Water for people.pdf - WHO Thailand Digital Repository

1 5 2 / C H A L L E N G E S T O L I F E A N D W E L L - B E I N GProtecting Ecosystems for People and Planetareas where both population growth and the likelihood ofagricultural expansion are highest.In recent years, an extension of the holistic approach implied byIntegrated Water Resources Management (IWRM) has emerged inwhich ecosystems themselves have become the subject ofconservation efforts. Instead of restricting efforts to individualspecies and aquatic sites, planning has now to expand in scope:■ geographically, to a scale appropriate to the size of catchmentbasins; and■ conceptually, aiming to maintain ecosystem processes and thecomponents of these systems, including human communities(the ‘ecosystems approach’, e.g. Reynolds, 1993).In practice, reconciling the many different concerned interests andcoordinating actions has proved difficult and is likely to remain so inmany situations. Maintaining biodiversity and conserving inlandwater capture fisheries (other than some lucrative sports fisheries),for example, have not ranked highly among these competinginterests, and it has thus proven difficult to impose catchment-wideregulations or remedial measures for their benefit.Although it is difficult to assess the outcome of all theseprocesses, in terms of beneficial effects on ecosystem condition(and results cannot yet be expected in many instances), theevidence reviewed above demonstrates the improving trend incertain variables that is apparent in some countries, and thedetermination of others to reverse recent decline in condition.However, such cases relate mainly to OECD and other developedcountries, and the overall global situation remains very hard toevaluate.ConclusionsProtection of ecosystems must remain central to sustainabledevelopment because environmental security, social well-being andeconomic security are intricately intertwined and fundamentallyinterdependent. Degradation of any one worsens the condition of allthree. We protect our ecosystems and their creatures for their inherentvalues and because of the benefits they yield to waste disposal,environmental health, natural resource production, and as water sources.Pressures on ecosystems are reasonably well understood, and a numberof practical tools exist that allow the condition of ecosystems to beassessed and monitored. These clearly show that freshwater ecosystemshave been hit much harder than land or sea ecosystems. In effect, amajority of the world’s largest rivers are substantially fragmented bydams, diversion and canals, and many fall far below accepted ecologicalquality guidelines. This is not only true for rivers, but also for lakes, theglobal condition of which is steadily deteriorating, and for wetlands,which are frequently converted to agricultural lands.In many places, water quality has deteriorated dramatically,particularly in regions with intensive agriculture and largeurban/industrial areas. Pollution from bacteria, human waste, highconcentrations of nutrients, sedimentation and rising salinity, is anever-growing problem throughout the world. Freshwater biodiversityhas been severely affected by this decline in water quality, amongother issues, and many species have become extinct.Although there is evidence of local – and sometimes national –improvement as well as action plans that are being implemented, theseare not yet stemming the global deterioration of ecosystem conditions.The future sum of the local gains will need to add up to much more ifthey are to have effect – and they must also counter the inevitablefuture population growth pressures from improvements in health, food,energy and industry. Thus, protecting ecosystems implies reconciling themany different water interests, through some kind of a global approachlike that claimed by IWRM. If this is not done, the economic and socialdevelopment targets to which the international community is committedwill be jeopardized.