Volume 16,Issue 6,2018 Table of Contents
2018, 16(6):1-8.
Abstract:
Glacial lake o ut burst floods ( GLOFs) ar e serious disasters in glacial ar eas. At pr esent, due to global w arming , g laciers are generally diminishing; thus increasing the glacial lake area and the o ut burst risk. Therefo re, the r esear ch on early w arning met ho ds for GLOFs is impo rtant to disast er preventio n and r elief in glacial ar eas. This pa per pro po ses an early war ning method using the temperatur e and rainfall as indices. We selected t he daily g row th rat e o f prio r period po sitiv e cumulat ive temperatur e and the prior thirty2day cumulat ive rainfall as the r epr esentativ e indices of temperature and r ainfall. Based o n the statistics of the 21 o utburst ev ents befo re 2010 and the data fr om the 21 nearby meteor olog ical statio ns, w e built an o utburst early w arning thresho ld and a flow chart o f t he GLOF early w ar ning sy stem. The sy st em w as verified by the GLOF event in the Ranzeaco gla2 cial lake on 2013207205.
Glacial lake o ut burst floods ( GLOFs) ar e serious disasters in glacial ar eas. At pr esent, due to global w arming , g laciers are generally diminishing; thus increasing the glacial lake area and the o ut burst risk. Therefo re, the r esear ch on early w arning met ho ds for GLOFs is impo rtant to disast er preventio n and r elief in glacial ar eas. This pa per pro po ses an early war ning method using the temperatur e and rainfall as indices. We selected t he daily g row th rat e o f prio r period po sitiv e cumulat ive temperatur e and the prior thirty2day cumulat ive rainfall as the r epr esentativ e indices of temperature and r ainfall. Based o n the statistics of the 21 o utburst ev ents befo re 2010 and the data fr om the 21 nearby meteor olog ical statio ns, w e built an o utburst early w arning thresho ld and a flow chart o f t he GLOF early w ar ning sy stem. The sy st em w as verified by the GLOF event in the Ranzeaco gla2 cial lake on 2013207205.
2018, 16(6):9-14.
Abstract:
On the basis o f t he rainsto rm and f loo d dat a of Zhengzho u in 2015, w e applied the emerg y analysis metho d to evaluat e the regional v ulner ability to floo d disasters fr om the ecolo gica l perspectiv e. The emer gy w as then considered as a normalized ba2 sis. Based o n the results of emer g y ev aluatio n and the emer gy index r epr esenting t he reg io nal v ulnerability to floo d disasters, w e used t he g eo gr aphic info rmatio n sy stem ( GIS) to analyze the spat ial difference o f vulnerability to flo od disasters in Zheng zhou. Results show ed t hat t her e w ere obvio us differences in the spatia l distribution of vulnerability to floo d disasters. The v ulnerabili2 ty of Xinm i was the hig hest and that o f Xinzheng w as the low est. I n a who le, the vulnerability to flo od disasters in Zhengzho u City tended to decrease from t he middle to the peripher y. Im pr oving the ada ptability of the sy stem effectively is the key to re2 ducing the vulnerability .
On the basis o f t he rainsto rm and f loo d dat a of Zhengzho u in 2015, w e applied the emerg y analysis metho d to evaluat e the regional v ulner ability to floo d disasters fr om the ecolo gica l perspectiv e. The emer gy w as then considered as a normalized ba2 sis. Based o n the results of emer g y ev aluatio n and the emer gy index r epr esenting t he reg io nal v ulnerability to floo d disasters, w e used t he g eo gr aphic info rmatio n sy stem ( GIS) to analyze the spat ial difference o f vulnerability to flo od disasters in Zheng zhou. Results show ed t hat t her e w ere obvio us differences in the spatia l distribution of vulnerability to floo d disasters. The v ulnerabili2 ty of Xinm i was the hig hest and that o f Xinzheng w as the low est. I n a who le, the vulnerability to flo od disasters in Zhengzho u City tended to decrease from t he middle to the peripher y. Im pr oving the ada ptability of the sy stem effectively is the key to re2 ducing the vulnerability .
2018, 16(6):15-20.
Abstract:
H ydro log ical simulatio n is impo rtant fo r flo od hazard mitig ation and water resources management. I n this st udy, we a2 dopted t he distributed hy drolog ical mo del HEC2H MS to simulate the flo od ev ents and daily runo ff o f the Weny u River basin in Beijing, China. The mo del was calibrated and validat ed w ith the data o f 6 storm events during 198022005 and daily str eam flow during 198321995. The results show ed that fo r all of t he 6 flo ods, the relat ive erro rs of peak flow and r unoff amo unt w ere less than 20% , and the peak time difference was w ithin 2 h. The aver age Nash efficiency co eff icient and averag e correlation co effi2 cient r w ere 01 82 and 01 92, r espectiv ely. Fo r the daily runoff simulation, the averag e Nash efficiency coefficient w as 01 6, the av2 er age correlation coefficient r was 01 78, and the av erag e relat ive error was 31 95% . Preliminar y analysis showed that the H EC2 HMS model a pplied w ell to the Wenyu Riv er basin. It can effect ively simulate the short2t erm and long2t erm r ainfall and r unoff pr ocesses in norther n China, and can be used fo r floo d fo recast, w ater r eso ur ces evaluation and management in this area.
H ydro log ical simulatio n is impo rtant fo r flo od hazard mitig ation and water resources management. I n this st udy, we a2 dopted t he distributed hy drolog ical mo del HEC2H MS to simulate the flo od ev ents and daily runo ff o f the Weny u River basin in Beijing, China. The mo del was calibrated and validat ed w ith the data o f 6 storm events during 198022005 and daily str eam flow during 198321995. The results show ed that fo r all of t he 6 flo ods, the relat ive erro rs of peak flow and r unoff amo unt w ere less than 20% , and the peak time difference was w ithin 2 h. The aver age Nash efficiency co eff icient and averag e correlation co effi2 cient r w ere 01 82 and 01 92, r espectiv ely. Fo r the daily runoff simulation, the averag e Nash efficiency coefficient w as 01 6, the av2 er age correlation coefficient r was 01 78, and the av erag e relat ive error was 31 95% . Preliminar y analysis showed that the H EC2 HMS model a pplied w ell to the Wenyu Riv er basin. It can effect ively simulate the short2t erm and long2t erm r ainfall and r unoff pr ocesses in norther n China, and can be used fo r floo d fo recast, w ater r eso ur ces evaluation and management in this area.
2018, 16(6):21-26.
Abstract:
The hydro logic cycle r esearch under changing env ironment is o ne of the hot topics in water science study. The study on the re2 sponse mechanism to hydrological process chang es is of great practical significance to futur e water r esources planning and management. In this study, based on the Budyko hypo thesis, we conducted attribution analysis of the streamflow chang es in the Zoige basin by sensi2 tivity analysis, and the results showed that: the sensitiv ity coefficients of streamflow to precipitation, potential evapotranspiration, and catchment characteristic parameter were 01 654 1, - 01 234 7, and - 1821 205 0, respectively, which means that every 1 mm increase in precipitatio n would induce a 01 654 1 mm increase in str eamflow; every 1 mm increase in potential ev apotranspiration would induce a 01 234 7 mm decrease in streamflow ; every increase of 1 in the catchment characteristic parameter would induce a 1821 205 0 mm de2 crease in streamflow . The streamflow of the Zoige basin showed a sig nificantly decreasing tr end. Compared with the reference period ( 196021990) , the streamflow o f the chang e perio d ( 199122011) decreased by 561 23 mm ( 201 48% ) . The main influence factor w as the change of underlying surface characteristics, whose contribution rate reached 931 46%. The climate chang e only contributed 51 . 57% .
The hydro logic cycle r esearch under changing env ironment is o ne of the hot topics in water science study. The study on the re2 sponse mechanism to hydrological process chang es is of great practical significance to futur e water r esources planning and management. In this study, based on the Budyko hypo thesis, we conducted attribution analysis of the streamflow chang es in the Zoige basin by sensi2 tivity analysis, and the results showed that: the sensitiv ity coefficients of streamflow to precipitation, potential evapotranspiration, and catchment characteristic parameter were 01 654 1, - 01 234 7, and - 1821 205 0, respectively, which means that every 1 mm increase in precipitatio n would induce a 01 654 1 mm increase in str eamflow; every 1 mm increase in potential ev apotranspiration would induce a 01 234 7 mm decrease in streamflow ; every increase of 1 in the catchment characteristic parameter would induce a 1821 205 0 mm de2 crease in streamflow . The streamflow of the Zoige basin showed a sig nificantly decreasing tr end. Compared with the reference period ( 196021990) , the streamflow o f the chang e perio d ( 199122011) decreased by 561 23 mm ( 201 48% ) . The main influence factor w as the change of underlying surface characteristics, whose contribution rate reached 931 46%. The climate chang e only contributed 51 . 57% .
2018, 16(6):27-32.
Abstract:
Based on the mo nt hly precipit at ion dat a of Zheng zhou meteor olog ical statio n fr om 1955 to 2015, using lo ng2and sho rt2 cy cle droug ht2f loo d abrupt alter nat ion index, Linear Tendency Estimation, Mann2Kendall test and other mathematical models, we analy zed the annual precipitation and the evolut ion of dr ought2floo d during June to September in Zheng zho u. T he r esults wer e as follow s: T he annual precipitation significantly decreased at a rate of - 71 87 mm/ ( 10a) . T he chang e t rend of the LDFAI in Zheng zhou w as not o bv io us, but the intensit y of LDFAI ex hibited periodic changes, including t wo str ong and tw o w eak peri2 o ds. The intensity of LDFAI g reater than 1 accounted for 371 7% in the r ecent 61 years, w hich meant droug ht2f loo d abrupt alter2 natio n o ccurred f requent ly. The sho rt2cy cle dro ug ht2flo od abrupt alt ernation index bet ween adjacent months had t he most f re2 quent fluctuation from June t o July , the second most from July to Aug ust , and it lev eled off from August to September. In g ener2 al, the intensity of lo ng2cycle flo od2 to2droug ht tr ansit ion w as g ener ally st rong er t han t hat of dr ought2to2flo od tr ansit ion. Bo th long2and sho rt2cy cle dr ought2floo d abrupt alter nat ion phenomena showed a trend o f decline
Based on the mo nt hly precipit at ion dat a of Zheng zhou meteor olog ical statio n fr om 1955 to 2015, using lo ng2and sho rt2 cy cle droug ht2f loo d abrupt alter nat ion index, Linear Tendency Estimation, Mann2Kendall test and other mathematical models, we analy zed the annual precipitation and the evolut ion of dr ought2floo d during June to September in Zheng zho u. T he r esults wer e as follow s: T he annual precipitation significantly decreased at a rate of - 71 87 mm/ ( 10a) . T he chang e t rend of the LDFAI in Zheng zhou w as not o bv io us, but the intensit y of LDFAI ex hibited periodic changes, including t wo str ong and tw o w eak peri2 o ds. The intensity of LDFAI g reater than 1 accounted for 371 7% in the r ecent 61 years, w hich meant droug ht2f loo d abrupt alter2 natio n o ccurred f requent ly. The sho rt2cy cle dro ug ht2flo od abrupt alt ernation index bet ween adjacent months had t he most f re2 quent fluctuation from June t o July , the second most from July to Aug ust , and it lev eled off from August to September. In g ener2 al, the intensity of lo ng2cycle flo od2 to2droug ht tr ansit ion w as g ener ally st rong er t han t hat of dr ought2to2flo od tr ansit ion. Bo th long2and sho rt2cy cle dr ought2floo d abrupt alter nat ion phenomena showed a trend o f decline
6 Simulating the daily evapotranspiration in Heihe river basin with multi-sensor remote sensing data
2018, 16(6):33-38.
Abstract:
Vegetation evapotranspirat ion is an import ant parameter involving gr ound surface w ater and heat balance. It is also an import ant index to measur e veg etation g rowth and cr op yield and the basis fo r o ptimized allocation of w atershed w ater re2 sour ces. T he remote sensing technolog y has become an impo rtant metho d for simulat ion of reg ional scale evapotr anspir ation. With t he Heihe Riv er Basin as a case study , w e constructed a r emote sensing2driven evapotr anspir atio n simulatio n model, combi2 ning multi2source remo te sensing data ( M ODIS, TRMM, etc. ) and GLDAS data, we simulated the pot ential ev apo transpiratio n and actual ev apo transpiratio n of H eihe Riv er basin in 2005, 2010 and 2015 on daily sca le at a 12km spatial r eso lutio n. The r esults show ed that: the po tent ial ev apo transpiratio n v aried sig nificantly betw een differ ent mo nths, starting to gr ow in May, peaking in July, and then g radually decreasing . The actual eva pot ranspiratio n varied sig nificantly betw een the months and r eached the high2 est value in 2015. The results of pr ecision test show ed t hat t he tw o mo dels used in this study bo th had g ood effects. The Kris2 tensen2Jensen model w as mo re suitable fo r the H eihe river basin. T his r esear ch can prov ide im po rtant diurnal ev apo transpiratio n data fo r the Heihe riv er basin surface feature dat aset.
Vegetation evapotranspirat ion is an import ant parameter involving gr ound surface w ater and heat balance. It is also an import ant index to measur e veg etation g rowth and cr op yield and the basis fo r o ptimized allocation of w atershed w ater re2 sour ces. T he remote sensing technolog y has become an impo rtant metho d for simulat ion of reg ional scale evapotr anspir ation. With t he Heihe Riv er Basin as a case study , w e constructed a r emote sensing2driven evapotr anspir atio n simulatio n model, combi2 ning multi2source remo te sensing data ( M ODIS, TRMM, etc. ) and GLDAS data, we simulated the pot ential ev apo transpiratio n and actual ev apo transpiratio n of H eihe Riv er basin in 2005, 2010 and 2015 on daily sca le at a 12km spatial r eso lutio n. The r esults show ed that: the po tent ial ev apo transpiratio n v aried sig nificantly betw een differ ent mo nths, starting to gr ow in May, peaking in July, and then g radually decreasing . The actual eva pot ranspiratio n varied sig nificantly betw een the months and r eached the high2 est value in 2015. The results of pr ecision test show ed t hat t he tw o mo dels used in this study bo th had g ood effects. The Kris2 tensen2Jensen model w as mo re suitable fo r the H eihe river basin. T his r esear ch can prov ide im po rtant diurnal ev apo transpiratio n data fo r the Heihe riv er basin surface feature dat aset.
2018, 16(6):39-45.
Abstract:
The pr obabilistic flo od fo recasting can pro v ide a predictio n inter val w ith a certain reliabilit y, and can be used to e2 v aluat e the reliability of fo recasting results. It can pro v ide an im portant basis fo r floo d co ntro l scheduling . We too k Wa ng jia2 ba cr oss2sectio n, a key f lo od contr ol sectio n of H uaihe River, as the resear ch object. Based on the predict ion results of API and XAJ mo dels, using t he M odel condit ional pr ocesso r ( MCP) to deduce the co nditio na l pro ba bility distributio n function of the for ecasting runo ff of floo ds o f different m agnitudes, w e r ealized pro babilistic flo od fo recasting . T he pr edictio n results w ere analyzed in terms of the dete rministic precision evaluatio n o f m edian number and the r eliability ev aluat ion of pro babilis2 tic for ecasting . The r esults show ed that the M CP pr obabilistic floo d fo recasting has a high r eliability, a nd its median number predictio n has a hig her pr edictio n accur acy t ha n the determinist ic mo del, indicating that M CP has a certain ability of co rr ec2 tion and prediction.
The pr obabilistic flo od fo recasting can pro v ide a predictio n inter val w ith a certain reliabilit y, and can be used to e2 v aluat e the reliability of fo recasting results. It can pro v ide an im portant basis fo r floo d co ntro l scheduling . We too k Wa ng jia2 ba cr oss2sectio n, a key f lo od contr ol sectio n of H uaihe River, as the resear ch object. Based on the predict ion results of API and XAJ mo dels, using t he M odel condit ional pr ocesso r ( MCP) to deduce the co nditio na l pro ba bility distributio n function of the for ecasting runo ff of floo ds o f different m agnitudes, w e r ealized pro babilistic flo od fo recasting . T he pr edictio n results w ere analyzed in terms of the dete rministic precision evaluatio n o f m edian number and the r eliability ev aluat ion of pro babilis2 tic for ecasting . The r esults show ed that the M CP pr obabilistic floo d fo recasting has a high r eliability, a nd its median number predictio n has a hig her pr edictio n accur acy t ha n the determinist ic mo del, indicating that M CP has a certain ability of co rr ec2 tion and prediction.
2018, 16(6):46-52.
Abstract:
We to ok the Xiaoqing Riv er basin as the study area. Based o n the daily pr ecipitation data from 1977 to 2014 at fiv e rainfall stations, w e used the Mann2Kendall t rend test to analy ze the variatio n tr end o f flood2seaso n precipitation at each st ation; then we used M orlet wav elet to analyze the perio dical variatio n of flo od2seaso n precipitation. We detected the abr upt chang e po ints o f the precipit ation series using various metho ds, including the Mann2Kendall metho d, sliding t test, sequential clust ering analysis, and Yamamo to method. Finally, we used the H urst exponent method to pr edict the future trend of the flood2seaso n pr ecipitatio n at each statio n. T he results show ed that the flo od2seaso n precipitatio n tended to incr ease, but the abr upt chang e po ints w ere insig nificant. T he period of the flo od2season pr ecipitation was about 22 years. T he abr upt change analysis show ed that the abrupt chang e points of the f loo d2season pr ecipitation detected by different metho ds w ere no t consistent, and the futur e variatio n o f the estimated flo od2seaso n precipitat ion showed a weak upw ard tr end.
We to ok the Xiaoqing Riv er basin as the study area. Based o n the daily pr ecipitation data from 1977 to 2014 at fiv e rainfall stations, w e used the Mann2Kendall t rend test to analy ze the variatio n tr end o f flood2seaso n precipitation at each st ation; then we used M orlet wav elet to analyze the perio dical variatio n of flo od2seaso n precipitation. We detected the abr upt chang e po ints o f the precipit ation series using various metho ds, including the Mann2Kendall metho d, sliding t test, sequential clust ering analysis, and Yamamo to method. Finally, we used the H urst exponent method to pr edict the future trend of the flood2seaso n pr ecipitatio n at each statio n. T he results show ed that the flo od2seaso n precipitatio n tended to incr ease, but the abr upt chang e po ints w ere insig nificant. T he period of the flo od2season pr ecipitation was about 22 years. T he abr upt change analysis show ed that the abrupt chang e points of the f loo d2season pr ecipitation detected by different metho ds w ere no t consistent, and the futur e variatio n o f the estimated flo od2seaso n precipitat ion showed a weak upw ard tr end.
2018, 16(6):53-59.
Abstract:
Based on the daily measured dischar ge and sediment data of three stations in Raohe River basin from 1952 to 2014, we studied the variation characteristics of the annual runoff and sediment transport. The results showed that: 1) In terms of the reg ional composi2 tion of runoff and sediment transport in the Raohe River basin, the Changjiang River, Lecan River, and Dong dahe River took up 20%2 35% , and the sediment transport and the runoff were directly proportional to each other. 2) The r unoff in the Raohe River basin show ed prominent interannual variations. The flow in the 1990s was g reater than the normal lev el ( by 20% ) . The main perio d of the r unoff and sediment tr ansport series w as 20 years, but the future runoff showed pr ominent r andomness. 3) The sediment load declined significantly after 1998, causing a tur ning point on the do uble accumulative curve of runo ff and sediment. The future sediment load mig ht keep declining. 4) One of the reasons for the r eduction o f sediment load in Raohe Riv er basin w as the reduct ion of runo ff after 2000 ( by 10% ) . Another main factor w as the int ercept ion o f sediment by la rge and medium water co nserv ancy pro2 jects built betw een 1998 and 2007. Ow ing to t he contro l of soil erosion and constructio n of w ater conservancy projects, the sedi2 ment in Rao he River basin is ex pected to decline further in the futur e. The results can pro vide a r eference for the comprehensiv e utilization and dev elopment of w ater r eso ur ces and t he w ater ecolog ical pro tection in Rao he River Basin.
Based on the daily measured dischar ge and sediment data of three stations in Raohe River basin from 1952 to 2014, we studied the variation characteristics of the annual runoff and sediment transport. The results showed that: 1) In terms of the reg ional composi2 tion of runoff and sediment transport in the Raohe River basin, the Changjiang River, Lecan River, and Dong dahe River took up 20%2 35% , and the sediment transport and the runoff were directly proportional to each other. 2) The r unoff in the Raohe River basin show ed prominent interannual variations. The flow in the 1990s was g reater than the normal lev el ( by 20% ) . The main perio d of the r unoff and sediment tr ansport series w as 20 years, but the future runoff showed pr ominent r andomness. 3) The sediment load declined significantly after 1998, causing a tur ning point on the do uble accumulative curve of runo ff and sediment. The future sediment load mig ht keep declining. 4) One of the reasons for the r eduction o f sediment load in Raohe Riv er basin w as the reduct ion of runo ff after 2000 ( by 10% ) . Another main factor w as the int ercept ion o f sediment by la rge and medium water co nserv ancy pro2 jects built betw een 1998 and 2007. Ow ing to t he contro l of soil erosion and constructio n of w ater conservancy projects, the sedi2 ment in Rao he River basin is ex pected to decline further in the futur e. The results can pro vide a r eference for the comprehensiv e utilization and dev elopment of w ater r eso ur ces and t he w ater ecolog ical pro tection in Rao he River Basin.
2018, 16(6):60-67.
Abstract:
In or der to illustrat e t he v ariat ion char acteristic of precipitation in Wuzhishan City in the r ecent 60 y ears, based on the data o f 17 rainfall statio ns/ meteo ro log ical statio ns, we used different interpolation metho ds t o co nduct monthly inter po lation and compar ed the r esults w ith the Seco nd Evaluation results of H ainan Pr ovince, and thus selected the reasonable method. We ana2 lyzed t he spat ial and tempora l changes of precipitation using sliding av erag e method, cumulativ e anomaly method, Mann2Kendall no nparametric test, and M orlet w av elet analy sis. T he r esults w ere as fo llows: ( 1) The aver age precipitat ion in the past 60 years of Wuzhishan was 1921. 3mm and show ed a g radually declining tr end spatially fr om the no rtheast and north to the southwest. ( 2) The distributio n o f pr ecipitatio n differed slig htly across different scenarios, but show ed co nsistent response to topog raphy. ( 3) The annual pr ecipitatio n generally show ed a significant increasing trend, w ith a sudden change from decreasing to increasing around 1988. ( 4) The r esults of attribution analy sis w ith SPSS show ed that the ev apo ratio n mainly affected the v ariation patter n of precipitation in Wuzhishan. ( 5) T her e are multi2scale time effects o f precipitatio n and majo r cy cles of 23 years and 16 years wit h alternatio ns between wet and dr y y ears. T he next few years w ill be w et years. The abov e results hav e r ealist ic sig nificance to the dev elopment, utilization, and planning of w ater r eso urces in Wuzhishan.
In or der to illustrat e t he v ariat ion char acteristic of precipitation in Wuzhishan City in the r ecent 60 y ears, based on the data o f 17 rainfall statio ns/ meteo ro log ical statio ns, we used different interpolation metho ds t o co nduct monthly inter po lation and compar ed the r esults w ith the Seco nd Evaluation results of H ainan Pr ovince, and thus selected the reasonable method. We ana2 lyzed t he spat ial and tempora l changes of precipitation using sliding av erag e method, cumulativ e anomaly method, Mann2Kendall no nparametric test, and M orlet w av elet analy sis. T he r esults w ere as fo llows: ( 1) The aver age precipitat ion in the past 60 years of Wuzhishan was 1921. 3mm and show ed a g radually declining tr end spatially fr om the no rtheast and north to the southwest. ( 2) The distributio n o f pr ecipitatio n differed slig htly across different scenarios, but show ed co nsistent response to topog raphy. ( 3) The annual pr ecipitatio n generally show ed a significant increasing trend, w ith a sudden change from decreasing to increasing around 1988. ( 4) The r esults of attribution analy sis w ith SPSS show ed that the ev apo ratio n mainly affected the v ariation patter n of precipitation in Wuzhishan. ( 5) T her e are multi2scale time effects o f precipitatio n and majo r cy cles of 23 years and 16 years wit h alternatio ns between wet and dr y y ears. T he next few years w ill be w et years. The abov e results hav e r ealist ic sig nificance to the dev elopment, utilization, and planning of w ater r eso urces in Wuzhishan.
2018, 16(6):68-73.
Abstract:
Acco rding to the connotatio n of surface w ater resour ces vulnerability and the characteristics o f surface water r eso urces in Baoding, 10 evaluatio n indexes are selected fr om three aspects: natural vulnerability, human vulnerability and burden v ulner a2 bility . T he w eig ht o f each index is calculated by AH P, and the vulnerability o f surface w ater resour ces is quantitat ively ev aluated by comprehensiv e index method and GIS/ RS technolog y. T he r esults show that the surface w ater r eso ur ces in Bao ding are gen2 er ally v ulner able, and t he mo st v ulnerable ar eas ar e the northwestern, western, east2cent ral, and so ut heastern parts of Baoding . Accor ding to the vulner ability structure, these ar eas are div ided into three cat eg ories: natur al v ulnerability2dominant a reas, hu2 man vulnerability2dom inant areas and burden v ulner ability2dominant a reas. Fo r the natural v ulner ability2dominant and human vulnerability2dominant areas, some countermeasures ar e put forw ar d such as construction of w at er co nser vancy facilities and ex2 pansion of aff orestation ar ea; for the burden vulner abilit y2dominant ar eas, this paper pr oposes contro lling water co nsumption and po pulat ion g row th, eliminating backwar d pr oductio n capacity, dev elo ping water2sav ing techno lo gies and promoting water2saving know ledge.
Acco rding to the connotatio n of surface w ater resour ces vulnerability and the characteristics o f surface water r eso urces in Baoding, 10 evaluatio n indexes are selected fr om three aspects: natural vulnerability, human vulnerability and burden v ulner a2 bility . T he w eig ht o f each index is calculated by AH P, and the vulnerability o f surface w ater resour ces is quantitat ively ev aluated by comprehensiv e index method and GIS/ RS technolog y. T he r esults show that the surface w ater r eso ur ces in Bao ding are gen2 er ally v ulner able, and t he mo st v ulnerable ar eas ar e the northwestern, western, east2cent ral, and so ut heastern parts of Baoding . Accor ding to the vulner ability structure, these ar eas are div ided into three cat eg ories: natur al v ulnerability2dominant a reas, hu2 man vulnerability2dom inant areas and burden v ulner ability2dominant a reas. Fo r the natural v ulner ability2dominant and human vulnerability2dominant areas, some countermeasures ar e put forw ar d such as construction of w at er co nser vancy facilities and ex2 pansion of aff orestation ar ea; for the burden vulner abilit y2dominant ar eas, this paper pr oposes contro lling water co nsumption and po pulat ion g row th, eliminating backwar d pr oductio n capacity, dev elo ping water2sav ing techno lo gies and promoting water2saving know ledge.
2018, 16(6):74-79.
Abstract:
Disso lved pollutants are an important pa rt o f urban rainfall r unoff po llut ion. T o r eveal their t ranspo rt pro cess during the rainfall r uno ff stage is of gr eat sig nificance to urban wastew ater t reatment. I n this study, w e conducted a series o f ex peri2 ments to study the pro cesses of r ainfall- runoff and dissolved pollutant tr ansport o ver imper vio us surface at different slopes ( 01 5b, 1b, 2b, 3b, 4b, 5b) . The results show ed that the hig her the surface slope, the sho rter the time of runoff yield and concentr a2 tion, and t he faster it to ok fo r the runoff volume to reach stability. T he po llutant concentr ation would decrease as the ra infall runo ff depth increased; the hig her the slope, the higher the initial concent ratio n, and t he faster the attenuation. T he pollutant transpo rt r ate wo uld incr ease first and then decrease with time; the hig her the slope, the larg er the peak o f pollutant transpo rt rate. T he peak of pollutant transpo rt r ate appeared when the cumulative runoff depth was 01 3 to 01 5 mm. T he pollutant trans2 port process co nfo rmed to the ex po nential wash2off model. The wash2off coefficient k w ould increase linearly f irst and then re2 main basically stable w hen the slo pe was abov e 3b. Com par ed w ith particulate po llutants, the disso lv ed po llutants had a lar ger was2off coefficient and wer e more likely to be washed o ff, especially in the initia l r unoff stag e.
Disso lved pollutants are an important pa rt o f urban rainfall r unoff po llut ion. T o r eveal their t ranspo rt pro cess during the rainfall r uno ff stage is of gr eat sig nificance to urban wastew ater t reatment. I n this study, w e conducted a series o f ex peri2 ments to study the pro cesses of r ainfall- runoff and dissolved pollutant tr ansport o ver imper vio us surface at different slopes ( 01 5b, 1b, 2b, 3b, 4b, 5b) . The results show ed that the hig her the surface slope, the sho rter the time of runoff yield and concentr a2 tion, and t he faster it to ok fo r the runoff volume to reach stability. T he po llutant concentr ation would decrease as the ra infall runo ff depth increased; the hig her the slope, the higher the initial concent ratio n, and t he faster the attenuation. T he pollutant transpo rt r ate wo uld incr ease first and then decrease with time; the hig her the slope, the larg er the peak o f pollutant transpo rt rate. T he peak of pollutant transpo rt r ate appeared when the cumulative runoff depth was 01 3 to 01 5 mm. T he pollutant trans2 port process co nfo rmed to the ex po nential wash2off model. The wash2off coefficient k w ould increase linearly f irst and then re2 main basically stable w hen the slo pe was abov e 3b. Com par ed w ith particulate po llutants, the disso lv ed po llutants had a lar ger was2off coefficient and wer e more likely to be washed o ff, especially in the initia l r unoff stag e.
2018, 16(6):80-88.
Abstract:
The assimilativ e capacity of a w ater function zone is the basis fo r gr oss co ntr ol o f po llutants discharg e. At present, the capacity is commonly calculated by ana lyt ical method, but the calculation r esults ar e no t accur ate. In this research, w e too k Jiu2 jiang industrial water funct ion zone beside Po yang Lake as the o bject of r esear ch, and calculat ed its assimilativ e capacity. The an2 alytica l method was used to calculate the initial value, and the numerica l method w as used t o optimize the initia l value. The cal2 culation results showed that the o ptimal assimilative capacit y of Jiujiang industrial w ater functio n zone beside Poy ang Lake for COD is 9 776 t/ a, and that fo r ammo nia nitro gen ( NH32N) is 142 t/ a. This study takes into acco unt such factors as the river mor pholog y, the chang e of insho re velocity , and the effects of characteristic hydrolog ical conditio ns. It can make up fo r the limi2 tat ions of the analytica l method and generate mor e reasonable results. It can prov ide a r eference fo r w at er pollutants g ro ss con2 tr ol in Jiujiang indust rial wat er functio n zone beside Poyang Lake.
The assimilativ e capacity of a w ater function zone is the basis fo r gr oss co ntr ol o f po llutants discharg e. At present, the capacity is commonly calculated by ana lyt ical method, but the calculation r esults ar e no t accur ate. In this research, w e too k Jiu2 jiang industrial water funct ion zone beside Po yang Lake as the o bject of r esear ch, and calculat ed its assimilativ e capacity. The an2 alytica l method was used to calculate the initial value, and the numerica l method w as used t o optimize the initia l value. The cal2 culation results showed that the o ptimal assimilative capacit y of Jiujiang industrial w ater functio n zone beside Poy ang Lake for COD is 9 776 t/ a, and that fo r ammo nia nitro gen ( NH32N) is 142 t/ a. This study takes into acco unt such factors as the river mor pholog y, the chang e of insho re velocity , and the effects of characteristic hydrolog ical conditio ns. It can make up fo r the limi2 tat ions of the analytica l method and generate mor e reasonable results. It can prov ide a r eference fo r w at er pollutants g ro ss con2 tr ol in Jiujiang indust rial wat er functio n zone beside Poyang Lake.
2018, 16(6):89-96.
Abstract:
Karst g roundw ater r eso urce is an impo rtant g ua rantee for the so cial and eco nomic develo pment in southwest China. With the continuous acceler ation of ur banizatio n pro cess, the pro blem of karst g ro undwater po llut ion in southwest China is be2 com ing increasingly prominent. Posing direct threats to the health and safety of the lo ca l people, it has become a ho t social issue. In this paper, w e studied the t ypical karst g r oundwater system po llution cases in southwest China. T hroug h t he analysis of the hy dr og eolog ical conditio ns, characteristics of pollution so urces, law o f pollutant mig ratio n, and po llution harm o f each karst gr oundwat er system, w e summarized the ty pical karst g ro undwater sy st em pollutio n models in southwest China, including inter2 mittent inf iltr atio n pollution, co nt inuo us infilt ratio n pollutio n, po uring pollutio n and leakage infiltrat ion po llution. This study can help r esear chers to better identify t he characteristics and law s of pollutants t ranspo rt, and mor e accurately g rasp the sco pe and ex tent of pollutio n. It can prov ide impo rtant refer ence for the preventio n and contr ol o f g r oundwater po llutants in karst areas in so uthw est China.
Karst g roundw ater r eso urce is an impo rtant g ua rantee for the so cial and eco nomic develo pment in southwest China. With the continuous acceler ation of ur banizatio n pro cess, the pro blem of karst g ro undwater po llut ion in southwest China is be2 com ing increasingly prominent. Posing direct threats to the health and safety of the lo ca l people, it has become a ho t social issue. In this paper, w e studied the t ypical karst g r oundwater system po llution cases in southwest China. T hroug h t he analysis of the hy dr og eolog ical conditio ns, characteristics of pollution so urces, law o f pollutant mig ratio n, and po llution harm o f each karst gr oundwat er system, w e summarized the ty pical karst g ro undwater sy st em pollutio n models in southwest China, including inter2 mittent inf iltr atio n pollution, co nt inuo us infilt ratio n pollutio n, po uring pollutio n and leakage infiltrat ion po llution. This study can help r esear chers to better identify t he characteristics and law s of pollutants t ranspo rt, and mor e accurately g rasp the sco pe and ex tent of pollutio n. It can prov ide impo rtant refer ence for the preventio n and contr ol o f g r oundwater po llutants in karst areas in so uthw est China.
2018, 16(6):97-102.
Abstract:
The effect of hydro dy namic conditio ns o n the self2purificat ion of w ater body w as studied thro ug h the w ater flume ex2 periments and theor etical analysis. It was found that flow velocity was o ne o f the main facto rs affecting the self2purificat ion of water bo dy , w hile differ ent sectio n and w ater depth co ndit ions did not make much difference on the self2purificat ion o f w ater bo dy . We adopted t he bio chemical ox yg en demand2disso lv ed ox yg en co upling mo del and chemical f irst2o rder r eaction to pr edict the v ariat ion of w ater quality with time. T o some extent, the increase o f w ater f low v elocity improv ed the reaerat ion ability of water bo dy and enhanced the self2purificatio n effect of w at er body . H ow ever, when the f low velo city ex ceeded a certa in value causing sediment resuspension, the self2purification effect o f the w ater body decreased shar ply in a sho rt time. In a w ater diver2 sio n pr oject, reasonable contro l and design of hy dr aulic parameters such as flow velo city and discharg e, w ater intake perio d and interval, and incr ease o f ener gy dissipation hy dr aulic str uctures are effectiv e measures to co ntr ol water quality.
The effect of hydro dy namic conditio ns o n the self2purificat ion of w ater body w as studied thro ug h the w ater flume ex2 periments and theor etical analysis. It was found that flow velocity was o ne o f the main facto rs affecting the self2purificat ion of water bo dy , w hile differ ent sectio n and w ater depth co ndit ions did not make much difference on the self2purificat ion o f w ater bo dy . We adopted t he bio chemical ox yg en demand2disso lv ed ox yg en co upling mo del and chemical f irst2o rder r eaction to pr edict the v ariat ion of w ater quality with time. T o some extent, the increase o f w ater f low v elocity improv ed the reaerat ion ability of water bo dy and enhanced the self2purificatio n effect of w at er body . H ow ever, when the f low velo city ex ceeded a certa in value causing sediment resuspension, the self2purification effect o f the w ater body decreased shar ply in a sho rt time. In a w ater diver2 sio n pr oject, reasonable contro l and design of hy dr aulic parameters such as flow velo city and discharg e, w ater intake perio d and interval, and incr ease o f ener gy dissipation hy dr aulic str uctures are effectiv e measures to co ntr ol water quality.
2018, 16(6):103-108.
Abstract:
It is an important task to improv e the w ater envir onment of the city as a lar ge number of the ur ban riv ers in China hav e turned black and smelly. It has become a trend to judg e the effect o f black and smelly w ater tr eat ment by the public satis2 factio n deg ree and the lo ng2term mechanism const ruct ion pro g ress. Based on the data of public satisfactio n assessment of 6 black and smelly rivers in Nanjing Gulou District, w e selected sev en factors which had significant influence o n public satisfactio n throug h the single2fact or v ariance analysis. By using the I nter pr etativ e St ruct ur al Mo deling method ( ISM) , w e analy zed the in2 ter nal relatio nships among the seven facto rs and built a hierarchical st ructur al model, w ith a v iew to pro viding refer ence to the gov ernment o n black and smelly water treatment. T he analy sis results showed that w ater o do r, abno rmal co lo r, cleanliness, and public aw areness o f the tr eat ment pr oject w ere dir ect influencing factors on public satisfaction of the black and smelly w ater treatment; the ident ity o f the respo ndents w as an indirect influencing facto r; dir ect sewag e discha rg e to the riv er and g arbag e stacking along the riv er w ere the roo t factors.
It is an important task to improv e the w ater envir onment of the city as a lar ge number of the ur ban riv ers in China hav e turned black and smelly. It has become a trend to judg e the effect o f black and smelly w ater tr eat ment by the public satis2 factio n deg ree and the lo ng2term mechanism const ruct ion pro g ress. Based on the data of public satisfactio n assessment of 6 black and smelly rivers in Nanjing Gulou District, w e selected sev en factors which had significant influence o n public satisfactio n throug h the single2fact or v ariance analysis. By using the I nter pr etativ e St ruct ur al Mo deling method ( ISM) , w e analy zed the in2 ter nal relatio nships among the seven facto rs and built a hierarchical st ructur al model, w ith a v iew to pro viding refer ence to the gov ernment o n black and smelly water treatment. T he analy sis results showed that w ater o do r, abno rmal co lo r, cleanliness, and public aw areness o f the tr eat ment pr oject w ere dir ect influencing factors on public satisfaction of the black and smelly w ater treatment; the ident ity o f the respo ndents w as an indirect influencing facto r; dir ect sewag e discha rg e to the riv er and g arbag e stacking along the riv er w ere the roo t factors.
2018, 16(6):109-118.
Abstract:
Taking Jiao zuo segment in the Middle Ro ute o f South2t o2North Water Transfer Project as the study area, using field in2 vestig ation and experimental analysis, w e collected soil samples from the industrial and mining area, urban area, and ag ricultural ar ea a2 long the main canal, measured the content of heavy metals ( Cr, Ni, Cu, Zn, As, Cd, Hg, and Pb) in the soil, and evaluated the condition of heav y2metal pollution and its potential ecolog ical risks using the single factor po llut ion index, Nemerow pollution index, and Hakanson comprehensive potential eco log ical risk index . The results show ed that, acco rding to the Grade ò criteria of the Standar d for So il Quality ( pH > 71 5) , the main heavy2metal po llution risk element w as Cd. The Nemerow pollutio n index of the ag ricultur al area, ur ban area, and industrial2m ining area was 371 56, 361 65, and 371 98, r espectively, all reaching sev ere po llution level. T he com2 prehensive potential risk index of the three areas was 41 8231 39, 18 9731 18, and 19 6591 09, respectively, all posing hig h ecolog ical risks. The ana lysis r esults show ed that the soil o f the ag ricultur al area, ur ban area, and industria l2mining ar ea along the ma in canal ar e all contaminated by heavy metals to differ ent deg r ees. The industrial2mining area has the most serious po llution, w hich po sed a gr eat threat to the w ater quality safety of the canal. T he abo ve results ar e of important sig nificance to water quality pro2 tectio n and so il po llut ion contro l in the riverside ar ea o f Jiaozuo segment of the South2to2North Water T ransfer Project .
Taking Jiao zuo segment in the Middle Ro ute o f South2t o2North Water Transfer Project as the study area, using field in2 vestig ation and experimental analysis, w e collected soil samples from the industrial and mining area, urban area, and ag ricultural ar ea a2 long the main canal, measured the content of heavy metals ( Cr, Ni, Cu, Zn, As, Cd, Hg, and Pb) in the soil, and evaluated the condition of heav y2metal pollution and its potential ecolog ical risks using the single factor po llut ion index, Nemerow pollution index, and Hakanson comprehensive potential eco log ical risk index . The results show ed that, acco rding to the Grade ò criteria of the Standar d for So il Quality ( pH > 71 5) , the main heavy2metal po llution risk element w as Cd. The Nemerow pollutio n index of the ag ricultur al area, ur ban area, and industrial2m ining area was 371 56, 361 65, and 371 98, r espectively, all reaching sev ere po llution level. T he com2 prehensive potential risk index of the three areas was 41 8231 39, 18 9731 18, and 19 6591 09, respectively, all posing hig h ecolog ical risks. The ana lysis r esults show ed that the soil o f the ag ricultur al area, ur ban area, and industria l2mining ar ea along the ma in canal ar e all contaminated by heavy metals to differ ent deg r ees. The industrial2mining area has the most serious po llution, w hich po sed a gr eat threat to the w ater quality safety of the canal. T he abo ve results ar e of important sig nificance to water quality pro2 tectio n and so il po llut ion contro l in the riverside ar ea o f Jiaozuo segment of the South2to2North Water T ransfer Project .
2018, 16(6):119-129.
Abstract:
Gr aphene ox ide has attr acted w idespread attent ion in wat er treatment field as a new nanomaterial. Because of its larg e specific surface area, abundant ox yg en2co nta ining functional g roups, ex cellent hy dr ophilia, and unique physical str ucture, it can adsor b heavy metal ions f rom w ater and its adso rption capacity is better than many kinds o f common adsorbents. H ow ever, its st ructur e and pr operty hav e limited its develo pment in w ater tr eat ment field. This pr oblem can be solv ed by combining gr aphene ox ide and other materials to form g raphene ox ide composit es. This review intro duces the str ucture and pr operty o f g raphene ox2 ide, its adso rption mechanism fo r heavy meta l io ns in wat er and the influence factors. At the same time, this review summarizes the adsor ption mechanism of g raphene ox ide composit es for heav y metal ions in w ater and its deso rption and reg ener atio n abili2 ties. In additio n, it summarizes and predicts the applicatio n po tential o f g raphene o xide and its compo sites as adso rbents to re2 mo ve heav y metal io ns from wat er.
Gr aphene ox ide has attr acted w idespread attent ion in wat er treatment field as a new nanomaterial. Because of its larg e specific surface area, abundant ox yg en2co nta ining functional g roups, ex cellent hy dr ophilia, and unique physical str ucture, it can adsor b heavy metal ions f rom w ater and its adso rption capacity is better than many kinds o f common adsorbents. H ow ever, its st ructur e and pr operty hav e limited its develo pment in w ater tr eat ment field. This pr oblem can be solv ed by combining gr aphene ox ide and other materials to form g raphene ox ide composit es. This review intro duces the str ucture and pr operty o f g raphene ox2 ide, its adso rption mechanism fo r heavy meta l io ns in wat er and the influence factors. At the same time, this review summarizes the adsor ption mechanism of g raphene ox ide composit es for heav y metal ions in w ater and its deso rption and reg ener atio n abili2 ties. In additio n, it summarizes and predicts the applicatio n po tential o f g raphene o xide and its compo sites as adso rbents to re2 mo ve heav y metal io ns from wat er.
2018, 16(6):130-141.
Abstract:
The process of w ater tr ansfo rmatio n in irrigation ar eas is com plicated due to the influence of natural and artificial fac2 to rs. Taking the irrigation area o f Zhanghe Reservoir in Hubei Province as a case study, w e described the water transformatio n process of a typical irrigation and drainag e system from both vertical and horizontal perspectives. Based on the principle o f water balance, we es2 tablished a simulation model that w as composed o f multiple modules for bo undary treatment and simulation of the w ater transfo rmation betw een multiple soil layers of the rice field, ponds and ditches. The model was calibrated and v erified based on the data of Tandian irri2 gation and drainage system in Zhang he district from 2014 to 2015. After sampling the model parameters using Latin hypercube, w e con2 ducted sensitivity analysis of the parameters using partial correlatio n analysis. The mo del calculat ion showed that the multiple corre2 latio n coefficients o f the simulation r esults fo r the br anch ditches in calibr ation and va lidatio n periods w ere 01 83 and 01 70 re2 spect ively, and the Ens co efficients w ere 01 81 and 01 68 respectively; the multiple co rrelatio n coefficients o f the simulation re2 sults fo r the tertiary ditches in calibratio n and v alidation perio ds w ere 01 79 and 01 68, and the Ens coefficients wer e 01 73 and 01 62, indicating that the model w as suitable for simulating the w ater tr ansfo rmatio n pro cess of irrig atio n and drainag e systems. As compared w ith the SWAT model, for t he same study a rea, the pro po sed model improv ed the mult iple correlation coefficient from 01 11 to 01 73 and the Ens coefficient from - 01 71 to 01 70, pro ving t he pro posed mo del w as superio r to the SWAT model. This study pro vided valuable info rmatio n fo r the study of w ater tr ansfo rmatio n in irrig ation and drainag e systems.
The process of w ater tr ansfo rmatio n in irrigation ar eas is com plicated due to the influence of natural and artificial fac2 to rs. Taking the irrigation area o f Zhanghe Reservoir in Hubei Province as a case study, w e described the water transformatio n process of a typical irrigation and drainag e system from both vertical and horizontal perspectives. Based on the principle o f water balance, we es2 tablished a simulation model that w as composed o f multiple modules for bo undary treatment and simulation of the w ater transfo rmation betw een multiple soil layers of the rice field, ponds and ditches. The model was calibrated and v erified based on the data of Tandian irri2 gation and drainage system in Zhang he district from 2014 to 2015. After sampling the model parameters using Latin hypercube, w e con2 ducted sensitivity analysis of the parameters using partial correlatio n analysis. The mo del calculat ion showed that the multiple corre2 latio n coefficients o f the simulation r esults fo r the br anch ditches in calibr ation and va lidatio n periods w ere 01 83 and 01 70 re2 spect ively, and the Ens co efficients w ere 01 81 and 01 68 respectively; the multiple co rrelatio n coefficients o f the simulation re2 sults fo r the tertiary ditches in calibratio n and v alidation perio ds w ere 01 79 and 01 68, and the Ens coefficients wer e 01 73 and 01 62, indicating that the model w as suitable for simulating the w ater tr ansfo rmatio n pro cess of irrig atio n and drainag e systems. As compared w ith the SWAT model, for t he same study a rea, the pro po sed model improv ed the mult iple correlation coefficient from 01 11 to 01 73 and the Ens coefficient from - 01 71 to 01 70, pro ving t he pro posed mo del w as superio r to the SWAT model. This study pro vided valuable info rmatio n fo r the study of w ater tr ansfo rmatio n in irrig ation and drainag e systems.
2018, 16(6):142-147.
Abstract:
Using the least squar e metho d to est imate t he parameters of the mo del o f cr op respo nse to w ater ( MCRW) may pres2 ent some pro blems such as unreasonable parameters, unsatisfying simulatio n accuracy, and inest imable par ameter due to insuffi2 cient irrigation ex perimental tr eat ments. T o so lv e these pr oblems, Free Sear ch ( FS ) w as used to estimat e the parameters of Jensen mo del in this paper. The po sitio n v ecto r of each ex plor ator y step of the individual animal of FS was taken as a set of po2 tential solutions o f t he parameter, and a set o f o ptimal parameters w as estimated based on t he animal g ro up mig ration o f the FS alg orithm. Thr ee case studies showed that the FS alg orithm can calibrate dir ectly the parameters o f Jensen mo del w ithout con2 v erting the mo del. FS can also effectively avo id unreasonable phenomenon such as a negative parameter or a parameter g reater than 1, and impr ove the simulation accuracy of the Jensen mo del. When it is difficult to adopt the linear r egr essio n metho d, FS alg orithm can be used to estimate the pa rameters of M CRW
Using the least squar e metho d to est imate t he parameters of the mo del o f cr op respo nse to w ater ( MCRW) may pres2 ent some pro blems such as unreasonable parameters, unsatisfying simulatio n accuracy, and inest imable par ameter due to insuffi2 cient irrigation ex perimental tr eat ments. T o so lv e these pr oblems, Free Sear ch ( FS ) w as used to estimat e the parameters of Jensen mo del in this paper. The po sitio n v ecto r of each ex plor ator y step of the individual animal of FS was taken as a set of po2 tential solutions o f t he parameter, and a set o f o ptimal parameters w as estimated based on t he animal g ro up mig ration o f the FS alg orithm. Thr ee case studies showed that the FS alg orithm can calibrate dir ectly the parameters o f Jensen mo del w ithout con2 v erting the mo del. FS can also effectively avo id unreasonable phenomenon such as a negative parameter or a parameter g reater than 1, and impr ove the simulation accuracy of the Jensen mo del. When it is difficult to adopt the linear r egr essio n metho d, FS alg orithm can be used to estimate the pa rameters of M CRW
2018, 16(6):148-156.
Abstract:
Air v alv es ar e important aux iliary elements in w ater div ersio n pr ojects, and ar e usually used to remov e the addit ional entr apped a ir in pipelines, mitig ate w ater hammer pressur e peaks, and admit air into pipes t o co unter sub2atmo spheric condi2 tions. The air release/ intake pro cesses of air valves invo lve complicated g as2liquid t ransient f low . T he dynamic behavio rs of the air v alv e ( such as t he air v alve dischar ge co efficient, the r esidual g as vo lume in the v alve chamber, the air valve closing time length, and the air valve opening and closing time) hav e dir ect effects o n the w ater hammer pressur e peaks. This paper critically reviews the curr ent desig ns, lay outs, physical model tests, and numerical simulations of air v alv es. It arg ues that there is a press2 ing need for a comprehensiv e, systematic and lar ge2scale test study on the dy namic behav iors of air valv es under the conditio n of gas2liquid transient flow , which will impro ve the current mathemat ical model and prov ide a theoret ical basis for the design, de2 tectio n, selectio n, and la yout of a ir v alves.
Air v alv es ar e important aux iliary elements in w ater div ersio n pr ojects, and ar e usually used to remov e the addit ional entr apped a ir in pipelines, mitig ate w ater hammer pressur e peaks, and admit air into pipes t o co unter sub2atmo spheric condi2 tions. The air release/ intake pro cesses of air valves invo lve complicated g as2liquid t ransient f low . T he dynamic behavio rs of the air v alv e ( such as t he air v alve dischar ge co efficient, the r esidual g as vo lume in the v alve chamber, the air valve closing time length, and the air valve opening and closing time) hav e dir ect effects o n the w ater hammer pressur e peaks. This paper critically reviews the curr ent desig ns, lay outs, physical model tests, and numerical simulations of air v alv es. It arg ues that there is a press2 ing need for a comprehensiv e, systematic and lar ge2scale test study on the dy namic behav iors of air valv es under the conditio n of gas2liquid transient flow , which will impro ve the current mathemat ical model and prov ide a theoret ical basis for the design, de2 tectio n, selectio n, and la yout of a ir v alves.
2018, 16(6):157-163.
Abstract:
In view of the problem of water level rising caused by emergency synchronous closure of contro l gates, this paper analyzes the influence of different closure time on the water level under the condition of sy nchrono us closure of multiple g ates. We established a one2 dimensional hydraulic simulation model, conducted plenty of calculations on clo sure conditions, and studied the influence of the closure of upstream and dow nstream contr ol gates on the w ater level before the gate. The r esults showed that the water level rise rate during the closur e process of the dow nstr eam control gate was much greater than that after the completion of the closure. On this basis, w e set dif2 ferent downstream gate closure time, and analyzed the influence of the closure time on the height and happening time of the max imum water level during the synchronous closure of upstream and downstream control gates. The results showed that the maximum w ater lev el appeared during the transmissio n of the upstream water wave to the downstream section or a short time after that, and the dow nstr eam gate closure time was the dominant factor affecting the w ater level. After analyzing the influence o f gate o peratio n in other po ols on the water level of the study poo l in a multi2channel system, we concluded that the water level of a poo l is basically affected by the operation of the upstream and dow nstr eam g ates of the poo l alone under the condition of sy nchronous closure. This paper can prov ide a reference fo r the optimization of the water level before the g ate under synchronous closure
In view of the problem of water level rising caused by emergency synchronous closure of contro l gates, this paper analyzes the influence of different closure time on the water level under the condition of sy nchrono us closure of multiple g ates. We established a one2 dimensional hydraulic simulation model, conducted plenty of calculations on clo sure conditions, and studied the influence of the closure of upstream and dow nstream contr ol gates on the w ater level before the gate. The r esults showed that the water level rise rate during the closur e process of the dow nstr eam control gate was much greater than that after the completion of the closure. On this basis, w e set dif2 ferent downstream gate closure time, and analyzed the influence of the closure time on the height and happening time of the max imum water level during the synchronous closure of upstream and downstream control gates. The results showed that the maximum w ater lev el appeared during the transmissio n of the upstream water wave to the downstream section or a short time after that, and the dow nstr eam gate closure time was the dominant factor affecting the w ater level. After analyzing the influence o f gate o peratio n in other po ols on the water level of the study poo l in a multi2channel system, we concluded that the water level of a poo l is basically affected by the operation of the upstream and dow nstr eam g ates of the poo l alone under the condition of sy nchronous closure. This paper can prov ide a reference fo r the optimization of the water level before the g ate under synchronous closure
2018, 16(6):164-170.
Abstract:
The expansive soil in the m iddle ro ute of South2to2North Water Div ersio n Pr oject in Nany ang w as taken as the re2 search object. Under t he conditio n o f keeping moistur e content and dr y density unchang ed at 20% and 11 7 g/ cm3 , respect ively, based on the 7. 5% optimum do sag e o f phosphate tailing s, w e mix ed EPS particles and polypro pylene fibers in different propor2 tions and added them into t he ex pansiv e soil for tests o f unloaded sw elling ratio , unconfined compr essive str eng th, and triax ial CU. The results show ed that EPS part icles can effectiv ely r estrain the ex pansion and shrinkag e o f ex pansiv e soil, but will r educe the str eng th and ductility of the ex pansive soil. With the increase of confining pr essure, the str ess2str ain curv es o f the modified so ils w ith mo re than 0% do sage w ill all incr ease and chang e from strain so ftening ty pe to str ain hardening ty pe, w ith 15% as the best dosage. Further analysis showed that the cohesion and inter nal f rictio n angle ar e both linearly neg ativ ely correlated with the dosag e. A fo rmula of shear str eng th r elated to dosage was obtained. Po lypr opylene fiber has smaller effects on the peak com2 pressiv e str eng th of the composite mo dif ied soil, but it can increase the ductility and r esidual strength o f the latter, so t hat the so il can be transformed fr om brittle failure to plastic failure. After comprehensiv e analy sis, we found the optimum dosag es of phosphorus tailings, EPS particles and po ly pr opylene fibers to be 71 5% , 15% , and 01 4% , respectively .
The expansive soil in the m iddle ro ute of South2to2North Water Div ersio n Pr oject in Nany ang w as taken as the re2 search object. Under t he conditio n o f keeping moistur e content and dr y density unchang ed at 20% and 11 7 g/ cm3 , respect ively, based on the 7. 5% optimum do sag e o f phosphate tailing s, w e mix ed EPS particles and polypro pylene fibers in different propor2 tions and added them into t he ex pansiv e soil for tests o f unloaded sw elling ratio , unconfined compr essive str eng th, and triax ial CU. The results show ed that EPS part icles can effectiv ely r estrain the ex pansion and shrinkag e o f ex pansiv e soil, but will r educe the str eng th and ductility of the ex pansive soil. With the increase of confining pr essure, the str ess2str ain curv es o f the modified so ils w ith mo re than 0% do sage w ill all incr ease and chang e from strain so ftening ty pe to str ain hardening ty pe, w ith 15% as the best dosage. Further analysis showed that the cohesion and inter nal f rictio n angle ar e both linearly neg ativ ely correlated with the dosag e. A fo rmula of shear str eng th r elated to dosage was obtained. Po lypr opylene fiber has smaller effects on the peak com2 pressiv e str eng th of the composite mo dif ied soil, but it can increase the ductility and r esidual strength o f the latter, so t hat the so il can be transformed fr om brittle failure to plastic failure. After comprehensiv e analy sis, we found the optimum dosag es of phosphorus tailings, EPS particles and po ly pr opylene fibers to be 71 5% , 15% , and 01 4% , respectively .
2018, 16(6):171-177.
Abstract:
Riv er confluence pr ovides convenience fo r the dev elopment of cities and has sig nificant inf luence on the reg ioncs flo od co nt rol, inland nav igat ion, and fluv ial pr ocesses. Aiming at the unidir ect ional flow s in a tidal river co nfluence ( Sanjiangkou, Ning bo city ) , w e established a two2dimensio nal hydro dy nam ic mathematical model using Delft23D. Based o n the measured hy dr olog ical and t opog raphic data, we applied four commo nly used parameters to calibr ate and validate the model r esults, focu2 sing on such flow characteristics as the tidal curr ent fields, velo city distribut ion and horizo nta l wat er lev el chang es at the max imum flood and ebb tides in w et and dry seasons. The results show ed that the f low f ield in the confluence area is analo go us to the distribut ary flow during t he flood tide, and is the co nfluence f low during the ebb t ide. There are tw o low2v elo city r eg io ns in the co nfluence vertex and the dow nstr eam of the left branch co nfluence area and they can form a separation reg ion. T he confluence flow v elocity during the ebb t ide is g enera lly lar ger than that during the flo od tide. The max imum f low velo cities in t he w et and dr y seasons ar e close. In additio n, the w ater surface of the thr ee ty pical cr oss2sections show s a sing le tr ansverse slo pe during the maximum floo d and ebb t ides. the w ater surface slo pe at the max imum ebb tide is g reater than that at the max imum f loo d tide. At the max imum ebb tide, the w ater surface of the confluence area is hig h near the mix ed layer and low at its tw o sides, show ing a " saddle shape" .
Riv er confluence pr ovides convenience fo r the dev elopment of cities and has sig nificant inf luence on the reg ioncs flo od co nt rol, inland nav igat ion, and fluv ial pr ocesses. Aiming at the unidir ect ional flow s in a tidal river co nfluence ( Sanjiangkou, Ning bo city ) , w e established a two2dimensio nal hydro dy nam ic mathematical model using Delft23D. Based o n the measured hy dr olog ical and t opog raphic data, we applied four commo nly used parameters to calibr ate and validate the model r esults, focu2 sing on such flow characteristics as the tidal curr ent fields, velo city distribut ion and horizo nta l wat er lev el chang es at the max imum flood and ebb tides in w et and dry seasons. The results show ed that the f low f ield in the confluence area is analo go us to the distribut ary flow during t he flood tide, and is the co nfluence f low during the ebb t ide. There are tw o low2v elo city r eg io ns in the co nfluence vertex and the dow nstr eam of the left branch co nfluence area and they can form a separation reg ion. T he confluence flow v elocity during the ebb t ide is g enera lly lar ger than that during the flo od tide. The max imum f low velo cities in t he w et and dr y seasons ar e close. In additio n, the w ater surface of the thr ee ty pical cr oss2sections show s a sing le tr ansverse slo pe during the maximum floo d and ebb t ides. the w ater surface slo pe at the max imum ebb tide is g reater than that at the max imum f loo d tide. At the max imum ebb tide, the w ater surface of the confluence area is hig h near the mix ed layer and low at its tw o sides, show ing a " saddle shape" .
2018, 16(6):178-186.
Abstract:
Wild and Scenic Rivers Sy stem ( WSRS) is an important pr otected a rea system on the feder al level of the United St at es, and the earliest river pro tected area in the w orld. Based o n literat ur e and inter view s, the hist ory of WSRS dev elopment is div ided into three phases by landma rk events. The gr eat achievements during each stag e ar e summarized and the main influen2 cing factors ar e analy zed. The results show that the develo pment of WSRS can be div ided into thr ee stages: pr epar atio n st age, re2 finement stage, and smoot h develo pment stage. T he aver age g row th rates during the thr ee stag es are 7. 3, 6. 0 and 3. 3 seg2 ments/ y ea r. During the preparation stag e, the concept of river pr otected area was put fo rw ard and the Wild and Scenic Rivers Act ( WSRA) w as promulgated. During the refinement stag e, WSRA w as revised further, and the manag ement mechanism w as improv ed. During the smo oth development stage, the treatment measures of t he feder al agencies tow ards WSRS w ere further im2 pro ved. Judg ing fr om the w hole develo pment pro cess, the ideo lo gy of w ildness prot ection is where the WSRS orig inates; the public needs of r ecreatio n is the public fo undat ion for WSRS; the anti2dam mo vement pushed the development of WSRS; and the gov ernance w as the main aspect fo r impro vement in t he WSRS. The main facto rs af fecting the development of WSRS include the push by the river protectionists, inter act ions betw een the political parties of the feder al g ov ernment, balance between river pro2 tectio n and eco nomic dev elo pment, and restriction caused by land ownership alo ng the riv ers.
Wild and Scenic Rivers Sy stem ( WSRS) is an important pr otected a rea system on the feder al level of the United St at es, and the earliest river pro tected area in the w orld. Based o n literat ur e and inter view s, the hist ory of WSRS dev elopment is div ided into three phases by landma rk events. The gr eat achievements during each stag e ar e summarized and the main influen2 cing factors ar e analy zed. The results show that the develo pment of WSRS can be div ided into thr ee stages: pr epar atio n st age, re2 finement stage, and smoot h develo pment stage. T he aver age g row th rates during the thr ee stag es are 7. 3, 6. 0 and 3. 3 seg2 ments/ y ea r. During the preparation stag e, the concept of river pr otected area was put fo rw ard and the Wild and Scenic Rivers Act ( WSRA) w as promulgated. During the refinement stag e, WSRA w as revised further, and the manag ement mechanism w as improv ed. During the smo oth development stage, the treatment measures of t he feder al agencies tow ards WSRS w ere further im2 pro ved. Judg ing fr om the w hole develo pment pro cess, the ideo lo gy of w ildness prot ection is where the WSRS orig inates; the public needs of r ecreatio n is the public fo undat ion for WSRS; the anti2dam mo vement pushed the development of WSRS; and the gov ernance w as the main aspect fo r impro vement in t he WSRS. The main facto rs af fecting the development of WSRS include the push by the river protectionists, inter act ions betw een the political parties of the feder al g ov ernment, balance between river pro2 tectio n and eco nomic dev elo pment, and restriction caused by land ownership alo ng the riv ers.
26 Analysis of main factors for landslide-triggered debris flow in Zhamunong gully on April 9th, 2000
2018, 16(6):187-193.
Abstract:
The landslide2trig g ered debris flow that occurred on April 9th, 2000 ( 2000 LTDF) in Zhamunong g ully had a volume of 3@ 108 m3 . We st udied the effects of inter nal and exter nal dynamic conditio ns o n the cause o f the 2000 LTDF. Based o n the ea rthquake data and temperature data fr om 1995 to 2000 and rainfall data from Mar ch to April 2000, we ana lyzed the spatio2 tempo ral co upling r elatio nship of the 2000 LTDF w ith seismicit y, freeze2thaw cy cle, and dry2w et cy cle. Based o n the structural char acteristics of g ranite r ock, w e analyzed the mechanism o f internal and ex ternal dy namic conditio ns on the cause of the 2000 LT DF. The results included two aspects. Firstly, the main facto rs of the 2000 LTDF wer e long2term fr eeze2thaw cycle, dry2wet cy cle, and seismicity. Earthquake of Ms 4. 8 w as the dir ect inducing facto r of t he 2000 LT DF. Seco ndly , t he long2term effect of seismicity, freeze2thaw cycle, and dry2wet cycle increased the vulnerability as well as t he surface fr act ur e of BH01 gr anite r ock mass. Due to the inf luence of the subsequent seepage of rain and melt water, the strength o f gr anite ro ck mass w as exhaust ed. Under the effect of the Ms 4. 8 earthquake, t he BH01 landslide occurr ed in 2000 and trig ger ed the debris f low
The landslide2trig g ered debris flow that occurred on April 9th, 2000 ( 2000 LTDF) in Zhamunong g ully had a volume of 3@ 108 m3 . We st udied the effects of inter nal and exter nal dynamic conditio ns o n the cause o f the 2000 LTDF. Based o n the ea rthquake data and temperature data fr om 1995 to 2000 and rainfall data from Mar ch to April 2000, we ana lyzed the spatio2 tempo ral co upling r elatio nship of the 2000 LTDF w ith seismicit y, freeze2thaw cy cle, and dry2w et cy cle. Based o n the structural char acteristics of g ranite r ock, w e analyzed the mechanism o f internal and ex ternal dy namic conditio ns on the cause of the 2000 LT DF. The results included two aspects. Firstly, the main facto rs of the 2000 LTDF wer e long2term fr eeze2thaw cycle, dry2wet cy cle, and seismicity. Earthquake of Ms 4. 8 w as the dir ect inducing facto r of t he 2000 LT DF. Seco ndly , t he long2term effect of seismicity, freeze2thaw cycle, and dry2wet cycle increased the vulnerability as well as t he surface fr act ur e of BH01 gr anite r ock mass. Due to the inf luence of the subsequent seepage of rain and melt water, the strength o f gr anite ro ck mass w as exhaust ed. Under the effect of the Ms 4. 8 earthquake, t he BH01 landslide occurr ed in 2000 and trig ger ed the debris f low
2018, 16(6):194-201.
Abstract:
The enco unter betw een the flo od fr om t he mainstr eam and its tributaries can easily lead to the backw ater phenome2 non, causing poo r drainag e of river channel f loo ds and g reatly incr easing the floo d contro l risk of t he riv er co urse. Taking the backwater effects o f the second Songhua riv er f loo d on the Nen riv er floo d as the pr oject backg round, we ado pted the one2dimen2 sio nal hydro dy namic method to simulate and calculate the backwat er effects o f t he second Song hua river floo d on the Nen river floo d under differ ent flood combinations, and further quantitat ively ana lyzed the affected distance and heig ht based on the model simulatio n r esults. The r esults show ed that the affected distance of Nen river due to t he seco nd Songhua river floo d is relativ ely complex , and is closely r elated to t he relativ e sizes of the floo ds from the t wo rivers. When the flo ods magnitudes in the tw o riv2 ers a re equal, the affected distance is abo ut 32 km aw ay fr om the Sancha est uar y. The g reater the flo od in the second So ng hua riv er, the g reater the af fected distance and height. U nder the combination of 10% fr equency flo od in Nen riv er and 2% fr equency floo d in the second Song hua river, the max imum affected distance of Nen riv er is 55 km aw ay f rom the Sancha est uar y, and the affected height r eaches 21 14 m.
The enco unter betw een the flo od fr om t he mainstr eam and its tributaries can easily lead to the backw ater phenome2 non, causing poo r drainag e of river channel f loo ds and g reatly incr easing the floo d contro l risk of t he riv er co urse. Taking the backwater effects o f the second Songhua riv er f loo d on the Nen riv er floo d as the pr oject backg round, we ado pted the one2dimen2 sio nal hydro dy namic method to simulate and calculate the backwat er effects o f t he second Song hua river floo d on the Nen river floo d under differ ent flood combinations, and further quantitat ively ana lyzed the affected distance and heig ht based on the model simulatio n r esults. The r esults show ed that the affected distance of Nen river due to t he seco nd Songhua river floo d is relativ ely complex , and is closely r elated to t he relativ e sizes of the floo ds from the t wo rivers. When the flo ods magnitudes in the tw o riv2 ers a re equal, the affected distance is abo ut 32 km aw ay fr om the Sancha est uar y. The g reater the flo od in the second So ng hua riv er, the g reater the af fected distance and height. U nder the combination of 10% fr equency flo od in Nen riv er and 2% fr equency floo d in the second Song hua river, the max imum affected distance of Nen riv er is 55 km aw ay f rom the Sancha est uar y, and the affected height r eaches 21 14 m.
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