Application of GIS and Multi-Criteria Analysis (MCA) in Land Evaluation at Ninh Phuoc District, Ninh Thuan Province, Vietnam

Abstract This study was conducted to assess land suitability (land evaluation) in the Ninh Phuoc districts in order to identify evidence for recommending main crops effectively and sustainably using agricultural land under drought conditions. Results indicated that Ninh Phuoc district had 83 land mapping units (LMUs), with 10 main land use types (LUTs) of rice, annual cash crops, and perennial plants. About 99.2% of agricultural land was classified as high suitability (S1), moderate suitability (S2), and marginal suitability (S3) for most LUTs, while non-suitability (N) lands were very small (0.8%). This study’s land suitability classification analysis has offered valuable insights into the current land use situation in Ninh Phuoc district and proposes sustainable land management recommendations. It has taken into account various land use criteria and assumptions. The study has proposed the following actions for sustainable land use: (i) Maintain highly suitable (S1) and moderately suitable (S2) land areas, (ii) Renovate or convert marginally suitable land (S3) to suitable tree planting/forestation, (iii) Convert unsuitable land (N) to forestry, grass, or plants that enhance soil quality, and (iv) Preserve existing forest areas without encroachment. Specific results in Ninh Phuoc district when applying land suitability classification for future orientation are as follows: maintain 14,859.31 ha, which has high suitability (S1) and moderate suitability (S2) levels; maintain 30.78 hectares of grass and convert 335 hectares to other suitable trees/forest plantations for the suitable marginal area (S3); Convert 122 ha of Not Suitable (N) to afforestation/grass/apply land soil improvement measure; For more than 3700 hectares of unused land, put into use 343.53 ha for growing spice plants, 8.67 ha for rice, 677.18 ha for planting forest trees, 2,691.50 ha for development of pasture and grazing.