荒漠绿洲区干旱遥感监测指数的对比分析

Comparison and analysis of drought monitoring remote sensing indexes in the desert oasis area

绿洲农业在南疆经济社会发展进程中意义非凡,及时获取荒漠绿洲区土壤相对湿度数据,对有限水资源合理分配、促进绿洲农业和生态环境的健康持续发展至关重要,选择适宜的干旱遥感监测指数是干旱监测面临的问题。基于Landsat 8和实测土壤相对湿度数据,对比分析NDWI、VSWI、TVDI、MEI在荒漠绿洲区的有效性。结果表明,受人类活动等各种因素影响,4种指数在农田区域(棉田、枣地)效果不理想;4种指数均能反映研究区荒漠土壤相对湿度的空间特征,最佳监测深度为0~10 cm;从相关系数分析,NDWI、MEI监测效果优于VSWI和TVDI。受水资源分布和人类活动影响,塔里木河两岸及农田周边荒漠土壤相对湿度较高。

Oasis agriculture is of great significance in the process of economic and social development of Southern Xinjiang.Timely acquisition of soil relative humidity data in desert oasis areas is crucial for rational allocation of limited water resources and promotion of healthy and sustainable development of oasis agriculture and ecological environment.How to correctly select an appropriate drought monitoring remote sensing index is a problem for monitoring drought.The effectiveness of NDWI,VSWI,TVDI and MEI in desert oasis areas was compared and analyzed based on Landsat 8 and measured soil relative humidity data.The results showed that the four indices were not effective in agricultural areas(cotton and date fields)due to various factors such as human activities;All four indices reflect the spatial characteristics of the relative humidity of desert soils in the study area,with the optimal monitoring depth ranging from 0 to 10 cm;From the correlation coefficient analysis,the monitoring effect of NDWI and MEI were better than VSWI and TVDI.The relative humidity of the desert soil was higher along the banks of the Tarim river and around the farmland due to water distribution and human activities.