基于TVDI的河南省遥感土壤墒情反演研究

Remote Sensing Retrieval for Soil Moisture in Henan Province Based on TVDI

【目的】精准高效地监测土壤墒情是现代化农业发展的重要环节。【方法】以我国农业大省河南省为研究区,基于MODIS遥感数据,提取归一化植被指数(NDVI)和增强型植被指数(EVI)分别与地表温度和地表温差建立温度-植被指数特征空间和温差-植被指数特征空间。通过研究区土壤水分站点的数据,讨论分别由Ts-NDVI、Ts-EVI、DT-NDVI和DT-EVI特征空间计算得到的温度植被干旱指数(TVDI)与土壤墒情站点的数据的相关性,以此验证基于MODIS数据的TVDI反演大区域土壤墒情的能力。【结果】Ts-EVI特征空间构建的TVDI与实测土壤墒情具有较稳定的相关性。【结论】TVDI不仅能够反映土壤表层的干湿状况;还能有效的反映土壤湿度的时空差异,是一种有效的实时监测土壤干湿状况的手段。

[Purposes] Accurate and efficient retrieval of soil moisture is an important link in the development of modern agriculture.[Methods] In this paper,Henan Province is taken as the study area.Based on MODIS remote sensing data,the normalized vegetation index(NDVI) and enhanced vegetation index(EVI) extracted from MODIS remote sensing data are respectively used to establish the surface temperature-vegetation index space and the temperature difference-vegetation index space.Through the data of soil moisture stations in the study area,the correlation between the temperature vegetation dryness index(TVDI) calculated from the Ts-NDVI、Ts-EVI、DT-NDVI and DT-EVI characteristic spaces and the data of soil moisture stations is discussed,so as to verify the ability of TVDI based on MODIS data to retrieve soil moisture in large regions.[Findings] The results showed that the TVDI constructed by Ts-EVI feature space has a stable correlation with the measured soil moisture.[Conclusions]TVDI could not only reflect the dry and wet condition of soil surface;It can also effectively reflect the temporal and spatial differences of soil moisture,and is an effective means of real-time monitoring of soil moisture status.