SPATIO-TEMPORAL VARIATION OF WATER QUALITY PARAMETERS, SEDIMENTS ORGANIC CARBON AND ORGANIC MATTER OF DIFFERENT STATIONS OF KAPTAI LAKE, RANGAMAT

Abstract

This research delves into the physical and chemical conditions of Kaptai Lake in Bangladesh. The study spanned six months (March - August), involving the collection of water samples monthly from four distinct sampling points: Jolojan Ghaat, Kandemu, Shubholong Jhorna, and Shubholong Bazar. Throughout this period, notable temporal fluctuations in various physical and chemical parameters were observed. July 2022 recorded the highest water temperature at 32±0.68 °C, while the lowest was noted in March 2022 at 26.87±2.11 °C. The concentration of dissolved oxygen (DO) ranged between approximately 5.14 to 8.8 mg/L. Conversely, the pH levels consistently indicated an alkaline nature, oscillating between 7.0 and 8.3. Total alkalinity demonstrated variability, ranging from 40 mg/l in July to 82 mg/l in May, while water hardness exhibited fluctuations from 36 mg/l in August to 86 mg/l in June. Concentrations of NH3-N spanned roughly from 0.50 to 1.50 mg/L. Deeper sampling stations exhibited higher organic matter content, with Kandemu showcasing the greatest depth at 54.167±6.145 ft and organic matter content at 3.488±1.618 %. In contrast, Jolojan Ghaat displayed lower values, with a depth of 18.417±6.003 ft and organic content of 1.756±1.618 %. Surface water indicated elevated temperatures and dissolved oxygen levels, while bottom water stood out with higher total dissolved solids (TDS) content. These findings collectively affirmed that the lake's physical and chemical attributes fell within ranges conducive to supporting aquatic life, including the thriving ecosystem necessary for fish production by providing comprehensive baseline data on the monthly dynamics of Kaptai Lake's physical and chemical parameters, this study offers invaluable insights for the sustainable management and preservation of this vital ecosystem.