Electronic Theses and Dissertation

Sub das krueng seulimeum merupakan bagian dari das krueng aceh di kabupaten aceh besar dengan luas 26.497,08 ha. penurunan tutupan hutan dari 70,86% (1977) menjadi 27,51% (2011) akibat konversi lahan telah menurunkan kapasitas infiltrasi dan meningkatkan limpasan permukaan di wilayah tersebut. penelitian ini bertujuan menghitung nilai curve number tertimbang (cnw), debit limpasan rancangan untuk tiga periode ulang, serta sebaran spasial potensi limpasan menggunakan metode scs–cn berbasis gis, dengan ruang lingkup dibatasi pada limpasan permukaan tanpa mencakup erosi maupun sedimentasi. data curah hujan harian maksimum tahunan periode 2015–2024 dari stasiun padang tiji (bobot thiessen 0,9283) dan stasiun meteorologi sim (bobot 0,0717) menghasilkan curah hujan rata-rata wilayah 115,04 mm/tahun. distribusi log-pearson type iii dipilih karena cs = 2,49 tidak memenuhi syarat distribusi normal, log-normal, maupun gumbel, dan diterima melalui uji smirnov-kolmogorov (Δmaks = 0,1148 < Δkritis = 0,410), menghasilkan curah hujan rancangan 96,09 mm, 134,88 mm, dan 173,31 mm untuk periode ulang 2, 5, dan 10 tahun. klasifikasi hsg terhadap 74 satuan peta tanah menunjukkan dominasi hsg b (62,56%), dengan tutupan lahan didominasi pertanian lahan kering campur (31,36%) dan savanna/padang rumput (17,26%). nilai cn tertimbang (cnw) diperoleh sebesar 69,50 kategori sedang, dengan s = 111,47 mm, ia = 22,29 mm. debit limpasan rancangan diperoleh sebesar 90,16 m³/s, 173,49 m³/s, dan 266,44 m³/s masing-masing untuk periode ulang 2, 5, dan 10 tahun. sebaran spasial menunjukkan kelas limpasan rendah mendominasi 92,69% wilayah pada periode ulang 2 tahun tanpa kelas tinggi, sedangkan pada periode ulang 10 tahun kelas sedang dan tinggi bersama-sama mencakup 88,37% wilayah. hasil penelitian ini diharapkan menjadi acuan pengelolaan sub das krueng seulimeum secara berkelanjutan, dengan rekomendasi kalibrasi cn berbasis data lapangan serta integrasi pemodelan hec-hms atau swat untuk analisis hidrologi yang lebih menyeluruh.

The Krueng Seulimeum ​​sub-watershed is part of the Krueng Aceh watershed in Aceh Besar Regency, covering an area of ​​26,497.08 hectares. The decline in forest cover from 70.86% (1977) to 27.51% (2011) due to land conversion has reduced infiltration capacity and increased surface runoff in the area. This study aims to calculate the weighted Curve Number (CNw), design runoff discharge for three return periods, and the spatial distribution of potential runoff using the GIS-based SCS–CN method, with a scope limited to surface runoff, excluding erosion and sedimentation. Data on the maximum annual daily rainfall for the 2015–2024 period from the Padang Tiji Station (Thiessen weight 0.9283) and the SIM Meteorological Station (weight 0.0717) yield an average regional rainfall of 115.04 mm/year. The Log-Pearson Type III distribution was chosen because Cs = 2.49 did not meet the requirements of the Normal, Log-Normal, or Gumbel distributions, and was accepted through the Smirnov-Kolmogorov test (Δmax = 0.1148 < Δcritical = 0.410), resulting in design rainfall of 96.09 mm, 134.88 mm, and 173.31 mm for return periods of 2, 5, and 10 years, respectively. The HSG classification of 74 Soil Map Units shows a dominance of HSG B (62.56%), with land cover dominated by Mixed Dryland Agriculture (31.36%) and Savanna/Grassland (17.26%). The weighted CN value (CNw) obtained was 69.50 in the moderate category, with S = 111.47 mm, Ia = 22.29 mm. The design runoff discharge was obtained at 90.16 m³/s, 173.49 m³/s, and 266.44 m³/s for 2, 5, and 10-year return periods, respectively. Spatial distribution shows that the low runoff class dominates 92.69% of the area in the 2-year return period without the high class, while in the 10-year return period the medium and high classes together cover 88.37% of the area. The results of this study are expected to be a reference for sustainable management of the Krueng Seulimeum ​​Subwatershed, with recommendations for CN calibration based on field data and integration of HEC-HMS or SWAT modeling for a more comprehensive hydrological analysis.