Monitoring vegetation water content by using optical vegetation index and microwave vegetation index: Field experiments and applications

Information about vegetation status has widespread utility in agriculture, forestry, hydrology, and land-atmosphere interaction study. This paper presents an attempt to monitor the vegetation water content (VWC) by merging visible/infrared remote sensing and microwave remote sensing. We first derived a relationship between VWC and microwave vegetation index (MVI) through a field experiment. The relationships between VWC and Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) were also studied. We found that MVI has the largest correlation coefficient with VWC, while NDWI has the second largest one. The VWC-MVI relationship derived from field experiment was used to estimate VWC from AMSR-E data at Mongolia sites. The results were compared with AMSR-E standard VWC products. We found the new method overestimated VWC but highly correlated to the AMSR-E products. This study reveals the potential of MVI to monitoring VWC variation.