华北平原的水土资源平衡研究

Balance between land use and water resources in the North China Plain

采用精确的水土资源平衡计算模型 ,辅以田间观测资料 ,分析计算了华北平原农业水资源量与作物需水量之间的平衡问题。结果显示 :在充分供水的条件下 ,本区农田 (884.8万hm2)需水量为744.36亿m3,相应的作物亏水量为309.37亿m3,有效灌溉面积 (653.2万hm2)上的亏水量为228.73亿m3;而1995年水利工程提供的农业总用水量已达261.78亿m3,但仍有116.16亿m3的亏水量 ;文中同时对评价区内农田的有效降水量、灌溉水的田间利用量、毛管上升水量等进行估算。指出 ,虽然冬小麦的平均水分满足率为82 % ,但关键期的水分满足率 (64 % )仍然制约粮食产量的增长 ,设想通过提高渠系利用系数和优化灌溉等措施 。

Researches on the balance between land use and water resources in the North China Plain have been done recently with an accurate soil water balance model,which take the land use and the precipitation on it into account along with comparisons of the water demand and deficits of different crops.Results show that water demand for all crops on the farmland(8848 thousand ha)is 74 436 billion m3,the corresponding water deficits is 30 937 billion m3;in the irrigated area(6532 thousand ha),the water deficits is 22.873 billion m3.However,the water supply system provided 26.178 billion m3 of water for agriculture in 1995,because of the lower effective utilization,the irrigated area still had 11.616 billion m3 of water deficits.The effective precipitation and irrigation on the plain are evaluated.Observed data show that although there is 82% of water supply for the growth period of winter wheat,key phase water supply(64%)restricts the grain production.To keep the supply water meeting the demand measures of raising water efficiency and optimizing irrigation are recom mended.