一、概况宁夏引黄灌区位于黄河上游下段的干旱区,年降水量不足200毫米,年水面蒸发量高达1200毫米.灌区有主要干渠14条,总长1400公里,设计引水能力744秒立方米,已砌护245公里(完好率约50%,下同),占总长度的18%,其中全断面砌护的有51公里,仅占总长度的3.6%,其余仅是护坡、护半坡,主要是防险.灌区有支、斗渠2959 I. Overview Ningxia Yellow River Irrigation Area is located in the lower reaches of the Yellow River in the arid zone, the annual rainfall of less than 200 mm, annual water evaporation as high as 1200 mm Irrigation area has 14 main trunk, a total length of 1400 km, the design of water diversion capacity of 744 seconds cubic meters, has Lying 245 km (good rate of about 50%, the same below), accounting for 18% of the total length, of which full-section Zhuanwu 51 km, accounting for only 3.6% of the total length, the rest is only slope protection, Ban Banpo, the main Is a security. Irrigation area has a branch, fighting canal 2959