tailieunhanh - Drought risk assessment during the dry season in Tien River estuary

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. | DROUGHT RISK ASSESSMENT DURING THE DRY SEASON IN TIEN RIVER ESTUARY Abstract. 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. Keywords Drought Index NDVI SPI Risk assessment Tien river estuary. 1. Introduction Drought together with climate change is one of the prominent global issues so many authors in the world have studied drought research. But this is inherently severe natural phenomena with high complexity so far there is no general method to study the problems of drought. However it is now common in the world for researchers to use drought indicators in their research. Among the meteorological indicators since 1996 the group of authors Michael J. Hayes Mark. D. Svoboda et al. 1 studied drought through the Standardized Precipitation Index SPI . And then a .