Evaluation of infrastructures and riparian area toward the potency of debris flow effect in Putih river watershed, Indonesia

Abstract

Putih River is one of the rivers which was affected by debris flow after the eruption of Mount Merapi in 2010. The impact of the damage included riparian areas and infrastructures took place along the river. This research aims to evaluate the condition of riparian area in Putih river watershed with the established rules of Indonesian government and conditions of infrastructures that constructed along the river. The research was carried out by field survey that supported by Survey123 for ArcGIS and data processing using ArcGIS software. Based on the results, it shows that Jumoyo village had the largest of riparian area with 2.1 Ha for riparian area by 5 m width and 10 Ha for riparian area by 50 m width. The result also showed that Jumoyo village had the highest approximate population number within the riparian areas with 656 people for riparian area with 5 m width and 1465 people for riparian area with 50 m width. From the field survey result, it shows that there are 35 buildings/infrastructures in Putih River, consisting of 2 dams, 11 bridges, 1 ground sill, 20 sabo dams, and 1 sand pocket.