面向水资源短缺风险规避的灌区需水结构优化布局研究

Water shortage is a key restricting factor for the sustainable development of the irrigation district. For canal irrigation district, the irrigated surface water is random, and the water use is controlled by water demand structure. Under a changing environment, the water shortage risk aversion must be combined with the supply and demand of water resources. Taking the typical canal irrigation district in northern China-Luhun irrigation district in Henan province as an example, and with a long series of data, the changing laws and features of the irrigated surface water and water demand are analyzed deeply, the statistical characteristics and correlations of the hydrological and meteorological variables (scuh as rainfall, irrigated surface water, ect.)and crop water requirement are also explored. With the copula method, the joint distribution models of water shortage risk with different irrigated surface water and water demand are built. Finally, combined with irrigational development planning, water shortage risks with different situations are simulated and regulated, and water demand structure optimization with high drought resistance ability is presented eventually, which provides a reference to enhance water security and maintaining economic development for canal irrigation district of northern China.

水资源短缺是制约灌区可持续发展的关键因素。对渠灌灌区而言，灌区来水具有随机性，而灌区用水又受控于需水结构，因此，灌区水资源短缺风险规避必须与变化环境下的水资源供给与需求相结合。本项目以我国北方典型渠灌灌区-陆浑灌区为例，借助长系列数据资料，深入剖析灌区来水和需水变化发展规律，探究降水、可灌溉水量等主要水文气象变量与作物需水量的统计分布特性及其相关关系；应用Copula函数，构建不同来水和需水结构条件下的灌区水资源短缺风险联合分布模型；结合灌区农业发展规划，模拟预测灌区未来不同情境下的水资源短缺风险及其调控机制，提出抵抗水资源变动风险能力较强的灌区需水结构布局模式，以期为我国北方渠灌灌区提升用水安全和维护经济发展提供参考。

灌区用水安全受供水和需水综合影响，降雨、灌溉用水和作物需水是灌区进行灌溉规划和规避水资源短缺风险的重要依据。本项目通过对灌区降雨量、灌溉用水量和作物需水量的长时间历史数据资料统计分析，运用多时间尺度分析方法、集对分析法和协整理论，分析了灌区降雨量、灌溉用水量和作物需水量的多时间尺度波动特征和变化规律，解释了三者之间两两存在的不确定性关系；对降雨量、灌溉用水量和作物需水量这三个变量之间的相关性进行量化；应用水文统计分析方法，选用相应的随机变量概率分布函数，分别分析降雨量、灌溉用水量、参考作物腾发量的概率分布特性；应用二维Copula函数，分别构建降雨量与作物需水量、灌溉用水量与作物需水量相耦合的灌区水资源短缺风险联合概率分布模型，分析不同量级降雨量与作物需水量、灌溉用水量与作物需水量遭遇组合的联合概率分布、条件概率分布与遭遇组合重现期以及丰枯遭遇频率，揭示自然降雨条件下和人工供水条件下的灌区水资源短缺风险；应用三维Copula函数，构建降雨量、灌溉用水量和作物需水量相耦合的灌区水资源短缺风险联合概率分布模型，分析不同量级降雨量、灌溉用水量和作物需水量遭遇组合的联合概率分布、条件概率分布与遭遇组合重现期以及丰枯遭遇频率，用于揭示自然降雨和灌溉用水量组合来水条件下的灌区水资源短缺风险；根据灌区现状及未来发展规划，设定灌区需水结构调整方案，利用灌区水资源短缺风险联合概率分布模型，分析未来不同情景下的灌区水资源短缺风险，并进行方案对比分析。本项目的研究对规避灌区缺水风险，优化灌区需水结构以及抗旱减灾方面均具有重要的理论价值和实践意义。