基于SWAT模型的不同土地利用结构对流域水沙的影响  

Effects of varied land use structures on runoff-sediment yield based on SWAT model

作　　者：朱楠[1] 马超[1,2] 王云琦[1,2] 张会兰[1,2] 朱锦奇[1] 

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]北京林业大学北京市水土保持工程技术研究中心,北京100083

出　　处：《中国水土保持科学》2016年第4期105-112,共8页Science of Soil and Water Conservation

基　　金：青年教师科学研究中长期项目"土壤侵蚀过程与机理"(2015ZCQ-SB-01)

摘　　要：为明确不同土地利用结构对流域产流产沙及其过程的影响,以黄土高原沟壑区典型小流域罗玉沟流域为例,基于1986—2000年气象资料,以该流域4种主要土地利用类型及调整后的土地利用结构为假设情景,通过SWAT模型模拟探讨土地利用结构对流域水沙的影响。结果表明:1)与1995年土地利用结构下的产流产沙量相比,极端情景下,林地和梯田可分别减少径流56.86%、11.97%,减少泥沙达80%以上;2)林地集中分布较分散分布的水沙量最大可分别减少4%、27%左右,但集中程度可能存在一个阈值,大于该阈值后流域产流产沙量无太大变化;3)相同面积比例的土地利用类型在流域中分布位置不同,流域出口的产沙量也较1995年有不同程度减少,最大可减少26.79%,产流量无明显差异,但流域内部产流产沙过程有所不同,林地分布在上游时,流域上中游的水沙量最低。因此,调整流域土地利用结构时可适当提高林地集中程度;重视流域上游尤其是源头的土地利用结构优化,在流域产流产沙源头可采取减水减沙效果更好的植被措施,梯田等受人类活动影响的措施尽量布设在流域中下游。[Background] An unreasonable land use structure causes severe soil erosion and increases runoff-sediment yield or even major environment problems,especially brings huge negative effects on ecologically fragile arid and semiarid area. The objectives of this study were to model the effects of the changes of land use structure on reducing runoff-sediment yield in the Luoyugou watershed,a typical case of gully region of the Loess Plateau. [Methods]The Soil and Water Assessment Tool（ SWAT） was used to model daily runoff and sediment data from this basin collected from 1986 to 2000. First,the model was used to determine acceptable values of the P-factor,R-factor,coefficient of determination（ R2）,and the Nash-Sutcliffe coefficient（ Ens） during both the calibration and validation periods. Then,the model was used to determine which kind of major land use in Luoyugou watershed can be chosen with the least runoff and sediment yield. Next,the land use structure of Luoyugou Watershed were adjusted to six types,and the model was used to simulate the six scenarios with 1986—2000 meteorological data of this basin.[Results]1） Compared with those in 1995,the effect on reducing runoff and sediment yield of forest and terraced fields were better than the grassland and slope farmlands. Under extreme scenario simulation,runoff under forest and terraced fields decreased about 56. 86% and 11. 97% respectively,while the sediment decreased about 80% of corresponding runoff-sediment yield in 1995. 2） The runoffsediment yield was influenced by the concentration of forest land. Compared with the low concentration of forest,runoff amount and sediment under high concentrated forest decreased at most of 4% and 27%respectively. However,there was probably a threshold of concentration,and if the concentration degree was greater than the threshold value,the watershed runoff-sediment yield was almost invariable,but it remains to be further validated. 3） The runoff and sediment yield under various land use types with the same area

关 键 词：SWAT模型 土地利用 林地 产流量 产沙量 

分 类 号：S157.1[农业科学—土壤学]