Integrated Analytical Hierarchical Process and Geographical Information System for Allocation of Compatible Land Uses along Uluguru Mountain Slopes

Abstract

The northern slope of the Uluguru mountain, that falls under the sovereignty of Morogoro’s urban area, has steadily become populated and connected with uncontrolled human activity, which has had a harmful effect on the ecosystem. The rapid conversion of natural forests to farms and settlements has a severe effect on biodiversity and the land’s productive capacity. In order to assist the identification of compatible land uses for managing degradation and restoration of degraded land, as well as ensuring the long-term use of natural resources, this study applied the integration of Geographical Information System and Analytical Hierarchical Process. The land resources of the research area were identified using a Geographical Information System to guide in the evaluation of various land uses’ suitability. Land resource values were generated from different sources of data whereby elevation, slope, temperature, rainfall, soil properties, soil moisture index, and land surface temperature classifications were obtained. The land resource classification values throughout the study area were used to create land mapping units. The results of the criteria classification were integrated into questionnaires together with proposed compatible land uses obtained from the literature review. These well-structured questionnaires were used to retrieve expert opinions on land use allocation from environmental beneficiary institutions in the area. The influence of criteria on each suggested land use was assessed accordingly based on the score provided by Saaty’s scale. The weight of each criterion at each land mapping unit toward proposed compatible land uses for mapping purposes was calculated using the Analytical Hierarchical Process (AHP) technique. The weighted criteria produced by the AHP technique were integrated into GIS using the weighted overlay method to produce a map that reflects expert judgments on mountain slope planning for long-term natural resource management. A literature review reveals that conservation agriculture, agroforestry, and forest land use types are compatible in the management of natural resources in the area, while settlements have to be integrated to accommodate the existing situation. The integration of GIS and AHP produced a plan that consists of conservation agriculture that covers the majority of the study area (50%) and is generally found in the foothills of the mountains up to land mapping unit 3. Agroforestry is the second-largest land use, accounting for 19% of the study area and being concentrated in the second and third land mapping units. Settlements, which occupy 17% of the study area and are mostly located at the foothills of the mountain, are the third most covered land use. Finally, forest land use is distributed at the top of the research area, inside land mapping units 4 and 5, and accounts for 13% of the total study area. According on the findings of this study, a sustainable land use plan is recommended. Economic activity that could assist in the management of natural resources would be advantageous to both parties. Planning of the moun tainous slopes within urban areas that are not designated as conservation zones should be done with great care, and only economic activities that assist management of natural resources should be permitted.