摘要
选取风速、日照、气温年较差、相对湿度、坡度、坡向、植被盖度、土壤可蚀性K值、海拔和冰川积雪变化因子作为西藏那曲地区融水侵蚀强度评价的影响因子,运用主成分分析方法提取融水侵蚀的主要影响因素,并计算不同环境背景条件下的融水侵蚀强度因子,利用GIS技术对那曲地区融水侵蚀进行分级评价,分析那曲地区融水侵蚀分布特征。结果显示,融水侵蚀主要影响因素分别是地形地貌因素、气候因素、土壤因素和冰川积雪变化因素。那曲地区融水侵蚀分级结果表明,研究区融水侵蚀各强度等级所占面积由大到小依次为微度(40%)、极强度(24%)、中度(16%)、轻度(8%)、剧烈(7%)、强度(5%)。
Ten influencing factors were selected as indicators to evaluate the meltwater erosion intensity in Naqu district,as wind speed,total sunshine,annual range of temperature,relative humidity,slope gradient,aspect,NDVI,soil erodibility,elevation and snow change factor.The dominant influencing factors on meltwater erosion intensity were extracted by the method of principal components analysis,and the index of meltwater erosion intensity for each evaluation unit was calculated under different environmental backgrounds.Moreover,the meltwater erosion degrees were evaluated based on GIS software and the spatial distribution characteristics of meltwater erosion were analyzed in Naqu district.The results showed four dominant influencing factors on meltwater erosion,as geomorphology factor,climate factor,soil factor and snow change factor.Six degrees were classified for the meltwater erosion intensity in the study area.The percentage of areas with different meltwater erosion intensity degrees are:extremly slight erosion(40.0%),extremly serious erosion(24.0%),medium erosion(16.0%),slight erosion(8.0%),violent erosion(7.0%),serious erosion(5.0%).
引文
[1]Swift D A,Nienow P W,Hoey T B.Basal sediment evacuation by subglacial meltwater:suspended sediment transport from Haut Glacierd’Arolla,Switzerland[J].Earth surface Processes and Landforms,2005,30:867-883.
[2]张建国,刘淑珍,杨思全,等.西藏冻融侵蚀分级评价[J].地理学报,2006,61(9):911-918.
[3]张亦超,史明昌,岳德鹏,等.基于GIS的土壤风蚀模型软件构建[J].中国水土保持科学,2013,11(1):69-74.
[4]朱惇,李璐,韩小波.基于空间主成分分析的湖北省土壤侵蚀敏感性评价[J].中国水土保持,2013(4):40-44.
[5]张红坡,张海峰.SPSS统计分析应用宝典[M].北京:清华大学出版社,2012.
[6]中华人民共和国水利部.土壤侵蚀分类分级标准(SL190-2007)[S].北京:中国水利水电出版社,2008.
[7]方海燕,孙莉英,聂斌斌,等.基于WaTEM/SEDEM模型的双枫潭流域侵蚀产沙模拟[J].陕西师范大学学报:自然科学版,2014,42(1):92-97.
[8]朱惇,王天巍,蔡崇法,等.基于模糊神经系统与GIS的区域土壤侵蚀快速评价[J].农业工程学报,2010,26(1):103-109.
[9]许明祥,刘国斌,赵允格.黄土丘陵区土壤质量评价指标研究[J].应用生态学报,2005,16(10):1843-1848.
[10]张文柯.论GIS技术在环境影响评价中的应用[J].陕西师范大学学报:自然科学版,2008,36(s1):165-167.
[11]赵英时.遥感应用分析原理与方法[M].北京:科学出版社,2003:374-375.
[12]Jonsson P,Eklundh L.TIMESAT:A program for analyzing time-series of satellite sensor data[J].Computers and Geosciences,2004,30(8):833-845.
[13]王小丹,钟祥浩,王建平.西藏高原土壤可蚀性及其空间分布规律初步研究[J].干旱区地理,2004,27(3):343-346.
[14]马蔼乃.地理遥感信息模型[J].地理学报,1996,51(3):266-271.
[15]Ma A N.A Geo-code model for the use of GIS[C]∥International Archives of Photogrammetry and Remote Sensing,Japan:ISPRS,1988,27(4):585-591.
[16]Smith J W F,Campbell I A.Error in polygon overlay processing of geomorphic data[J].Earth Surface Processes and Landform,1989,14:703-717.
[17]李朝峰,杨中宝.SPSS主成分分析中的特征向量计算问题[J].统计教育,2007(3):10-11.