Short-term Flood Mitigation Measures of Karun River System

Karun river basin as the biggest water course of Iran, has accommodated a large number of hydro projects including reservoirs, hydropower plants (HPPs), water convey systems, and irrigation networks in south west of the country. The region is vulnerable to flood the damages was remarkable in under construction dam sites in last decade. Although there is master plan for flood mitigation measures, it needs long time and sufficient budget to implement all elements of the master plan in the basin. However, structural measures have traditionally been used as one of the measures in local areas and short term structural and nonstructural approaches have been pursued to reduce vulnerability of the region after extreme floods of 2005 and 2006. This paper discusses the historical flood events of the basin and introduces short term solutions which implemented in the basin recently. Basically the short term solution consists of resistible cofferdams in under construction dam sites in along with early flood forecasting system (EFFS) and emergency action plan (EAP). In this regard, rehabilitated diversion systems and new projects cofferdams have changed to armored soil or roller compact concrete (RCC) after 2005. Implemented EFFS contains regional numerical weather forecast system, rainfall-runoff models, reservoir flood control simulation, flood routing and two dimensional inundation models. Maximum lead time of forecast is about 4 to 5 days depends on the location of the sites, nevertheless, the time is sufficient to evacuate the damage centers before flood occurrence. In addition, EAP of dam break and extreme flood events has been identified after determining potential damages and hazard zones based on inundation areas and depth, flow velocity, and properties of the region. EAP includes guidelines of warning for different hazards and accessing to safe zones as well as planning maps of surviving service.

کلیدواژه ها:

Flood ، mitigation ، measure ، vulnerability ، Karun