Trend of Water Quality and Model for Forecasting Eutrophication Occurrence in Songkhla Lake, Thailand

Abstract

The Songkhla Lake Basin is one of rapid economic growth region, with associated discharges of waste products and conflicts of land use change. This study aims to investigate water quality and develop a statistical model for estimating when water quality conditions are conducive given Chlorophyll-a concentration exceeds 10 mg/l. The model is based on multivariate correlations between Chlorophyll-a concentration and limnological characteristics, season, climatic factors and water quality parameters from official data at 25 stations around Songkhla Lake collected by the National Institute of Coastal Aquaculture (NICA), Department of Fisheries of Thailand, from March 1992 to December 2003. The resultant forecasting model gave an r-squared of 50.5% and statistically significant associations with Lake Zone, season, climatic factors (air temperature and rainfall) and water quality parameters (temperature, salinity, dissolved oxygen, pH, transparency, total organic carbon, orthophosphate and ammonia). This model can provide a practical lake management tool for eutrophication surveillance. Furthermore, the study raised the problem of high potential risk and exceeding the relevant the surface water standards of some water quality parameter. We suggest that environmental awareness among the public is the first key to success in sustainable development of the Songkhla Lake Basin.