【摘要】 通过对宁夏南部山区黄土高原王洼流域降雨量、蒸发量及不同土地利用模式下径流小区坡面多年土壤侵蚀特征进行分析.结果表明:宁夏南部山区黄土高原王洼流域蒸发量是降雨量的3.2倍,蒸发量的峰值出现在6月份.降雨侵蚀力和降雨量的季节分布明显为单峰形.月降雨侵蚀力和降雨量所占比例季节分布不一致.不同土地利用方式、不同坡度下土壤侵蚀特征各不相同.各种土地利用方式下,均表现为随坡面坡度的增加,径流量、径流系数、侵蚀模数逐渐增加.林作方式下有较低的径流量和泥沙量,仅为相同坡度下农田和自然荒坡地的24.99%~46.56%,16.08%~49.0%.复合农业措施比单一农作更有利于降低坡面土壤侵蚀.宁夏南部山区黄土高原植被的截流、地面植被的覆盖以及土地耕作方式是影响土壤侵蚀的主要因素.不同土地利用方式下,土壤侵蚀峰值多出现在8月份,8月份径流量可占到全年径流量的19%~40%,和降雨量及降雨侵蚀力的分布相一致.4种利用方式各月的土壤侵蚀模数变异都较大,改变土地利用方式会明显改变土壤侵蚀状况.合理的农业布局及农业配置方式是控制土壤侵蚀的主要途径.更多还原

【Abstract】 The rainfall,the evaporation and the characteristics of soil erosion on the sloping land under different land uses were analyzed on the Wangwa watershed in the loess plateau of south Ningxia.The results showed that the amount of evaporation was more than 3.2 times the rainfall of the Wangwa watershed in the loess plateau of south Ningxia.The amount of evaporation also had a peak value in June.The seasonal distribution of erosivity of rainfall(R factor) and rainfall obviously had a single peak value.The proportion of R factor was not consistent with the proportion of rainfall per month.The characteristic of soil erosion in the slope was not homogenous with different gradient and land use manner.Runoff index and sediments gradually increased with all kinds of land use,when the slope gradient was increased.There was the lowest runoff and least sediments under the condition of forest land use,which was only about 24.99 to 46.56%,16.08 to 49.0% of the amount of runoff and sediments on the farmland and natural sloping field at the same gradient.Complex farming measures can effectively reducee the soil erosion of the farming slope more than single use farming.The greatest effect factor of soil erosion was(the field cultivation) manner、the overlay and the holding up of the vegetation in the loess plateau.The peak value of soil erosion appeared in August every year under the different land uses.The amounts of runoff in August accounted for 19% to 40% of the whole year’s runoff.The change in runoff was the same with the rainfall and R factor.The variance of soil erosion module per month was obviously different for four kinds of land use.The amount of soil erosion was also clearly changed when the land use manner was changed.The reasonable distribution and the configuration manner of agriculture would be the best approach to controlling soil erosion in the loess plateau of south Ningxia.更多还原