2000—2016年黄土高原地区荒漠化遥感分析  

Monitoring of Desertification and Drought in Loess Plateau Based on NDVI-albedo Space

作　　者：刘英[1] 李遥 鲁杨 岳辉[1] LIU Ying;Li Yao;LU Yang;YUE Hui(College of Geomatics,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]西安科技大学测绘科学与技术学院,西安710054

出　　处：《遥感信息》2019年第2期30-35,共6页Remote Sensing Information

基　　金：国家自然科学基金(41401496);中国博士后科学基金(2016M592815)

摘　　要：鉴于利用NDVI-albedo特征空间的方法进行黄土高原荒漠化的研究较少,利用MODIS归一化差异植被指数(normalized difference vegetation index,NDVI)和地表反照率(albedo)数据,构建NDVI-albedo特征空间,计算荒漠化差值指数(desertification difference index,DDI)和植被条件反照率干旱指数(vegetation condition albedo drought index,VCADI),并利用实测土壤湿度数据进行验证,分析黄土高原2000—2016年土地荒漠化和旱情的时空分布规律和影响因素。结果表明,DDI、VCADI与土壤湿度分别呈正相关和负相关,均通过了显著性检验,均可作为土地荒漠化和旱情监测指标;17年间,黄土高原重度荒漠化面积逐渐缩小,土地荒漠化改善面积占84.55%,荒漠化加重区域仅占5.61%;旱情改善面积占67.07%,加重区域占19.44%;荒漠化与降水量呈负相关关系,与气温呈正相关关系,而旱情与降雨量、年均温度均呈正相关关系。NDVI-albedo space was constructed using MODIS normalized difference vegetation index (NDVI) and surface albedo (albedo) data,and the desertification difference index (DDI) and the vegetation condition albedo drought index (VCADI) were obtained and verified by the data of meteorological stations.The correlation was analyzed between DDI,VCADI and the measured 10 cm depth soil moisture.The spatial and temporal distribution characteristics of the desertification and drought in the loess plateau from 2000 to 2016 were evaluated by DDI and VCADI,respectively.The linear regression analysis method was used to analyze the change trend of desertification and drought of the loess plateau in the past 17 years.Finally,the natural driving factors liking annual precipitation and temperature which resulted in the change of desertification and drought were analyzed.The results showed that there was a positive correlation between DDI and soil moisture (R 2 =0.281 8) and negative correlation between VCADI and soil moisture (R 2 =0.283 1) which passed the 90% significance test.DDI and AVDI could be used as indicators for monitoring desertification and drought,respectively.In the past 17 years,the area of severe desertification in the loess plateau gradually decreased.The light desertification and non-desertification area spread to the northwestern of the loess plateau.The area of desertification improved accounted for 84.55% and the desertification aggravated only accounted for 5.61%.The area of drought improved accounted for 67.07% while the drought aggravated accounted for 19.44% of the total area.There was a negative correlation between desertification and precipitation and a positive correlation with temperature,while the drought had a positive correlation with precipitation and annual average temperature,respectively.

关 键 词：荒漠化 NDVI-albedo特征空间 荒漠化差值指数 植被条件反照率干旱指数 黄土高原 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]