面向农业灌区水资源的高效利用和区域生态环境保护，需要从流域整体出发，研究灌区水碳循环多环节和多尺度的水量能量转化过程，结合气候变化的预测和节水措施的效用，明晰变化环境下的水碳交互演化。本项目以西北旱区农业实验站多年观测数据为基础，研究在变化环境（如大气二氧化碳浓度增加、灌溉引起的地表温度变化）下， 西北灌区典型农作物（玉米、小麦）光合和呼吸作用对蒸发蒸腾量和碳循环变化的作用机理和模拟方法；提升陆面水文模型在灌区的应用精度，开展不同RCP情景和农业格局变化下灌区的水量能量过程演化模拟；研究非充分灌溉等节水调控下水量能量循环的响应机制，以及流域范围内与水相关生态指标（如地下水位和生态流量）的连锁效应。项目以北方典型农田水碳循环过程研究为突破口，在现有陆面水文模型中融入农业灌区水碳热通量传输机制，开展蕴含农业特色的生态水文系统模拟，从而为以流域整体为背景的农业与生态可持续发展提供科学依据。

Understanding the hydrological and ecological responses to both climate change and human activities, in irrigated agricultural area, is of great importance to agricultural water resources management and ecological environment conservations. An integrated approach over such basin is expected, including the studies on multi-process and multi-scale water and energy transitions, the impacts of climate evolution and water-saving measures, and the water-carbon actions under the changing climate. Based on long-term observations in the agricultural experiment station for a typical irrigated agricultural region in Northwest China, this research will (1) study the responses of evapotranspiration and carbon cycle, for the typical crop types (i.e., Maize and Wheat), to the elevated carbon dioxide and the irrigation-induced temperature changes, by examing the photosynthesis and respiration processes; (2) improve the performance of terrestiral hydrolgoical model in agrcultural lands, and model the water and energy evolutions under different Representative Concentration Pathways (RCPs) and irrigation patterns; (3) study the water and energy changes under deficit irrigations, and the chain-reacting on groundwater level and downstream ecological flow. This proposal is aimed at multi-scale water-carbon cycle modelling under the changing climate, where the agricultural lands play an important role in the changing cycles due to climate change and irrigation interference. The scientific goal is to better understand how to incorporate the transformation mechanisms of water-carbon cycle in agricultural lands into regional hydrological model, develop the systematical modele characterized by agricultural aspects, and how to simulate these processes in a changing environments. The methodological goal is to provide scientific basis for the sustainable development of regional agriculture and ecosystem in the context of the basin-scale water-carbon cycles.