Spatial and Temporal Variations in Physical and Chemical Parameters in Water of Rupsha River and Relationship with Edaphic Factors in Khulna

Abstract: The physical and chemical condition of Rupsha River of Khulna and Edaphic factors of the study area was chemically analyzed for 12 months (January-December, 2011). Temporal variation in physical and chemical parameters was found in all cases. Though spatial variations were slight in case of water temperature, dissolved oxygen amount, turbidity and salinity but changes were significant in case of transparency and the amount of free carbon-dioxide. Spatial variation in case of water pH was very little that can be ignored. There was noticeably temporal variation of water temperature between summer (33.1±3.79 ºC at July) and winter season (11.6±5.89 ºC at December). Transparency was lower in June (15.7±3.61cm) and higher in December (42.4±8.72cm). Turbidity level of the Rupsha river was lower in December (14.2±5.29 NTU) and higher in June (26.22±3.61 NTU). PH of the water of the river was lower in June (7.58±0.14) and higher in December (8.58±0.29). In the present study, slight change was observed incase of temporal variation of dissolved oxygen amount in water. Dissolved oxygen was higher in December (6.71±0.06 mg/l) and lower in June (5.09±0.06 mg/l). Free carbon dioxide is the highest in July (9.75±0.10 mg/l) and the lowest in January (7.19±0.05 mg/l). Alkalinity was lower in January (225±2.65mg/l) and higher in June (362±2.00mg/l). Atmospheric temperature and rainfall showed positive correlation with all physical and chemical parameters except transparency, amount of dissolved oxygen (DO) and pH