LAND CARRYING CAPACITY, WATER SAFETY, AND COMMUNITY HEALTH UNDER POPULATION PRESSURE: A MULTIDISCIPLINARY ASSESSMENT OF HILLSIDE SETTLEMENT IN NEGERI BATU MERAH, AMBON, INDONESIA

Background Small island cities grow on scarce, steep, and hazard-prone land. Negeri Batu Merah, a customary village in Ambon City, is classified as a heavy slum area with 66,424 people on 911 ha. Its dense settlement relies on septic tanks and shallow wells, linking land limits to water safety, and maternal and child health. This study assesses Batu Merah’s land-carrying capacity, measures how existing settlements are distributed across it, and interprets the results for engineering, water safety, community health, access, and spatial governance. Methods Nine land capability units were analyzed following Minister of Public Works Regulation No. 20/PRT/M/2007 and converted into potential, limitation, and constraint zones. Settlement from the 2018 national land cover map is overlaid on these zones and each unit. Published water quality and health studies on Ambon were compiled, and the results were interpreted from eight disciplines, including chemistry, global health, and midwifery. Results The village had moderately high (56.14%), moderate (42.87%), and low land capability (0.99%). Settlement covers 600.61 ha at about 110 persons per settled hectare. The potential zone was 96.5% built-up, and the constraint zone was almost entirely. All 97.67 ha of settlement in the limitation zone stands on land with low foundation stability, moderate slope stability, and a moderately high hazard potential. The waste disposal capability was only moderate under 77.6% of settlement. The Wai Batu Merah River exceeds the national standard for ammonia and coliforms, and in Batu Merah, poor water, sanitation, and hygiene conditions increase the odds of stunting in children under two 2.7-fold. Conclusions Future growth will move onto land requiring specific technical measures. Controlling this requires explicit zoning requirements, communal wastewater treatment, monitoring of wells and refill depots, maternal and child health services that reach hillside neighborhoods, and the involvement of customary institutions when customary land changes hands.