ro ot w ater upt ake mo del is essential to the study of v eg etatio n ev apo transpirat ion. I n arid and semi2arid reg io ns, the soil of ten has w ater str ess, which makes the ro ot w ater uptake pro cess even mo re complicat ed. I n o rder to describe t he r oot water uptake mor e accurately, the compensated roo t w ater uptake mo del w as co nceptualized in 1989 and became an important research directio n. There are many ex plo ratio ns abroad, but few in China. Although certain pr og ress has been made on the com2 pensated roo t water uptake mo del, it still has some physical defects. This paper summarizes and analyzes t he dev elo pment histo2 r y o f the compensat ed r oot w ater uptake mo del. It po ints out that the compensated water uptake mo del ov erlooks the physical mechanism of water str ess restr aining the r oot w ater uptake and that using plant stress index to judge w hether there is compen2 sated water uptake has certa in limitatio ns. Based on comprehensiv e analysis, this paper pro po ses that the compensated r oot w a2 ter uptake model should consider the g r ow ing env ir onment of plant ro ots and the supply2demand relationship betw een po tential transpiratio n and available soil moist ur e. The compensated model should co uple the plant stress function, the characteristics of so il moisture distribution, and the dynamic char acteristics of gr oundwater.
2018, 16(5):128-138.
Abstract:
( 1. H ubei Pr ovincial Water Resources and H y dr op ow er P lanning S urvey and Desig n I nstitute, Wuhan 430064, China; 2. S tate K ey Labor ator y of Water R esources and H y dr op ow er Eng ineering Science, Wuhan University , Wuhan 430072, China; 3. Dep artment of H y dr aulics, Yang tz e R iver Scientif ic Research I nstitute, Wuhan 430010, China)
( 1. H ubei Pr ovincial Water Resources and H y dr op ow er P lanning S urvey and Desig n I nstitute, Wuhan 430064, China; 2. S tate K ey Labor ator y of Water R esources and H y dr op ow er Eng ineering Science, Wuhan University , Wuhan 430072, China; 3. Dep artment of H y dr aulics, Yang tz e R iver Scientif ic Research I nstitute, Wuhan 430010, China)
2018, 16(5):139-143.
Abstract:
In winter, the co ntr olling gates of the M iddle Ro ute of South2to2 No rth Water Diversion Pr oject ar e o per ated under small opening conditio n. The submer ged hydr aulic jum p is accompanied by sever e turbulence behind the sluice g ates. To evaluat e the safety of g ate o perat ion under small opening conditio n, we conducted field t ests on the Puyang Riv er Gates and measur ed the par ameters of g ate vibr ation under the conditio ns of differ ent gat e opening s. The test results indicated that t he maximum dy2 namic str ess of the gates is 11 33 MPa, sma ller than 20% of the allow able st ress, i. e. about 32 MPa. The max imum v ibration dis2 placement 151 97 Lm is less than the upper limit displacement 501 8 Lm, below which the hazard of g ate v ibr atio n can be neg li2 g ible. The relation between amplitude A and frequency f follow s lgA< ( 31 14- 11 16 lg f ) . T he evaluat ion results o f the above 3 kinds of criteria ar e consistent; therefor e, the hazard o f g ate v ibration induced by submerg ed hydraulic jump is neg ligible, and the gate structure is safe and stable w hen the sluice gates are o per ated in small opening conditio n.
In winter, the co ntr olling gates of the M iddle Ro ute of South2to2 No rth Water Diversion Pr oject ar e o per ated under small opening conditio n. The submer ged hydr aulic jum p is accompanied by sever e turbulence behind the sluice g ates. To evaluat e the safety of g ate o perat ion under small opening conditio n, we conducted field t ests on the Puyang Riv er Gates and measur ed the par ameters of g ate vibr ation under the conditio ns of differ ent gat e opening s. The test results indicated that t he maximum dy2 namic str ess of the gates is 11 33 MPa, sma ller than 20% of the allow able st ress, i. e. about 32 MPa. The max imum v ibration dis2 placement 151 97 Lm is less than the upper limit displacement 501 8 Lm, below which the hazard of g ate v ibr atio n can be neg li2 g ible. The relation between amplitude A and frequency f follow s lgA< ( 31 14- 11 16 lg f ) . T he evaluat ion results o f the above 3 kinds of criteria ar e consistent; therefor e, the hazard o f g ate v ibration induced by submerg ed hydraulic jump is neg ligible, and the gate structure is safe and stable w hen the sluice gates are o per ated in small opening conditio n.
2018, 16(5):144-151.
Abstract:
In view of the fact that there are many w ide2shallow canal pr ojects t hat cannot transfer water under the ice cov er in winter in Xinjiang Autonomo us Reg ion and Qinghai Pr ovince, w e studied the transpo rt mechanism and operat ion reg ulatio n techniques of ice2w ater tw o2phase flow . It has important significance to solving the pr oblem o f water sho rtag e during w inter in these areas. Taking the drainage canal o f a power st ation in norther n Xinjiang Region as a case study, we co nstr ucted a one2di2 mensional mechanical2mathematical mo del of canal ice and w ater t o study the char acteristics o f ice tr ansport and evo lutio n. We analyzed the influence o f key thermodynamic factors o n ice, including air t em perat ur e, outbo und w ater temper atur e, and w ater transfer vo lume. Finally, we proposed some safe o perat ion measures for ice2w ater tw o2phase flow cana l. This study has some reference value for realizing the safe hy dr aulic co nt rol o f ice2w ater tw o2phase f low and solving the w ater shortag e pr oblem in winter in the no rthwest o f China.
In view of the fact that there are many w ide2shallow canal pr ojects t hat cannot transfer water under the ice cov er in winter in Xinjiang Autonomo us Reg ion and Qinghai Pr ovince, w e studied the transpo rt mechanism and operat ion reg ulatio n techniques of ice2w ater tw o2phase flow . It has important significance to solving the pr oblem o f water sho rtag e during w inter in these areas. Taking the drainage canal o f a power st ation in norther n Xinjiang Region as a case study, we co nstr ucted a one2di2 mensional mechanical2mathematical mo del of canal ice and w ater t o study the char acteristics o f ice tr ansport and evo lutio n. We analyzed the influence o f key thermodynamic factors o n ice, including air t em perat ur e, outbo und w ater temper atur e, and w ater transfer vo lume. Finally, we proposed some safe o perat ion measures for ice2w ater tw o2phase flow cana l. This study has some reference value for realizing the safe hy dr aulic co nt rol o f ice2w ater tw o2phase f low and solving the w ater shortag e pr oblem in winter in the no rthwest o f China.
2018, 16(5):152-158.
Abstract:
In view of the structural characteristics o f the hig h face ro ckfill dam, w e calculated and analyzed the dynamic response char acteristics and the seismic safety of the dam by the t hr ee2dimensional nonlinear f inite element method. In the dy namic calcu2 latio n, the dam material and ov erburden lay er wer e simulat ed acco rding to the equiv alent linear visco elastic model with consider2 ation to the confining pressure effect. A linea r elast ic model was used fo r the calculatio n of concrete dy namics. The permanent deformatio n o f the dam was calculated based o n the dy namic str ess2r esidual strain mo del, w hich co uld be used to calculate the residual bo dy strain and r esidual ax ial str ain. T he r esults show ed that the max imum permanent defo rmatio n along the river w as 15cm and the max imum permanent deformat ion in the v ertical directio n was 49 cm; bo th at the dam crest. I n the thr ee2dimen2 sio nal analy sis, the ho rizo ntal abso lute accelerat ion r esponse of the r ockfill w as 9 m/ s2 , and the max imum amplificatio n fact or was 41 2. The maximum earthquake r esponse of the ro ckfill and the panel occurred at the to p of the dam, show ing an obvious whiplash effect.
In view of the structural characteristics o f the hig h face ro ckfill dam, w e calculated and analyzed the dynamic response char acteristics and the seismic safety of the dam by the t hr ee2dimensional nonlinear f inite element method. In the dy namic calcu2 latio n, the dam material and ov erburden lay er wer e simulat ed acco rding to the equiv alent linear visco elastic model with consider2 ation to the confining pressure effect. A linea r elast ic model was used fo r the calculatio n of concrete dy namics. The permanent deformatio n o f the dam was calculated based o n the dy namic str ess2r esidual strain mo del, w hich co uld be used to calculate the residual bo dy strain and r esidual ax ial str ain. T he r esults show ed that the max imum permanent defo rmatio n along the river w as 15cm and the max imum permanent deformat ion in the v ertical directio n was 49 cm; bo th at the dam crest. I n the thr ee2dimen2 sio nal analy sis, the ho rizo ntal abso lute accelerat ion r esponse of the r ockfill w as 9 m/ s2 , and the max imum amplificatio n fact or was 41 2. The maximum earthquake r esponse of the ro ckfill and the panel occurred at the to p of the dam, show ing an obvious whiplash effect.
2018, 16(5):159-164.
Abstract:
Impulse w ave g ener ated by landslide in the r eser voir ar ea w ill adversely affect nearby bank slo pes and may cause sec2 o ndary disasters. This study took the ev olution pr ocess of the impact o f impulse w ave generated by r ocky landslide on bank slopes as the study o bject , and established a 3D geomechanical model o f impulse wav e g ener ated by ro cky landslide in the Thr ee Gor ges r eser voir ar ea w it h a similarity ratio of 1 B 70. We studied the law of run2up of impulse w ave g enerated by ro cky land2 slide thr ough 27 sets o f mo del tests with different combinat ions o f w idth, thickness, and slip angle o f the landslide, and pr oposed a fo rmula for estimating the run2up o f im pulse w ave generated by ro cky landslide. The r esults showed that the r un2up of impulse wav e w ould increase w ith the incr ease in w idth, thickness, and slip ang le o f the landslide. The w idth of the landslide had the most signif icant effect o n the impulse wav e r un2up, followed by the thickness of the landslide and the slip ang le of the landslide. The result of the ex isting w ave r un2up estimatio n formula differ ed gr eatly fr om that of the r ocky landslide mo del test value. Based o n the ex periment, w e pr oposed a formula fo r estimating the w ave run2up using the relat ive depth, Potain, and bank slope ang le, which can pro vide a theor et ical basis for estimating r un2up o f impulse wav e g ener ated by r ocky landslide in the r eser vo ir area.
Impulse w ave g ener ated by landslide in the r eser voir ar ea w ill adversely affect nearby bank slo pes and may cause sec2 o ndary disasters. This study took the ev olution pr ocess of the impact o f impulse w ave generated by r ocky landslide on bank slopes as the study o bject , and established a 3D geomechanical model o f impulse wav e g ener ated by ro cky landslide in the Thr ee Gor ges r eser voir ar ea w it h a similarity ratio of 1 B 70. We studied the law of run2up of impulse w ave g enerated by ro cky land2 slide thr ough 27 sets o f mo del tests with different combinat ions o f w idth, thickness, and slip angle o f the landslide, and pr oposed a fo rmula for estimating the run2up o f im pulse w ave generated by ro cky landslide. The r esults showed that the r un2up of impulse wav e w ould increase w ith the incr ease in w idth, thickness, and slip ang le o f the landslide. The w idth of the landslide had the most signif icant effect o n the impulse wav e r un2up, followed by the thickness of the landslide and the slip ang le of the landslide. The result of the ex isting w ave r un2up estimatio n formula differ ed gr eatly fr om that of the r ocky landslide mo del test value. Based o n the ex periment, w e pr oposed a formula fo r estimating the w ave run2up using the relat ive depth, Potain, and bank slope ang le, which can pro vide a theor et ical basis for estimating r un2up o f impulse wav e g ener ated by r ocky landslide in the r eser vo ir area.
2018, 16(5):165-170.
Abstract:
The excessive ex traction of gr oundw ater caused obv ious g ro und subsidence in the southeastern co astal areas o f China. Ex plo itatio n restrict ion and artificial r echar ge o f gr oundw ater have significant effects on mitig at ing t he g ro und subsidence. These measures lead to dr ast ic f luct uations o f w ater level and sig nificant sett lement and r ebo und deformation of the widespread so ft soil in the coastal areas. In or der to investig ate t he defo rmation and str eng th o f so ft so il under w ater lev el fluctuat ion, by u2 sing the cy linder mo del ex periment dev ice to simulate w ater lev el fluctuatio n, we conducted hig h2pr essure consolidat ion test, di2 r ect shear test, and triax ial t est on the soft soil aft er differ ent times of wat er level fluctuatio n. Based o n the analy sis o f the influ2 ence deg ree of w ater level fluctuation on the deformation behav io r and str eng th characteristics of soft so il, we presented a rela2 tional ex pression of t he residual str eng th o f soft soil aft er differ ent times of w ater lev el fluctuat ion using initial st rength and w a2 ter content. The test results showed that as the fr equency of w ater level fluctuatio n increased, the deformatio n pro perties of the so ft soil wer e enhanced and the str eng th w as reduced. T he cohesion and internal friction ang le decreased linearly w ith the in2 cr ease of water level fluctuations. T he strength index o f the so ft so il under the same times of water lev el fluctuat ion declined significantly w ith the incr ease of wat er co ntent. The r esults have import ant practical sig nificance and application value on ex ploring the action mechanism of w at er level fluctuation o n gr ound subsidence and bearing capacity chang es, impro ving the level o f scien2 tific decision2making , and m itig ating enviro nmental g eolog ical disasters in coastal cities.
The excessive ex traction of gr oundw ater caused obv ious g ro und subsidence in the southeastern co astal areas o f China. Ex plo itatio n restrict ion and artificial r echar ge o f gr oundw ater have significant effects on mitig at ing t he g ro und subsidence. These measures lead to dr ast ic f luct uations o f w ater level and sig nificant sett lement and r ebo und deformation of the widespread so ft soil in the coastal areas. In or der to investig ate t he defo rmation and str eng th o f so ft so il under w ater lev el fluctuat ion, by u2 sing the cy linder mo del ex periment dev ice to simulate w ater lev el fluctuatio n, we conducted hig h2pr essure consolidat ion test, di2 r ect shear test, and triax ial t est on the soft soil aft er differ ent times of wat er level fluctuatio n. Based o n the analy sis o f the influ2 ence deg ree of w ater level fluctuation on the deformation behav io r and str eng th characteristics of soft so il, we presented a rela2 tional ex pression of t he residual str eng th o f soft soil aft er differ ent times of w ater lev el fluctuat ion using initial st rength and w a2 ter content. The test results showed that as the fr equency of w ater level fluctuatio n increased, the deformatio n pro perties of the so ft soil wer e enhanced and the str eng th w as reduced. T he cohesion and internal friction ang le decreased linearly w ith the in2 cr ease of water level fluctuations. T he strength index o f the so ft so il under the same times of water lev el fluctuat ion declined significantly w ith the incr ease of wat er co ntent. The r esults have import ant practical sig nificance and application value on ex ploring the action mechanism of w at er level fluctuation o n gr ound subsidence and bearing capacity chang es, impro ving the level o f scien2 tific decision2making , and m itig ating enviro nmental g eolog ical disasters in coastal cities.
24 Model test of flow improvement effect of the permeable oblique sill on the bend in spillway chute
2018, 16(5):171-178.
Abstract:
In or der t o ex plor e t he flow improv ement effect of permeable o blique sill o n the spillw ay chute bend, w e carried o ut a model test of fiv e permeable o blique sills ( laid at an ang le o f 45b) w ith a permeable rate of 271 9% , 371 9% and 491 5% . Based o n the test r esults, we calculated the water surface ev enness and the co rresponding impro vement rate, the w at er surface difference betw een concave bank and convex bank and the corresponding decrease rate, so as to analyze the effect o f different permeable rates of the sill and differ ent flow rates on impr oving the flow o f the bend. The results w ere as follow s. Firstly , t he permeable oblique sill set at the bend co uld stro ng ly impr ove the bend f low , incr ease water surface ev enness at t he bend, and decrease w ater surf ace difference. Secondly, permeable rate could affect the f low impro vement effect. Under t he same flow r ate, the smaller the permeable rate, the better the effect of the sill on flow impro vement. T hirdly , t he effect o f the sill on flow impro vement wo uld vary w ith the flow r ate; the effect w as mo re obvio us when the flow r ate w as low . Reg arding the im pr ovement effect on the w ater surf ace evenness at the bend, the different permeable rates or flow r ates did not make much difference.
In or der t o ex plor e t he flow improv ement effect of permeable o blique sill o n the spillw ay chute bend, w e carried o ut a model test of fiv e permeable o blique sills ( laid at an ang le o f 45b) w ith a permeable rate of 271 9% , 371 9% and 491 5% . Based o n the test r esults, we calculated the water surface ev enness and the co rresponding impro vement rate, the w at er surface difference betw een concave bank and convex bank and the corresponding decrease rate, so as to analyze the effect o f different permeable rates of the sill and differ ent flow rates on impr oving the flow o f the bend. The results w ere as follow s. Firstly , t he permeable oblique sill set at the bend co uld stro ng ly impr ove the bend f low , incr ease water surface ev enness at t he bend, and decrease w ater surf ace difference. Secondly, permeable rate could affect the f low impro vement effect. Under t he same flow r ate, the smaller the permeable rate, the better the effect of the sill on flow impro vement. T hirdly , t he effect o f the sill on flow impro vement wo uld vary w ith the flow r ate; the effect w as mo re obvio us when the flow r ate w as low . Reg arding the im pr ovement effect on the w ater surf ace evenness at the bend, the different permeable rates or flow r ates did not make much difference.
2018, 16(5):179-185.
Abstract:
To so lv e the pro blems of the leakag e monitoring equipment fo r hig h2filled canals in pro ducing lar ge comprehensive er2 r or and being unable to mo nitor the seepage between canal sect ions, w e desig ned a mov able and non2dest ruct ive leakage monito2 ring sy stem for the hig h2filled canal o f the Middle Ro ut e of the So uth2to2No rth Water Diversion Pro ject and established a fusio n model based on Kalman2BP for leakage monito ring o f hig h2filled canals. Firstly, we const ruct ed a mult i2zo ne leakag e info rmatio n detectio n platform based o n wireless sensor netw ork, and w e desig ned the sensors as po rtable and movable cone devices t hat can be inserted into the soil. T he info rmation of temperatur e, humidity, soil w ater content, seepag e, and GPS lo cation w as collected in real t ime and then w as transmitted wirelessly thro ug h t he ZigBee and GPRS. Using the flow field leakag e detectio n method, we selected the characteristic variables that w ere relevant t o high2filled canal leakag e t hr ough the ex perimental model. Then, w e used Kalman algo rithm t o filter and valuate the associated phy sical variables. Finally, we submitted the multi2senso r data t o the BP neural netw or k for leakag e state patter n r eco gnition and realized the predictio n of slo pe leakag e state and determined the safety lev el o f slope leakag e. The experimental r esults show ed that the Kalman2BP fusion mo del has smaller erro r in r eco gnizing the leakag e o f the hig h2f ill canal, and can monito r in real t ime the leakage state betw een the canal sections. It can r ealize no n2de2 str uctive online mo nitoring of t he slope seepage of t he Middle Ro ut e o f the So ut h2to2Nort h Water Diversion Pro ject.
To so lv e the pro blems of the leakag e monitoring equipment fo r hig h2filled canals in pro ducing lar ge comprehensive er2 r or and being unable to mo nitor the seepage between canal sect ions, w e desig ned a mov able and non2dest ruct ive leakage monito2 ring sy stem for the hig h2filled canal o f the Middle Ro ut e of the So uth2to2No rth Water Diversion Pro ject and established a fusio n model based on Kalman2BP for leakage monito ring o f hig h2filled canals. Firstly, we const ruct ed a mult i2zo ne leakag e info rmatio n detectio n platform based o n wireless sensor netw ork, and w e desig ned the sensors as po rtable and movable cone devices t hat can be inserted into the soil. T he info rmation of temperatur e, humidity, soil w ater content, seepag e, and GPS lo cation w as collected in real t ime and then w as transmitted wirelessly thro ug h t he ZigBee and GPRS. Using the flow field leakag e detectio n method, we selected the characteristic variables that w ere relevant t o high2filled canal leakag e t hr ough the ex perimental model. Then, w e used Kalman algo rithm t o filter and valuate the associated phy sical variables. Finally, we submitted the multi2senso r data t o the BP neural netw or k for leakag e state patter n r eco gnition and realized the predictio n of slo pe leakag e state and determined the safety lev el o f slope leakag e. The experimental r esults show ed that the Kalman2BP fusion mo del has smaller erro r in r eco gnizing the leakag e o f the hig h2f ill canal, and can monito r in real t ime the leakage state betw een the canal sections. It can r ealize no n2de2 str uctive online mo nitoring of t he slope seepage of t he Middle Ro ut e o f the So ut h2to2Nort h Water Diversion Pro ject.
2018, 16(5):186-192.
Abstract:
In or der t o study the influence of different g uide v ane o penings on the pressur e pulsat ion characteristics and flow2in2 duced no ise in Fr ancis tur bine, we used CFD and LM S Virtual Lab softw are to calculate t he unsteady flow field and sound field in a Francis turbine under three g uide v ane o pening degr ees. The results showed that the pressure pulsat ion in the Francis tur2 bine was mainly affected by the r otation fr equency of blade ( 1081 33 H z) and the low2fr equency pressur e2pulse ( 41 15 Hz) . With the increase of t he g uide v ane opening, the influence of blade frequency on the pr essure pulsatio n in t he inlet of the r unner and the v olute w ould g radually increase. The distributio n of o utfield noise accor ded w ith the g eometric contour of the Fr ancis tur2 bine. T he elbow section o f the draft t ube w as helpful for the attenuation o f the flow2induced no ise of the Francis turbine. T he gr eat er the guide vane opening , the g reater the sound pr essure of the exter na l no ise g enerat ed by the Francis tur bine, and the more o bv ious the dipo le cha racteristics. The research results can pr ovide a r efer ence fo r the stable o per atio n o f Francis turbine and the co nt rol of flow2induced noise.
In or der t o study the influence of different g uide v ane o penings on the pressur e pulsat ion characteristics and flow2in2 duced no ise in Fr ancis tur bine, we used CFD and LM S Virtual Lab softw are to calculate t he unsteady flow field and sound field in a Francis turbine under three g uide v ane o pening degr ees. The results showed that the pressure pulsat ion in the Francis tur2 bine was mainly affected by the r otation fr equency of blade ( 1081 33 H z) and the low2fr equency pressur e2pulse ( 41 15 Hz) . With the increase of t he g uide v ane opening, the influence of blade frequency on the pr essure pulsatio n in t he inlet of the r unner and the v olute w ould g radually increase. The distributio n of o utfield noise accor ded w ith the g eometric contour of the Fr ancis tur2 bine. T he elbow section o f the draft t ube w as helpful for the attenuation o f the flow2induced no ise of the Francis turbine. T he gr eat er the guide vane opening , the g reater the sound pr essure of the exter na l no ise g enerat ed by the Francis tur bine, and the more o bv ious the dipo le cha racteristics. The research results can pr ovide a r efer ence fo r the stable o per atio n o f Francis turbine and the co nt rol of flow2induced noise.
2018, 16(5):193-199.
Abstract:
Acco rding to the double por osity media f low theor y and the co nstr uction technolog y of com posite f oundatio n, with al2 luv ial sand and riv er sand as ex perimental padding, we carried out a sand ho le infilt ratio n test in the silt and medium sand st rata, and studied the efficiency of sand ho le infiltr atio n. The r esults show ed that the separated por ous media w as mor e suitable for filling sand holes. River sand was mor e effective as padding than alluvial sand. Infilt ratio n efficiency was o bv io usly affected by a2 queo us medium. Using sand hole infiltration for differ ent litho log ical char acteristics showed obviously differ ent infilt ratio n effi2 ciency. The infiltration eff iciency of medium sand st ratum w as 71 6 t imes o f that of the silt str atum and 481 1 t imes o f that of the silt surface. U sing different infiltration mo des for the same lit ho lo gical char acteristic also show ed v ery different infiltrat ion effi2 ciency. The infilt ratio n efficiency of silt stratum was 61 3 times of that of t he silt surface. Sand hole infiltration is a manag eable technical metho d w hich can speed up the inf ilt ratio n r ate. It w ill pr omot e the co nv ersio n of the per co lation t heo ry into t echnolo2 g ies for alleviating flo od disasters in urban o r mountainous ar eas. It w ill enhance the effect ive ut ilizat ion of water resources, and pr omot e t he self2r ecover y and healt hy dev elopment of w ater cycle sy stem.
Acco rding to the double por osity media f low theor y and the co nstr uction technolog y of com posite f oundatio n, with al2 luv ial sand and riv er sand as ex perimental padding, we carried out a sand ho le infilt ratio n test in the silt and medium sand st rata, and studied the efficiency of sand ho le infiltr atio n. The r esults show ed that the separated por ous media w as mor e suitable for filling sand holes. River sand was mor e effective as padding than alluvial sand. Infilt ratio n efficiency was o bv io usly affected by a2 queo us medium. Using sand hole infiltration for differ ent litho log ical char acteristics showed obviously differ ent infilt ratio n effi2 ciency. The infiltration eff iciency of medium sand st ratum w as 71 6 t imes o f that of the silt str atum and 481 1 t imes o f that of the silt surface. U sing different infiltration mo des for the same lit ho lo gical char acteristic also show ed v ery different infiltrat ion effi2 ciency. The infilt ratio n efficiency of silt stratum was 61 3 times of that of t he silt surface. Sand hole infiltration is a manag eable technical metho d w hich can speed up the inf ilt ratio n r ate. It w ill pr omot e the co nv ersio n of the per co lation t heo ry into t echnolo2 g ies for alleviating flo od disasters in urban o r mountainous ar eas. It w ill enhance the effect ive ut ilizat ion of water resources, and pr omot e t he self2r ecover y and healt hy dev elopment of w ater cycle sy stem.
2018, 16(5):200-208.
Abstract:
The H anjiang2to2Weihe riv er w ater transfer pro ject is an im po rtant pro ject to so lv e water sho rtag e in the cent ral Shaanx i plain and northern Shaanxi. It will pass thro ug h the main ridg e section of the Qinling Mo untains and is mainly construc2 ted by the TBM method. T his paper intends to clarify the diffusion rule o f thermal hazard in the constructio n env ir onment of the TBM t unneling sectio n t o guide the co nstr uction of the TBM tunnel. This paper is based on t he t unneling project of the Han2 jiang2to2Weihe river w ater transfer project. Numerical calculatio n w as used to calculate t he thermal hazard diffusion rule in the co nstr uction env iro nment of TBM tunneling sectio ns under different surr ounding r ock g rades and differ ent ventilatio n condi2 tions. Results show ed that in the const ruct ion o f class IV surr ounding ro ck, the ambient air t emperat ur e of the T BM section w as less than 28 e , w hich met the specification r equirements. With the improv ement of the surro unding ro ck gr ade, the temperatur e near the driving surface and the sco pe of hig h2t emperat ur e ar ea w ould g radually increase. The maximum temper ature reached 50 e and the maximum diffusion rang e o f thermal hazard reached 165 m. The minimum effective v ent ilation coo ling distance w as only 45 m. With t he increase o f w ind speed at the o ut let of the air duct and the decrease o f the supply air temperatur e, the diffu2 sio n range of thermal hazard w ould gr adually decrease; but the ambient temper ature near the driv ing surface still could no t meet the specificatio n r equir ements. T her efore, this pa per recommends using lo cal cooling measures in the vicinity of the driv ing sur2 face.
The H anjiang2to2Weihe riv er w ater transfer pro ject is an im po rtant pro ject to so lv e water sho rtag e in the cent ral Shaanx i plain and northern Shaanxi. It will pass thro ug h the main ridg e section of the Qinling Mo untains and is mainly construc2 ted by the TBM method. T his paper intends to clarify the diffusion rule o f thermal hazard in the constructio n env ir onment of the TBM t unneling sectio n t o guide the co nstr uction of the TBM tunnel. This paper is based on t he t unneling project of the Han2 jiang2to2Weihe river w ater transfer project. Numerical calculatio n w as used to calculate t he thermal hazard diffusion rule in the co nstr uction env iro nment of TBM tunneling sectio ns under different surr ounding r ock g rades and differ ent ventilatio n condi2 tions. Results show ed that in the const ruct ion o f class IV surr ounding ro ck, the ambient air t emperat ur e of the T BM section w as less than 28 e , w hich met the specification r equirements. With the improv ement of the surro unding ro ck gr ade, the temperatur e near the driving surface and the sco pe of hig h2t emperat ur e ar ea w ould g radually increase. The maximum temper ature reached 50 e and the maximum diffusion rang e o f thermal hazard reached 165 m. The minimum effective v ent ilation coo ling distance w as only 45 m. With t he increase o f w ind speed at the o ut let of the air duct and the decrease o f the supply air temperatur e, the diffu2 sio n range of thermal hazard w ould gr adually decrease; but the ambient temper ature near the driv ing surface still could no t meet the specificatio n r equir ements. T her efore, this pa per recommends using lo cal cooling measures in the vicinity of the driv ing sur2 face.
Mobile website
® 2024 All Rights Reserved
冀公网安备13010502002656号
冀公网安备13010502002656号 冀ICP备14004744号-5