基于联系数的大型灌区水资源空间均衡评价与优化调控

Evaluation and optimal regulation of spatial equilibrium of water resources in large irrigation area based on connection number

区域水资源空间均衡评价与调控是水资源开发利用与经济社会协调发展的重要技术基础和科学管理手段。可供水量与需水量是区域自然资源条件和经济社会活动对水资源系统的综合体现指标,二者之间的平衡关系可以直观地揭示水资源系统的单元供需均衡和空间均衡程度。针对水资源空间均衡研究现状,首先以供需差占供需总量比定义并计算水资源系统的单元供需均衡度;再以各单元面积、人口和经济占比确定单元的系统权重,并运用七元联系数将各单元均衡度综合为系统空间均衡等级并识别均衡状态;以淠河灌区现状及远景规划年为例,对有无水量调配下水资源空间均衡状态开展评价计算与对比分析,最后针对性地提出提高灌区水资源空间均衡状态的优化调控方案。研究结果表明:现状水平年灌区水资源空间均衡状态经系统内水资源调配后有明显提升;远景规划年不同来水情景下,水资源供需矛盾较为尖锐,只有在充分节水基础上借助系统内、外多水源调配方能使灌区水资源系统达到基本均衡;单元供需均衡度能同时表达缺水型失衡和余水型失衡而更有普适性;改进的七元联系数评价模型可更加细致地刻画复杂水资源系统的不确定性,为准确判别区域水资源系统所处空间均衡状态提供了新思路新途径;大型灌区内部由于县市之间自然禀赋和经济社会不同导致水资源均衡度差异明显,而通过系统内单元间水资源优化调配以及系统外多水源调配能有效改善区域单元供需均衡度和空间均衡状态,对促进水资源与经济社会环境协调发展、保障区域远景规划的顺利实施具有重要的支撑作用。

The spatial equilibrium evaluation and regulation of regional water resources is the important technical basis and scientific management method of development and utilization of water resources coordinated with economic and ecological environment development.The amount of water demand and supply respectively are comprehensive indicators of natural resource conditions and economic and social activities on water resources,of which the balance relationship can directly reveal the unit supply-demand equilibrium degree and spatial equilibrium degree of water resources system.In this paper a method for evaluating the spatial equilibrium degree of regional water resources is proposed on the basis of the relationship between water supply-demand and seven-element connection number,at the meantime an evaluation and regulation study is carried out in the water resources system of large irrigation area.Firstly,the water resource system supply-demand equilibrium degree of each unit(county or city)is defined and calculated by the ratio of supply and demand difference to total supply and demand.Then,a comprehensive evaluation method based on the seven-element connection number is constructed,and the evaluation and comparative analysis of the spatial equilibrium degree of water resources system with and without water resources configuration within the system are carried out.Then,the amount of water demand and supply in the long-term planning year(2035)is forecast.On this basis,the evaluation and calculation of the unit equilibrium degree of water resources in each county or city and the overall water resource spatial equilibrium degree of water resources system of irrigation area are carried out in 2035.Finally,the optimal regulation scheme to improve the spatial equilibrium of water resources in irrigation area are put forward.The results show that in the current level year,the spatial equilibrium degree value of the Pihe Irrigation Area has been significantly improved after the allocation of water resources in the system.Under different inflow conditions in the long-term planning year,the contradiction between supply and demand of water resources is more acute,which can be solved by the water resources configuration from multiple sources within and outside the system on the basis of mighty water saving.This study shows that the evaluate method of supply-demand equilibrium degree of water resources can express the disequilibrium of regional water shortage and excess water,so it can be widely applied to various situations.The improved seven-element connection number evaluation model can describe the uncertainty of complex water resources system in more detail,and provide a new way to accurately identify the spatial equilibrium state of regional water resources system.Due to the difference of the condition of nature and economic society,the equilibrium degree of water resources of different counties and cities are obviously different in a same large irrigation area.The optimal allocation of water resources among units in the system and the allocation of multiple external water sources,can effectively improve the spatial equilibrium degree,which plays an important role in promoting the coordinated development of water resources and economic society and ensuring the smooth implementation of regional long-term planning.