DROUGHT RISK ASSESSMENT DURING THE DRY SEASON IN TIEN RIVER ESTUARY

DOI: 10.18173/2354-1059.2020-0040

Tóm tắt

Drought simply is a period of moisture deficiency. It depends on temperature, evaporation capacity, vegetation cover, topography, etc., in addition, it often happens on a large scale making it difficult to use traditional research methods. With the development and widespread application of remote sensing technology and geographic information systems (GIS), the use of satellite images as well as GIS software is becoming more and more effective in monitoring, monitoring and assessing drought. In this study, the author assessed the risk of drought at Tien river estuary through two indices: Normalize Difference Vegetation Index (NDVI) and Standardized Precipitation Index (SPI) during the dry season months of 1991, 2001, 2010 and 2018. SPI values are interpolated to construct spatial modeling of meteorological drought levels. Through the LANDSAT satellite image, NDVI is calculated and built on a map of drought levels. Weighted overlay SPI and NDVI map layers for a drought risk map. Research results have shown that the Tien river estuary area is divided into 2 zones: light drought and moderate drought occurs in the dry season. Drought occurred with strong intensity in the eastern coastal area of Ben Tre and Tra Vinh provinces, the deeper the inland the level of drought decreased.