Agriculture's role in flood adaptation and mitigation - policy issues and approaches
Flooding remains the most significant natural hazard worldwide. In the period 1985 – 2008 extreme rainfall events may have been responsible for USD 700 billion of damages. There is a general belief that such events will occur more frequently in the future due to climate change and changes in land use.
It is generally thought that the intensification of agriculture in the past five decades has resulted in greater and more rapid floods following extreme rainfall. Changing land management practices have reduced the infiltration capacity of the soil and drainage systems have been “improved” to evacuate water from agricultural land more quickly. Agricultural land is often the receptor of flooding.
The impact of flooding on agriculture varies considerably according to tolerance of the particular crop or land use activity to excess water, and the frequency, duration, depth and seasonality of the event.
National initiatives such as “Making Space for Water” (England & Wales) or “Space for Rivers” (the Netherlands), have encouraged a re-appraisal of land management options for floodplain areas. Agricultural land in washlands, polders and flood retention basins may be used for floodwater storage to mitigate flood risk elsewhere in the catchment.
In future, given the prospect of increased flood probability associated with climate change, agricultural land is likely to play an important role in mitigation and adaptation strategies for flood risk management. Policies that are able to combine flood risk management with other objectives, such as, depending on priorities, nature conservation, the protection of natural resources and agricultural production and livelihoods, are likely to offer the best long term solutions. Where particular agricultural land management practices are known to result in serious flood risk, there may be a call for regulation and compliance with ‘good practice’. Where farmers purposefully manage land to retain and store potential floodwater to reduce flood risk for the benefit of others, there is scope for policies to reward them accordingly.
For the most part, agriculture’s role in flood mitigation and adaptation will be an adjunct to other flood risk management strategies, such as engineered flood defences for urban areas, rather than a complete substitute for them.
flood risk management; agriculture; policy; OECD countries