Factors Driving Rice Land Change 1989-2018 in the Deli Serdang Regency, Indonesia

The Deli Serdang Regency produces amongst the highest amounts of rice in the province of North Sumatera in Indonesia. Due to land use change and stagnant productivity, the total rice land area and its production have gradually decreased over the years. Hence, understanding this issue is crucial, especially to ensure the sustainability of rice production in the future. The objectives of this study were to identify the trends in land use change (especially regarding rice land) and to investigate the factors affecting rice land change. We classified the satellite images acquired for the years 1989, 1994, 2003, 2009, and 2018 to determine the total area of various land uses. The factors driving rice land change were analyzed using biophysical and socio-economic factors identified from the collected primary and secondary data. The primary data were derived from field surveys, soil analysis, and household surveys, and the secondary data were derived from the Statistical Institution of the Deli Serdang Regency. Correlation analysis, principle component analysis, binary logistic regression, normalization, and weighted index were used to investigate the factors driving rice land change. The results show that forest and rice land have continuously decreased, while plantations and urban areas have continuously increased over this period. We found that the majority of rice land has been converted to plantation expansion and urban development, especially from 2009 to 2018. The factors most affecting rice land change were the distance of rice land to the district capital, the distance of rice land to the provincial capital, population density, slope, and the distance of farmers' rice land to a road. A suitability map for rice land was generated. All the outputs could help with making appropriate strategic decisions to achieve sustainable land use management, especially for rice land.