一、前言徐州市位于江苏西北部,沂、沭、泗流域中下游,不仅洪涝矛盾突出,干旱缺水也十分严重。特别是南四湖西三千余平方公里面积,地面水更为缺乏,地下水也不丰富,多年平均降雨量不足800毫米,时空分布又极不均,严重影响了农业生产的发展。建国以后,水利建设有了很大的发展,初步改变了生产条件。但由于水源不足,干旱缺水的矛盾长期没能得到解决。近年来,机井灌溉的发展及梯级河网的逐步实施,为开采地下水、拦蓄地面水、充分利用本地水资源创造了条件。随着南水北调的逐步实现,灌溉水源不足的局面将得到根本改变。但是如何合理开采地下水、利用地面水和回归水、引用 I. Introduction Xuzhou City is located in the northwestern part of Jiangsu Province, the middle and lower reaches of the Yishu, Shu and Si basins, not only highlighting the contradictions of floods but also suffering from severe drought and water shortage. In particular, there are more than 3,000 square kilometers of land in Nansihu Lake. There is a lack of surface water and groundwater, mean annual rainfall is less than 800 millimeters. There are also extremely uneven distributions in time and space, seriously affecting the development of agricultural production. After the founding of the PRC, water conservancy construction has made great progress, initially changing the production conditions. However, due to the shortage of water resources, the contradiction between drought and water shortage has not been solved for a long time. In recent years, the development of well irrigation and the progressive implementation of cascaded river networks have created the conditions for exploitation of groundwater, interception of surface water and full utilization of local water resources. With the gradual realization of the South-to-North Water Diversion Project, the situation of insufficient irrigation water resources will be fundamentally changed. However, how to reasonably exploit groundwater, make use of surface water and return water, and quote it