Assessing the impacts of surface properties of the catchment area on the biodiversity of the Nakivubo stream.

Abstract

Nakivubo stream is the main stormwater drainage channel for the city of Kampala whose level of urbanization interms of imperviousness is high,this greatly affects the water quality and macroinvertebrates with in the stream. In this study water samples and macroinvertebrates were collected from the paved and unpaved catchments and the results of this study indicated TDS range from 0.250 to 0.38 mg/l, EC range from 367.7to 546 µScm-sand DO range from 2.16 to 2.4mg/l. pH range from8.6 to 8.7 while temperature ranged from 23oC to 24oC. The results of Shannon Weinner diversity and Simpson’s diversity index shown a high diversity of macroinvertebrates in the unpaved catchments compared to the paved catchments. A correlation between the abundance of macroinvertebrates and the water quality parameters shown a positive relationship between temperature, ph and Oligocheata, a negative relationship between the other macroinvertebrates and all the water quality parameters. Stream water quality in the watershed is influenced by many factors such as meteorological conditions and anthropogenic activities, only considering the imperviousness can not perfectly represent the status of stream water quality with in the watershed