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民勤湖区是石羊河终端湖盆退缩而发展成的内陆湖积盆地。西、北、东三面为巴旦吉林与腾格里沙漠包围。由于地形的半封闭,水、土含盐量高。长期以来干旱、盐碱、风沙三大灾害严重威胁着这一地区的农业生产。五十年代中期以前,湖区有耕地30万亩,石羊河下泻至该地的地表水年约2亿立米以上,净进地可达250—300立米/亩,能基本满足淋洗耕层盐份所需。长期延用冬季大定额饱灌安种水结合洗盐,作物生长期基本不灌溉的半旱农耕制,由于地下水位较高,也可获得一定
Minqin Lake area is the terminal lake basin shiyang retreat and developed into the lacustrine basin. West, North and East on three sides surrounded by Pakistan Dan Jilin and Tengger Desert. Due to the semi-closed terrain, water and soil have high salinity. For a long time, the three major disasters of aridity, saline-alkali and wind-blown sand have seriously threatened the agricultural production in this area. Before the mid-1950s, there were 300,000 mu of cultivated land in the lake area, and the surface water of the Shiyang River which dropped to the area was about 200 million cubic meters or above. The net advance could reach 250-300 cubic meters per mu, basically meeting the requirement of leaching topsoil Required. Long-term extension of the use of winter fixed-scale irrigation and water combined with salt washing, crop growth basically irrigated semi-dry farming system, due to the higher groundwater level, but also get a certain