Integrated disaster risk reduction in flood-affected areas by local communities (ប្រទេសតាហ្ស៊ីគីស្ថាន)

Climate change and land degradation in upper catchment areas cause an increasing frequency and intensity of flash flood and debris flows affecting settlements and productive areas. GIZ in collaboration with the Committee on Emergency Situations assisted local communities in the implementation of integrated preventive measures.

Villages and associated productive lands like orchards, gardens and arable fields in the lower parts of the northern main slope of the Turkestan mountain range are typically located in the valleys of rivers and streams. Water discharge in these rivers and streams is seasonally highly variable. During the wet season water flow is very high, while during the dry summer and fall months almost no water is visible at the surface and the limited discharge takes place in the gravel of the riverbed. After rainfall and during snowmelt extreme flow events happen with discharges several times exceeding the average of the wet season. Flashfloods with high speed and energy typically cause the transportation of large amounts of debris. These debris flows can be much more destructive than ordinary high water events. The resulting riverbank erosion is in some extent a natural element of the morphological dynamic of rivers and streams.

Land-use related factors have increased the vulnerability of communities to these flashfloods and debris flows as well as their destructiveness. Population growth, the expansion of settlements and the reclamation of more lands for irrigated orchards, gardens and arable fields have brought more people and values into potentially risky areas. The degradation of the vegetation in upper catchments has contributed to reduced infiltration of water and high and fast surface runoff. The riparian forests and woodlands which in some extent slow down flashfloods and keep sediment have been largely destroyed by clearing, livestock grazing and by the increasing intensity of flashflood events.

These problems are increasingly exacerbated by the impact of climate change. The already visible trends and predictions show higher levels of aridity, higher temperatures during the vegetation season, reduced overall precipitation in catchment areas – all affecting the retention potential of upper catchment areas – and more irregular rainfall patterns, reduced snow packs and accelerated snow melt as well as the loss of glaciers as buffers of water flow. These factors all contribute to a higher frequency and intensity of flashflood and debris flows.

These events threaten settlements, infrastructure and human lives, but they also pose substantial risks to the stability and functioning of irrigation canals, cause irreversibly losses of productive lands and thus threaten livelihoods of farmers and food security.

The approach brought together the Committee of Emergency Situations, affected local people and the administrative communities, the mahalla committees, which represent the inhabitants of one village or a section of a larger village. These institutions are called communal self-governance structures, but are subordinated to the government as they are reporting to the sub-district or jamoat. Assisted by experts provided by the project, the situation was jointly analyzed; risks identified and integrated intervention planned. Typically the interventions consisted of a combination of “grey” (i.e. constructive structures) and “green” (i.e. protective vegetation) measures. Most of the upper catchment areas belong to different communities, often to different districts and substantial parts are located in neighboring Kyrgyzstan. Therefore addressing the degradation of these areas and a reduction of disaster risk through integrated watershed management in the entire catchments was rarely possible.

The project assisted with technical planning, construction supervision, purchase and transportation of construction materials. The communities would contribute about 30% of the overall costs, mainly in form of voluntary communal work, the so called hashar, as well as in form of locally available construction materials. The community is also in charge of future operation and maintenance of the riverbank protection structures.