STUDY ON POTENTIAL APPLICATION OF GREEN INFRASTRUCTURE AS FLOOD CONTROL IN MAKASSAR CITY

• Main Author: Wahyuningsih, Tri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43354
• Institution: Institut Teknologi Bandung

Makassar City is determined as one of the 20 flood-prone cities in Indonesia due to land cover changes. The increase of land cover changes results in catchment area reduced and runoff volume increased so that flooding occurs during high rainfall. Green infrastructure has been implemented in several countries to reduce urban flooding in order towards sustainability. Makassar Department of Public Works has formulated a green infrastructure as a flood control program in Strategic Plan 2014- 2019. Implementing green infrastructure requires a suitable location based on type and location criteria. Therefore, this study aims to formulate the potential application of green infrastructure as flood control, especially in reducing runoff. This research used a quantitative research method with a facilitated positivistic approach. Data analysis is divided into 4 stages: the impact of land cover changes on floods; the capacity of primary drainage; the type and location of green infrastructure; and the potential application of green infrastructure in reducing runoff. The analysis of land cover changes in Makassar City using spatial analysis shows that built-up land increase average 17,82% resulting in an increased runoff of 3,63% in the period 1999 - 2017. Primary drainage capacity in Tallo Zone is no longer able to accommodate excess runoff discharge of 31,79 m3/second so that flooding occurs. By using intersect overlay analysis, five types of green infrastructure that can be applied to the Pampang Zone including dry pond (577,62 ha), infiltration basin (80,08 ha), infiltration trench (1,11 ha), bioretention (0,07 ha), and sand filter (22,40 ha). Green infrastructures that can be applied to the Tallo Zone are dry pond (311.09 ha), infiltration basin (25,46 ha), infiltration trench (0,02 ha), sand filter (21,25 ha), and vegetated filter strips (0,51 ha). The analysis of runoff reduction using the SCS-CN method shows that the highest runoff reduction percentage is 7,578% through the application of dry ponds. Other green infrastructure can only reduce runoff <1%. Thus, the application of green infrastructure that emphasizes the principle of infiltration is less potential to be applied in Makassar City. If reviewed based on the potential for runoff reduction per 1 ha, the application of dry pond can reduce runoff by an average of 339,97 m3/ha, infiltration basin (254,89 m3/ha), infiltration trench (245.40 m3/ha), bioretention (273,15 m3/ha), sand filter (214,43 m3/ha) and vegetated filter strip (251,70 m3/ha)