Spatio-Temporal Distribution of Water Quality Parameters in Ramsar Site-Kolleru Lake

Abstract

Kolleru lake is one of Asia’s largest freshwater lakes, which has undergone tremendous changes in the water quality due to the sewage, pollution and development of aquaculture in its surrounding area. This study is undertaken to evaluate the present water quality scenario existing in Kolleru lake, which has been affected seriously due to the anthropogenic disturbances since long. Water samples were collected from ten sampling locations within the lake during pre and post-monsoon seasons of 2017-18. A total of 11 water quality parameters were analysed such as pH, temperature, EC, TDS, TSS, total alkalinity, total hardness, dissolved oxygen, salinity, COD, and nitrates. Parameters were estimated by using a standard protocol of APHA 2012. The spatial distribution maps of water quality were generated from pre and post monsoon data using Arc GIS software. Spatio-temporal variation of all parameters indicated that the water quality found was unsatisfactory within the Kolleru lake. The present study shows the better water quality in the post-monsoon season. The Inverse Distance Weighting (IDW) interpolation spatial mapping was also used for water quality mapping to observe the environmental variation for protecting the important freshwater ecosystem-Kolleru lake. The outcome of GIS analysis demonstrated the spatial visualization of the lodging evolution and geographical distribution trends of water quality parameters within the study area.