Environmental rainfall baseline and climate-responsive stormwater planning for peri-urban residential development

Zul Janwar (Department of Environmental Engineering, Universitas Syekh Yusuf Al Makassari Gowa, Gowa, South Sulawesi 92111)
Zulkarnain (Department of Biology, Faculty of Science and Technology, Universitas Islam Negeri Alauddin Makassar, Makassar, South Sulawesi 90222)
Hajrah (Department of Biology, Faculty of Science and Technology, Universitas Islam Negeri Alauddin Makassar, Makassar, South Sulawesi 90222)

Ecovision: Journal of Environmental Solutions
Vol. 3 No. 2: August (2026)

Background: Peri-urban residential expansion in tropical Indonesia increasingly requires environmental baselines that connect routine climatic evidence with practical stormwater planning. This article develops a decadal rainfall baseline for the planned Sunville Residence area in Paccinongang, Somba Opu District, Gowa Regency, South Sulawesi, using a 2015-2024 monthly precipitation matrix extracted from NASA POWER data. Methods: The study applies descriptive climatology, interannual variability analysis, Schmidt-Ferguson wet-dry month classification, and Oldeman agroclimatic interpretation. Annual and monthly rainfall were summarized to identify seasonal concentration, wet and dry month structure, and planning-relevant hydrological implications. Findings: Mean annual rainfall reached 2,178.64 mm, with substantial interannual variability from 1,345.22 mm in 2019 to 2,955.56 mm in 2022. The rainfall regime was strongly seasonal, with December, January, February, November, and March forming the main wet-season core, while July to September represented the driest period. Using direct rainfall thresholds, the mean number of wet months was 7.3 and dry months was 3.2, producing a Schmidt-Ferguson Q value of 43.84%, which places the site in type C or moderately wet climate. Oldeman interpretation of the monthly climatological pattern indicates a C3-type agroclimate, characterized by approximately five wet months and four dry months. Conclusion: The baseline indicates that the site is not climatically dry; rather, its environmental risk is shaped by high wet-season water input, pronounced seasonality, and the possibility of rapid runoff if land conversion increases impervious cover. Novelty/Originality of this article: The article translates a project-level rainfall dataset into an international-style environmental planning approach by linking climate classification, peri-urban land conversion, and stormwater-sensitive design recommendations for a specific Indonesian residential development context.