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(一) 内蒙古自治区土地辽阔,自然条件复杂,地域类型差异很大,冬季寒冷期长、夏季温凉短促,降水量由东向西递减,高者达400～500mm,少者仅50～100mm,属干旱半干旱地区。这里的农牧林业生产长期处于低而不稳状态,加之历史上广种薄收,自然放牧,导致土地沙化、草场退化,水土流失相当严重。 据70年代统计,全区以水蚀为主的水土流失面积18.6万km~2,占总面积的15.3％。全区100旗(县)中就有60个水土流失旗(县),水土流失区人口1000多万、耕地5000万亩,约占自治区总人口、总耕地面积的一半以上。水土流失地区主要分布在黄河、辽河流域,其次是海滦河、内陆河及嫩江右岸。年土壤侵蚀模数10000t/km~2左右,最高达22000t/km~2。每年仅向黄河、辽河输沙2.8亿吨,境内皇甫川、窟野河、柳河是黄河、辽河粗沙的主要来源地。 长期以来,严重的水土流失,给农牧业生产带来很大威胁,已成为自治区经济腾飞的主要障碍之一。全区38个贫困旗(县)中有34个是水土流失旗(县)。治理水土流失已显得尤其必要和紧迫。
(1) Inner Mongolia Autonomous Region has vast land with complicated natural conditions and great geographical differences. The winter cold period is long and the summer is cool and short. The precipitation decreases from east to west, with the highest reaching 400-500 mm and the less being only 50-100 mm. Is arid and semi-arid areas. The production of agriculture, animal husbandry and forestry here has long been in a low and unsteady state. In addition, the history of extensive harvesting and natural grazing has led to the desertification of land and the degradation of grasslands, and the soil and water loss is quite serious. According to the statistics of the 1970s, the water and soil loss mainly caused by water erosion was 186,000 km2, accounting for 15.3% of the total area. There are 60 soil and water loss flags (counties) in 100 banners (counties) in the whole region, with a population of more than 10 million and a cultivated area of 50 million mu, accounting for more than half of the total population in the autonomous region and the total cultivated area. Soil erosion areas are mainly distributed in the Yellow River, Liaohe River Basin, followed by the sea Luanhe, inland rivers and Nenjiang right bank. Annual soil erosion modulus of 10000t / km ~ 2, up to 22000t / km ~ 2. Only 280 million tons of sediment are transported to the Yellow River and Liao River each year. Huangfu River, Kuye River and Liuhe River are the main sources of coarse sand in the Yellow River and Liaohe River. For a long time, severe soil and water loss has brought great threat to the production of agriculture and animal husbandry and has become one of the major obstacles to economic development in the autonomous region. Among the 38 poverty-stricken banners (counties) in the region, 34 are soil and water loss flags (counties). Soil erosion has become particularly necessary and urgent.