长江流域灌溉工程老化损坏状况及其改造措施

Ageing/damage of irrigation works in the Yangtze Valley and their reform measures

长江流域灌溉面积占全国３０％，粮食产量占全国３８％，其中水稻占全国２／３。灌溉面积上生产粮食占８０％。而８０年代以后有效灌溉面积一直维持在１４４４万公顷左右，处于徘徊状态，其中原因之一是灌区工程老损严重。据全流域５４个大型灌区统计，工程完好率约６３．１％，又据３４个大型灌区老损调查与评价，被划为Ⅰ类老化的１１个，Ⅱ类老化的１２个，Ⅲ类老化的９个，Ⅳ类老化的２个。面对这种严峻局面，必须对老化工程进行更新改造，为２０００年全国达到小康水平提供丰富的农产品。

The irrigated area in Yangtze river basin amounts to 30% of china's total area,and the grain yield amounts to 38% of China's total with its paddy being two thirds of China's total.The grain produced in irrigated area in the basin amounts to 80% of the basin total.After 1980's the effective irrigated area always maintains a level of some 14.44 Mha,in a fluctuating state.One of the reasons for this is that the irrigation projects are seriously aging and damaged. According to statistics of 54 large irrigation districts in the whole basin,the rate of the projects in good condition is 63.1 %.Also according to investigations and assessments of 34 large irrigation districts,aging projects when classified as gradeⅠ,Ⅱ,Ⅲand Ⅳ are 11, 12,9 and 2 in numbers respectively. Faced with such a serious situation,it is necessary to renew or reform the aging projects to provide abundant agricultural products by the year 2000 in order to make China reach a level of comparative well-off.