A study of the long-term dynamics of soil moisture in the bac binh district (binh thuan province, Vietnam) using landsat multispectral images [Изучение многолетней динамики влажности почвы района Бак Бинь (провинция Бинь Тхуан, Вьетнам) по данным многозональной спутниковой съёмки Landsat]

Drought and desertification are considered one of the most damaging natural disasters in Vietnam, which affects the economy, environment, human well-being and threatens food security. The paper presents results of soil moisture evaluation from LANDSAT multi-temporal and multispectral images of Bac Binh district, Binh Thuan province, Vietnam. Soil moisture assessment was carried out by using temperature vegetation dryness index (TVDI) calculated basing on land surface temperature and normalized difference vegetation index NDVI. The linear relationships between soil moisture determined from the results of meteorological observations and TVDI, NDVI indices and land surface temperature have significant correlation coefficients. It is shown that remote sensing techniques which have advantages over traditional methods can be effectively applied for soil moisture in the agricultural territories of Vietnam. Finally, an analysis of the results obtained for the period 2002–2017 indicates the presence of progressive desertification, which is the consequence of global climate change and anthropogenic impact. © 2018 Space Research Institute of the Russian Academy of Sciences. All Rights Reserved.