In this study, hydrologic regimes of the Palas basin have been investigated with land use/land cover
(LULC) change. To investigate the relationship between precipitation and surface runoff, a SWAT (Soil and
Water Assessment Tool) model was developed and runoff response was analysed under different LULC conditions.
Firstly, Post classification change detection technique was used to prepare time series LULC maps of
the years 1987, 2000 and 2011. The overall classification accuracy of 86% and Kappa Coefficient (K) of 0.82
were achieved. Then model was manually calibrated using monthly historical streamflow records. The calibration
was successful with coefficient of determination (R2) value of 0.61 and the Nash and Sutcliffe efficiency
value of 0.55. Validation of the calibrated model using independent dataset shows even better model
performance with Nash and Sutcliffe efficiency value of 0.62 and R2 value of 0.85. The results of this research
study are as follows. Agriculture area in Palas Basin considerably expanded (47%) in the last 24 years. Consequently,
the area of bare soil declined (36%) markedly during the period 1987–2011. Simulations of runoff
for the 2000–2011 period with the SWAT model showed that, under the LULC conditions of 1987, surface
runoff would be 40% lower compared to runoff under the LULC conditions of 2011. For the development of
sustainable water resource strategies, it is essential to establish interaction between land use changes and local
hydrology. Although more observed data is needed for model accuracy, SWAT can provide useful data for
water sources planners and policy makers.