气候、地表覆被变化对砒砂岩区风蚀时空变化的影响  

Influence of Climate and Surface Cover Changes on Spatiotemporal Changes of Wind Erosion in Pisha Sandstone Area

作　　者：杜睿哲 李文栋 高文浩 付金霞[1] 齐雁冰[1] 李志[1] DU Ruizhe;LI Wendong;GAO Wenhao;FU Jinxia;QI Yanbing;LI Zhi(College of Natural Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学资源环境学院,杨凌712100

出　　处：《水土保持研究》2023年第5期31-40,共10页Research of Soil and Water Conservation

基　　金：国家重点研发计划项目课题(2022YFF1300805);国家自然科学基金项目(U2243210,41807070)。

摘　　要：[目的]揭示气候、地表覆被变化对黄土高原北部砒砂岩区风蚀时空变化的影响,阐明砒砂岩区风蚀减弱的主控因素,进而为研究区风蚀综合治理提供科技支撑。[方法]基于修正WEQ(Wind Erosion Equation)风蚀模型和研究区1980—2017年日气象数据,1990年、1995年、2005年、2015年4期Landsat遥感影像和土地利用图,30 m分辨率DEM数据及土壤数据,利用GIS和RS技术分析了砒砂岩区1980s,1990s,2000s,2010—2017年风蚀强度的时空变化特征,基于像元尺度剖析风蚀气象因子(W)、植被覆盖度(VC)和土地利用变化对风蚀时空变化的影响。[结果]随着年代推移,风蚀气象因子先降低后升高并超过初始值、植被覆盖度持续升高并趋于平稳,土地利用中草地和耕地变化明显。4个时期的平均风蚀模数分别为4187 t/(km^(2)·a),599 t/(km^(2)·a),724 t/(km^(2)·a)和870 t/(km^(2)·a),风蚀呈先明显减弱后局部地区略有增强的趋势,其中,1990s风蚀在全境急剧减弱,2000s—2010s在西北、东南及北部局部地区侵蚀加重;强烈以上侵蚀区集中于西北、东南边缘及南部河沟地区。4个时期,风蚀模数与W呈显著正相关(相关系数0.248~0.678),W值增大会加剧风蚀波动增强;风蚀与VC呈显著负相关(相关系数-0.556~-0.490),低植被覆盖区易出现风蚀波动增强;草地、耕地是风蚀主要发生区,2000s—2010s草地区风蚀增幅较大,1990s后林地风蚀强度最小。覆土砒砂岩区风蚀对VC最为敏感,而覆沙砒砂岩区和裸露砒砂岩区则对W较敏感。VC和W对风蚀减弱贡献率之和在覆土区、覆沙区和裸露砒砂岩区分别为54%,72%,83%,其他因素对这3个区减蚀的贡献率分别为46%,28%和17%。[结论]VC和W对砒砂岩区风蚀减弱贡献率较大,植被覆盖度的提升对减蚀影响深远,未来应继续加强植被与工程措施的建设。[Objective]The aim of this study is to explore the influence of climate and surface cover changes on spatiotemporal changes of wind erosion in Pisha Sandstone Area in the northern Loess Plateau as well as its main control factors,and then to provide scientific support.[Methods]Based on Modified Wind Erosion Model(WEQ)and daily meteorological data from 1980 to 2017,Landsat remote sensing images and land use maps of four periods(1990,1995,2005,2015),30 m resolution DEM data and soil data of the study area,we analyzed the spatiotemporal change characteristics of wind erosion intensity in Pisha Sandstone Area in 1980s,1990s,2000s and 2010—2017 using GIS and RS technologies,and the impacts of wind erosion meteorological factors(W),vegetation coverage(VC)and land use change on the spatiotemporal changes of wind erosion based on the pixel scale.[Results]With the passage of time,the meteorological factors of wind erosion first decreased and then increased and exceeded the initial value,the vegetation coverage continued to increase and stabilized,and the changes of grassland and cultivated land in land use were obvious.The average wind erosion modulus in the four periods were 4187 t/(km^(2)·a),599 t/(km^(2)·a),724 t/(km^(2)·a)and 870 t/(km^(2)·a),respectively,and the wind erosion showed a trend of obvious weakening and then slightly strengthening in local areas.In the four periods,the wind erosion modulus was significantly positively correlated with W(correlation coefficient 0.248~0.678),and the increase of W value would aggravate the increase in wind erosion fluctuation;wind erosion and VC showed the significant negative correlation(correlation coefficient-0.556~-0.490),and the low vegetation cover area was prone to wind erosion fluctuation enhancement;grassland and cultivated land were the main areas of wind erosion,and the increase of wind erosion in grassland area in 2000s—2010s was large,and the wind erosion intensity of forest land was the smallest after 1990 s.Wind erosion was most sensitive to VC in soil-c

关 键 词：砒砂岩区 风蚀 修正WEQ模型 时空变化 影响贡献 弹性系数 

分 类 号：S157.1[农业科学—土壤学]