ESTIMATION OF COMPOSITE CURVE NUMBER (CNCOMPOSITE) IN UNDA RIVER BASIN

Main Author: Eryani, I Gusti Agung Putu
Format: Article PeerReviewed Book
Bahasa: eng
Terbitan: , 2019
Subjects:
Online Access: http://repository.warmadewa.ac.id/517/1/4.Estimation%20of%20Composite%20Curve%20Number%20.....pdf
http://repository.warmadewa.ac.id/517/
Daftar Isi:
  • The hydrological response of a river basin to rain to be transformed into discharge is influenced by the physical-climatic characteristics of the river basin and its land use. The approach in estimating the transformation of rain into discharge is an approach called the Soil Conservation Service run-off curve number (SCS-CN) model, which is a rain-discharge transformation model using an index of run-off curve number (CN).The Unda River Basin is one of the potential river basins in Bali Province that crosses Bangli Regency in the Upper, Karangasem Regency in the middle and Klungkung Regency in the downstream. The purpose of this research to evaluate the hydrological conditions in the river basin based on the CNcomposite of each sub-catchment in Unda River Basin.The steps of making CNcomposite value analysis begin with the preparation of the boundary map data, the Unda sub-catchment map, the land type shapefile data, the land use shapefile data. Then proceed with the classification of each parameter, then overlay the map, then the results are calculated to calculate the CN value for each type of land and land use. Then to find the CNcomposite value calculated using the CNcomposite formula. From the calculation, the CN composite value for Kaun sub-catchment is 51.76, Masin sub-catchment 51.24, Nyuling sub-catchment 51.48, Tanah sub-catchment is 52.86, Telagawaja sub-catchment is 48.58 and Undasub-catchment is 54.70. The biggest value is in the Unda sub-catchment and the smallest is in the Telagawaja sub-catchment. The smaller the CNcomposite value indicates the better hydrological conditions. So from the map of land use overlay results and soil types in the Unda river basin the best hydrological conditions are in the Telagawaja sub-catchment and the unfavorable ones are in the Unda sub-catchment.