Measuring protection of the world鈥檚 rivers
To 听what extent are the world鈥檚 rivers protected? 听
In 2010, the Convention on Biological Diversity (CBD), an international treaty for the conservation of biodiversity,听 for the protection of 鈥榠nland waters,鈥� including rivers.听But there was a problem: there was no good way to measure progress toward that target. 听
That situation is changing.听 A new study, co-authored by 成人VR视频 geography professor Bernhard Lehner with freshwater scientists from The Nature Conservancy, World Wildlife Fund, and Griffith University in Australia, uses a high-resolution dataset of the world鈥檚 rivers for a first-ever global assessment of the gap between actual protection of the world鈥檚 rivers and the CBD target.听
The study, published Nov. 9听finds that most river systems around the world fall far short of the 17% target set through the CBD. This is especially true when considering 鈥渋ntegrated protection,鈥� including upstream catchment areas. Nearly 70% of river reaches, by length, have no protected areas in their upstream catchments, and only 11% achieve full integrated protection.听Levels of protection vary widely by region: South America, dominated by the well-protected Amazon, has average local and integrated levels approaching 30%, whereas both levels are under 10% for the Middle East.
Integrated protection
Why is integrated protection important?
鈥淎s an illustration, imagine a headwater area where mining activity is discharging toxic pollution into a nearby stream,鈥� . 鈥淭hat pollution finds its way into a downstream river reach that flows through a well-protected reserve.听 Can we call that river reach protected if its aquatic species are being poisoned from toxins derived upstream?鈥澨�
The study outlines a new approach to measuring integrated protection, combining local and upstream protection and using a kind of sliding scale for sufficiency.听 Small headwater catchments might be expected to achieve nearly complete protected area coverage, while at the other end of the spectrum the world鈥檚 largest rivers with massive upstream catchments are considered to have sufficient upstream protection at lower levels.
鈥淢easuring the protection level of rivers is particularly difficult because of the connectedness of river networks where impacts may be propagated downstream over long distances,鈥� says Prof. Lehner. 鈥淏ut we believe that our new indicator of integrated river protection will help us to illuminate gaps and guide a more strategic design and management of freshwater conservation efforts.鈥澨�
PHOTO: Yamuna River in Uttarakhand, India;听CREDIT:听G眉nther Grill听
鈥淟ooking beyond the fenceline: assessing protection gaps for the world's rivers,鈥� Robin Abell, Bernhard Lehner, et al. Conservation Letters, published online Nov. 9, 2016. 听DOI:听10.1111/conl.12312
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