An application of GIS and remote sensing for land use evaluation and suitability mapping for yam, cassava, and rice in the Lower River Benue Basin, Nigeria

摘要

Agricultural production has contributed over time to food security and rural economic development in developing countries particularly supporting the countryside. Evidence show that crop yields are declining in the Lower River Benue Basin of Nigeria. This study conducted a land use evaluation and suitability mapping for production of yam, cassava and also assessed the possible socioeconomic impediments that may hinder or enhance sustainable agricultural development in the Lower River Benue Basin. The study adopted physical assessments and socioeconomic approach coupled with mapping which incorporated processing of satellite imagery. Statistical methods were used to measure the status, trends, level of dispersion, and relationships between the variables of physical and socioeconomic parameters. Modelling techniques for determining potential impacts assessment, agricultural suitability index, adaptive capacity index, finally producing suitability maps. Geo-informatics processes were used to produce a digital elevation model, land use and land cover map, and normalised difference vegetation index map. The results were thematic maps, weighted percentages of attribute data, and suitability maps produced through weighted overlay. An intensive analysis of climatological data depicted a progressive intensity of rainfall, and a decreasing trend in the number of rain days; a gradual temperature rise; and high relative humidity during the planting season which is about 168 days. Laboratory analysis show that soils in the study area require fertility enhancement with inorganic fertilisers to encourage better crop yield. Results show that the Lower River Benue Basin is suitable for yam, cassava, and rice cultivation as classified on maps of suitable areas. Rice had the highest suitability percentages (38.30%). The study area was found to be moderately suitable for each of the crops examined by more than 40% for each crop. Cassava had the least suitability percentages (34.47%). Evidence suggests that agricultural development in the Lower River Benue Basin is under threat from potential impacts of climate variability and change, population growth, and infectious diseases. The agricultural suitability index of the study area regards the study area as suitable (70.5%) and the adaptive capacity index of the study area was moderate (50.83%), but it was found that serious attention need to be given to farm technology and infrastructure. Mitigation strategies and recommendations which are beneficial to the sustainable development of agriculture have been provided in line with the established characteristics of the Lower River Benue Basin.