Home > Tropical Deforestation, People and Flooding
Tropical Deforestation, People and Flooding
A recent global analysis claiming that tropical deforestation amplifies flood risk and severity proves less than solidA recent study published in Global Change Biology attribute observed floods at national scale to 'deforestation' as major cause and suggests that 'reforestation' will stem the tide. The study re-opened the debate on forests and floods, where the study by FAO and CIFOR in 2005 concluded that there is no hard evidence that tropical forests protect people from (extreme) floods or that reforestation reduces the risk. The data in the Global Change Biology article, however, can be interpreted in multiple ways. Bruijnzeel et. al. (2007) provide an alternative interpretation and conclude that "There are many good reasons to protect remaining natural forests, but the hypothesis of 'flood protection' at national scale remains unsupported." Click here to read the full commentary [PDF]
Further ReadingBradshaw, C.J.A., Sodhi, N.S., Peh, K.S.-H. & Brook, B.W. Global Change Biol. 13, 1-17 (2007). http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2486.2007.01446.x?journalCode=gcb
Bruijnzeel, L.A., 2004. Hydrological functions of tropical forests: not seeing the soil for the trees?. Agriculture, Ecosystems & Environment, 104 (1): 185-228.
Laurance, W.F. Nature (News & Views Section) 449, 409-410 http://www.nature.com/nature/journal/v449/n7161/full/449409a.html
Do Forests Really Prevent Floods?
Every year, the media is dominated by stories about floods in Asia - floods that bring death, misery and poverty to millions of people, and economic havoc to developing nations. and every year the floods are blamed almost universally on upland farmers and loggers clearing and degrading forests. But in reality, the direct links between deforestation and floods are far from certain.
The conventional wisdom that forest prevents floods has clouded the perspectives of decision-makers. As a result, reforestation and forest protection policies recieve much greater emphasis than more holistic watershed and river-basin management.
Not only are reforestation and forest protection policies of dubious effect in preventing floods, they can severely undermine the efforts of the upland rural poor to combat poverty through farming and forestry activities. Policy makers must reevaluate the widely helf belief that forest are giant 'sponges' that soak up heavy rainfall and slowly release fresh water freshwater needs. More attention should be given to watershed management practices that evaluate, plan, restore and organize watershed use to provide desired environmental services while supporting livelihoods.
FAO-CIFOR. Forests and Floods: Drowning in Fiction or Thriving on Facts? (FAO-CIFOR, Bangkok-Bogor, 2005).
Van Noordwijk, M , Poulsen, JG , Ericksen, PJ, 2004. Quantifying off-site effects of land use change: filters, flows and fallacies2004 Agriculture, Ecosystems & Environment 104: 19-34 http://www.asb.cgiar.org/pdfwebdocs/AGEE_special_M_Van_Noordwijk_Quantifying_off-site_effects.pdf