image: The heavily deforested Dzalanyama Forest Reserve near Dedza, Malawi. view more
Credit: Image courtesy of Solomon Justus Sibale (photographer).
Deforestation in Malawi is linked to decreases in access to clean drinking water, a study finds. Forestry and hydrology studies have concluded that forest loss decreases the amount of precipitation that infiltrates the soil and increases the runoff volumes of streams and rivers. However, these findings do not reflect how the increase in runoff due to deforestation affects human access to clean water. Hisahiro Naito and Annie Mwayi Mapulanga examined links between deforestation and clean drinking water access in Malawi, a country with a high deforestation rate in sub-Saharan Africa. The authors linked satellite data quantifying deforestation area with Malawi census data. The authors also included data on household sources of drinking water and classified those sources as safe or unsafe. For each percentage point decrease in forest area, the probability of household use of safe drinking water decreased by 0.93 percentage points. Although loss of forest cover can increase runoff, the increased runoff can accelerate soil erosion and increase the sediment load and turbidity of water sources, thus decreasing the water quality. According to the authors, the cumulative effect of a 14% loss in forest area in Malawi on clean drinking water access is equivalent to a 9% decrease in precipitation, highlighting the link between forest and water source preservation.
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Article #18-14970: "Effect of deforestation on access to clean drinking water," by Annie Mwayi Mapulanga and Hisahiro Naito.
MEDIA CONTACT: Hisahiro Naito, University of Tsukuba, JAPAN; tel: +81-29-853-7431; e-mail: <naito@dpipe.tsukuba.ac.jp>
Journal
Proceedings of the National Academy of Sciences