Vol. 8, Issue 8, Part A (2022)

Abstract
A surface temperature is one of the important physical factors of water body having an impact on metabolic rate and biological activity of aquatic organism. This physical property can also affect the other physical and chemical parameters (pH, salinity, density, toxicity, photosynthesis rate, dissolved oxygen etc.) of water body. The study is about using remote sensing techniques to assess the surface temperature in Halda River, the third major river in Chittagong region and an ecologically sensitive spawning bed for Indian major carp community. Here, March months of Seven years with an interval of 5 years - 1990; 1995; 2000; 2006; 2010; 2015 and 2020 - are selected to calculate surface temperature by these techniques. The thermal band 6 of satellite imagery collected by ‘Landsat 5’ and ‘Landsat 7 ETM +’ satellite are interpreted with the help of USGS website and ArcGIS 10.4 software. Following several equations and using data from those imageries, the respective average temperature of those seven years (March) are 21.6 ⁰C, 15.7 ⁰C, 19.5 ⁰C, 24.5 ⁰C, 27.3 ⁰C, 23.4 ⁰C and 26.9 ⁰C. And total average surface temperature of March months of all 7 years is 22.7 ⁰C by which we are informed about the temperature condition of this river easily and correctly. So, these modern applications might be an effective way to have a regular monitor on this vital physical factor which will help to ensure a proper management for not changing the aquatic life’s habitat and would be a useful medium for other hydrological study about this river.