Tuesday, July 26, 2011

Flood Disaster Mitigation in Yogyakarta

Disasters are a frequent occurrence in recent years and the disaster is no longer a strange word to us. Almost every season, even every month is always a disaster. Rainy season for example, for some people this season is a season that brings a blessing, but some people again this season will bring disaster. For farmers, for example, an initial planting of the rainy season where water is easily available and the plants can grow. Rain stopped some time ago and with a sufficiently high temperature, making the farmers and the government concerned about the shortage of food supplies.
This concern did not last long, after several weeks of rain fell. When it rains it comes the various disasters that many casualties. Landslides in West Java and the floods in Jakarta are some disasters that hit the country after it rains. Catastrophic events in the form of floods and landslides triggered by the reduced area of ​​forest cover due to deforestation happening everywhere. Watershed (DAS) that serves as the main regulator of the water cycle and nutrient cycle of decreased function and quality are very large. In 2005 the government has established 62 DAS in critical condition with 17 watershed of which are in Java (Department of Public Works, 2006).
Damage to the environment and the criticality of the Watershed is one of the causes of the disaster that struck the State Capital. Region upstream land use and poor drainage systems for waste and decreasing the location of the water catchment is a culprit of floods in Jakarta. Flooding is not the first time struck the State Capital, almost every rainy season, Jakarta is always flooded. Floods that occur every year it always should be addressed by the government and certainly working with the community.
In a watershed system Jakarta is included in the downstream region, with its upstream region is Bogor. Bogor as the upstream region, has now been converted to dense residential areas. Over the function of this region will of course affect the water catchment. The water should penetrate through the plant, but the water is directly flowing into the river, and of course with a fairly high attrition rate. The high erosion of the existing upstream region, will affect the river silting. Shallowness of this river will reduce the ability of rivers to hold water. Siltation of the river occurred in all the rivers that pass through the city of Jakarta. Siltation of the river is exacerbated by dumping waste into rivers. Trash will certainly clog the flow of water, resulting in water flow be impeded so that when large volumes of water, then it is not possible the water will overflow.

Jakarta's population density causes all areas of the city inhabited by the population, including flood plains and marsh areas. The area along the river and the swamp is the region's water, where every rain water will always be toward the region. But when this happens, the areas had been transformed into densely populated settlements, so that when the water came, the area will be submerged by water. In addition, the establishment of various buildings in Jakarta without regard to the drainage system is also one of the causes of the flooding. This indicates that the lack of public knowledge about the environment, and weak enforcement of existing laws in this country. 

How to Yogyakarta?Yogyakarta is now developed into a big city, along with the increasing population and a growing number of new building, such as malls and housing, then it is unlikely the city will be flooded as Jakarta. This is because with the increase in building then it will reduce the water catchment zones and would interfere with existing drainage system in this city. In addition, the increased density of population in this city of course will affect the amount of waste. Trash is not trivial, and the public schools would have to be it. Every society shall be responsible for the waste generated, and trash should not be wasted in a river. Various kinds of things should be a serious concern by the government and people of Yogyakarta.

In a watershed system is the central region of Yogyakarta city, with Mount Merapi and some areas in Sleman district as the region upstream and downstream areas in Bantul regency. Coordination of the third region is between the upstream, midstream and downstream should always be done. The rate of land conversion in the upstream area to be controlled, if land use is not controlled then it is not possible upstream region will be met by buildings which of course would reduce the water catchment zone. Besides the destruction of the upstream region of course will increase erosion and silting of the river as a result will occur.Drainage system, also affects the flow of water. Any building or community responsible for the drainage in the vicinity.
Poor drainage system or damage has occurred in Yogyakarta, this is proven when it rains there are some streets are flooded. High standing water is about 20-30 centimeters, and a puddle of water was enough to disrupt traffic flow. This, if ignored or not immediately repaired, then the longer the puddles on the road will be higher, and is not likely to occur, such as Jakarta floods.

Yogyakarta is traversed by several major rivers like the river that divides jogja code is not likely to overflow and cause flooding. Residents who live along the river code is pretty solid. Flood plains should not be used for residence, because the region is a place for the overflow of water if the river is not able to accommodate the flow of water. But now already, along the river in Yogyakarta has been packed by residential areas. This is now done is to keep the river may be able to accommodate the water and running it without transferring water to the river banks. This can be done by not throwing garbage in rivers.
Yogyakarta is a pilot area in terms of the arrangement of settlements in flood plains. Home residents should not be back to the river, houses should face the river, it indicates that the river is not a place of exile.
Water recharge zones should be maintained, because this zone serves to accommodate the water during the rainy season, so when it rains the water does not go directly into the river but stuck in this zone. Examples of this are water catchment basin and the pond water at UGM stadium complex Tridadi Sleman Regency. In addition to the zone, catchment wells must be made or maximized function. Recharge zone is in addition serves to hold water in the rainy season will certainly affect the water conditions in the dry season, so the drought can be prevented.

Sand mining in the area of ​​Mount Merapi will also affect the water flow. When sand is mined by large-scale and without control, then the water should be hampered by sand in the upstream region and can be absorbed by plants will be directly forwarded to the downstream region and of course with a high attrition rate. As a result, downstream areas will receive water runoff is greater than ever before. High rates of erosion can cause siltation of the river, so the river becomes shallow and the water runoff becomes larger, and it is not likely the water will overflow.
Government, civil society and academia must work together in flood disaster mitigation efforts. All three elements must not be separated to mitigate. All have to work integrally. The government has the authority in managing the environment with the help of research from academia and society as executors. Various causes of flooding problems mentioned above, should be a concern of all parties, both government and society.
Awareness is needed to manage the environment if not a disaster, and it becomes our collective responsibility, not just law enforcement and government regulations in force, relating to the establishment of buildings and logging should also be made by the government and each founder has the responsibility for building surrounding environment. The government should also be able to control the rate of land use, by arranging the layout of his city. Disasters in other regions should be lesson for other cities, not only for the affected areas
  

No comments:

Post a Comment