Demand for fresh water, as one of the major natural resources, is increasing rapidly with increasing development and environmental degradation. The continued abstraction of water from Lake Ziway and its main feeder ri...Demand for fresh water, as one of the major natural resources, is increasing rapidly with increasing development and environmental degradation. The continued abstraction of water from Lake Ziway and its main feeder rivers Meki and Katar for irrigation indicates that the water demand may soon exceed the supply. To illustrate disparities in spatial distribution of water resources, the Upper Awash sub-basin, which shares a water-divide with the CRVL sub-basin, has large flow volumes particularly in the rainy season and suffers with seasonal flooding. The rationale behind regaining the water in CRVL relies on this non-uniform spatial distribution of fresh water, calling for a balance between water surplus and deficit regions. For this reason, Inter Basin Water Transfer (IBWT) is suggested as a viable option to augment utilizable water resources of the Upper Awash sub-basin to reduce the significant pressure on the water supply of the rapidly developing urban and irrigation areas in the CRVL sub-basin. A water evaluation and planning (WEAP) model was used to quantify the amount of surplus water in the donor basin, when examining the hydrological dynamics of the basins. Furthermore, optimal flow diversion scenarios were generated by maintaining two baseline scenario constraints. The estimated surplus water in the rainy season is expected to contribute 18 million cubic meters (mcm), 88 mcm and 192 mcm in months June, July and August respectively under average conditions. The optimal amount of diverted water could potentially stabilize the environmental degradation of Lake Ziway and Lake Abijata by compensating for development-driven abstraction and surface water evaporation respectively.展开更多
The local characteristics of multi-dimensional random variables are seldom considered in the general modeling method of multivariate copula.A new modeling method,called pair-copula construction,is introduced to remedy...The local characteristics of multi-dimensional random variables are seldom considered in the general modeling method of multivariate copula.A new modeling method,called pair-copula construction,is introduced to remedy this defect.Different types of copula distribution functions are allowed to be introduced in this method.Correspondingly,the related characteristics of complex multivariate can be described by a cascade of pair-copula acting on two variables at a time.In the analysis of asynchronism-synchronism of regional precipitation in WED interbasin water transfer areas,the pair-copula construction method is compared with the general modeling method of multivariate copula.The results show that the local dependence structure would exist among hydrologic variables even in three-dimensional cases.In this situation,the general modeling method of multivariate copula would face difficulties in fitting distribution.However,the pair-copula construction method could capture the local information of hydrologic variables efficiently by introducing different types of copula distribution functions.Moreover,the compensation capacity of water resources is strong in different hydrological areas of WED water transfer project.The asynchronous frequency of wetness and dryness is 69.64% and the favorable frequency for water transfer is 46.15%.展开更多
Inter-basin Water Transfer Projects require the appropriate financing model to attract large amounts of social investment.Therefore,financing model decision becomes the key of engineering construction.In three aspects...Inter-basin Water Transfer Projects require the appropriate financing model to attract large amounts of social investment.Therefore,financing model decision becomes the key of engineering construction.In three aspects,such as the subject,the object and the target of the financing model,Grey Target Model is established in this paper.First,the complex financing mode decision problems of Inter-basin Water Transfer Projects are decomposed by using hierarchical decomposition method.Then Analytical Hierarchy Process(AHP) method is used to calculate the comprehensive weight of evaluation index.Experts' opinions financing model are transformed into the evaluation matrix based on the Dephi method.The Weighted Grey Target Model is used to calculate the approaching degree of financing model and assists financing mode decision.In addition,this paper takes the water diversion project from the Han to the Wei River of Shaanxi Province as a verification example for the model.For other water diversion projects,the evaluation results are also reliable and provide theoretical references for the financing model decision of Inter-basin Water Transfer Projects.展开更多
This paper develops a new inter-basin water transfer-supply and risk assessment model with consideration of rainfall forecast information. Firstly, based on the current state of reservoir and rainfall forecast informa...This paper develops a new inter-basin water transfer-supply and risk assessment model with consideration of rainfall forecast information. Firstly, based on the current state of reservoir and rainfall forecast information from the global forecast system (GFS), the actual diversion amount can be determined according to the inter-basin water transfer rules with the decision tree method; secondly, the reservoir supply operation system is used to distribute water resource of the inter-basin water transfer reservoir; finally, the integrated risk assessment model is built by selecting the reliability of water transfer, the reliability (water shortage risk), the resiliency and the vulnerability of water supply as risk analysis indexes. The case study shows that the inter-basin water transfer-supply model with rainfall forecast information considered can reduce the comprehensive risk and improve the utilization efficiency of water resource, as compared with conventional and optimal water distribution models.展开更多
The joint operation of inter-basin water transfer-supply(IBWTS)project can be more complex when there is joint water demand in multi-reservoir system and multi-importing reservoirs simultaneously transferring water fr...The joint operation of inter-basin water transfer-supply(IBWTS)project can be more complex when there is joint water demand in multi-reservoir system and multi-importing reservoirs simultaneously transferring water from exporting reservoir.In this study,a joint operating rule is proposed for the purpose of solving such complex operation problem.This rule is composed of a set of sub-rules,including hedging rule curves of virtual aggregation reservoir(i.e.equivalent reservoir)and other individual reservoirs,water-transfer rule curves of each individual reservoir,as well as some of important assisted rules.These assisted rules refer to allocation models for water transfer-supply.In the proposed rule,an equivalent reservoir is established to determine under what condition the water supply should be reduced and specify the total supplied water for joint water demand(i.e.aggregation method).Allocation models are developed to distribute the total transferred water into each importing reservoir and determine the water releases for joint water demand by each member reservoir of the aggregation system(i.e.decomposition method).And these models are integrated with a set of influence factors such as hydrologic characteristics,reservoir storage or vacant storage,regulating ability,water-supply pressure,and so on.The aggregation of multi-reservoirs and the disaggregation of water quantities are taken into a whole consideration to reduce the complexity in reallocation of water target storage or water release.Finally,the proposed rule is applied to the North-line IBWTS Project in Liaoning Province,China.The results indicate that the proposed rule can take full advantage of hydrologic compensation in basins and capacity compensation in reservoirs.Thus it can improve the utilization efficiency of water resources in system.展开更多
To meet the increasing need of fresh water and to improve the water quality of Taihu Lake, water transfer from the Yangtze River was initiated in 2002. This study was performed to investigate the sediment distribution...To meet the increasing need of fresh water and to improve the water quality of Taihu Lake, water transfer from the Yangtze River was initiated in 2002. This study was performed to investigate the sediment distribution along the river course following water transfer. A rainfall-runoff model was first built to calculate the runoff of the Taihu Basin in 2003. Then, the flow patterns of river networks were simulated using a one-dimensional river network hydrodynamic model. Based on the boundary conditions of the flow in tributaries of the Wangyu River and the water level in Taihu Lake, a one-dimensional hydrodynamic and sediment transport numerical model of the Wangyu River was built to analyze the influences of the inflow rate of the water transfer and the suspended sediment concentration (SSC) of inflow on the sediment transport. The results show that the water transfer inflow rate and SSC of inflow have significant effects on the sediment distribution. The higher the inflow rate or SSC of inflow is, the higher the SSC value is at certain cross-sections along the river course of water transfer. Higher inflow rate and SSC of inflow contribute to higher sediment deposition per kilometer and sediment thickness. It is also concluded that a sharp decrease of the inflow velocity at the entrance of the Wangyu River on the river course of water transfer induces intense sedimentation at the cross-section near the Changshu hydro-junction. With an increasing distance from the Changshu hydro-junction, the sediment deposition and sedimentation thickness decrease gradually along the river course.展开更多
The over-exploitation of water resources in the Haihe River Basin (HRB) has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of ov...The over-exploitation of water resources in the Haihe River Basin (HRB) has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of over-exploited groundwater has reached over 1000×108m3. It is important to note that the exploitation of water resources in HRB was reasonable before 1979. After 1980, however, over-exploitation happened with an annual average amount of 40×108m3. Both the dry season and rapid economic growth in HRB took place at the same time. Therefore, the over-exploitation of water in HRB was actually the negative result of the conjunction of a continuous dry season and rapid economic growth. So the over-exploitation would not be as serious as it is today if either of the above two stopped. After the first stage of south-to-north water transfer project, the water shortage problem in HRB could be eased for the following reasons: fi rstly, water transfer project will bring to the Basin 60×108m3 water resources; secondly, a wet season will come back eventually according to natural law of climate variability; finally, its agricultural and industrial use and total water consumption all have decreased from the peak value, so that the groundwater table will raise certainly and ecological water in rivers and lakes that were dried-up will be partly restored. In the future, the main problem of water resources security in HRB will include water pollution, operation risk of the south-to-north water transfer project, groundwater pollution and engineering geological hazards that may be brought by groundwater rise. The proposed countermeasures are as follows: keeping strengthening water demand management, raising water price as well as subsidies for the low-income family and improving other water related policies, preventing and dealing with water pollution seriously and getting fully prepared for the operation of south-to-north water transfer project.展开更多
为揭示南水北调中线工程水体中溶解性有机质(Dissolved Organic Matter,DOM)的组成变化特征,采集南水北调中线总干渠沿线及丹江口水库水样,利用傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometr...为揭示南水北调中线工程水体中溶解性有机质(Dissolved Organic Matter,DOM)的组成变化特征,采集南水北调中线总干渠沿线及丹江口水库水样,利用傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR MS)分析了DOM的分子组成及其空间变化,并探讨了总干渠沿线DOM变化成因和环境意义。结果表明:丹江口水库和总干渠均检出DOM物质3200余种,仅含C、H和O的物质(CHOs)为主要组分,约占所有检出物质的61%,含C、H、O和N的物质(CHONs)占30.5%~31.5%,含C、H、O和S的物质(CHOSs)仅占7.3%~8.4%,结合O/C和H/C分类,丹江口水库和总干渠水体DOM主要组分为木质素(60%以上)。相较于丹江口水库,总干渠水体DOM组分发生了较大变化,蛋白质类组分占比由3.70%升至8.65%,表明总干渠中有蛋白质生成;稠环类物质占比由9.43%下降至4.77%,单宁酸类的变化趋势与稠环类物质类似。总干渠局部区域藻类增殖过程是引起总干渠中CHONs和CHOSs类DOM组分和占比升高的主要原因。研究成果可为科学认识南水北调中线工程水体水质变化过程提供科学依据。展开更多
文摘Demand for fresh water, as one of the major natural resources, is increasing rapidly with increasing development and environmental degradation. The continued abstraction of water from Lake Ziway and its main feeder rivers Meki and Katar for irrigation indicates that the water demand may soon exceed the supply. To illustrate disparities in spatial distribution of water resources, the Upper Awash sub-basin, which shares a water-divide with the CRVL sub-basin, has large flow volumes particularly in the rainy season and suffers with seasonal flooding. The rationale behind regaining the water in CRVL relies on this non-uniform spatial distribution of fresh water, calling for a balance between water surplus and deficit regions. For this reason, Inter Basin Water Transfer (IBWT) is suggested as a viable option to augment utilizable water resources of the Upper Awash sub-basin to reduce the significant pressure on the water supply of the rapidly developing urban and irrigation areas in the CRVL sub-basin. A water evaluation and planning (WEAP) model was used to quantify the amount of surplus water in the donor basin, when examining the hydrological dynamics of the basins. Furthermore, optimal flow diversion scenarios were generated by maintaining two baseline scenario constraints. The estimated surplus water in the rainy season is expected to contribute 18 million cubic meters (mcm), 88 mcm and 192 mcm in months June, July and August respectively under average conditions. The optimal amount of diverted water could potentially stabilize the environmental degradation of Lake Ziway and Lake Abijata by compensating for development-driven abstraction and surface water evaporation respectively.
基金Supported by National Natural Science Foundation of China (No. 50979011)
文摘The local characteristics of multi-dimensional random variables are seldom considered in the general modeling method of multivariate copula.A new modeling method,called pair-copula construction,is introduced to remedy this defect.Different types of copula distribution functions are allowed to be introduced in this method.Correspondingly,the related characteristics of complex multivariate can be described by a cascade of pair-copula acting on two variables at a time.In the analysis of asynchronism-synchronism of regional precipitation in WED interbasin water transfer areas,the pair-copula construction method is compared with the general modeling method of multivariate copula.The results show that the local dependence structure would exist among hydrologic variables even in three-dimensional cases.In this situation,the general modeling method of multivariate copula would face difficulties in fitting distribution.However,the pair-copula construction method could capture the local information of hydrologic variables efficiently by introducing different types of copula distribution functions.Moreover,the compensation capacity of water resources is strong in different hydrological areas of WED water transfer project.The asynchronous frequency of wetness and dryness is 69.64% and the favorable frequency for water transfer is 46.15%.
基金partly supported by the National Natural Science Foundation of China (Grant Nos.51209170,and 51479160)the foundation for the Plan Projects of Water Conservancy Science and Technology of Shaanxi Province (Grant No.2013SLKJ05)the Project Supported by Natural Science Basic Research Plan in Shaanxi Province of China (Grant No.2016JQ5061)
文摘Inter-basin Water Transfer Projects require the appropriate financing model to attract large amounts of social investment.Therefore,financing model decision becomes the key of engineering construction.In three aspects,such as the subject,the object and the target of the financing model,Grey Target Model is established in this paper.First,the complex financing mode decision problems of Inter-basin Water Transfer Projects are decomposed by using hierarchical decomposition method.Then Analytical Hierarchy Process(AHP) method is used to calculate the comprehensive weight of evaluation index.Experts' opinions financing model are transformed into the evaluation matrix based on the Dephi method.The Weighted Grey Target Model is used to calculate the approaching degree of financing model and assists financing mode decision.In addition,this paper takes the water diversion project from the Han to the Wei River of Shaanxi Province as a verification example for the model.For other water diversion projects,the evaluation results are also reliable and provide theoretical references for the financing model decision of Inter-basin Water Transfer Projects.
基金supported by the National Natural Science Foundation of China (Grant No. 50979011)
文摘This paper develops a new inter-basin water transfer-supply and risk assessment model with consideration of rainfall forecast information. Firstly, based on the current state of reservoir and rainfall forecast information from the global forecast system (GFS), the actual diversion amount can be determined according to the inter-basin water transfer rules with the decision tree method; secondly, the reservoir supply operation system is used to distribute water resource of the inter-basin water transfer reservoir; finally, the integrated risk assessment model is built by selecting the reliability of water transfer, the reliability (water shortage risk), the resiliency and the vulnerability of water supply as risk analysis indexes. The case study shows that the inter-basin water transfer-supply model with rainfall forecast information considered can reduce the comprehensive risk and improve the utilization efficiency of water resource, as compared with conventional and optimal water distribution models.
基金supported by the Major International(Regional)Cooperation Project(Grant No.51320105010)the National Natural Science Foundation of China(Grant Nos.51379027,51109025)the Fundamental Research Fund for the Central Universities(Grant No.DUT13JS06)
文摘The joint operation of inter-basin water transfer-supply(IBWTS)project can be more complex when there is joint water demand in multi-reservoir system and multi-importing reservoirs simultaneously transferring water from exporting reservoir.In this study,a joint operating rule is proposed for the purpose of solving such complex operation problem.This rule is composed of a set of sub-rules,including hedging rule curves of virtual aggregation reservoir(i.e.equivalent reservoir)and other individual reservoirs,water-transfer rule curves of each individual reservoir,as well as some of important assisted rules.These assisted rules refer to allocation models for water transfer-supply.In the proposed rule,an equivalent reservoir is established to determine under what condition the water supply should be reduced and specify the total supplied water for joint water demand(i.e.aggregation method).Allocation models are developed to distribute the total transferred water into each importing reservoir and determine the water releases for joint water demand by each member reservoir of the aggregation system(i.e.decomposition method).And these models are integrated with a set of influence factors such as hydrologic characteristics,reservoir storage or vacant storage,regulating ability,water-supply pressure,and so on.The aggregation of multi-reservoirs and the disaggregation of water quantities are taken into a whole consideration to reduce the complexity in reallocation of water target storage or water release.Finally,the proposed rule is applied to the North-line IBWTS Project in Liaoning Province,China.The results indicate that the proposed rule can take full advantage of hydrologic compensation in basins and capacity compensation in reservoirs.Thus it can improve the utilization efficiency of water resources in system.
基金supported by State Key Development Program of Basic Research of China (Grant No.2010CB429001)the National Natural Science Foundation of China (Grant No. 51009062)the Special Fund of Hydrology-Water Resources and Hydraulic Engineering (Grant No. 2009586812)
文摘To meet the increasing need of fresh water and to improve the water quality of Taihu Lake, water transfer from the Yangtze River was initiated in 2002. This study was performed to investigate the sediment distribution along the river course following water transfer. A rainfall-runoff model was first built to calculate the runoff of the Taihu Basin in 2003. Then, the flow patterns of river networks were simulated using a one-dimensional river network hydrodynamic model. Based on the boundary conditions of the flow in tributaries of the Wangyu River and the water level in Taihu Lake, a one-dimensional hydrodynamic and sediment transport numerical model of the Wangyu River was built to analyze the influences of the inflow rate of the water transfer and the suspended sediment concentration (SSC) of inflow on the sediment transport. The results show that the water transfer inflow rate and SSC of inflow have significant effects on the sediment distribution. The higher the inflow rate or SSC of inflow is, the higher the SSC value is at certain cross-sections along the river course of water transfer. Higher inflow rate and SSC of inflow contribute to higher sediment deposition per kilometer and sediment thickness. It is also concluded that a sharp decrease of the inflow velocity at the entrance of the Wangyu River on the river course of water transfer induces intense sedimentation at the cross-section near the Changshu hydro-junction. With an increasing distance from the Changshu hydro-junction, the sediment deposition and sedimentation thickness decrease gradually along the river course.
基金supported by the National Natural Sciences Fund of China (40971298)
文摘The over-exploitation of water resources in the Haihe River Basin (HRB) has now become a serious problem. This is clearly evidenced by the fact that many local rivers and lakes are drying up and the total amount of over-exploited groundwater has reached over 1000×108m3. It is important to note that the exploitation of water resources in HRB was reasonable before 1979. After 1980, however, over-exploitation happened with an annual average amount of 40×108m3. Both the dry season and rapid economic growth in HRB took place at the same time. Therefore, the over-exploitation of water in HRB was actually the negative result of the conjunction of a continuous dry season and rapid economic growth. So the over-exploitation would not be as serious as it is today if either of the above two stopped. After the first stage of south-to-north water transfer project, the water shortage problem in HRB could be eased for the following reasons: fi rstly, water transfer project will bring to the Basin 60×108m3 water resources; secondly, a wet season will come back eventually according to natural law of climate variability; finally, its agricultural and industrial use and total water consumption all have decreased from the peak value, so that the groundwater table will raise certainly and ecological water in rivers and lakes that were dried-up will be partly restored. In the future, the main problem of water resources security in HRB will include water pollution, operation risk of the south-to-north water transfer project, groundwater pollution and engineering geological hazards that may be brought by groundwater rise. The proposed countermeasures are as follows: keeping strengthening water demand management, raising water price as well as subsidies for the low-income family and improving other water related policies, preventing and dealing with water pollution seriously and getting fully prepared for the operation of south-to-north water transfer project.
文摘为揭示南水北调中线工程水体中溶解性有机质(Dissolved Organic Matter,DOM)的组成变化特征,采集南水北调中线总干渠沿线及丹江口水库水样,利用傅里叶变换离子回旋共振质谱(Fourier Transform Ion Cyclotron Resonance Mass Spectrometry,FT-ICR MS)分析了DOM的分子组成及其空间变化,并探讨了总干渠沿线DOM变化成因和环境意义。结果表明:丹江口水库和总干渠均检出DOM物质3200余种,仅含C、H和O的物质(CHOs)为主要组分,约占所有检出物质的61%,含C、H、O和N的物质(CHONs)占30.5%~31.5%,含C、H、O和S的物质(CHOSs)仅占7.3%~8.4%,结合O/C和H/C分类,丹江口水库和总干渠水体DOM主要组分为木质素(60%以上)。相较于丹江口水库,总干渠水体DOM组分发生了较大变化,蛋白质类组分占比由3.70%升至8.65%,表明总干渠中有蛋白质生成;稠环类物质占比由9.43%下降至4.77%,单宁酸类的变化趋势与稠环类物质类似。总干渠局部区域藻类增殖过程是引起总干渠中CHONs和CHOSs类DOM组分和占比升高的主要原因。研究成果可为科学认识南水北调中线工程水体水质变化过程提供科学依据。