陕北黄土高原多沙粗沙区乡村聚落土壤水蚀定位观测研究

为研究乡村聚落的土壤侵蚀,在陕北榆林、绥德、延安建立观测站,于2003年对乡村聚落中的户间道路、户间空地、院落在降雨时的次径流泥沙含量、平均含沙量、次侵蚀强度及观测期降雨形成的总侵蚀强度,进行了观测与分析。其观测结果,均说明户间道路、户间空地径流平均含沙量较大,榆林为29.37g/L、29.96g/L,缓德为21.06g/L、17.53g/L、延安为54.6g/L2、9.18g/L,而院落平均径流含沙量较小,榆林、绥德、延安分别为9.47g/L、8.64g/L、14.87g/L。观测期降雨侵蚀总强度,三个观测站均以户间道路最大,分别为1142t/km2、2156.6t/km26、285.7t/km2;户间空地次之,分别为744.5t/km2、1192.6t/km2、1953.2t/km2;院落较小,分别为161.1t/km23、78.7t/km2、1274.3t/km2。说明乡村聚落土壤侵蚀不可忽视,应加强防治。

Field Survey and Analysis on Soil Erosion of the Rural Settlements in Coarse Sediment Region of Loess Platean of Northern Shaanxi Province

After setting three observation stations in Yulin,Suide and Yanan respectively,this research observes the soil erosion of rural settlements formed by rainfalls from Jul 22 to Oct 13,2003. The paper also analyses the runoff sand amount per rainfall,average runoff sand amount,per rainfall amount and total erosion intensity by all the rainfalls on the roads and open space between houses and the settlement yards.The results of the observations show that the average sand runoff amount of roads and open space between houses is greater,that is,the amount is 29.37g/L and 29.96g/L in Yulin,21.06g/L and 17.53g/L is Suide,54.6g/L and 29.18g/L in Yanan.But the average sand runoff amount of settlement yard is little,that is,the amount of Yulin,Suide and Yanan are 9.47g/L,8.64g/L and 14.87g/L respectively.The total erosion intensity by all the rainfalls in the observation period is greater in the roads between houses(1142/km~(2)in Yulin,2156.6t/km~(2)in Suide and 6285.7t/km~(2)in Yanan),middle in the open space(744.5t/km~(2)in Yulin,1192.6t/km~(2)in Suide and 1953.2t/km~(2)in Yanan),little in the settlement yards(161.1t/km~(2)in Yulin,378.7t/km~(2)in Suide and 1274.3t/km~(2)in Yanan).It is concluded that soil erosion of rural settlements can not be ignored and must be paid attention to its prevention.