Land-use systems based approach for land degradation assessment

Land degradation is one of the most threatened issues in the world. It has many consequences for sustainability of the natural resources. Land degradation directly links with land-use and influenced by many other factors. LADA-QM is a tool designed for mapping land degradation by integrating local understanding and expert judgement on degradation status in spatial units of land-use-systems (LUS). This approach was successfully tested for many other countries and accepted as common method which allow comparison among countries. The study aimed at evaluating LADA-QM approach for assessment of land degradation status in central province of Sri Lanka. GIS map of LUS was generated with 18 land-use classes by aggregating 35 land-use categories following LADA-QM guidelines. Degradation status was evaluated through guided brain-storming sessions and field assessment with locally experienced expert group. LUS specific information on degradation type, degradation intensity trends and degradation area proportions were assessed and generated maps. The degradation results found comparable with results of previous studies. The land degradation was high in lands under annual crops, marginal tea lands and un-organized construction sites. Lack of land ownership, poverty and population pressure were also identified as prominent land degradation drivers. Though, initial data preparation is intensive, the LADA-QM approach is relatively more time saving and cost effective than other input data intensive assessment methods.