华北地区粮食生产与水供应情势分析

Crop yield and water supply in North China

华北地区是我国重要的粮食生产基地 ,其粮食产量在全国粮食总产中的比重由1949年的22%上升到1998年的29.6%。灌溉是保证该区粮食高产稳产的重要保证。华北地区目前用水处于严重紧张状态 ,1997年人均综合用水量为315m3,农业是用水大户 ,工农业用水比为1∶5 ,水资源供需的主要矛盾在农业。华北地区水资源利用率高达98.5% ,整体供水潜力所剩无几 ;随着工业和城镇的发展 ,农业用水分额将继续减少 ;同时 ,受频繁的旱涝灾害、日益严重的水污染和大面积的地下水位下降的影响 ,农业供水保证率将进一步降低。分析指出 ,若无连续丰水年和外调水源的补给 ,要继续保证或发展本区的粮食生产规模 ,本区的农业用水情势有恶化之势 ,急需研究并制定出解决本区粮食生产和水资源供给不足矛盾的办法。

North China is one of the most important grain production bases of the country and plays an important role in the national food security.The present population,cultivated land and crop production all have exceeded 1/4 of the national total.The crop yield accounts for 22% of the national total crop yield in 1949 and 29.6% of that in 1998.Irrigation serves as an essential guarantee to obtain high stable crop yield in the region because the distribution of water resources is inconsistent with the regional arable land,light and heat. The water resources in North China are characterized by water shortage per capita and per unit arable land as well,uneven distribution in space and in time,and stable ground water resources.The status of water use in North China is quite serious,per capita water use amount is 315 m3 in 1997.Agriculture is the main water consumer,and the water consumption in agriculture is 5 times as much as that in industry.The conflict between water supply and demand in agriculture is becoming more and more severe.While the future water supply for agriculture will be quite unpleasant both in quantity and quality.First,there is no much water supply potential left since the water resources exploitation rate is 98.5%. Second,the agriculture water supply quota is going to decrease in the process of industrialization and urbanization in North China.Third,the water supply guarantee will be lowered resulted from frequent drought and flood,severe water pollution and extensive groundwater level decline.The water supply for agriculture can not meet the water demand to maintain and raise the crop yield in North China if there is no successive high flow years or no new water sources.Therefore,it is urgent to make a set of feasible measures in order to solve the conflict between crop production and water shortage.