[This article is extracted from ICIMOD official website. To view full text with pictures, please visit the source : http://www.icimod.org/?q=10932. Editor]
While the world is waking up to the news of the horrific scale of the recent flood disaster in the Mahakali basin of Nepal and Uttarakhand in India, several questions are being asked: what kind of climatic events led to this disaster? Could anything have been done to reduce the loss of life and property? What can we learn from this disaster for the future? In this brief note, we address some of these burning questions.
Mahakali flood disaster
The Mahakali river is a transboundary river between Nepal and India with a catchment area of 14,871 km2. It flows for about 223 km in Nepal and around 323.5 km in India to its confluence with the Karnali River in India. The recent rainfall events in the western and far western regions of Nepal and India affected 20 districts in Nepal and several districts in the Indian states of Uttarakhand and Himachal Pradesh. The floods and landslides that ensued have left hundreds of people dead or missing and destroyed property worth millions of dollars. While this is not the first event of this kind (see annexes), it is certainly the most severe in the last 50 years and it happened at the beginning of the monsoon when no one was expecting.
Intense rainfall events
The monsoon rains usually hit Central Nepal around 15 June and Far Western Nepal around 20 June. This year, the monsoon quickly engulfed the region (http://www.imd.gov.in/; Figure 2). The real-time monitoring station in Nepal reported 80.4 mm of rain on 16 June and 221.8 mm on 17 June at Dipayal, which adjoins the Mahakali flood disaster area (http://dhm.gov.np/; Figure 3 and Figure 4). Surrounding areas such as Dadeldhura, Dhangadi, and Birendranagar in the Far Western Development Region of Nepal recorded more than 150 mm of rainfall in 24 hours on 17 June 2013. Continuous rain in the upper catchments caused the water level in the Seti river east of the Mahakali to rise from 6.94 m to 11.56 m and 5.53 m to 12.81 m in the Karnali at Chisapani on 17 June, as measured by Department of Hydrology and Meteorology, Nepal’s real time network. Unfortunately, there are no real time stations installed by the Department on the Mahakali river. One to three day weather forecasts provided by United States National Oceanic and Atmospheric Administration (NOAA) also indicated heavy rainfall on 17 and 18 June on the border of Nepal and India (Figure 5). Cumulative 3 day TRMM rainfall estimates from 16 June to 18 June show heavy rainfall in the flood affected regions of Nepal and India (Figure 6). The discharge in the Mahakali river rose from 139,000 cubic feet per second to 440,716 cubic feet per second on 17 June – well in excess of the flow of 398,000 cubic feet seconds recorded in the 2012 monsoon (http://www.kantipuronline.com/2013/06/18/top-story/massive-floods-in-mahakali-river-6-killed-update/373456/).
Impact
What we have learnt from this series of events?
- Put in place institutional mechanisms that that can use technological advances in forecasting:
Although some warnings were disseminated by the India Meteorological Organization about the possibility of high to intense rainfall, this information was not transmitted to thepeople at risk. There is a need to strengthen disaster management and preparedness mechanisms, which requires awareness and sensitization at various levels to ensure that early warning information is conveyed to end users well in advance. Advances in technology have made it possible to provide three to four hours warning of such events – which is enough to save lives. We need to develop the institutional mechanisms to fully use such technological advances.
- Set up more hydrometeorological stations on transboundary rivers:
There is no river-level hydrological monitoring station on the Mahakali river for flood forecasting and early warning. It is recommended that a river monitoring station for early warning be set up jointly by Nepal and India to provide people with some lead-time and improve flood forecasting and management in the basin.
- Carefully plan infrastructure in the mountains:
The Hindu newspaper put it succinctly when it said that damage could have been contained through proper policies, especially regarding infrastructure development. The development of infrastructure in mountain areas, whether roads or buildings, is challenging. Many mountain roads are contributing a huge sediment load to our rivers and inviting landslides. Many of the settlements are located along flood plains and have developed over the years, encroaching the river banks and increasing the vulnerability to floods. These settlements include residential homes, offices, resorts and restaurants to name a few. There has been limited or no efforts to move these settlements to higher grounds. In the recent floods, large stretches of road and settlements were washed away stranding thousands of people and raising questions about their design, construction, and monitoring. Infrastructure development in the mountains has to be undertaken with caution and proper planning, and must apply different standards to that in the plains.
- There is also a need to investigate whether or not there have been significant land use changes in the basin resulting in increased runoff.
ICIMOD’s role in Disaster Risk Reduction
- assessment of vulnerability of communities and building their resilience to multi-hazards;
- assessment of the impact of climate change on ecosystems, natural hazards, and human health;
- delivery of training in disaster risk reduction; and
- provision of a platform for sharing knowledge and experiences within disaster risk reduction.
Annex 1. Recent floods in Nepal with disaster details
Region |
Year |
Disaster |
|
Mahakali |
June 2013 |
Final report still to be prepared |
|
Dang |
June 2012 |
145 families were displaced and 2,200 household were affected by flash floods |
|
Batadi, Achham, Kalikot, Jajrkot, Rukum, Rolpa, Kaski, Tanahu, Makwanpur, Gorkha, Nuwakot, Sindhuli, Sarlahi, Solukhumbu |
June 2011 |
14 districts affected by floods and landslide; 25 deaths; 2 missing; 4 injured; 515 houses destroyed |
|
Dailekh, Jajarkot, Rukum, Palpa, Rupandehi, Parbat, Dhading, Sindhuli, Solukhumbu, |
August 2011 |
9 districts affected; 65 deaths; 35 missing; 24 injured; 110 houses destroyed |
|
Kanchanpur |
September 2010 |
60 houses damaged on the Mahakali river |
|
Dadeldhura, Bajura, Achham, Rukum, Kaski, Illam |
June–August 2010 |
6 districts affected; 98 deaths; 8 missing; 29 injured; 2,835 houses destroyed; 39,000 people affected |
Annex 2. Recent floods in India with disaster details
Region |
Year |
Disaster |
|
Uttarakhand, Shimla, Himachal Pradesh |
June 2013 |
Final report still to be prepared |
|
Guwahati, Brahmaputra river overflow |
July 2012 |
80 deaths from flood; 16 buried in landslide; 11 missing |
|
Assam |
July 2012 |
95 deaths; 12 missing |
|
Uttarkashi district, Ganga flood |
August 2012 |
34 deaths; 80 houses damaged |
|
Uttar Pradesh, Bihar |
September 2011 |
30 deaths; 10 missing in Brahmani river |