Changes in Cropland between 1986 and 2019 in Kitui Central Sub-County, Kitui County, Kenya

Abstract

Remote sensing and geospatial technologies are instrumental in identifying, mapping and quantifying changes in valuable resources like croplands. Cropland maps are important in crop monitoring, food security, land planning and management. However, Kitui Central Sub-County has limited cropland maps. This study, therefore, aimed at detecting and quantifying the changes in cropland in Kitui Central Sub-County from 1986 to 2019 using multispectral data obtained from Landsat archives. Cropland, built-up areas, bushland, grassland and water bodies were identified as the main land cover classes in the study area through a reconnaissance study done before the land use and land cover classification. Supervised classification was performed using the Maximum Likelihood Classifier algorithm to map land use and land cover classes of 1986, 2001, 2011 and 2019. Change detection analysis was then performed using post-classification comparison method in order to identify the changes in cropland over the period of study. The results showed that there was an increase in cropland area from 185.23 km2 in 1986 to 327.28 km2 in 2001. This was followed by a decrease to 231.15 km2 in 2011 and a rise to 357.37 km2 in 2019. Knowledge of such trends in cropland can be used by agricultural resource managers in sustainable agriculture to manage croplands and boost food production and security in Kitui Central.