三峡库区小流域修正通用土壤流失方程适用性分析  

Adaptability analysis on revised universal soil loss equation in small catchment of Three Gorges Reservoir Region

作　　者：俱战省[1,2] 文安邦[1] 严冬春[1] 史忠林[1] 王彬俨[1,2] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所/山地表生过程与生态调控重点实验室,成都610041 [2]中国科学院大学,北京100049

出　　处：《农业工程学报》2015年第5期121-131,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：中国科学院西部行动计划项目(KZCX2-XB3-09);国家科技支撑计划项目(2011BAD31B03);国家自然科学基金青年基金项目(41201275);西部之光“西部博士”项目

摘　　要：土壤侵蚀量的定量研究可为国家生态环境建设和水土保持宏观决策的制定提供重要的依据。修正通用土壤流失方程(revised universal soil loss equation,RUSLE)是开展土壤侵蚀定量评价的主要手段。该文在地理信息系统(geographic information system,GIS)的支持下,依据中国土壤流失方程各因子的算法确定RUSLE模型各因子值,估算了三峡库区黄冲子小流域不同时期的土壤侵蚀量,并与基于泥沙平衡原理计算的土壤侵蚀量比较后分析RUSLE模型在库区小流域的适用性。结果表明,基于RUSLE模型估算的小流域1963-2000年(农地小流域)和2001-2014年(林地小流域)的年均土壤侵蚀模数分别为2246.09和868.3 t/(km2·a),其结果与采用137Cs和210Pb技术的塘库沉积物定年结果基本吻合,表明210Pb定年结果可靠。依据泥沙平衡原理计算的小流域1963-2000年和2001-2014年的年均土壤侵蚀模数分别为942.48和811.47t/(km2·a)。RUSLE模型估算小流域1963-2000年和2001-2014年的土壤侵蚀模数相对误差分别为138.32%和7.00%。因此RUSLE模型适用于库区林地小流域,而不适用于库区农地小流域;但是基于地形因子(LS因子)修正的RUSLE模型估算结果相对误差减少至8.14%,其适用于库区农地小流域。Soil erosion by water is a serious problem in southwestern China, particularly in the Three Gorges Reservoir Region （TGRR）, which is one of the regions prone to desertification. Soil erosion in the TGRR not only affects soil quality, in terms of agricultural productivity, but also reduces the capacity of flood storage and the projected life span of the Three Gorges Reservoir. The revised universal soil loss equation （RUSLE） has been widely deployed to quantitatively assess soil erosion by water from a small catchment based on a grid cell basis. This study was conducted on the Huangchongzi small catchment in TGRR, to predict different periods’ annual soil erosion modulus using the RUSLE model, and to analyze its adaptability with the help of a sediment budget approach. According to the study area data and the calculation methods for each factor of the Chinese soil loss equation applied in the first national water conservation survey, each factor value of RUSLE was determined. The results from the RUSLE model indicated that the annual soil erosion modulus for 1963-2000 （agricultural catchment） and 2001-2014 year （forested catchment） in the Huangchongzi small catchment was 2246.09 and 868.30 t /（km2·a）, respectively. The latter was obviously smaller than the former due to the implementation of the Grain-to-Green project, converting slope croplands into forest or grassland. The sediment yields for the 1963-2000 and the 2001-2014 years in the study catchment were 1228.71 and 322.71 t, respectively when 137Cs and210Pb dating methods had been used as chronometers for sediment deposition in the pond. More importantly,210Pb-derived dates corresponded well with the results from137Cs geochronology for pond sediment cores, and this indicated that the dating result by210Pb technology was correct and reliable. The annual sedimentation amount in the paddy fields was estimated to be 27.11t/a on the basis of the137Cs tracer method. Therefore, the sediment deposition amount for the 1963-2000 and the 2001-201

关 键 词：土壤 侵蚀 地理信息系统 模型 CS 修正通用土壤流失方程 三峡库区 

分 类 号：S124.2[农业科学—农业基础科学] S157