Explanation Text

Explanation

Rainfall on January 1, 2020 around Jakarta, according to the Meteorology, Climatology and Geophysics Agency (BMKG), is among the most extreme and highest since 154 years ago. Floods triggered by heavy rains have submerged parts of the nation's capital and surrounding buffer cities.

To this day, more than 50 people have died and more than 170 thousand people have become imprisoned refugees because their homes were swept away by the flood.

There have been many studies and studies to deal with the Jabodetabek flood. Both the central and regional governments have produced planning documents, spatial planning, master plans and programs.

But only a few of these plans have actually been implemented. The implementation of the flood prevention plan is still partial, short term, and not yet integrated.

With extreme weather getting worse due to the effects of climate change all levels of government need to issue radical policies in collaboration with the public, private sector, NGOs and institutions as well as the international community.

Cause of flooding
Excessive exploitation of groundwater in Jakarta causes the capital city of this country to continue to sink, with an average rate of land subsidence of around 3-18 cm per year. This condition has worsened in North Jakarta, which borders the sea. Land surface height in this region is 1.5 meters lower than sea level as a result of climate change. As a result, water flow from upstream (Bogor and Depok) cannot be discharged into the sea.
In addition to land subsidence, there are several other factors that have caused flooding in Jakarta, Bogor, Depok, Tangerang and Bekasi.

Channels and catchments (reservoirs, rivers, flood canals, drainage and green open spaces) that have less capacity to accommodate large volumes of water due to extreme rainfall. The flow and border of the river narrows because some of the rivers in Jabodetabek experience siltation. Some of the catchment areas and reservoirs are also less than optimal because of changing functions.

In addition, the existing water channels are clogged with garbage due to poor waste management. DKI Jakarta produces approximately 7,500 tons of waste per day or 2.7 million tons per year. The amount does not include 300-400 tons of garbage dumped by residents into rivers, especially during the rainy season.

Stagnant water is also caused by an old issue, namely the closure of the surface of the land covered with concrete or material that holds water to seep in the soil. Population and economic growth, massive infrastructure development and urbanization have made land occupations increasingly narrow.

According to data from the Central Statistics Agency, Jakarta's population continues to grow, reaching 201.46 million in 2018. This causes Jakarta's land to continue to decrease. In 2014, around 83% of the 674km2 of the Jakarta area had been used, according to research by Mathias Garschagen and colleagues (2008). So naturally the carrying capacity of the city continues to decline.