Assessing Rainwater Harvesting Suitability Through Integrated GIS and Multi‐Criteria Decision‐Making Approaches

ABSTRACT Water scarcity and uneven rainfall continue to affect many parts of Yunnan Province, despite its generally high rainfall. This study used Geographic Information Systems (GIS) and three Multi‐Criteria Decision‐Making (MCDM) models: Multi‐Influence Factor (MIF), Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC) to map rainwater harvesting (RWH) suitability. Eleven parameters were included, covering topographic, hydrological, environmental, and accessibility factors: rainfall, slope, elevation, soil type, land use/land cover, drainage density, lineament density, TWI, distance to rivers, distance to roads, and distance to built‐up areas. Across all three models, the northern and north‐western mountainous regions were consistently mapped as very low to low suitability, dominated by steep slopes and fast runoff. Under the MIF model, very low (15.42%) and low suitability (33.89%) together covered nearly half the province, while moderate suitability was highest at 34.23%, followed by high (11.95%) and very high (4.50%). The AHP‐based WLC model classified 12.78% as very low, 33.79% as low, 30.24% as moderate, 20.83% as high and 2.36% as very high. The standalone WLC model showed 25.16% very low, 29.40% low, 25.47% moderate, 15.56% high and 4.41% very high suitability. Despite numerical differences, all models consistently identified the central, southern and southeastern regions as the main RWH hotspots, driven by gentler topography and favourable moisture conditions. These results show that a significant portion of Yunnan, especially the moderate‐ and high‐suitability zones, can support small‐scale RWH structures such as check dams, contour trenches and percolation tanks. The strong agreement among the three models increases confidence in the mapped zones.