IMPACT OF RESERVOIRS ON MORPHOMETRIC CHARACTERISTICS OF STREAMS: A CASE OF SHASHE DAM IN NORTH-EASTERN BOTSWANA

摘要

Impoundment of water through construction of damsrnacross rivers ranks among the most prominent man-madernmodifications of the natural systems with the main aim ofrnimproving the lives of the people and yet with some farrnreaching implications on the dynamics of the riverrnsystems which can not be ignored. In this study, analysisrnof stream characteristics (Horton order ratios as well asrnStream frequency and Density) of Shashe river in northeasternrnBotswana has been undertaken for the periods atrnthe dam construction (1970) and after dam constructionrn(1990). It was found out that the morphometry of the riverrnsystems has changed as a result with RA and RB decreasesrnaveraging 40 % and 20 % respectively. Increases arernevident for RL, Drainage density and Stream frequency atrn8 %, 26 % and 10 % respectively.