Integration of remote sensing and GIS in monitoring the dynamics of
land cover in Oroba-Kibos catchment area, Kenya |
| |
Authors: | Were KO Owenga PO Wagate PN and Orlale R |
| |
Institution: | Kenya Agricultural Research Institute,Kenya Soil Survey,Nairobi,P.O.Box 14733-00800,Kenya |
| |
Abstract: | Land cover in Kenya is in a state of fl ux at different spatial and temporal scales. This compromises environmental
integrity and socioeconomic stability of the population hence increasing their vulnerability to the externalities of environmental
change. The Oroba-Kibos catchment area in western Kenya is one locality where rapid land use changes have taken place over
the last 30 years. The shrubs, swamps, natural forests and other critical ecosystems have been converted on the altar of agriculture,
human settlement, fuel wood and timber. This paper presents the results of a study that aimed at providing spatially-explicit
information for effective remedial response through (a) Mapping the land cover; (b) Identifying the spatial distribution of land
cover changes; (c) Determining the nature, rates and magnitude of the land cover changes, and; (d) Establishing the drivers of
land use leading to land cover changes in Oroba-Kibos catchment area. Bi-temporal Landsat TM imagery, fi eld observation,
household survey and ancillary data were obtained. Per-fi eld classifi cation of the Landsat TM imagery was performed in a GIS
and the resultant land cover maps assessed using the fi eld observation data. Post-classifi cation comparison of the maps was then
done to detect changes in land cover that had occurred between 1994 and 2008. SPSS was used to analyze the household survey
data and attribute the detected land cover changes to their causes. The fi ndings showed that 9 broad classes characterize the
catchment area including the natural forests, swamps, natural water bodies, woodlands, shrublands, built-up lands, grasslands,
bare lands and croplands. Croplands are dominant and accounted for about 65% (57122 ha) of the total land in 1994, which increased
at the rate of 0.89% to 73% (64772 ha) in 2008, while natural water bodies has the least spatial coverage accounting for
about 0.6% (561 ha) of the total land in 1994, which diminished at the rate of 3.57% to 0.3% (260 ha) in 2008. Climate, altitude,
access and rights to land, demographic changes, poverty, political governance, market availability and economic returns are the
interacting mix of proximate and underlying factors that drive the land cover changes in Oroba-Kibos catchment area. |
| |
Keywords: | land cover classifi cation change detection remote sensing GIS Oroba-Kibos catchment |
本文献已被 CNKI 万方数据 等数据库收录! |
| 点击此处可从《遥感学报》浏览原始摘要信息 |
| 点击此处可从《遥感学报》下载免费的PDF全文 |
|