Could Local Perceptions of Water Stress be Explained by LULCC?

Ayeni, A. O ; Cho, M. A ; Ramoelo, A ; Mathieu, R ; Soneye, A. S. O ; Adegoke, J. O (2013-03-29)


Mapping land use/land cover changes (LULCC) is essential for a wide range land use planning and adaptation mechanisms to global warming/climate change, impacts of natural hazard and socio-economic dynamics on the local to global scales. In this study, we seek to investigate whether water stress in the induced savanna of Southwestern, Nigeria as perceived by the various communities can be explained by LULC changes in the region. LULCC was conducted using orthorectified Landsat multi-temporal imageries for 1970/1972, 1986/1987, 2000/2001 and 2006 using maximum likelihood classification and change detection techniques in ENVI 4.4 software. The results showed a decrease in the forest area and an increase in built-up and cultivation/others (open space, bare land, grassland etc.) areas. Between 1972 and 2006, forest had reduced by about 50% while built-up almost increased by about 300% of its size in 34years ago. Forest loss was found to be higher in the Northeast part of forest – savanna fringe and in areas where built-up used to be sparse in the past. The matrix analysis of change detection between 1972 and 1987, 1987 and 2002, and between 2002 and 2006 depicted -20,963.53 km2 (48.96%), -4,551.08 km2 (20.82%), and -1,156.33 km2 (6.68%) image difference in forest landcover with almost 60% loss to ultivation/others class. Notably, however, in areas where forest lost prevailed, increased fetch to the storage water (surface earth dams). Between 1987 and 2006, five dams were constructed in the area which is suspected to have reduced rivers and streams input to the area. Ab initio, the communities’ perception generated from social survey indicate that changes in climatic condition e.g. decreasing rainfall, continuous forest degeneration in the last 30years, and diversion of rivers and streams into surface storages (earth dams and reservoirs) are the major factors responsible for water stress and scarcity in most rural communities in the region. In conclusion, this study provides an opportunity to better understand the usefulness of LULCC in explaining local perception to water stress and the expected implications.