EFFECT OF EARTH COVERING AND WATER BODY ON LAND SURFACE TEMPERATURE (LST)

  • Md. Jahir Uddin professor
  • Chandan Mondal

Abstract

Land surface covering and water body play an important role on local environment especially on Land Surface Temperature (LST). In study above mentioned concept has been conducted on the drainage basin of Atai-Bhairab-Rupsha river confluence which is an important place both for agriculture and trade in the south-western part of Bangladesh. Here the impact of both surface covering and water body on local environmental factor like LST is being analyzed to determine the main catalyst in ever changing LST. LST study in this area which is changed dramatically recently may be a well-defined index, reflects environmental conditions. LST is mainly altered by the factors like land surface covering such as vegetation represented by NDVI, water body by NDWI, and barren or urban area by NDBI but only few are key factors. The gradual changes of these four parameters (LST, NDVI, NDWI, and NDBI) are studied for the years 1991, 1996, 2002, 2006, 2011 and 2017. From the LST study, it is observed that from 1991 to 2017 highest temperature decreased significantly and the difference between 1991 and 2017 is greater than 100C. Variation of lowest temperature all these years are insignificant. Meanwhile, from NDVI analysis if is observed that area of vegetation coverage increased in a significant rate from the years 1991 to 2017. The area of water body is being found almost unchanged in this time period from the NDWI analysis. Nevertheless, from the NDBI analysis it is found that the barren area is diminished significantly in this period and is obviously replaced by vegetation. At all, it can be said that the highest value of NDVI in 1991 is greater than 2017 denotes some short of drought or increasing salinity condition but in general viewpoint vegetation helps to keep surface temperature under control.

Published
2020-04-26