Abstract:
The hydrology of the Little Ruaha River which is a major catchment of the
Ihemi Cluster in the Southern Agricultural Growth Corridor of Tanzania (SAGCOT)
has been studied. The study focused on the hydrological assessment
through analysis of the available data and developing a model that could be
used for assessing impacts of environmental change. Pressures on land and
water resources in the watershed are increasing mainly as a result of human
activities, and understanding the hydrological regime is deemed necessary. In
this study, modeling was conducted using the Soil and Water Assessment
Tool (SWAT) in which meteorological and streamflow data were used in the
simulation, calibration and evaluation. Calibration and evaluation was done at
three gauging stations and the results were deemed plausible with NSE ranging
between 0.64 and 0.80 for the two stages. The simulated flows were used
for gap filling the missing data and generation of complete daily time series of
streamflow at three gauging stations of Makalala, Ihimbu and Mawande. Results
of statistical trends and flow duration curves, revealed decline in magnitudes
of seasonal and annual flows indicating that streamflows are changing
with time and may have implications on envisioned development and the water
dependent ecosystems.
