CAJ | 학술논문

小流域土壤侵蚀量和养分损失量的定量研究可为南水北调水源区的生态保护、水土保持和生态补偿提供重要的依据.该文在地理信息技术(geographic information system,GIS)的支持下,应用修正通用土壤流失方程(revised universal soil loss equation,RUSLE)估算了丹江鹦鹉沟流域的土壤侵蚀量和养分损失量,并进行了土壤侵蚀强度分级.结果表明,流域的年均土壤侵蚀模数为3140 t/km2,侵蚀强度为中度.其中强度侵蚀以上的土地面积占流域总面积的24.1%,侵蚀量为4573.0 t,却占年侵蚀总量的84.8%,其主要是坡度较大的坡耕地,是流域需要重点治理的区域.不同土地利用类型的土壤侵蚀量差异较大,林地、草地和农地的年均土壤侵蚀模数分别为509.7、1511.8和4606.5 t/km2.林草地年侵蚀量较小,农地土壤侵蚀量占流域总侵蚀量的95.3%.坡度每增加5°,不同土地利用的土壤侵蚀模数增加量比坡长每增加5 m的增加量要大1~2倍.研究区表土流失造成的全氮、全磷和有机质损失量分别为3.81、3.52和101.45 t,其中农地的养分损失量最为严重.流域泥沙中全氮、全磷和有机质的年均流失模数分别为1.01、0.75和38.43 t/(km2×a).该研究可为水源区水土流失和非点源污染治理以及清洁小流域建设提供科学依据.
소류역토양침식량화양분손실량적정량연구가위남수북조수원구적생태보호、수토보지화생태보상제공중요적의거.해문재지리신식기술(geographic information system,GIS)적지지하,응용수정통용토양류실방정(revised universal soil loss equation,RUSLE)고산료단강앵무구류역적토양침식량화양분손실량,병진행료토양침식강도분급.결과표명,류역적년균토양침식모수위3140 t/km2,침식강도위중도.기중강도침식이상적토지면적점류역총면적적24.1%,침식량위4573.0 t,각점년침식총량적84.8%,기주요시파도교대적파경지,시류역수요중점치리적구역.불동토지이용류형적토양침식량차이교대,임지、초지화농지적년균토양침식모수분별위509.7、1511.8화4606.5 t/km2.림초지년침식량교소,농지토양침식량점류역총침식량적95.3%.파도매증가5°,불동토지이용적토양침식모수증가량비파장매증가5 m적증가량요대1~2배.연구구표토류실조성적전담、전린화유궤질손실량분별위3.81、3.52화101.45 t,기중농지적양분손실량최위엄중.류역니사중전담、전린화유궤질적년균류실모수분별위1.01、0.75화38.43 t/(km2×a).해연구가위수원구수토류실화비점원오염치리이급청길소류역건설제공과학의거.
The quantitative study of soil erosion and nutrient loss in a small watershed can provide an important basis for ecological protection, soil, and water conservation, and ecological compensation in the water source areas of the South to North Water Diversion Project. Revised universal soil loss equation (RUSLE) was used to estimate the soil erosion and nutrient loss supported by the geographic information system (GIS) in the Yingwugou watershed;however, the soil erosion intensity of the study area was classified. The results indicated that the annual soil erosion modulus in the Yingwugou watershed was 3140 t/km2. This falls in the category of moderate degree erosion. The area above high soil erosion intensity only accounted for 24.1%but the soil erosion amount was 4573.0 t, which accounted for 84.8%of the annual soil erosion amount. The high soil erosion area was mainly distributed in sloping cropland with big slopes, which was the key management area. Soil erosion amounts under different land-use types showed great differences. The annual soil erosion moduluses of forestland, grassland, and cropland were 509.7, 1511.8, and 4606.5 t/km2, respectively. The annual soil erosion amount of forestland and grassland was relatively small and the annual soil erosion amount of cropland accounted for 95.3%of the total soil erosion amount in the study area. For each additional 5°slope, the increased soil erosion modulus of different land uses was 1 to 2 times greater than that of each additional 5m for slope length. The annual loss amount of total nitrogen, total phosphorus, and organic matter in topsoil was 3.81, 3.52, and 101.45 t, respectively. The nutrient loss of cropland was serious. The annual loss moduluses of total nitrogen, total phosphorus, and organic matter with sediment were 1.01, 0.75, and 38.43 t/(km2×a), respectively. The study could provide a scientific basis for the control of soil erosion and water loss, non-point source pollution, and the construction of clean, small watersheds in the water source area.