The Relationship between the Distribution of IrrigatedCrops and the Supply Capability of Regional WaterResources in North China Plain
华北平原区域水资源特征与作物布局结构适应性研究

Integrated field survey shows that the total yield of foodstuff has been increased continuously in the past fifty years in North China plain, which has caused the increasing exploitation of groundwater; on the other hand, the saving level of the irrigation water in the farmland has also been continuously improved so as to alleviate the rate of increasing groundwater exploitation. The increase of every 10000t of wheat and corn yield had caused the increase of 14?106 m3 groundwater exploitation before 1977, but has resulted in the increase of 4?106 m3 groundwater exploitation since 1978. The exploitation averagely increased 2.45?108 m3/a every five years due to foodstuff increase according to the average intensity of exploiting groundwater (0.53 m3/kg) for irrigating farm-land from 2001 to 2005; in contrast, the exploitation averagely increased 9.45?108 m3/a every five years according to the average intensity of exploiting groundwater (3.11 m3/kg) from 1953 to 1970. The influence of the precipita-tion variation on regional groundwater is of an interactive mechanism. If the annual precipitation decreases or in-creases 10%, the water quantity of the regional groundwater system correspondingly decreases 7.98 % or increases 7.67%, and the groundwater level falls or rises correspondingly. Therefore, the important measure for relaxing the status of excessive exploitation of groundwater in the North China plain lies in the energetic development of drought-enduring, and water-saving crops and the regulation of agricultural planting structure in a reasonable way.