2012 Bududa Landslide, Eastern Uganda

It was very sad to read last week of another large landslide on the slopes of Mount Elgon, in eastern Uganda. Heavy rains resulted in a large landslide sweeping away three villages, and burying an estimated 70 people.This area of Uganda has been hit by other landslides in recent years. In March 2010 an estimated 350+ people were buried by a large landslide, and in August 2011 a landslide killed an estimated 24 people.

These articles proposed a series of measures that should be considered in order to reduce the risk of further disasters: 

1) RELOCATION: A thorough and detailed examination of the Mount Elgon area to determine the areas at greatest risk of landslides. Those at greatest risk should be relocated. The Governments plans to relocate over half a million people have proved to be slow and unrealistic, but some relocation must occur to avoid further serious tragedy. 

2) INCREASED SUSTAINABLE FARMING: Working with communities to encourage a more sustainable farming method in the region, reducing deforestation, undercutting of slopes and increasing natural drainage. There are significant concerns that over-farming on these slopes is increasing soil erosion, reducing natural anchorage and thus continually increasing the vulnerability of these slopes. 

3) ENGINEERING SOLUTIONS: Improving draining of the slopes and toe weights at the foot of particularly vulnerable slopes to increase stability. In addition some instrumental measurement of the slope condition could provide valuable information.

A holistic, multi-faceted approach is essential, as all three of the above have their challenges and limitations. Many people do not want to be relocated, as the slopes of Mount Elgon have good, fertile soil. Compulsory relocation has its challenges, and so there must also be investment in training for farmers - relating to reducing soil erosion and deforestation, and improving drainage. Possible engineering investments should also be considered. Without some form of action the images that we have seen in the past week are likely to be seen again and again.

As Dave Petley has written on The Landslide Blog, this has not been the only landslide recently. There have been significant landslides in Bangladesh and India as well, with a number of fatalities, injuries and missing people.

Friday Photo (35) - Lake Bunyonyi, Uganda

UGANDA: LAKE BUNYONYI
A beautiful location in Uganda, close to the border with Rwanda. Lake Bunyonyi  is popular with tourists due to its stunning location and water activities.
(c) Geology for Global Development 2012

Friday Photo (6) - Geotourism (Uganda)

UGANDA: TOURISTS VISIT WATERFALL IN EAST UGANDA
In many countries, geological and geographical features such as waterfalls, canyons, mountains and volcanoes attract tourists and photographers - generating income for the local community. It is important that sustainability and conservation are considered.
(c) Geology for Global Development 2011

Newswatch - September 2011

Newswatch is a regular round up of some of the key stories relating to the geosciences and international development. This month we look at typhoon triggered landslides, the landslides in Bulambuli (Uganda), World Water Week and the crisis in the Horn of Africa.


Typhoon Triggered Landslides 
Dave Petley's Landslide Blog - hosted by the AGU - has some remarkable pictures of a landslide in Taiwan, triggered by typhoon Namadol, with one comment suggesting the landslide had a runout of 2km. It is well worth having a look at the rest of his site also - with reports from typhoon triggered landslides in Japan also.

Mt Elgon Slopes, Uganda

Uganda Landslides
Following last month's landslide in the Bulambuli area of Uganda, there have been a few reports giving updates about the situation there. One report suggests that food aid has only just reached the 800+ households affected, due to many roads being severely affected by the heavy rains. The Uganda Red Cross has managed to distribute medicine, clothes, blankets, water purifiers, mosquito nets, jerrycans and saucepans - however the need for food has been desperate as many crops were buried by the landslide. Flooding in the area, following heavy rains, has affected a wider area with widespread flooding of pit latrines - putting people at risk of water-borne diseases such as cholera.


World Water Week
Following last week's post about World Water Week here are another couple of blogs written by those who were there. The first is on the End Water Poverty blog and the second, looking at the role of the private sector, is on the Tearfund blog. 

Horn of Africa Drought & Famine
It was welcome to see the terrible situation in the Horn of Africa raised in Prime Minister's Questions yesterday, and it is to be hoped that the political will to continue addressing this crisis is maintained. For the latest information on the situation, The Guardian publish online a weekly blog outlining the funds required and received, and further information.     

2011 Bulambuli Landslide, Eastern Uganda

A major landslide has affected the slopes of Mount Elgon in the Bulambuli District of Eastern Uganda. The landslide has been attributed to heavy rains in the region which is prone to large landslides. In a region hit by drought, with many requiring food aid following the lack of April-May rain, these torrential rains, flooding and landslides are a further blow for local communities. 

The landslide in Bulambuli is believed to have killed at least 24 people, including many children. An entire village is reported to have been buried in mud - which suggests that the death toll could rise as the rescue process continues. Sources suggest that further landslides are possible as heavy rains continue and one report suggested that experts had identified a 40km crack along the slopes of Mount Elgon that could put over 8000 people at risk from major landslides. It is believed that these observations were made by researchers at the University of Makerere in Uganda.

In March I wrote a report of a major landslide that had occurred a year earlier (March 2010) in Bududa, Eastern Uganda. The article highlighted the series of problems that led to the landslide occurring and made some recommendations in order to reduce the risk of future disasters. The article called for:

1) RELOCATION: A thorough and detailed examination of the Mount Elgon area to determine the areas at greatest risk of landslides. Those at greatest risk should be relocated. The Governments plans to relocate over half a million people have proved to be slow and unrealistic (as I suggested in March), but some relocation must occur to avoid further serious tragedy.

2) INCREASED SUSTAINABLE FARMING: Working with communities to encourage a more sustainable farming method in the region, reducing deforestation, undercutting of slopes and increasing natural drainage. There are significant concerns that over-farming on these slopes is increasing soil erosion, reducing natural anchorage and thus continually increasing the vulnerability of these slopes.

3) ENGINEERING SOLUTIONS: Improving draining of the slopes and toe weights at the foot of particularly vulnerable slopes to increase stability. In addition some instruments could be used to  measure the conditions of the slope, instruments such as inclinometers (to measure deviation from the vertical - i.e. if the slope is moving) and piezometers (to measure the pore fluid pressure).

Case Study: Bududa Landslide, Uganda - March 2010

The United Nations Office for the Coordination of Humanitarian Affairs (UNOCHA), have stated (October 2010) that one of their key concerns in Eastern Uganda is flooding and landslides as a result of environmental degradation.

Eastern Uganda is generally a flat plateau, with the border between Kenya and Uganda dominated by the beautiful hills and slopes associated with Mount Elgon, an extinct shield volcano. These slopes are home to a number of communities. The higher elevation provides a more moderate climate than the plateau below, and the fertile soils are used by communities to grow crops, especially coffee. The slopes are also home to a wide variety of plants and forest – although a deforestation programme has been taking place in recent years.

Foothills of Mount Elgon

The slopes of Mount Elgon have been prone to a number of landslide events, as can be seen on aerial photographs. One of the biggest was this time last year (March 1^st 2010) in Bududa. This landslide was preceded by significant rains. The slopes of Mount Elgon are the catchment area for a number of streams and rivers. The heavy rain caused a significant swell of these, and groundwater levels to rise. As groundwater levels rose, the instability of the slope increased due to the decrease in effective stress. This was likely exacerbated by the deforestation, with the soil losing anchorage and surface erosion more likely.

The total impact and effects of this landslide are unknown. Estimates of those who died are currently about 388, and significant numbers were left displaced as soil, mud and boulders submerged three villages. A number of school pupils took shelter in a health centre, which was tragically then destroyed.

From: http://www.afronline.org/?p=3835

As Uganda is entering a new rainy season one year on – there is a possibility that old landslides will be reactivated and new landslides occur. So what can be done to help reduce the tragic loss of life and economic costs of these disasters? In many ways it is hard to answer this question without fully understanding the landslide mechanisms and causes.

The Government of Uganda has criticised the communities for living in these high-vulnerability places, and advised that people move off the landslide prone slopes. This is, however, around half a million people – most of whom are subsistence or crop farmers. Relocating this amount of people, and finding the land for them to make a living, is no easy task. A review of vulnerability in the area could give more specific advice on which communities to relocate – but if crop yields (coffee etc) are less productive than their original plots, it may be difficult to persuade people not to return.

Research published this year in the African Journal of Agricultural Research suggests that farmers have a reasonably good knowledge of where landslides might hit, and some things they avoid (such as terracing) that can trigger landslides. The research suggests that possible interventions could be done using participatory methods. This would aim to help farmers better recognise causes and effects of landslides, and reduce activities that lead to instability - such as undercutting slopes for house construction. The research did not, however, discuss the effects of deforestation with the farmers. It is also unlikely that the threat could be removed simply by getting the farmers to change some practices. A bigger scale intervention, reseeding degraded land, planning and organising the slope-sided farming and improving drainage on the slopes would also be required.

Foothills of Mount Elgon: Concave Slopes identified by farmers as areas more vulnerable to landslides

It is likely that the best way to help reduce the effects of landslides in this area is a combination of a number of things:

• Relocation in some areas of very high risk
• Working with farmers to ensure their farming is more sustainable and avoids environmental degradation. Offering alternative housing styles to prevent the need for undercutting slopes.
• Some possible engineering solutions - improving drainage and increasing toe weights to prevent instability.

It is hoped that the Ugandan Government and their development partners will act strongly to reduce the possibility of future disaster in this area.