中文摘要：

诺思中国是中国的最重要的食物篮子，在小麦和玉米的多数被生产的地方。在诺思中国种的大多数庄稼被灌溉，因此浇安全食物安全。自从 1980 年代，弄干经常被观察了，在降水由减小出现在 riverflow 的截止，和湖的收缩。弄干的这增加不能被气候变化独自解释。我们建议在在最近的十年的这个区域的集中的陆地使用有重要影响。学习的目的是在诺思中国开发气候变化和陆地使用的并发的过程的一个量的模型，并且在观察弄干上估计各个的相对贡献。我们在模型的综合相关社会经济的数据，陆地使用数据，和气候数据，并且执行了详细 multitemporal (十年，年，白天) 分析。结果证明自从 1999，陆地使用极大地变化了。这个变化主要与被联系一极其重要把农田和放牧土地还给森林和草地的 1999 国家政策。我们发现了在 riverflow，流量，和土壤水分蒸发蒸腾损失总量上的气候变化和陆地使用政策之间的一个有趣的相互作用。在 1970 年代和 1980 年代期间，气候变化解释了超过 80% ，当陆地使用变化解释仅仅， 10% riverflow 变化时。相对贡献在 1980s-1990s 是 45 和 45% ， 35 和 55% 分别地为气候变化和陆地使用在 1990s-2000s 变化。因为 1990 年代陆地使用变化也贡献了更多到流量，比气候变化变化。相反的趋势被作出对有利的裁决在土壤水分蒸发蒸腾损失总量的变化。为在北中国的农业的水可获得性被广泛的变化同时在陆地使用和快速的气候变化强调。生态的原则的改编，例如到森林和草地的回来的 farmland/grazing 陆地，经济发展策略的政策，和另外的调整能是有效工具在北中国减轻水缺乏问题并且支持持续农业并且食物开发。

英文摘要：

North China is the most important food basket of China, where the majority of wheat and corn are produced. Most crops grown in North China are irrigated, thus water security is food security. Since the 1980s, drying has been frequently observed, as shown by a reduction in precipitation, cutoff in riverflow, and shrinkage of lakes. This increase in drying cannot be explained by climate change alone. We propose that intensive land-use in this area in recent decades has had a significant impact. The objectives of the study are to develop a quantitative model of the concurrent processes of climate change and land-use in North China, and to estimate the relative contributions of each on the observed drying. We integrated relevant socioeconomic data, land-use data, and climate data in the model, and carried out a detailed multi-temporal （decade, year, day） analysis. Results showed that land-use has greatly changed since 1999. This change is mainly associated with an extremely important 1999 national policy of ＂returning farmland and grazing land to forest and grassland＂. We found an interesting interaction between climate change and land use policy on riverflow, runoff, and evapotranspiration. During 1970s and 1980s, climate change explained more than 80%, while the land-use change explained only 10% of the riverflow change. The relative contributions were 45 and 45% in the 1980s-1990s and 35 and 55% in the 1990s-2000s respectively for climate change and land-use change. Since the 1990s land-use change has also contributed more to runoff change than climate change. The opposite trend was found for changes in evapotranspiration. Water availability for agriculture in northern China is simultaneously stressed by extensive changes in land-use and rapid climate change. Adaptation of ecological principles, such as the ＂returning farmland/grazing land to forest and grassland＂ policy, and other adjustments of economic developmental strategies can be effective tools to mitigate the water shortage problem in northern