Abstract:
Nguruman sub-catchment has undergone rapid land use and land cover changes (LULCC) in the past decades. Statement It is not known to what extend this changes could impact on the socio-ecological environment. The current study employed Geographic Information System (GIS) and LANDSAT images to determine the dynamics and underlying drivers of LULCC in the sub-catchment. LANDSAT Images for the period 1994, 2004 and 2014 were purposely acquired and supervised classification performed using ENVI 4.7 software. The classification resulted into seven LULCC classes identified as Cropland, Forestland, Open grassland, Open Water, Bare land, Swamp and Wooded grassland. The area under each LULCC was determined and subjected to a change detection analysis using ArcGIS 9.3 for the periods 1994-2004, 2004-2014 and 1994-2014. Cropland and Open water showed a significant overall increase (P<0.05) of 181.5% and 91.93% respectively from 1994 to 2014. Bare land reduced significantly by 35% in the same period. Areas occupied by Forestland, Open grasslands and Swamps increased by 19.45%, 11.82% and 14.6% respectively from 1994-2014, though this was not significant (P>0.05). There was a non-significant (P>0.05) reduction in Wooded grasslands between 1994 and 2014 by of 6.30%. Regression analysis was further performed to determine 25 year projection for the various land use categories revealed that cropland, bare land and wooded grassland will expand by the year 2040. While there will be reductions in forestland, swamps and open water in the same period. The consequences are expected to have negative impacts on hydrological functions of the catchment with increase in runoff and sedimentation in the streams. Sustainable land use measures are needed to address the challenges of prevailing land use practices. |
