Volume 18,Issue 6,2020 Table of Contents
2020, 18(6):1-16.
Abstract:
The prediction of precipitation changes in the future can provide a basis for research on water resource changes in the upper Jinghe Riv er basin. The GCMs are ranked according to the site measured data and monthly GCMs data. The statistical downscaling model SDSM is constr ucted based on daily data of 6 GCM models selected from 21 GCMs, the climate models integrated by 6 GCMs, in situstations data, and NCEP reanalysis data, to predict the future precipitation change in the upper reaches of Jinghe Riv2 er. The results show that the SDSM is reliable for precipitation simulation. The R2 of each model is between 0.228 and 0.324 , the standard error is between 0.354 and 0.450, respectively. The simulated monthly average precipitation in the periodic and verification periods is similar to the measured v alue and the distribution is similar within a year. The integr ated model performs best in the downscaling performance evaluation perio d. Under the RCP 4.5 scenario, most future precipitation models and integrated models in the upper Jing he River show an increasing tr end. By the 2030s, precipitation in the upper Jinghe River may increase by 4.8% , and local rainfall in spring also exhibits an incr easing trend, and summer rainfall may decrease.
The prediction of precipitation changes in the future can provide a basis for research on water resource changes in the upper Jinghe Riv er basin. The GCMs are ranked according to the site measured data and monthly GCMs data. The statistical downscaling model SDSM is constr ucted based on daily data of 6 GCM models selected from 21 GCMs, the climate models integrated by 6 GCMs, in situstations data, and NCEP reanalysis data, to predict the future precipitation change in the upper reaches of Jinghe Riv2 er. The results show that the SDSM is reliable for precipitation simulation. The R2 of each model is between 0.228 and 0.324 , the standard error is between 0.354 and 0.450, respectively. The simulated monthly average precipitation in the periodic and verification periods is similar to the measured v alue and the distribution is similar within a year. The integr ated model performs best in the downscaling performance evaluation perio d. Under the RCP 4.5 scenario, most future precipitation models and integrated models in the upper Jing he River show an increasing tr end. By the 2030s, precipitation in the upper Jinghe River may increase by 4.8% , and local rainfall in spring also exhibits an incr easing trend, and summer rainfall may decrease.
2020, 18(6):17-26.
Abstract:
In order to evaluate and investigate the correlation structures of hydro-meteo rological variables in the Wei River basin, the t ime-frequency domain correlation analysis and long-range correlation analysis were carried out by cross wavelet analysis, detrended fluctuat ion analysis ( DFA ) , detrended cross-correlation analysis ( DCCA) , and detrended partial cross-correlation analysis ( DPXA) . The results of cross wavelet analysis show that correlation between precipitation ( P) , panevaporation ( E) , and runoff depth ( R) differ at different time-frequency domain. In terms of correlation structure, there were 122 years and 82 year periods existed in the system co nsisted of P, R, and E. On the macroscale, the multi-scale correlation structures between precipitation and runoff degraded and resonance period were reduced. Long-range correlation analysis showed that the Hurst index of R, E, and P sequences were greater than 0. 5, showing long-term persistence characteristics. The current precipitation ( runoff and evaporation) might have an impact on the pr ecipitation ( runoff and evaporation) at a certain time in the future. The DCCA results show that there was a long-rang ecorrelation between P and R, while an inverse long-range correlation existed between P2E and R2E, showing different cross-correlation structures. The DPXA results show that the long-range correlation change and turn into long-rang ecorrelation, implying the feed-back characterist ics of long-range correlation among P, R, and E. Compared with the results of DCCA, the DPXA was more persuasive. The sliding-window analysis ( 30 years) showed that the long-rang ecorrelation between P2R and P2E did not change in the time domain, and the possible incr ease of precipitation in the future may lead to the increase of runoff and indirectly lead to the incr ease of evapor ation in the Wei River basin. The long-range correlation betwen R2E changed from long-range inverse correlation to long-range correlation in 1962, and then the long-rang ecorrelation continued to increase, indicating that future evaporation changes in the Wei River basin may cause more runoff fluctuations. Therefore, water resources management based on ET control may have a certain significance to increase the av ailable water amount in the Wei River basin.
In order to evaluate and investigate the correlation structures of hydro-meteo rological variables in the Wei River basin, the t ime-frequency domain correlation analysis and long-range correlation analysis were carried out by cross wavelet analysis, detrended fluctuat ion analysis ( DFA ) , detrended cross-correlation analysis ( DCCA) , and detrended partial cross-correlation analysis ( DPXA) . The results of cross wavelet analysis show that correlation between precipitation ( P) , panevaporation ( E) , and runoff depth ( R) differ at different time-frequency domain. In terms of correlation structure, there were 122 years and 82 year periods existed in the system co nsisted of P, R, and E. On the macroscale, the multi-scale correlation structures between precipitation and runoff degraded and resonance period were reduced. Long-range correlation analysis showed that the Hurst index of R, E, and P sequences were greater than 0. 5, showing long-term persistence characteristics. The current precipitation ( runoff and evaporation) might have an impact on the pr ecipitation ( runoff and evaporation) at a certain time in the future. The DCCA results show that there was a long-rang ecorrelation between P and R, while an inverse long-range correlation existed between P2E and R2E, showing different cross-correlation structures. The DPXA results show that the long-range correlation change and turn into long-rang ecorrelation, implying the feed-back characterist ics of long-range correlation among P, R, and E. Compared with the results of DCCA, the DPXA was more persuasive. The sliding-window analysis ( 30 years) showed that the long-rang ecorrelation between P2R and P2E did not change in the time domain, and the possible incr ease of precipitation in the future may lead to the increase of runoff and indirectly lead to the incr ease of evapor ation in the Wei River basin. The long-range correlation betwen R2E changed from long-range inverse correlation to long-range correlation in 1962, and then the long-rang ecorrelation continued to increase, indicating that future evaporation changes in the Wei River basin may cause more runoff fluctuations. Therefore, water resources management based on ET control may have a certain significance to increase the av ailable water amount in the Wei River basin.
2020, 18(6):27-41.
Abstract:
There is a critical stage in the process from drought to disaster. In order to identify the critical state of drought disaster, a metho d based on principal component a nalysis and support vector machine is proposed. The principal component analysis method is used tor educe the dimensionality of severa lindexes that can reflect the duration, severity , and extremum of drought, and to remove the r edundant information of the correlated multiple indicators. The support vector machine is used to find the optimal classification plane based on the historical drought records. The potential drought samples are classified into drought samples a nd disaster samples based o n this classification plane. This classification plane can be phenom enologically defined as the critical state plane of drought-disa stert ransition. The development process and trend of drought can berevea led more intuitively , which is convenient to popularize and a pply to assess drought warnings. The sub-basin above Shiquan in the Hanjiang River basin is selected as a case study , and 1 07 po tential drought samples are selected according to certain principles. The above-proposed method is used to identify the disaster samples according to the historical drought records, with accuracies of 8 8.6% and 78.6 % in calibration and validation periods, respectively .
There is a critical stage in the process from drought to disaster. In order to identify the critical state of drought disaster, a metho d based on principal component a nalysis and support vector machine is proposed. The principal component analysis method is used tor educe the dimensionality of severa lindexes that can reflect the duration, severity , and extremum of drought, and to remove the r edundant information of the correlated multiple indicators. The support vector machine is used to find the optimal classification plane based on the historical drought records. The potential drought samples are classified into drought samples a nd disaster samples based o n this classification plane. This classification plane can be phenom enologically defined as the critical state plane of drought-disa stert ransition. The development process and trend of drought can berevea led more intuitively , which is convenient to popularize and a pply to assess drought warnings. The sub-basin above Shiquan in the Hanjiang River basin is selected as a case study , and 1 07 po tential drought samples are selected according to certain principles. The above-proposed method is used to identify the disaster samples according to the historical drought records, with accuracies of 8 8.6% and 78.6 % in calibration and validation periods, respectively .
2020, 18(6):42-63.
Abstract:
Eight quantitative WEF nexus ( the water-energy-foo d nexus) research methods are frequently used or have great potential in the current research of WEF nexus. These methods include WEFN exus Tool 2.0, Life Cycle A ssessment ( LCA) , Computable General Equilibrium model ( CGE) , System Dynamics modeling ( SD) , Climate, Land, Energy and Water Strategies ( CLEWS) , MultiScale Integrated Analysis of So cietal and Ecosystem Metabolism ( MuSIASEM ) , Market Allocation/ The Integrated MARKA L-EFOM System ( MARKAL / TIMES) and Water Evaluation and Planning-Long-range Energy Alternatives Planning System ( WEAP-LEAP) . By summarizing the generation, development, and characteristics of 8 quantitative research methods, and citing cases to discuss their scope of application, the advantages and disadvantages of each research method and the key points that need to be paid attention for further use were analyzed. Besides, the tr end of the development of quantitative research methods of WEF nexus in the future was also discussed. It is believed that with the increasing attention on sustainable development and the ex- ploration of the internal mechanism of WEF nexus, the quantitative research met hods of WEF nex us may need more attention to the accuracy of quantification and the interoperability of data, as well as the interdisciplinary research and multi-methodcou- pling . This article can provide references for the selection and optimization of quantitative research methods of WEF nex us.
Eight quantitative WEF nexus ( the water-energy-foo d nexus) research methods are frequently used or have great potential in the current research of WEF nexus. These methods include WEFN exus Tool 2.0, Life Cycle A ssessment ( LCA) , Computable General Equilibrium model ( CGE) , System Dynamics modeling ( SD) , Climate, Land, Energy and Water Strategies ( CLEWS) , MultiScale Integrated Analysis of So cietal and Ecosystem Metabolism ( MuSIASEM ) , Market Allocation/ The Integrated MARKA L-EFOM System ( MARKAL / TIMES) and Water Evaluation and Planning-Long-range Energy Alternatives Planning System ( WEAP-LEAP) . By summarizing the generation, development, and characteristics of 8 quantitative research methods, and citing cases to discuss their scope of application, the advantages and disadvantages of each research method and the key points that need to be paid attention for further use were analyzed. Besides, the tr end of the development of quantitative research methods of WEF nexus in the future was also discussed. It is believed that with the increasing attention on sustainable development and the ex- ploration of the internal mechanism of WEF nexus, the quantitative research met hods of WEF nex us may need more attention to the accuracy of quantification and the interoperability of data, as well as the interdisciplinary research and multi-methodcou- pling . This article can provide references for the selection and optimization of quantitative research methods of WEF nex us.
NI Hanxi
,
SHU Longcang
,
H AN Gang
,
ZHANG Manqi
,
WANG Xin
,
WANG Xiaobo
,
YU Yafei
,
OPOKU Portia Annabelle
,
2020, 18(6):64-70.
Abstract:
To study the effects of urbanization and the impact of land-use on atmospheric precipitation infiltration recharge in Jinan of China, the Feflow softw are and the remote sensing data for the years of 1980, 1990, 2000, and 2018 were used to identify the atmospheric pr ecipitation infiltration rate in different periods in Baotu Spring basin. The results revealed that: the area of cultivated land and for est land has decreased sharply, while the built-up areas have increased significantly for they ears from 1980 t o 2018; the impervious area had increased by 213.13 km2 , while the atmospheric precipitation infiltration rate has decreased by 26.25 million m3 for the years o f 2000 and 2018. The results of this study co uld be used as a `scientific reference for future planning o f the Jinan city and also pr ovide effective data to a id in the sustainability and prot ection of the Spring basin
To study the effects of urbanization and the impact of land-use on atmospheric precipitation infiltration recharge in Jinan of China, the Feflow softw are and the remote sensing data for the years of 1980, 1990, 2000, and 2018 were used to identify the atmospheric pr ecipitation infiltration rate in different periods in Baotu Spring basin. The results revealed that: the area of cultivated land and for est land has decreased sharply, while the built-up areas have increased significantly for they ears from 1980 t o 2018; the impervious area had increased by 213.13 km2 , while the atmospheric precipitation infiltration rate has decreased by 26.25 million m3 for the years o f 2000 and 2018. The results of this study co uld be used as a `scientific reference for future planning o f the Jinan city and also pr ovide effective data to a id in the sustainability and prot ection of the Spring basin
6 Precipitation prediction using LS-SVM and ARIMA combined model based on wavelet packet decomposition
2020, 18(6):71-77.
Abstract:
An annual precipitation prediction method is proposed based on wavelet packet decomposition of LS-AVM and ARI- MA combined model because the precipitation has a complex non-stationary, nonlinear, and noisy time series. The wavelet packet is used to decompose the precipitation sequence into a low-frequency trend sequence and high-frequency detail sequence. The LS-SVM model is used to predict the low-frequency trend sequence, and the ARIMA model is used to predict the high-frequency detail sequence. The prediction results of the two models are superimposed to get the predicted value of annual precipitation. The case study shows that: the decomposition of time series by wavelet packet is more precise than the wavelet decomposition, the combined model prediction can comprehensively extract the information contained in the precipitation sequence, better reflect the change of precipitation with time, and improve the annual precipitation forecast which provides a new met hod for the prediction of precipitation.
An annual precipitation prediction method is proposed based on wavelet packet decomposition of LS-AVM and ARI- MA combined model because the precipitation has a complex non-stationary, nonlinear, and noisy time series. The wavelet packet is used to decompose the precipitation sequence into a low-frequency trend sequence and high-frequency detail sequence. The LS-SVM model is used to predict the low-frequency trend sequence, and the ARIMA model is used to predict the high-frequency detail sequence. The prediction results of the two models are superimposed to get the predicted value of annual precipitation. The case study shows that: the decomposition of time series by wavelet packet is more precise than the wavelet decomposition, the combined model prediction can comprehensively extract the information contained in the precipitation sequence, better reflect the change of precipitation with time, and improve the annual precipitation forecast which provides a new met hod for the prediction of precipitation.
2020, 18(6):78-84.
Abstract:
To establish a hydrological model suitable for the sub-humid area of Yantai city, the Xincanjiang-Haihe model was used to simulate the runoff in the five typical basins in Yantai city from 2011 to 2018. Since 2014, Yantai city has been dry for three consecutive years, the river has dried up, and the runoff has decreased significantly compared with that before 2014. Considering the influence of drought , the Mann-Kendal test is used to test the abrupt change of annual runoff sequence, and 2014 is determined as the abrupt change point of annual runoff. The simulation sequence is divided into two time periods and is simulated in segments. T he results sho wed that: after subsection simulation o f the runoff process, the runoff simulation accuracy of the X inc anjiang-Haihe model in the typical basin of Yantai city is higher, and the parameters are more reasonable. The Xin’anjiang-Haihe model can reflect the actual production confluence and has good applicability.
To establish a hydrological model suitable for the sub-humid area of Yantai city, the Xincanjiang-Haihe model was used to simulate the runoff in the five typical basins in Yantai city from 2011 to 2018. Since 2014, Yantai city has been dry for three consecutive years, the river has dried up, and the runoff has decreased significantly compared with that before 2014. Considering the influence of drought , the Mann-Kendal test is used to test the abrupt change of annual runoff sequence, and 2014 is determined as the abrupt change point of annual runoff. The simulation sequence is divided into two time periods and is simulated in segments. T he results sho wed that: after subsection simulation o f the runoff process, the runoff simulation accuracy of the X inc anjiang-Haihe model in the typical basin of Yantai city is higher, and the parameters are more reasonable. The Xin’anjiang-Haihe model can reflect the actual production confluence and has good applicability.
WANG Xingju
,
SUN Jiehao
,
ZHAO Ranhang
,
WANG Haofang
,
MA Jigang
,
ZHAO Hong li
,
GU Shisheng
,
ZHAO Libin
2020, 18(6):85-92.
Abstract:
The optimization of water resources scheduling in the Jiao dong water transfer project is studied to achieve the efficient utilization o f water resources. Based on the analysis of the actual water allocation and socio-economic indicators of Weifang , Qing dao , Yantai, and Weihai, the variable fuzzy set theory is used to establish avariable fuzzy optimization model of external water transfer volume to calculate the optimal allocation coefficient. The allocation of external water transfer volume is optimized from the four cities and t he coupling coordination degree between the optimized external water transfer volume and regional socio-economic development is calculat ed. An objective function is established and the solution is programmed by Lingo software based on the principle of the highest water tr ansfer efficiency and the minimum total water deficit in the four cities. The optimal water resources regulation is carried out in the m edian water year, low water year, and the extremely low water year, respectively. The results of optimal water resources regulation and planning indicator regulation are compared and analyzed. The results show that : the two sch eduling results meet the minimum water dem and of each water-diversion; the optimal allocation of external water transfer volume increases the coupling coordination degree between water resources and socio-economic development in the four cities of Jiao dong , after the optimal water resources regulation, the wat er deficient ratio is significantly decreased in Qing dao , while the water-deficient ratio in ot her cities decreases slightly .
The optimization of water resources scheduling in the Jiao dong water transfer project is studied to achieve the efficient utilization o f water resources. Based on the analysis of the actual water allocation and socio-economic indicators of Weifang , Qing dao , Yantai, and Weihai, the variable fuzzy set theory is used to establish avariable fuzzy optimization model of external water transfer volume to calculate the optimal allocation coefficient. The allocation of external water transfer volume is optimized from the four cities and t he coupling coordination degree between the optimized external water transfer volume and regional socio-economic development is calculat ed. An objective function is established and the solution is programmed by Lingo software based on the principle of the highest water tr ansfer efficiency and the minimum total water deficit in the four cities. The optimal water resources regulation is carried out in the m edian water year, low water year, and the extremely low water year, respectively. The results of optimal water resources regulation and planning indicator regulation are compared and analyzed. The results show that : the two sch eduling results meet the minimum water dem and of each water-diversion; the optimal allocation of external water transfer volume increases the coupling coordination degree between water resources and socio-economic development in the four cities of Jiao dong , after the optimal water resources regulation, the wat er deficient ratio is significantly decreased in Qing dao , while the water-deficient ratio in ot her cities decreases slightly .
2020, 18(6):93-100.
Abstract:
A surface w ater quality predictio n model is developed to analyze the inherent water quality variation tendencies and provides r eal-time early warnings according to the high-frequency water quality historical observation data. The developed water quality prediction model is integrated by an improved genetic algorithm ( IGA) and a Back Propagation Neural Network ( BPNN) . To verify the accuracy and reliability of the river water quality prediction model based on IGA-BPNN, the method is applied to the Potomac River in the United States to predict its water quality parameters, turbidity ( TURB) and conductivity ( SC) , and to analyze the performance of the prediction results. The prediction results demonstrate that the developed IGA-BPNN model can provide a more accurate prediction result than the BPNN model. Since the PIPC values of TURB and EC predictio n can reach 991.81% and 100% under normal stable conditions, GA2BPNN model also can provide a reliability prediction result. Meanwhile, the developed IGA-BPNN models can reflect the long period and iso lated sharp peaks of the water quality variations, and effectively provide real-time early warning for emergency response.
A surface w ater quality predictio n model is developed to analyze the inherent water quality variation tendencies and provides r eal-time early warnings according to the high-frequency water quality historical observation data. The developed water quality prediction model is integrated by an improved genetic algorithm ( IGA) and a Back Propagation Neural Network ( BPNN) . To verify the accuracy and reliability of the river water quality prediction model based on IGA-BPNN, the method is applied to the Potomac River in the United States to predict its water quality parameters, turbidity ( TURB) and conductivity ( SC) , and to analyze the performance of the prediction results. The prediction results demonstrate that the developed IGA-BPNN model can provide a more accurate prediction result than the BPNN model. Since the PIPC values of TURB and EC predictio n can reach 991.81% and 100% under normal stable conditions, GA2BPNN model also can provide a reliability prediction result. Meanwhile, the developed IGA-BPNN models can reflect the long period and iso lated sharp peaks of the water quality variations, and effectively provide real-time early warning for emergency response.
2020, 18(6):101-109.
Abstract:
To verify the ability of Headwall hyperspectral imagery for monitoring water quality , three turbidity retrieval models including band-ratio, first-derivative, and partial least-squares models were established with the Headw all airborne hyperspectral imagery and sy nchronous measured turbidities in Hulunnaoer on September 17th, 2018. The three models were adopted to estimate the spatial distributions of turbidity in Hulunnaoer. The results showed that: the three constructed models based on the airborne Headwall hy perspectral data verify that the root mean square error ( RMSE) is less than the verification sample turbidity extreme value differ ence of 5.3 NTU, and the MRE is less than 10% , the three models had good performances in turbidity retrieval and the Headw all hy perspectral imagery could be used for water quality retrieval; the partial least squares model with adeterm ination coefficient R2 ( 01 95) , and a comprehensive error CE( 1.74% ) showed the better performance compared to the band ratio model and the first-order differ ential model, which was the optimal model for turbidity retrieval in Hulunnaoer; the range of turbidity was between 21.2 and 54.4 NTU in the eastern area of Hunlunnaoer on September 17th, 2018, the distributions of turbidity in Hunlunnaoer showed an increasing trend from north to south, the turbidity in the center was relatively low , while the turbidity in the southern area was relatively high due to the exists of algae. This study quantitatively retrieved turbidity, which can provide a reference for remote sensing of water quality based on aerial hyperspect ral remote sensing imageries in the future.
To verify the ability of Headwall hyperspectral imagery for monitoring water quality , three turbidity retrieval models including band-ratio, first-derivative, and partial least-squares models were established with the Headw all airborne hyperspectral imagery and sy nchronous measured turbidities in Hulunnaoer on September 17th, 2018. The three models were adopted to estimate the spatial distributions of turbidity in Hulunnaoer. The results showed that: the three constructed models based on the airborne Headwall hy perspectral data verify that the root mean square error ( RMSE) is less than the verification sample turbidity extreme value differ ence of 5.3 NTU, and the MRE is less than 10% , the three models had good performances in turbidity retrieval and the Headw all hy perspectral imagery could be used for water quality retrieval; the partial least squares model with adeterm ination coefficient R2 ( 01 95) , and a comprehensive error CE( 1.74% ) showed the better performance compared to the band ratio model and the first-order differ ential model, which was the optimal model for turbidity retrieval in Hulunnaoer; the range of turbidity was between 21.2 and 54.4 NTU in the eastern area of Hunlunnaoer on September 17th, 2018, the distributions of turbidity in Hunlunnaoer showed an increasing trend from north to south, the turbidity in the center was relatively low , while the turbidity in the southern area was relatively high due to the exists of algae. This study quantitatively retrieved turbidity, which can provide a reference for remote sensing of water quality based on aerial hyperspect ral remote sensing imageries in the future.
11 One-year monitoring of rain and snow water quality and its pollution causes in a campus in Tianjin
2020, 18(6):110-115.
Abstract:
In order to reduce the cost of rainwater utilization and ensure the quality of rainwater that can be used, discharge first flush and special rainwater with poor water quality has become an important way in rainwater utilization. Therefore, it is necessary to determine the reasonable rainwater discharge method thr ough long-term continuous monitoring of key water quality indicators such as nitrogen, pho sphor us, and chemical oxygen demand in rain or snow water. One-year continuous monitoring of rain and snow water was conducted in the Peiyang Campus of Tianjin University in 2018. Results show that: the average mass concentration of ammonia nitrogen ( 6.75 mg/ L) and total nitrogen ( 9.36 mg / L) in rain and snow water in March and April was about 1.5 and 2.1-folds times the annual average mass concentration of ammonia nitrogen and total nitrogen in rain and snow water; the mass concentration of contaminants in the first r ainwater in spring is much higher than that of the first snow in winter, and air pollution in winter is the key factor for poor r ainwater quality of the first rainfall in spring ; in addition, the influence sequence of the air contaminants to the rainwater and snow water quality was PM2. 5 > PM 10 > NO2 > SO2 > CO> O3_8h . The mass concent ration of contaminants in the first two rainw ater in spring was higher than the other rain and snow water, but the quantity of precipitation was very small. Therefore, the first two rainfall in spring ( precipitation less than 10 mm) may be directly discharged to the wastewater treatment plant rather than directly flow into the r ainwater recycling facilities.
In order to reduce the cost of rainwater utilization and ensure the quality of rainwater that can be used, discharge first flush and special rainwater with poor water quality has become an important way in rainwater utilization. Therefore, it is necessary to determine the reasonable rainwater discharge method thr ough long-term continuous monitoring of key water quality indicators such as nitrogen, pho sphor us, and chemical oxygen demand in rain or snow water. One-year continuous monitoring of rain and snow water was conducted in the Peiyang Campus of Tianjin University in 2018. Results show that: the average mass concentration of ammonia nitrogen ( 6.75 mg/ L) and total nitrogen ( 9.36 mg / L) in rain and snow water in March and April was about 1.5 and 2.1-folds times the annual average mass concentration of ammonia nitrogen and total nitrogen in rain and snow water; the mass concentration of contaminants in the first r ainwater in spring is much higher than that of the first snow in winter, and air pollution in winter is the key factor for poor r ainwater quality of the first rainfall in spring ; in addition, the influence sequence of the air contaminants to the rainwater and snow water quality was PM2. 5 > PM 10 > NO2 > SO2 > CO> O3_8h . The mass concent ration of contaminants in the first two rainw ater in spring was higher than the other rain and snow water, but the quantity of precipitation was very small. Therefore, the first two rainfall in spring ( precipitation less than 10 mm) may be directly discharged to the wastewater treatment plant rather than directly flow into the r ainwater recycling facilities.
2020, 18(6):116-121.
Abstract:
Taking a reservoir in Tianjin as the research object, the distribution law of inorganic nitrogen indifferent seasons and the correlation of reservoir water environmental factors were analyzed, and the morphological changes of inorga nicnitrogen were discussed. The results show that the temperature of the reservoir was lower than that of the inlet and outlet . The dissolved oxygen mass concentration was hig her in the inlet water than in the outlet water, and the dissolved oxygen content was highest in the middle position. In summer, ORP w as lower than in autumn, while stronger the oxidization and the nitrification, and lower the ammonia nitrogen mass concentration. The T DS decreased with the increase of depth, the water outlet was closer to the coast , and the TDS of water was higher. The pH was higher in autumn than in summer. The west bank of NH3-N was higher than the east bank, and the mass concentration in the inlet direction was higher than that in the outlet direction. The mass concentration of NO2-N decr eased with the increase of depth at most of the sites, and the salinity showed a significant positive correlation with NO2-N. The main form of inorganic nitrogen as nitrate nitrogen, whose mass concentr ation was higher at the outlet compared to the inlet. Ammonia nitrogen and nitrate nitrogen mass concentration were spring> summer> autumn, respectively. Dissolved inorganic nit rogen( DIN) was mainly nitrate nit rogen, acco unting for 81.97% on aver age.
Taking a reservoir in Tianjin as the research object, the distribution law of inorganic nitrogen indifferent seasons and the correlation of reservoir water environmental factors were analyzed, and the morphological changes of inorga nicnitrogen were discussed. The results show that the temperature of the reservoir was lower than that of the inlet and outlet . The dissolved oxygen mass concentration was hig her in the inlet water than in the outlet water, and the dissolved oxygen content was highest in the middle position. In summer, ORP w as lower than in autumn, while stronger the oxidization and the nitrification, and lower the ammonia nitrogen mass concentration. The T DS decreased with the increase of depth, the water outlet was closer to the coast , and the TDS of water was higher. The pH was higher in autumn than in summer. The west bank of NH3-N was higher than the east bank, and the mass concentration in the inlet direction was higher than that in the outlet direction. The mass concentration of NO2-N decr eased with the increase of depth at most of the sites, and the salinity showed a significant positive correlation with NO2-N. The main form of inorganic nitrogen as nitrate nitrogen, whose mass concentr ation was higher at the outlet compared to the inlet. Ammonia nitrogen and nitrate nitrogen mass concentration were spring> summer> autumn, respectively. Dissolved inorganic nit rogen( DIN) was mainly nitrate nit rogen, acco unting for 81.97% on aver age.
2020, 18(6):122-129.
Abstract:
The tap water samples were collected at main districts of Tianjin in 2017. The tap water samples were collected from the direct and seco ndary water supply in the central urban city and Xiqing District in 2019. All water samples were analyzed on the compositions of stable hydrogen and oxygen is otopes and majorions. The range of stable oxygen is otope (∮18 O) in the tap water was from - 4. 41‰ to - 10. 06 ‰ , and the range of hydrogen isotope (∮D) was from - 52. 4‰ to - 74. 4 ‰ , respectively. The isotopes in the tap water ( Hanjiang river as the water source) were located near the Global Meteoric Water Line ( GMWL) , however, the reservoir storage may cause the isotopic enrichment in the tap water. The stable isotopes were depleted in the tap water which used the deep groundwater as the w ater source. The water type of tap water in the central urban area and Xiqing , Jinnan, Beichen, Wuqing and Jizhou districts was Ca· Mg-HCO3. The water type of tap water in Binhai New Area andBaodi district was Na·Mg2SO4 . The tap water in Ninghe district was the type of Na-HCO3 . The tap water quality in Tianjin was under the national guideline of drinking water. There was no significant different in hydro chemical composition of tap water between the direct water supply and the secondary water supply . Thus, the water quality of tap water from Hanjiang river was better than that from the local deep groundwater. The ion mass concentrat ions of Na+ and SO4 2- in the t ap water were high at the Binha i New Area due to the reser voirstorage. The mass concentration of Na+ in the tap water at Ning he district and the NO3 - in the tap water at Jizhou district was the highest. Consequently, the protection of groundwater and the safety of drinking water in the centralized water supply areas should require more attention and improvement.
The tap water samples were collected at main districts of Tianjin in 2017. The tap water samples were collected from the direct and seco ndary water supply in the central urban city and Xiqing District in 2019. All water samples were analyzed on the compositions of stable hydrogen and oxygen is otopes and majorions. The range of stable oxygen is otope (∮18 O) in the tap water was from - 4. 41‰ to - 10. 06 ‰ , and the range of hydrogen isotope (∮D) was from - 52. 4‰ to - 74. 4 ‰ , respectively. The isotopes in the tap water ( Hanjiang river as the water source) were located near the Global Meteoric Water Line ( GMWL) , however, the reservoir storage may cause the isotopic enrichment in the tap water. The stable isotopes were depleted in the tap water which used the deep groundwater as the w ater source. The water type of tap water in the central urban area and Xiqing , Jinnan, Beichen, Wuqing and Jizhou districts was Ca· Mg-HCO3. The water type of tap water in Binhai New Area andBaodi district was Na·Mg2SO4 . The tap water in Ninghe district was the type of Na-HCO3 . The tap water quality in Tianjin was under the national guideline of drinking water. There was no significant different in hydro chemical composition of tap water between the direct water supply and the secondary water supply . Thus, the water quality of tap water from Hanjiang river was better than that from the local deep groundwater. The ion mass concentrat ions of Na+ and SO4 2- in the t ap water were high at the Binha i New Area due to the reser voirstorage. The mass concentration of Na+ in the tap water at Ning he district and the NO3 - in the tap water at Jizhou district was the highest. Consequently, the protection of groundwater and the safety of drinking water in the centralized water supply areas should require more attention and improvement.
14 Recognition method for scale-free area of Chishui River plane morphology and fractal characteristics
2020, 18(6):130-137.
Abstract:
Taking 86 groups of curved river sections selected from the mainstream of the Chishui River as the research object, the information dimension of the length of the waterline and the information dimension of the riverbed water landform area are calculated based on the g rid covering method. By summarizing the variation law of fractal dimension " rough calculation value" , a met hod of scale-free interv al identification is obtained, and the plane morphological and geomorphic characteristics of the selected curved river section are analyzed. The results show that: The " instability " phenomenon of the rough calculation value can be used as the criterion to ef fectively identify the scale-free interval of the fractal body, and [ 10, 40] is the scale-free area of the information dimension calculation; the information dimension range of the water edge line of the measured curved river section is [ 0.915 7, 1.042 1] with an averag evalue of 0. 997 9, the landform area information dimension range is [ 1.301 3, 1.923 0] with an averag evalue of 1.676 0, and the tortuosity value range is [ 1.025 9, 2.651 2] , the averag evalue is 1.271 2, respectively ; in the middle and lower reaches of the Chishui River, the correlation coefficients of the waterfront information dimension and the to rtuosity are 0.469 and 0.644 respectively , both of which are significantly correlated, and the degree of correlation is gradually strengthened. The correlation between the info rmation dimension of the landform area and the information dimension of the waterfront line and the curvature rate is weak and has a neg ative correlation with the information dimension of the water frontline.
Taking 86 groups of curved river sections selected from the mainstream of the Chishui River as the research object, the information dimension of the length of the waterline and the information dimension of the riverbed water landform area are calculated based on the g rid covering method. By summarizing the variation law of fractal dimension " rough calculation value" , a met hod of scale-free interv al identification is obtained, and the plane morphological and geomorphic characteristics of the selected curved river section are analyzed. The results show that: The " instability " phenomenon of the rough calculation value can be used as the criterion to ef fectively identify the scale-free interval of the fractal body, and [ 10, 40] is the scale-free area of the information dimension calculation; the information dimension range of the water edge line of the measured curved river section is [ 0.915 7, 1.042 1] with an averag evalue of 0. 997 9, the landform area information dimension range is [ 1.301 3, 1.923 0] with an averag evalue of 1.676 0, and the tortuosity value range is [ 1.025 9, 2.651 2] , the averag evalue is 1.271 2, respectively ; in the middle and lower reaches of the Chishui River, the correlation coefficients of the waterfront information dimension and the to rtuosity are 0.469 and 0.644 respectively , both of which are significantly correlated, and the degree of correlation is gradually strengthened. The correlation between the info rmation dimension of the landform area and the information dimension of the waterfront line and the curvature rate is weak and has a neg ative correlation with the information dimension of the water frontline.
2020, 18(6):138-147.
Abstract:
The contamination of 13 PPCPs( pharmaceuticals and personal care pro ducts) were analyzed in 5 river samples and 43 groundwater samples using RQ model to evaluate the potential risk during dry and rainy season to investigate the pollution characteristics and ecological risk of PPCPs in Beiyun river and groundwater of the North Canal. The results revealed that 11 out of the 13 target PPCPs were detected in Beiyun river and g roundw ater except for SMM ( Sulfamonomethoxine) and CAP ( Chloramphenicol) , SMZ ( Sulfamet hazine) was the dominant contaminant with concentr ations up to 1 373. 1 ng/ L. Concentrations of PPCPs were higher in the groundwater than river ( w ith a lower detection frequencies) , and and the mass concentr ation of pollut ants decreases as the distance from the river increases. Concentr ations of PPCPs were higher in confined aquifer than unconfined aquifer; total concentration of PPCPs in wet season was sig nificantly higher than dry season. The results of the risk assessment indicated that IBU ( Ibuprofen) may pose high risks to the eco logical environment while other PPCPs were found to be of medium or low ecological risk in the study area.
The contamination of 13 PPCPs( pharmaceuticals and personal care pro ducts) were analyzed in 5 river samples and 43 groundwater samples using RQ model to evaluate the potential risk during dry and rainy season to investigate the pollution characteristics and ecological risk of PPCPs in Beiyun river and groundwater of the North Canal. The results revealed that 11 out of the 13 target PPCPs were detected in Beiyun river and g roundw ater except for SMM ( Sulfamonomethoxine) and CAP ( Chloramphenicol) , SMZ ( Sulfamet hazine) was the dominant contaminant with concentr ations up to 1 373. 1 ng/ L. Concentrations of PPCPs were higher in the groundwater than river ( w ith a lower detection frequencies) , and and the mass concentr ation of pollut ants decreases as the distance from the river increases. Concentr ations of PPCPs were higher in confined aquifer than unconfined aquifer; total concentration of PPCPs in wet season was sig nificantly higher than dry season. The results of the risk assessment indicated that IBU ( Ibuprofen) may pose high risks to the eco logical environment while other PPCPs were found to be of medium or low ecological risk in the study area.
2020, 18(6):148-155.
Abstract:
To prevent the high-filled section of a large-scale artificial water conveyance channel from breaking under abnormal external forces, it is necessary to establish an appropriate scenario analysis method to simulate and evaluate the effectiveness of the combined applicat ion of multiple control measures in the emergency response under different breach scale. Using the flood simulation model independently developed by the China Institute of Water Resources and Hydro power Research, by improving the topological relationship of crossed channels and simulation method of recession sluices, a dike break flood in undation model of one-dimensional channel, breach flow , and two-dim ensional simultaneous coupling calculation on both banks was established. Taking a ty pical high-filled reaches of a lar ge-scale artificial water supply channel as an example, the changes in flood inundation characte ristics under 12 scenarios, including different breach width, gate closing time, and whether the retreat gate is opened or not, are classified and analyzed. The results show ed that: the increase of breach width had less impact on inundation extent and degree of outburst flood; the earlier the closure time of sluice gates was, the better the decr ease of inundation area and wate rdepth was, while the effect was more obvious during the first 3 hours after dike-breaking happened. When the terrain and ground objects distribution were conductive to flood diffusion, closing the sluice gate early could decrease more inundation area , otherwise, in areas where flood was not easy to spread, it was more effective for the decrease of inundation depth. The mitigation function of recession sluice for inundation was relevant to the relative position and distance between the gate and breach, the sluice located in the upper stream of the breach with closer distance was more effective to decrease the inundation. The basic method and basis are provided for the formulation or improvement of corresponding emergency plans of the large-scale artificial water supply channel.
To prevent the high-filled section of a large-scale artificial water conveyance channel from breaking under abnormal external forces, it is necessary to establish an appropriate scenario analysis method to simulate and evaluate the effectiveness of the combined applicat ion of multiple control measures in the emergency response under different breach scale. Using the flood simulation model independently developed by the China Institute of Water Resources and Hydro power Research, by improving the topological relationship of crossed channels and simulation method of recession sluices, a dike break flood in undation model of one-dimensional channel, breach flow , and two-dim ensional simultaneous coupling calculation on both banks was established. Taking a ty pical high-filled reaches of a lar ge-scale artificial water supply channel as an example, the changes in flood inundation characte ristics under 12 scenarios, including different breach width, gate closing time, and whether the retreat gate is opened or not, are classified and analyzed. The results show ed that: the increase of breach width had less impact on inundation extent and degree of outburst flood; the earlier the closure time of sluice gates was, the better the decr ease of inundation area and wate rdepth was, while the effect was more obvious during the first 3 hours after dike-breaking happened. When the terrain and ground objects distribution were conductive to flood diffusion, closing the sluice gate early could decrease more inundation area , otherwise, in areas where flood was not easy to spread, it was more effective for the decrease of inundation depth. The mitigation function of recession sluice for inundation was relevant to the relative position and distance between the gate and breach, the sluice located in the upper stream of the breach with closer distance was more effective to decrease the inundation. The basic method and basis are provided for the formulation or improvement of corresponding emergency plans of the large-scale artificial water supply channel.
2020, 18(6):156-163.
Abstract:
After the operation of the Three Gorges Project , the water and sediment process in the downstream of the dam has undergone major adjusted, which has a greater impact on the river bed erosion and deposition of the Xiong jiazhou-Cheng lingji sand-stone-type river section of the Jing jiang River, which may affect the stability , flood control, and navigation of the river in this section. The chang es in water and sediment conditions and their impact on the river bed adjustment procedures were analyzed based on the latest measured data. The research results show that: the runoff of the downstream dam of the Three Gorges reservoir has increased significantly during the dry season, which makes the mainstream of the curve long-term to the convex bank, causing a large erosion of the convex bank, this may be one of the main reasons for the recent occurrence of "squatting and cutting the beach"; with the successive construction and operation of the main and tributary reservoirs in the upperr eaches of the Three Gorges, the rivers downstream of the dam may be subject to long-term cleansing , the typical curved river channel may be in the long-term scouring stage, and the riverbed may have a one-way scouring downward trend, and the main plane of the curved top section may oscillate, Which may be larger, and the top punching point of the curve may also move down correspondingly , and which may cause the distance of the mainstream sticking shore to further defer, causing the collapse of the riverbank line, and the local river potential change is still obvious in the future.
After the operation of the Three Gorges Project , the water and sediment process in the downstream of the dam has undergone major adjusted, which has a greater impact on the river bed erosion and deposition of the Xiong jiazhou-Cheng lingji sand-stone-type river section of the Jing jiang River, which may affect the stability , flood control, and navigation of the river in this section. The chang es in water and sediment conditions and their impact on the river bed adjustment procedures were analyzed based on the latest measured data. The research results show that: the runoff of the downstream dam of the Three Gorges reservoir has increased significantly during the dry season, which makes the mainstream of the curve long-term to the convex bank, causing a large erosion of the convex bank, this may be one of the main reasons for the recent occurrence of "squatting and cutting the beach"; with the successive construction and operation of the main and tributary reservoirs in the upperr eaches of the Three Gorges, the rivers downstream of the dam may be subject to long-term cleansing , the typical curved river channel may be in the long-term scouring stage, and the riverbed may have a one-way scouring downward trend, and the main plane of the curved top section may oscillate, Which may be larger, and the top punching point of the curve may also move down correspondingly , and which may cause the distance of the mainstream sticking shore to further defer, causing the collapse of the riverbank line, and the local river potential change is still obvious in the future.
2020, 18(6):164-169.
Abstract:
The geometric model of vertical axial flow pump with siphon outlet channel and the 3D unsteady numerical simulation method of blade angle adjusting process was developed, whiledy namic grid and grid reconstruction method was adopted to realize the blades rotation wit h the impeller in the compound movement. Three adjusting rules were selected for numerical simulation too btain the changing rules of relevant working parameters and internal flow field changes. The results showed that: the flow rate increased by 4.4% ~ 4.9% , and the impeller torque increased by 5.1% ~ 5.9% , when the blade angle was increased by 2°at three different times; the static pressure fluctuation range of the impeller inlet and outlet plane was found large; during the process, the flow pattern in the impeller region deteriorated, vortex cores were distributed in the impeller region and there were low-pressure regions with uneven distribution on the blade suction surface; when the opening time was adjusted 1 second, the fluctuation range of static pressure at the impellercs inlet and outlet plane and impeller torque and the distribution of vortex core in the impeller region was larger than the other two working conditions, therefore, increasing the blade angle in a short time will increase the instability of the impeller area.
The geometric model of vertical axial flow pump with siphon outlet channel and the 3D unsteady numerical simulation method of blade angle adjusting process was developed, whiledy namic grid and grid reconstruction method was adopted to realize the blades rotation wit h the impeller in the compound movement. Three adjusting rules were selected for numerical simulation too btain the changing rules of relevant working parameters and internal flow field changes. The results showed that: the flow rate increased by 4.4% ~ 4.9% , and the impeller torque increased by 5.1% ~ 5.9% , when the blade angle was increased by 2°at three different times; the static pressure fluctuation range of the impeller inlet and outlet plane was found large; during the process, the flow pattern in the impeller region deteriorated, vortex cores were distributed in the impeller region and there were low-pressure regions with uneven distribution on the blade suction surface; when the opening time was adjusted 1 second, the fluctuation range of static pressure at the impellercs inlet and outlet plane and impeller torque and the distribution of vortex core in the impeller region was larger than the other two working conditions, therefore, increasing the blade angle in a short time will increase the instability of the impeller area.
2020, 18(6):170-175.
Abstract:
Fish passing experiments were conducted in a fishway model to figure out the influence of water temperature on the fish migration behaviors. A hydraulic model with a scale of 1：4 was established based on the gravity similarity criterion, and the juvenile grass car p was selected as the test fish. Camer as were used to monitor the migration process of the test fish, and the fish passage rate and passage time were counted and analyzed quantitatively. The experimental results showed that : the total passing rate of juvenile grass carp was more than 70% in the water temperature range of 18.5~ 22.5 e , and there was no significant change in passing rate in differ ent water temperature ranges, the influence of water temperature on the fish passage rate is not obvious; the SPSS so ftware used to test the significance which showed that the passing time of juvenile grass carp had no significant correlation with water temperature. Based on the above results, the influence of water temperature can be neglected in the future research of the grass carp migration behavior test in the range of 18.5~ 22.5 e .
Fish passing experiments were conducted in a fishway model to figure out the influence of water temperature on the fish migration behaviors. A hydraulic model with a scale of 1：4 was established based on the gravity similarity criterion, and the juvenile grass car p was selected as the test fish. Camer as were used to monitor the migration process of the test fish, and the fish passage rate and passage time were counted and analyzed quantitatively. The experimental results showed that : the total passing rate of juvenile grass carp was more than 70% in the water temperature range of 18.5~ 22.5 e , and there was no significant change in passing rate in differ ent water temperature ranges, the influence of water temperature on the fish passage rate is not obvious; the SPSS so ftware used to test the significance which showed that the passing time of juvenile grass carp had no significant correlation with water temperature. Based on the above results, the influence of water temperature can be neglected in the future research of the grass carp migration behavior test in the range of 18.5~ 22.5 e .
2020, 18(6):176-183.
Abstract:
Using the semi-loose coupling numerical simulation method of groundwater and surfacewater, the Su-Mi-Huai area of Beijing is selected, and the groundwater recharge in the plain was taken and the groundwater recharge in the mountain area was obtained from the long time series SWAT model as transfer variables to replace the research ideas of rainfall infiltration supply and mounta in front lateral supply in MODFLOW model, and the semi-loose SWAT-MODFLOW coupling model was established to verify the coupling model of groundwater level and the groundwater balance in Su-Mi-Huai area was analyed. The results showed that this method could improve the accuracy of the groundwat er model, and the rainfall infiltration recharge calculated by the coupled model that was reduced by 0.54×10 8 m3 / a when compared w ith the traditional method. This reflected that with the increase of underlying surface conditions and the thickness of the vadose zone, the rainfall recharge of the aquifer was decreased. This study may provide technical support for the accurate evaluation of water resour ces.
Using the semi-loose coupling numerical simulation method of groundwater and surfacewater, the Su-Mi-Huai area of Beijing is selected, and the groundwater recharge in the plain was taken and the groundwater recharge in the mountain area was obtained from the long time series SWAT model as transfer variables to replace the research ideas of rainfall infiltration supply and mounta in front lateral supply in MODFLOW model, and the semi-loose SWAT-MODFLOW coupling model was established to verify the coupling model of groundwater level and the groundwater balance in Su-Mi-Huai area was analyed. The results showed that this method could improve the accuracy of the groundwat er model, and the rainfall infiltration recharge calculated by the coupled model that was reduced by 0.54×10 8 m3 / a when compared w ith the traditional method. This reflected that with the increase of underlying surface conditions and the thickness of the vadose zone, the rainfall recharge of the aquifer was decreased. This study may provide technical support for the accurate evaluation of water resour ces.
2020, 18(6):184-190.
Abstract:
The permeability coefficient is the main parameter to characterize permeability, and has strong spatial variability. Taking the piedmont coastal area of North China Plain as the study area, eight boreholes were selected, and the permeability coefficient is calculated by the inversion formula and the improved Archie formula. The spatial variability of vertical permeability coefficient is studies using time series method and random forests algorithm based on fully considering the influencing factors of vertical permeability coefficient in the study area. The result showed that the influencing factors of the vertical permeability coefficient could be divided into three categories: sedimentary environment, formation pressure, and random error; after removing the influence of sediment ary environment and random error, the permeability coefficient decreased with the increase of depth, and the sensitivity of the permeability coefficient to the formation pressure decreased gradually from the piedmont to the coastal area. A scientific basis was provided for understanding agricultural irrigation, pollutant migration, site selection of landfill sites, and development of deep groundwater resources in North China Plain.
The permeability coefficient is the main parameter to characterize permeability, and has strong spatial variability. Taking the piedmont coastal area of North China Plain as the study area, eight boreholes were selected, and the permeability coefficient is calculated by the inversion formula and the improved Archie formula. The spatial variability of vertical permeability coefficient is studies using time series method and random forests algorithm based on fully considering the influencing factors of vertical permeability coefficient in the study area. The result showed that the influencing factors of the vertical permeability coefficient could be divided into three categories: sedimentary environment, formation pressure, and random error; after removing the influence of sediment ary environment and random error, the permeability coefficient decreased with the increase of depth, and the sensitivity of the permeability coefficient to the formation pressure decreased gradually from the piedmont to the coastal area. A scientific basis was provided for understanding agricultural irrigation, pollutant migration, site selection of landfill sites, and development of deep groundwater resources in North China Plain.
2020, 18(6):191-200.
Abstract:
A calculation model is established to evaluate the level of water conservancy green development in 31 provinces ( autonomous regions or cities) of China in 201 7. S patial autocorrelation and spatial hotspot detection are introduced to analyze the spatial heterogeneity of China's water conservancy green development level. The dominant factors are identified from the criterion and the index level. T he results showed that: The water conser vancy green development level is higher in the east than in the west, and the provinces with ex cellent grades are mainly distributed in north and east China; The level of water conservancy green development in China showed strong hetero geneity in space, and the hot spots of water conservancy green development levels are distributed in Beijing and Tianjin, while the cold spots are located in Xinjiang , Tibet, Qing hai, Gansu, and Heilong jiang provinces or antonomous regions; The spatial differ ence of water conservancy green development level is greatly influenced by soil erosion control rate, water conservancy inform atizatio n level, ecological water use ratio, comprehensive economic efficiency of production water use, and the proportion of managers above co llege level have a greater impact.
A calculation model is established to evaluate the level of water conservancy green development in 31 provinces ( autonomous regions or cities) of China in 201 7. S patial autocorrelation and spatial hotspot detection are introduced to analyze the spatial heterogeneity of China's water conservancy green development level. The dominant factors are identified from the criterion and the index level. T he results showed that: The water conser vancy green development level is higher in the east than in the west, and the provinces with ex cellent grades are mainly distributed in north and east China; The level of water conservancy green development in China showed strong hetero geneity in space, and the hot spots of water conservancy green development levels are distributed in Beijing and Tianjin, while the cold spots are located in Xinjiang , Tibet, Qing hai, Gansu, and Heilong jiang provinces or antonomous regions; The spatial differ ence of water conservancy green development level is greatly influenced by soil erosion control rate, water conservancy inform atizatio n level, ecological water use ratio, comprehensive economic efficiency of production water use, and the proportion of managers above co llege level have a greater impact.
2020, 18(6):201-208.
Abstract:
The spatiotemporal variation and influencing factors of different corn water productivity index are analyzed based on the corn plant ing, irrigation water consumption data and meteorological data of the 14 cities of Liaoning Province from 2005 to 2017 using linear tendency estimate and global spatial auto correlation analysis method under different rainfall year type ( dry, flat, wet) perspective. The results show that: On the time scale, the entire province perennial average corn irrigation water productivity is 1. 63 kg/ m3 , and the overall corn water productivity fluctuated at a rate of 0.04 kg / m3 per 10 years. On the spatial scale, the annual corn irrigation water productivity of the whole province is high in the northwest and low in the southeast. In the dry year ( 2006) and flat year ( 2007) , corn water productivity was high in the northeast and low in the southwest, while in the wet year ( 2012) , it was high in the no rthwest and low in the southeast, respectively . Single corn yield is the most significant factor that affected the water productiv ity indices. The research results can provide some references for improving agricultural water use efficiency and relieving water r esource pressure in Liao ning Province.
The spatiotemporal variation and influencing factors of different corn water productivity index are analyzed based on the corn plant ing, irrigation water consumption data and meteorological data of the 14 cities of Liaoning Province from 2005 to 2017 using linear tendency estimate and global spatial auto correlation analysis method under different rainfall year type ( dry, flat, wet) perspective. The results show that: On the time scale, the entire province perennial average corn irrigation water productivity is 1. 63 kg/ m3 , and the overall corn water productivity fluctuated at a rate of 0.04 kg / m3 per 10 years. On the spatial scale, the annual corn irrigation water productivity of the whole province is high in the northwest and low in the southeast. In the dry year ( 2006) and flat year ( 2007) , corn water productivity was high in the northeast and low in the southwest, while in the wet year ( 2012) , it was high in the no rthwest and low in the southeast, respectively . Single corn yield is the most significant factor that affected the water productiv ity indices. The research results can provide some references for improving agricultural water use efficiency and relieving water r esource pressure in Liao ning Province.
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