East Flood Way is one of the rivers in Semarang City that often cause flooding. Flood water level in the East Flood Way is affected by the discharge of storm water runoff and tide (rob). Facts on the ground indicate

ABSTRAK

Inundation of flood and rob (flood due to high tides) in Semarang City is increase wtithin area and depth. It be more seroius condition because of land subsisdence that happened in coastal area of Semarang City. This research is foccused on prediction and mapping of inundation flood and rob due to land subsidence effect in East Semarang, especially Tenggang Watershed and Sringin Watershed. On this research, data analysis including analysis of land subsidence, analysis of hydrological data, analysis of flood discharge with HEC-HMS, hydraulics analysis with HEC-RAS and then mapping the results of the flood inundation with Arc GIS. The inundation will be create with overlay the DEM of flood water level and DEM of topographic. According to the results of analysis is known that minimum land subsidence is 0 cm/year that happened in south area of Semarang and more higher ini north area with maximum land subsidence is 5.58 cm/year. On periode   2014-2031, the contribute of land subsidence to increase the inundation of flood and rob is 1.39%/year.

No abstract

Increased urbanization has an impact on increased impervious surface, consequently the urban drainage system becomes gradually overloaded, with frequent spills and inundate urban areas. Upgrade or re-design the existing drainage system is not an effective solution because it does not address the source of the problem. It is necessary strategies for urbanization reduction of storm-water runoff. These strategies are aimed to reduce storm-water runoff mainly through water infiltration. One of the strategies is to develop permeable pavement. This study is aimed to test the capacity of permeable pavement through the development of full scale physical models in the parking lot. The results show that proposed permeable pavement are able to significantly reduce volume and peak discharge of storm-water runoff, delay the start of runoff and slow the peak discharge. The application of this proposed permeable pavement in the urban area is strongly recommended to reduce drainage load as well as to increase groundwater recharge.