40-Rejuvenation of urban lakes in dry tropics - Problems and perspectives

Abstract

For more than three decades, inland water bodies are subjected to increasingly high human pressure through direct discharge and through changes in land-use by forest thinning, grazing, cultivation and excavation for mineral extraction (Rhazi et al., 2001). In tropics where light and temperature are generally optimal, nutrient status becomes the major determinant of aquatic ecosystem properties (Wetzel, 2001). Terrestrial systems contribute to surface waters by adding nutrients through run-off. The nature of such addition depends on catchment characteristics, land-use pattern, human modifications and atmospheric depositions (Nagakwa and Iwatsubo, 1999; Rhazi et al., 2001; Pandey and Yaduvanshi, 2003). Such additions not only regulate water chemistry and biology but also effects microbial biomass dynamics at land-water interface which in turn, regulates nutrient pulsation in lake water and consequently phytoplankton bloom (Pandey and Pandey, 2001)