作物生长模型与灌区水转化模型是量化灌区水分生产力形成过程的主要方法。目前区域水转化模型缺乏考虑地下水对整个区域水循环贡献以及地下水侧向径流交换过程，没有将土壤水-地下水真正耦合起来，对灌区内作物种植结构的提取考虑不足，难以真实描述复杂作物种植条件下灌区生产力过程。基于此，本项目将以定量评估灌区水分生产力形成过程和其空间分布为目标，研究灌溉排水过程-土壤水盐与作物生长过程-地下水过程耦合方法，发展基于作物生长和水盐过程耦合的灌区水分生产力模型，探索灌区水分生产力对环境变化和农业节水的响应规律。本项目将重点解决干旱地下水浅埋灌区的土壤水盐过程和作物生长过程耦合模拟方法和复杂种植结构条件下灌区土壤水盐与地下水盐时空尺度耦合方法两个关键科学问题。本研究旨在回答“变化环境下如何准确量化干旱地下水浅埋区灌区水分生产力形成过程？”这一科学问题，为变化环境下灌区农业水分生产力提升提供理论依据。

Crop model and irrigated area water cycle model are essential methods to quantify the forming processes of water productivity. Most of the current regional water cycle models have not fully considered the contribution of shallow groundwater to the hydrological process and the groundwater lateral exchange process, which means that the movement of unsaturated soil water and groundwater are not really coupled. Additionally, it is ignored in most of the regional hydrological models to accuratedly extract the cropping patterns, which results in the difficulty in truly describing the water productivity for the irrigated area with complex cropping patterns. The objective of this study is to quantify the driving mechnism of irrigated area water productivity and its spatial distribution. Considering the processes of irrigation and drainage, soil water and salt processes, crop growth process and groundwater process, a regional water productivity model coupling muti-processes for irrigated area with shallow groundwater and complex cropping patterns is developed. Based on that, the response regulation of regional irrigated water productivity to chaning environment factors and agricultural water saving are studied. This study will focus on two key scientific problems including the coupling method of crop growth and soil water-salt processes, and the coupling method of water-salt movement in unsaturated soil profile and groundwater in arid irrigated area with shallow groundwater and complex cropping pattern conditions. Besides, this study aims to be able to answer the scientific question that how accurately quantify the different processes in forming the regional water productivity for irrigated areas in arid regions with shallow groundwater and complex cropping patterns under changing environments. The investigation results will provide theoretical principle for improving regional agricultural water productivity under chaninging environements.