It's a classical word that institution/government reacts aftermaths rather than preventive countermeasures. See the recent disaster of the dam burst, Situ Gintung. The water authority has been immediately issuing responses to take actions for similar cases may occurred.
http://www.malangpostnews.co.id/index.php?option=com_content&view=article&id=690:waspadai-bendungan-karangkates&catid=47:agropolitan&Itemid=75
Surely there is an emergency action plan (Rencana Tindak Darurat-RTD ?) for such hazard due to flash flood caused by dam break for any dams and water structures. Definitely, this plan is including the worst scenarios and the mitigation plan. It is an obligation for most of water projects. Then how it's being implemented. Are there any early warning systems? or just pile up the documents in the office.
Moreover, it's still questionable and debatable on the accuracy of past RTD studies. The rising question is when the study was carried out and what kind approaches they used. If it was done several years or even decades ago, no doubt to revise it.
Take a simple fact. Was RTD being studied with 1D model? If the answer is yes, definitely it has to be updated. But if the answer is no (used advanced approaches) another question is still coming.
What kind of topography data was taken? How was the land use data?
Doing study of flash flood, it's absolutely required high accuracy DEM. Using derived DEM from1:25.000 map is not sufficient enough since more details (roads, housing etc) will be uncovered. As consequences the results are inaccurate. The landuse during RTD studies and current situation is different. It has been altered. That sounds better if it was properly projected within these studies.
Then what shall we do?
Well. As I understand so far, this DEM problem is mostly concerns not only by developing countries but also developed countries. It is very costly to have it and needs more resources to analyze (eg. LiDAR data). Perhaps the aerial photo of the prone areas to inundation is a mid solution. If it's required the ground leveling has to be done at specific area needs to be detailed. Combined with the existing DEM, more accurate topography map could be obtained and a flash flood modeling could be set up. Alternatively, a physical model test with detail villages is also worth to be done.
Despite how much money will be spent on this study and who will do it, those are just about my opinions as water practitioner dealing with such flood risks. Indonesia is still my lovely country.
May God bless us, all victims and their family in this disaster, Amien.
http://www.malangpostnews.co.id/index.php?option=com_content&view=article&id=690:waspadai-bendungan-karangkates&catid=47:agropolitan&Itemid=75
Surely there is an emergency action plan (Rencana Tindak Darurat-RTD ?) for such hazard due to flash flood caused by dam break for any dams and water structures. Definitely, this plan is including the worst scenarios and the mitigation plan. It is an obligation for most of water projects. Then how it's being implemented. Are there any early warning systems? or just pile up the documents in the office.
Moreover, it's still questionable and debatable on the accuracy of past RTD studies. The rising question is when the study was carried out and what kind approaches they used. If it was done several years or even decades ago, no doubt to revise it.
Take a simple fact. Was RTD being studied with 1D model? If the answer is yes, definitely it has to be updated. But if the answer is no (used advanced approaches) another question is still coming.
What kind of topography data was taken? How was the land use data?
Doing study of flash flood, it's absolutely required high accuracy DEM. Using derived DEM from1:25.000 map is not sufficient enough since more details (roads, housing etc) will be uncovered. As consequences the results are inaccurate. The landuse during RTD studies and current situation is different. It has been altered. That sounds better if it was properly projected within these studies.
Then what shall we do?
Well. As I understand so far, this DEM problem is mostly concerns not only by developing countries but also developed countries. It is very costly to have it and needs more resources to analyze (eg. LiDAR data). Perhaps the aerial photo of the prone areas to inundation is a mid solution. If it's required the ground leveling has to be done at specific area needs to be detailed. Combined with the existing DEM, more accurate topography map could be obtained and a flash flood modeling could be set up. Alternatively, a physical model test with detail villages is also worth to be done.
Despite how much money will be spent on this study and who will do it, those are just about my opinions as water practitioner dealing with such flood risks. Indonesia is still my lovely country.
May God bless us, all victims and their family in this disaster, Amien.
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