Evaluating agricultural sustainability in tropical watersheds : An integrated geographical approac

A framework for evaluating agricultural sustainability in tropical watersheds was established using spatial multi-criteria analysis. This GIS-based decision support system was able to integrate localised sustainability indicators and reflect the vulnerability of the watershed's resources to land degradation processes. The derived spatial sustainability indices may now be able to support design of alternatives towards interventions for long-term productivity that could ensure food security to the community while at the same time preserving the environment.;The integration of all identified sustainability indicators enabled development of a comprehensive and powerful decision support tool for sustainable management of an agriculture dependent tropical watershed. The logical structure for the aggregation and hierarchies of the input indicators was organised in a user-defined criteria tree addressing a goal of locating vulnerable areas to land degradation processes. The entire procedure involved standardisation and assigning of weights to each input parameter prior to a weighted summation technique in the calculation of the resulting composite index map. The process was facilitated through utilisation of a GIS application termed Spatial Multi-Criteria Evaluation. The data driven approach in setting up the sustainability criteria and the exercise of value judgement rendered this framework more flexible for problem-solving and decision-making. The derived spatial sustainability indices illustrated varying degrees of vulnerability which could then be applied in prioritisation for the application of sustainability interventions. Strategies for employing site specific conservation measures particularly for dealing with high runoff and soil loss in cultivated areas were also developed and identified through scenario simulations of suitable input parameters for the spatial multi-criteria analysis. (Abstract shortened by ProQuest.).