退耕还林前后北洛河上游流域土壤侵蚀时空变化分析  

Spatial and Temporal Changes of Soil Erosion in the Upper Reaches of Beiluo River Watershed Before and After the Grain for Green Project

作　　者：陈浩 张晓萍 权伟 郭晋伟 袁阅 张思瑞 CHEN Hao;ZHANG Xiaoping;QUAN Wei;GUO Jinwei;YUAN Yue;ZHANG Sirui(College of Life Science,Yan’an University,Yan’an 716000,China;Shaanxi Engineering and Technological Research Center for Conversation and Utilization of Regional Biological Resources,Yan’an 716000,China;State Key Laboratory of Soil Erosion and Dry Land Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China;Qianxian County Agricultural and Rural Bureau,Qianxian 713300,China)

机构地区：[1]延安大学生命科学学院,陕西延安716000 [2]陕西省区域生物资源保育与利用工程技术研究中心,陕西延安716000 [3]西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [4]乾县农业农村局,陕西乾县713300

出　　处：《人民黄河》2023年第6期111-116,127,共7页Yellow River

基　　金：国家自然科学基金资助项目(42107359);中国博士后科学基金资助项目(2022MD713800);延安市高层次人才专项(2019-16);延安大学科研计划项目(YDBK2019-63);延安大学大学生创新创业训练计划项目(D2021118);陕西省大学生创新创业训练计划项目(S202110719116)。

摘　　要：为揭示退耕还林前后北洛河上游流域土壤侵蚀时空变化特征,采用通用土壤流失方程RUSLE,结合GIS和RS技术,分析了北洛河上游流域退耕还林前后1981—2010年(分为1981—1990年、1991—2000年和2001—2010年3个时段,编号分别为Ⅰ、Ⅱ、Ⅲ)土壤侵蚀时空变化特征。结果表明:(1)北洛河上游流域土壤侵蚀模数在空间上呈现西北高、东南低的分异特征,1981—2010年在降雨侵蚀力呈现波动上升趋势的情况下,平均土壤侵蚀模数呈持续下降趋势,尤其退耕还林(草)工程实施以后土壤侵蚀模数显著下降,时段Ⅰ、时段Ⅱ、时段Ⅲ流域平均土壤侵蚀模数分别为8 612.62、8 078.91、3 060.71 t/(km^(2)·a);(2)实施退耕还林(草)工程以后,流域内耕地面积锐减,林草地面积显著增加、植被覆盖度大幅提升,主要土地利用类型土壤侵蚀模数遵循耕地>草地>林地的规律,即土壤侵蚀模数随着植被覆盖度的提高呈现下降趋势;(3)3个时段土壤侵蚀随地形的分布特征具有一致性,1 350~1 550 m是北洛河上游流域土壤侵蚀分布的主要高程带,其侵蚀量约占流域侵蚀总量的80%,流域内72%的侵蚀量分布在坡角>15°的坡面,各时段不同坡向的平均土壤侵蚀模数均遵循阳坡>半阳坡>半阴坡>阴坡的规律。In order to reveal spatial and temporal variation characteristics of soil erosion in the upper reaches of Beiluo River watershed before and after the Grain for Green Project,the author used the revised universal soil loss equation(RUSLE)combined with GIS and RS technic to analyze the dynamic changes characteristics of soil erosion in the upper reaches of Beiluo River watershed before and after the Grain for Green Project from 1981 to 2010.The period from 1981 to 2010 was divided into three periods(1981-1990,1991-2000 and 2001-2010),which were numbered as I,ⅡandⅢ,respectively.The results show that a)the spatial distribution of soil erosion intensity in the upper reaches of Beiluo River watershed is higher in the northwest and lower in the southeast.During 1981 to 2010,the average soil erosion modulus of the watershed shows a continuous decreasing trend,especially after the Grain for Green Project,the soil erosion modulus is decreased significantly while the rainfall erosivity of the watershed shows a fluctuating increasing trend.The average annual soil erosion modulus of time period I,time periodⅡand time periodⅢis 8612.62,8078.91 and 3060.71 t/(km^(2)·a),respectively.b)After the Grain for Green Project,the area of cultivated land in the watershed is decreased sharply,the area of woodland and grassland is increased significantly,and the vegetation coverage has increased greatly.The soil erosion modulus of main land use types follow the rule of cultivated land>grassland>woodland,that is,the soil erosion modulus is decreased with the increase of vegetation coverage.c)Soil erosion in the three periods is consistent with the distribution characteristics of the terrain.1350-1550 m is the main elevation zone of soil erosion distribution in the watershed,which accounts for about 80%of the total erosion amount in the watershed,and 72%of the erosion amount is distributed in the slope>15°.The average soil erosion modulus of different slope directions follow the pattern of sunny slope>half⁃sunny slope>half⁃shad

关 键 词：通用土壤流失方程 土壤侵蚀模数 退耕还林(草) 北洛河上游 

分 类 号：S157.1[农业科学—土壤学]