Dry regions as the arid southern Africa are, on the one hand, strained by unfavourable climatic conditions. On the other hand, intensive land use as rangeland and for livestock farming leads to additional encroachment of these ecosystems. The consequence of this long-time stress is degradation in terms of loss of the vegetative cover and productivity. Albeit these are known facts there is still a lack of objectiveness in the long term assessment of degradation on a larger scale. In this work a method is presented, applying remote sensing time-series in a vegetation model that helps to fill this gap. The approach is based on time-series of the vegetative productivity computed by the vegetation model BETHY/DLR. The used data included SPOT-VGT LAI and ECMWF meteorology time-series for the period of 1999 to 2010. The trend-analysis of model output and climatic input results in a new land degradation index (LDI) that distinguishes between climatic and human-induced reduction of vegetative productivity.
Keywords: Vegetation Modelling; Land Degradation; Arid and semi-arid environments; Southern Africa
Schlagwörter: Vegetationsmodellierung; Landdegradation; Aride und semi-aride Gebiete; südliches Afrika
