As the Millennium Ecosystems Assessment report explains, the benefits people receive from nature are ‘ecosystem services’. Forests, aquifers, soils, lakes and wetlands provide water storage,wetlands and soils filter water, rivers provide conveyance and transportation and abundance of fish, floodplains and wetlands lower flood peaks in downstream cities, while mangroves, coral reefs and barrier islands protect coasts against storms and inundation. Nature recycles and absorbs excess nutrients and water pollution.Degradation of these services is costly – the TEEB – focused on water and wetlands provides great data to support this
Degradation of services has impacts on the nexus, for example: +Diama dam constructed in 1985, to stop dry season influx of saline water into the lower valley and to store water for irrigationill-conceived infrastructure: By 1997 only 44,000 ha of projected 375,000 ha of irrigation farmed. Rice yields ¼ of the assumed amounts in project justificationdead zone; invasive species... Fishermen’s income reduced and less grasses for weaving available livestock grazing reduced - livelihoods destroyed; ignoring ES meant less food security not more – poorer people and less water an food secure as a resultCritical services from nature equate to functions of infrastructure. With the term infrastructure defined as ‘the stock of facilities, services and installations needed for the functioning of a society’, nature is part of infrastructure portfolio of every country and every economy. This is ‘natural infrastructure’, which complements, augments or replaces conventional built infrastructure like reservoirs, dams, levees and canals. The natural infrastructure provided by ecosystems is usually highly cost-effective, and its restoration can provide attractive returns on investment in social and economic terms.
Ecosystems critical to the nexus. As we’ve seen then, services from ecosystems, natural infrastructure, underpin each of the three securities of water, food and energy. Without healthy ecosystems in well-functioning watersheds, the infrastructure built for irrigation, hydropower or municipal water supply does not function sustainably, and is unlikely to achieve the economic returns necessary to justify investments. With its functions integral to the three securities and their inter-dependence, nature is part of the infrastructure needed to manage the nexus and its resilience.
Offer a way of looking at the indicators in the context of the nexus:Availability = runoff – available water for withdrawal You can have a traffic light / scoring system which shows that if the for example demand is higher for irrigation than the water availability then the score is high - indicating danger to the nexus!
Compare health and degraded system - services
Natural infrastructure in the nexus_IUCN UNECE presentation_April2013
Natural infrastructure in the nexus andsuggested basin assessment indicators Rebecca Welling Project Officer IUCN Global Water Programme Gland, Switzerland
water for foodwater purificationflow regulationwater storage water supply water storage water supplyfisheries provision water conveyance cultural services water for energy
Ecosystems are infrastructure – part of the “the stock of facilities, services and installations needed for the functioning of a society” Nature is part of the infrastructure portfolio of every country and every economy
flood regulation water provisionwater purification water storage Nature+ nexusfisheries provision water for energy
Ecosystem indicators Biodiversity and habitat loss –Metrics: wetland disconnectivity, Red List Index Water management impacts on ecosystem integrity –Metrics: Estimated total river fragmentation, estimated total flow disruption, estimated total density of dams 6
Ecosystem indicators (continued) Fish threat –Metrics: Average annual catches of fish, estimated potential fish production, proportion of non- native fish species Basin productivity –Metrics: water storage capacity, flow variability, and regulation, filtering of water capacity, absorbing and buffering capacities 7
Understanding ecosystem indicatorsfor the nexus• Water for food – Agricultural water stress (cropland+irrigation vs. availability)• Water for energy – Disconnectivity-Wetland loss and river fragmentation, flow disruption by reservoirs• Water for nature – Environmental water stress (ecological requirement vs. availability)• Water for people – Human water stress (population vs. availability)8