基于SWAT模型的三峡库区大宁河流域产流产沙模拟及土壤侵蚀研究

发布时间：2018-09-03 13:42

【摘要】：为研究三峡库区大宁河流域土壤侵蚀的状况和特点,应用SWAT模型对大宁河流域进行了产流产沙模拟,并基于SWATCUP工具中的SUFI-2方法对模型进行了参数敏感性分析、校正、验证和不确定性分析(2008—2010年为校正期,2011—2013年为验证期),进而分析了流域内土壤侵蚀状况和不同土地利用、土壤类型和坡度对土壤侵蚀的影响,并提出了土壤流失超标区域防治措施。结果表明:(1)校正后的SWAT模型在大宁河流域产流模拟中,校正期和验证期的p-factor值分别为0.89和0.75,r-factor值分别为0.75和0.69,R~2分别为0.92和0.91,NS分别为0.87和0.91;在产沙模拟中,校正期和验证期的p-factor值分别为0.90和0.95,r-factor值分别为1.04和1.05,R~2分别为0.77和0.75,NS分别为0.74和0.72。构建的SWAT模型适合大宁河流域产流产沙模拟和土壤侵蚀状况研究,且不确定性满足要求。(2)整个大宁河流域2008—2013年的平均侵蚀模数为468.88t/(km~2·a),总体土壤侵蚀强度属于微度,但在局部子流域(1,2,3,4,22)的土壤侵蚀强度属于轻度,超过了流域土壤流失容许量500t/(km~2·a),其面积占整个流域的37.44%。(3)导致轻度土壤侵蚀区域土壤流失超标的因子包括土地利用类型中的耕地和草地、土壤类型中的深色淋溶土和饱和黏磐土以及坡度25°的耕地和草地,其中饱和黏磐土所占面积过多可能是导致轻度侵蚀区域土壤流失超标的最主要原因。建议在轻度土壤侵蚀区域,对饱和黏磐土、坡度25°的耕地和草地进行一定比例的退耕还林和退草还林。
[Abstract]:In order to study the status and characteristics of soil erosion in the Daning River basin of the three Gorges Reservoir area, SWAT model was used to simulate the runoff and sediment yield in the Daning River basin. The sensitivity of the model was analyzed and corrected based on the SUFI-2 method in the SWATCUP tool. Validation and uncertainty analysis (a correction period from 2008 to 2010 and a validation period from 2011 to 2013), and an analysis of the effects of different land use, soil types and slope levels on soil erosion in watersheds, The prevention and control measures of soil loss exceeding the standard were put forward. The results show that: (1) the corrected SWAT model is 0.89 and 0.75 and 0.69 r-factor in the simulation of Danning River basin runoff, respectively, and 0.87 and 0.91 in the sand production simulation, respectively, and 0.75 and 0.69 r-factor in the correction period and the verification period, respectively, and 0.87 and 0.91 respectively in the sand production simulation, and the results show that: (1) the corrected SWAT model is 0.87 and 0.91 respectively in the simulation of runoff production in the Daning River Basin. The p-factor values of correction period and verification period were 0.90 and 0.95 r-factor, respectively, 1.04 and 1.05 r-factor, 0.77 and 0.75 of NS, 0.74 and 0.72, respectively. The SWAT model is suitable for the simulation of runoff and sediment yield and soil erosion in Daning River Basin, and the uncertainty meets the requirements. (2) the average erosion modulus of the whole Daning River basin from 2008 to 2013 is 468.88t/ (the total soil erosion intensity of km~2 a), belongs to micro-degree). However, the soil erosion intensity in the local sub-watershed (1 ~ 2 ~ 2 ~ 3 ~ 3 ~ 3 ~ 4 ~ 4 ~ (-22) was mild. The soil loss tolerance 500t/ (km~2 a),) is more than 37.44% of the whole watershed. (3) the factors that lead to soil loss exceeding the standard in the mild soil erosion area include the cultivated land and grassland in the land use type. The dark leached soil and saturated clay rock soil in soil types, as well as farmland and grassland with a slope of 25 掳, may be the most important cause of soil loss exceeding the standard in mildly eroded areas, among which the excess area of saturated clay rock soil may be the most important cause. It is suggested that in the area of mild soil erosion, a certain proportion of cultivated land and grassland with a slope of 25 掳should be returned to forest and grassland.
【作者单位】：中国科学院生态环境研究中心环境水质学国家重点实验室;中丹科教中心;中国科学院大学;
【基金】：国家自然科学基金项目(21277169,51290283,21477158)
【分类号】：S157.1

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