Poster, EGU General Assembly 2017, Vienna: 2017-04-23 - 2017-04-28
The change of land use and land cover (LULC) is often driven by the growth of human population. In the Lambwe valley, Kenya, the most important reason for settlement was the control of tsetse fly, biological vector of trypanosomes. The huge programs for tsetse control in the 1970s lead to a rapidly expansion of the population of the Lambwe valley in Kenya and therefore the cultivated area. This increased the pressure on the governmental owned regions of the higher elevation and the Ruma National Park in the Lambwe valley, occupying one third of the valley. Here, we investigate if this pressure affects the land cover of the National Park and how the LULCs changes in the Lambwe valley. To answer this question, we analyse the surface reflectance of three Landsat images of Ruma National Park and surrounding in Kenya from 1984, 2002 and 2014 to detect changes in LULC in this region. Due to missing ground data, we produce a land cover map for 2014 and transfer it to the other two images. Therefore we locate unchanged pixels with the change vector analysis and cluster the image with clara, which is similar to k-means, but suitable for huge data sets. The best number of classes were determined to be 4. The land cover for the resulting classes were derived from the Landsat images themselves and Google Earth. The resulting classes are the forest dominant in high elevation; dense shrub land; savanna; and low covered soil including bare light soils with few vegetation, fields and settlements.The classified pixels serve as training data for supervised classification with random forest, which is carried out for each image separately. Subsequently the three different classifications are compared and land changes are mapped. We observe an increase of agricultural area in the western of the Lambwe valley, where high elevation vegetation is dominant. This goes hand in hand with farming on higher slopes and an decrease of the governmental owned forest. In the National Park itself the savanna increases about 8% and the proportion of low covered soil class decreases about 10%. We think this might be caused by the effect of fire management applied in the park and the recovering of burned areas.