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一、自然概况宁夏位于祖国西北边疆,自然地形大体分北部黄河冲积平原与南部山丘区两部,北部黄河冲积平原为引黄灌区,海拔1090～1300米,除贺兰山麓及山前洪积扇外,其余地势平坦,引水便利,为我区主要农业区,并有“塞上江南”之称.南部山区为黄土高原,海拔1300～2200米,地形起伏,沟壑发育,水土流失严重,黄河主要支流有清水河、祖历河、葫芦河、泾河.宁夏属大陆性气候,干旱少雨,风大沙多,但区内有明显差异,南部山区的固原以南属中温带半湿润区,多年平均降水600～800毫米,年蒸发量为1000～1200毫米,固原以北属中温带半干旱区,多年降水400～550毫米,年蒸发量1150～1600毫米,北部引黄灌区属中温带干旱区,多年平均降水180～200毫米,年蒸发1400～1600毫米,降水在时间和地区上分布不均,变率大保证率低,是山区干旱频繁的重要因素;在雨季又常以暴雨形式降落,易造成水土流失和山洪危害.
First, the natural overview Ningxia is located in the northwestern frontier of the motherland, the natural terrain generally divided into the northern Yellow River alluvial plain and southern hills two, the Yellow River alluvial plain in the northern Yellow River Irrigation District, 1090 ~ 1300 meters above sea level, in addition to Helan foothills and piedmont alluvial Fan, the rest of the flat, water diversion convenience, as my main agricultural areas, and “plug on the south.” The southern mountainous area is the Loess Plateau, 1300 ~ 2200 meters above sea level, undulating terrain, gully development, serious soil erosion, the Yellow River The main tributaries are Qingshuihe, Zulihe, Huluhe and Jinghe.Ningxia is a continental climate with aridity and windy, but there are significant differences in the area. The south of Guyuan in the southern mountainous area belongs to the temperate semi-humid zone, The annual average precipitation is 600-800 mm and the annual evaporation is 1000-1200 mm. The north of Guyuan belongs to the temperate semi-arid area, with annual precipitation of 400-550 mm and annual evaporation of 1150-1600 mm. The average annual rainfall is 180-200 mm and the annual evaporation is 1400-1600 mm. Precipitation is unevenly distributed both in time and in the area and the rate of change is large and the guarantee rate is low, which is an important factor of frequent mountainous droughts. In rainy season, it often falls in the form of heavy rain Easy to cause Soil erosion and flash floods hazards.