Ts /NDVI space based drought monitoring study from satellite remote sensing data in Heilongjiang

Combining the spectral vegetation index with thermal infrared information, Ts/NDVI triangle space can provide a promising measure in drought monitoring despite its regional and temporal dependence. A Ts/NDVI triangle space was constructed through Terra-MODIS NDVI and LST, and a triangle space based land surface dryness index VTCI was utilized to explore the dryness monitoring in Heilongjiang province. The spatial pattern and temporal evolution in VTCI demonstrates that the summer dryness is characterized with extensiveness, long duration and severity, especially in the main crop areas, and is more serious in early period. The approach was validated via ground-measured precipitation at the same period. A close linear correlation between VTCI and precipitation suggests that VTCI is related to not only local recent precipitation but also past cumulative precipitation and is a reasonable simplification of the Ts/NDVI triangle space, which can give a near-real time drought monitoring in Heilongjiang.