Land extension analysis for irrigated paddy fields using GIS-based multi-criteria and legacy land data: A case study of the West Sumatra, Indonesia

The demand for food is constantly increasing and becoming a problem in many parts of the world. Therefore, land resources must be optimally utilised to meet food needs and strengthen long-term food security. This research aimed to a) assess land suitability for irrigated paddy using GIS-based multi-criteria and analysing old land data and b) identify priority areas for the expansion of irrigated paddy in West Sumatra. The first phase of this research began with the creation of a geodatabase using GIS-based multi-criteria and old land data. Land suitability was analysed using the matching method. In addition, priorities for land expansion were evaluated based on land suitability, legal status of land, and existing land use. The results showed that 23% of the area in West Sumatra was suitable for irrigated paddy fields (827,065.5 ha). The suitability class consisted of an S2 class of 671,636.4 ha and an S3 class of 155,429.1 ha. The primary priority (P1) for the expansion of new paddy fields is 491,155.2 ha spread over 138,470.6 ha in Pasaman Barat, 99,713.7 ha in Dharmasraya and 57,892.2 ha in Pesisir Selatan. The second most important area (P2) in the area of convertible production forest (HPK) can be developed in Dharmasraya 14,951.0 ha, Pesisir Selatan 9,880.2 ha and Solok Selatan 7,078.2 ha. The limiting factors for suitability are mainly caused by slope factors and root media, such as poor drainage, coarse texture, and shallow soil depth.