An Integrated Approach of System Dynamics,Orthogonal Experimental Design and Inexact Optimization for Supporting Water Resources Management under Uncertainty

An integrated approach of system dynamics (SD), orthogonal experimental design (OED) and inexact optimization modeling was proposed for water resources management under uncertainty. The developed method adopted a combination of SD and OED to identify key scenarios within multiple factors, through which interval solutions for water demands could be obtained as input data for consequential optimization modeling. Also, optimal schemes could be obtained in the combination of inexact two-stage stochastic programming and credibility constrained programming. The developed method was applied to a real-world case study for supporting allocation of multiple-source water resources to multiple users in Dalian city within a multi-year context. The results indicated that a lower credibility-satisfaction level would generate higher allocation efficiency, a higher system benefit and a lower system violation risk. The developed model could successfully reflect and address the variety of uncertainties through provision of credibility levels, which corresponds to the decision makers’ preference regarding the tradeoffs between system benefits and violation risks.     

Optimization of Industrial Structure Considering the Uncertainty of Water Resources

This paper developed a stochastic linear fractional programming model for industry optimization allocation base on the uncertainty of water resources incorporating chance constrained programming and fractional programming. In this paper, the stochastic linear fractional programming is used in the real word. The development SLFP has the following advantages: (1) The model can compare the two aspects of the targets; (2) The model can reflect the system efficiency intuitively; (3) The model can deal with uncertain issues with probability distribution; (4) The model can give different optimal plans under different risk conditions. The model has a significant value for the industry optimization allocation under uncertainty in local and areas to achieve the maximum economic benefits and the full use of the water resources.     

Modeling of Water Resources Allocation and Water Quality Management for Supporting Regional Sustainability under Uncertainty in an Arid Region

In this study, a scenario-based interval-stochastic fraticle optimization with Laplace criterion (SISFL) method is developed for sustainable water resources allocation and water quality management (WAQM) under multiple uncertainties. SISFL can tackle uncertainties presented as interval parameters and probability distributions; meanwhile, it can also quantify artificial fuzziness such as risk-averse attitude in a decision-making issue. Besides, it can reflect random scenario occurrence under the supposition of no data available. The developed method is applied to a real case of water resources allocation and water quality management in the Kaidu-kongque River Basin, where encounter serve water deficit and water quality degradation simultaneously in Northwest China. Results of water allocation pattern, pollution mitigation scheme, and system benefit under various scenarios are analyzed. The tradeoff between economic activity and water-environment protection with interval necessity levels and Laplace criterions can support policymakers generating an effective and robust manner associated with risk control for WAQM under multiple uncertainties. These discoveries avail local policymakers gain insight into the capacity planning of water-environment to satisfy the basin’s integrity of socio-economic development and eco-environmental sustainability.     

IB-ICCMSP: An Integrated Irrigation Water Optimal Allocation and Planning Model Based on Inventory Theory under Uncertainty

In this study, an inventory-theory-based inexact chance-constrained multi-stage stochastic programming (IB-ICCMSP) model under multi-uncertainties is developed. IB-ICCMSP integrates inventory theory into an inexact chance-constrained multi-stage stochastic optimization framework. This method can not only effectively address system multiple uncertainties (e.g. discrete intervals and probability density functions) and dynamic features, but also provide water transferring and allocating schemes among multiple stages. The developed model is applied to irrigation water allocation optimization system in Zhangye City, Gansu province, China. Based on the runoff simulation prediction of Yingluo Gorge and water supply–demand balance analysis of the 12 irrigation areas in Zhangye City, different optimal irrigation water measures are generated under different flow levels and different probabilities in the planning year. The obtained results are valuable for supporting the adjustment of the existing irrigation patterns and identifying desired water-allocation plans for irrigation under multi-uncertainties.     

Development of a Dynamic Long-Term Water Allocation Model for Agriculture and Industry Water Demands

Demands growth and water resources limitation, enforce water sector policy makers to integrate water supply–demand interactions in a coherent framework for efficient water allocation. Water supply–demand interaction, changes long-term trend of water demands, which in turn has a substantial influence on water allocation. Researches on water allocation modeling lack adequate projection of relationship between water supply and demand. Socio-economic factors representing water allocation stakeholders’ benefits, account for the main share of water supply–demand interaction. Identification, representation and consideration of these factors in a water allocation model, is the main limitation of researches on this issue. In this paper a new long-term water allocation model at basin level is developed and introduced. This model considers water supply–demand interaction in agriculture and industry sectors, by use of socio-economic parameters; such as, production, cultivated land area, revenue and employment. The model main advantage is its ability to reflect the interrelationship between essential hydro-system and supply–demand components. It can explore both socio-economic and water allocation consequences of various policy choices. The model is used to assess two different development policies at basin level. The first one is fourth 5-year development plan of Iran, which fixes predefined growth rate for different sectors. The second one assumes the present state continues up to the end of planning horizon. A typical multi-reservoir water basin is modeled and analyzed for two policies. Indices that summarize long-term state of hydro-system and stakeholders are defined and used in policies assessment and decision making. Results of these assessments show fourth 5-year development policy provides opportunities for substantial improvement in water allocation and stakeholders’ benefits.     

基于多目标遗传算法的水资源优化配置

文章基于进化计算思想提出了水资源优化配置的多目标遗传算法,建立了基于并列选择多目标遗传算法的水资源优化配置模型.并结合实例分析,求出水资源优化配置问题的Pareto最优解.优化结果表明,该算法应用在水资源优化配置中是合理、有效的.     

Mitigating Socio-Economic-Environmental Impacts During Drought Periods by Optimizing the Conjunctive Management of Water Resources

Multi-period optimization of conjunctive water management can utilize reservoirs and aquifer carry-over to alleviate drought impacts. Stakeholders’ socio-economic and environmental indices can be used to minimize the socio-economic and environmental costs associated with water shortages in drought periods. The knowledge gap here is the evaluation and inclusion of the socio-economic and environmental value of conjunctive water management in terms of its drought mitigation capability. In this paper, an integrated water quantity-quality optimization model that considers socio-economic and environmental indices is developed. The model considers and integrates reservoir and aquifer carry-over, river-aquifer interaction and water quality with stakeholders’ socio-economic indices of production, net income and labor force employment to evaluate the socio-economic and environmental value of conjunctive water management. Total dissolved solid (TDS) is used as the water quality index for environmental assessments. The model is formulated as a multi-period nonlinear optimization model, with analysis determining the optimal decisions for reservoir release and withdrawal from the river and aquifer in different months to maximize the socio-economic indices of stakeholders within the environmental constraints. The proposed model is used in Zayandehrood water resource system in Iran, which suffers from water supply and pollution problems. Model analysis results show that conjunctive water use in the Zayandehrood water basin reduces salinity by 50 % in the wetland and keeps water supply reduction during a drought under 10 % of irrigation demand.     

基于混合算子遗传算法的水资源优化配置

构建了以经济效益、社会效益、生态效益为多目标的水资源配置模型,针对模型中存在的多目标多约束优化问题,对基本遗传算法进行改造,设计了一个混合算子遗传算法,并用算例进行验证,最后将水资源优化配置模型和算法应用于东江流域。实例计算结果表明,基于混合算子遗传算法的多目标水资源优化配置模型配置结果合理可行,可作为研究流域水资源配置的决策依据。遗传算法作为新型智能算法,可应用于水资源配置领域。     

A Dynamic Model for Vulnerability Assessment of Regional Water Resources in Arid Areas: A Case Study of Bayingolin, China

Water scarcity is a common problem in many countries, especially those located in arid zones. The vulnerability of water resources due to climate change is an imperative research focus in the field of water resources management. In this study, a System Dynamics (SD) model was developed to simulate the water supply-and-demand process in Bayingolin, a prefecture in China, and to evaluate water resources vulnerability currently as well as in the future. The model was calibrated and validated using historical data. Three alternative scenarios were designed by changing parameters to test the vulnerability of water resources: i) increase the Wastewater Treatment Rate by 50 %; ii) decrease the Irrigation Water Demand per Hectare by 20 %; iii) increase Total Water Supply by 5 %. Results show that the baseline vulnerability of study region is high. The agricultural irrigation is the largest water use, and the water demand structure will change in future. Decreasing the irrigation water demand is the most suitable intervention to relatively reduce the vulnerability. Results also demonstrated that SD is a suitable method to explore management options for a complex water supply and demand system.     

基于可变模糊集理论的跨流域调水工程 水资源优化调度

为实现水资源的高效利用, 对胶东调水工程进行水资源优化调度研究。基于受水区潍坊、青岛、烟台、威海等 4 市的实际配水量与社会经济指标分析, 利用可变模糊集理论, 建立地市外调水量可变模糊优选模型进行优化调配 系数计算, 优化调配 4 市外调水量, 并对优化后的外调水量与区域社会经济发展进行耦合协调度计算。以调水效率 最高为原则, 以 4 市缺水总量最小建立目标函数, 利用 Lingo 软件编程求解, 分别对平水年、枯水年、特枯年进行水资源优化调度。把基于调配水量调度与规划指标调度的结果进行对比分析。结果表明: 2 种调度结果均满足各分水口的最小需水要求; 外调水量的优化调配提高了胶东 4 市水资源与社会经济发展的耦合协调度, 调配水量调度后, 青岛市缺水率明显下降, 其他地市缺水率降幅则较小。     

A Conditional Value-at-Risk Based Inexact Water Allocation Model

A conditional value-at-risk (CVaR) based inexact two-stage stochastic programming (CITSP) model was developed in this study for supporting water resources allocation problems under uncertainty. A CITSP model was formulated through incorporating a CVaR constraint into an inexact two-stage stochastic programming (ITSP) framework, and could be used to deal with uncertainties expressed as not only probability distributions but also discrete intervals. The measure of risks about the second-stage penalty cost was incorporated into the model, such that the trade-off between system economy and extreme expected loss could be analyzed. The developed model was applied to a water resources allocation problem involving a reservoir and three competing water users. The results indicated that the CITSP model performed better than the ITSP model in its capability of reflecting the economic loss from extreme events. Also, it could generate interval solutions within which the decision alternatives could be selected from a flexible decision space. Overall, the CITSP model was useful for reflecting the decision maker’s attitude toward risk aversion and could help seek cost-effective water resources management strategies under complex uncertainties.     

基于GIS网络模型的水资源优化配置系统设计与实现

基于GIS网络模型的水资源优化配置系统是一个基于数据库、Arc Engine技术、C~#语言等联合开发的决策支持系统,该系统利用GIS的可视化技术以及几何网络模型将水资源优化配置模型概化,绘制相应的水资源配置系统网络图,通过对复杂的水资源、社会经济、生态环境系统进行简化和抽象,以节点和线要素构成网络图反映三大系统内在的逻辑关系,利用灵活的模块化数学模型对多目标的水资源管理进行调配,最终得到优化配置结果,为水资源管理提供技术支持。通过示范区域赣江流域水资源优化配置模型的应用,表明该系统是一个简捷实用、易操作的决策支持系统平台。     

Water Productivity in a Rigid Irrigation Delivery System

The rotational irrigation water delivery (warabandi) system practiced in the Indus river basin of Pakistan has continued for 100 years. Irrigation water allocated to the farmers under the warabandi system is proportional to farm size and is fixed. This rigid allocation system has been partly justified by its contribution to social equity though this may have been at the cost of economic gains. In order to assess the operation of warabandi’s basic rules, a farmers’ survey was completed from 124 farmers located on five watercourses. A questionnaire was administered to each farmer and farm management data were gathered. As fresh water resources are under stress and becoming scarce their efficient use in all applications should be assured in water allocations. It is shown from the survey results that water allocation based on very limited criteria does not maximize the socio-economic benefits gained from the use of scarce water. Thus, it is suggested that the existence or non-existence of fresh groundwater resources along with other critical variables should be taken into consideration when making canal water allocation decisions. Missed water deliveries due to failure of the canal system appear to be the largest cause of losses. Water charges need to be increased to fund large improvements in canal maintenance programs. It is pointed out that a framework should be developed as a tool to improve water productivity for Pakistan. This should include: consideration of the gross area of a tertiary canal, sensitivity of crop growth stage to water shortage, crop value, bias of allocation towards most water use efficient areas and water use efficient crops, the potential losses from water deficiency.     

乌鲁木齐市经济社会用水结构变化及未来趋势分析

分析城市用水结构的变化并科学预测未来需水结构,是编制水资源利用规划的前提和基础,对区域水资源的合理配置具有重要意义。在分析乌鲁木齐市社会经济各业用结构变化及其规律的基础上,探讨了其变化的主要原因,并预测了未来用水结构的发展趋势及其对未来水资源供需形势的影响,对协调未来可能利用水资源与社会经济发展的关系、制定合理的水资源配置方案、促进经济社会可持续发展提供参考。     

海河流域水资源脆弱性及其评价

水资源脆弱性是评价水资源系统对自然条件变动或人类开发利用影响承载能力的重要指标,其评价对于水资源保护工作非常重要。从自然因素、人为因素、综合因素三方面给出13个指标,利用层次分析法确定各指标的权重,综合相关研究及经验确定各指标的标准值,综合进行区域水资源脆弱性评价。以海河流域为例开展了实例研究,海河流域现状的水资源脆弱度为59.7,属于中度脆弱区;在未来气候变化条件下,经过人工水资源调控措施,海河流域2020年、2030年水资源脆弱度分别为58.64、58.63,证明水资源调控措施将会改善海河流域水资源条件。该方法对流域级水资源系统的脆弱性评价有重要意义。     

基于可控蒸散发的狭义水资源配置

以流域"天然-人工"二元水循环模式和水资源优化配置模型为基础,构建针对区域目标蒸散发(ET)的狭义水资源评估模型。结合流域分区经济耗水和生态耗水计算方法,给出评估模型分析过程,提出基于可控ET的水资源可持续利用评价指标。以湟水干流为例,利用针对区域目标ET的狭义水资源评估模型,阐述当地近5 a水资源开发利用过程中存在的问题,为社会经济发展规划和水资源配置格局提供建议。实例应用表明,基于区域目标ET的狭义水资源评估模型,可为流域分区的水资源配置和管理提供依据。     

区域水资源调度-分配迭代优化模型

在对水资源系统组成和结构分析的基础上,运用大系统优化理论建立了区域水资源系统多目标优化配置数学模型,包括水源优化调度、水量优化分配和调度分配迭代3个子模型。水源优化调度模型的求解采用轮库迭代方法和动态规划方法,水量优化分配模型的求解采用大系统分解协调中的D-W分解原理。对江苏省连云港市区水资源优化配置问题进行了研究,建立并求解了优化配置模型,结果表明,该市各区在2020规划水平年工业、农业、生活和环境部门都将出现不同程度的缺水情况。     

基于系统动力学模型的南渡江流域水资源脆弱性评价

水资源安全影响区域社会经济的健康发展,全球气候变化与人类活动已对流域水资源安全造成巨大压力.建立水资源、水环境及社会经济系统动力学(SD)模型,以层次分析法构建水资源脆弱性评价指标体系与评价标准,设置常规、技术革新型、经济优先型以及综合发展4种模式,采用综合指数加权法对2010-2035年南渡江流域水资源脆弱性进行评价...     

改进的风险决策及NSGA-Ⅱ方法在马莲河流域水资源综合管理中的应用

将马莲河流域系统概化为5个水资源分区,采用指标分析法进行2020和2030年供需水量预测和平衡分析。利用改进的决策树法进行风险分析,将专家咨询概率法引入到决策树敏感性分析中,最终得到2020、2030年的推荐水资源供需分配方案。然后,利用系统分析理论和优化技术建立了流域的大系统、多目标水资源优化配置模型,并采用优化的NSGA-Ⅱ方法进行求解,得到流域2030年推荐水资源配置方案下的最佳分配方案。最后,根据最佳分配方案和预测的流域需水量,进行了流域的水资源平衡分析,通过平衡分析的结果进行流域的综合管理研究。最佳配置方案实现了流域内水资源的最优分配,使宝贵、有限的水资源产生最大的社会、经济及环境效益,为流域经济、能源产业的快速发展提供水资源保障。     

天津市水资源多目标优化配置研究

在综合考虑经济、社会、生态、水环境等因素的基础上,建立天津市区域水资源多目标优化模型,利用遗传算法结合理想点法对多目标模型进行求解,在最终对各用水部门给予政策倾斜的前提下,给出不同水资源优化配置方案,以协助决策者制定切实可行的用水方案,实现水资源的可持续发展。