Technologies can tame landslides

Mar 15, 2010

ONE morning I was in office, thinking about the landslides disaster in eastern Uganda, when a friend, who was equally distressed, sent me an e-mail demanding to know whether there is anything the conservationists could do to tame the landslides.

ONE morning I was in office, thinking about the landslides disaster in eastern Uganda, when a friend, who was equally distressed, sent me an e-mail demanding to know whether there is anything the conservationists could do to tame the landslides.

I feel I should use the media to reply her and broadly share some tips for prevention, mitigation and risk management for land slides at farm level.

So why does rainfall trigger landslides? This is because when water enters the pores of the soil, it loosens the soil particles. When the slope fills with water, the fluid pressure gives the soil momentum to move. In some cases water can create pressure as a result of groundwater flow which will decreases the stability of soil and thus cause down slope failure.

The best approaches to mitigate landslides must focus on how to improve slope stabilisation. Three approaches have been broadly suggested:- Changing the geometry of the hillside e.g slope reduction; lowering the groundwater level and using mechanical and chemical methods e.g retaining walls to stabilise the slope.
These structures may not be applicable in our farms in Mt. Elgon and Kigezi because they are expensive, however, the principle of slope stabilisation can be borrowed and used at farm level.

The technologies include the construction of simple, but effective structures such as Fanya Juus, terraces, banks, bonds, cut-off drains and barriers. This works hand-in-hand with conservation farming practices such as contour farming and hedge row planting.

Tree planting on open slopes can stop hillside movement and nearly all erosion. If fragile slopes must be utilised, selective clearing must be applied, however, if deemed necessary by authorities settlement or farming on such slopes should be outlawed.

Much as certain conservation measures can promote soil stabilisation and reduce the risk of landslides, it must be noted that no single effort can achieve total slope protection. Efforts must be made to include everyone because the protection of slopes is to ensure safety for all of us.

As the country deals with these disasters, my heart goes out to the people of Bududa and Kabaale. Those who have lost loved ones, homes and have been displaced, we pray for you.

The writer is a scientist at the National Agricultural Research Organisation

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