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4 Water and the Environment
Pages 66-99

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From page 66...
... To a large degree, environmental quality refers to the area's ecosystems, and without the goods and services of natural ecosystems, sustaining supplies of high-quality water for people will be extremely difficult and expensive. Environmental concerns are central to sustainable water resource planning.
From page 67...
... When activities destroy or impair the ability of natural ecosystems to provide these goods and services, the goods and services must be replaced by artificial means. Examples of such replacements are wastewater treatment plants, water filtration and purification systems, erosion control programs, and so on.
From page 68...
... Soil retention is linked to water-related ecosystem services, and these are directly related to sustainable water supplies. Another important ecosystem service is the maintenance of the hydrological cycle.
From page 69...
... Furthermore, many of these aquatic ecosystems are under intensive management or have been totally replaced by terrestrial ones. The following section addresses ecosystem services of the study area's streams, lakes, and wetlands.
From page 70...
... Thus, the water bodies, constructed for the sole function of water treatment or supply, become intensively managed ecosystems, with ecosystem functions shaped by the wild species that successfully colonize them. Like natural and less intensively managed ecosystems, constructed aquatic ecosystems provide the ecosystem service of promoting wastewater treatment.
From page 71...
... For example, woodland ecosystems are relatively rare in the study area, but their sharp contrast with the more common deserts make them important recreationally and inspirationally. Aquatic ecosystems are even more valuable in these respects, especially when they occur in deserts, such as the Azraq Oasis or wetlands and oases around the Dead Sea.
From page 72...
... ecosystems, namely, in the wild. But their progenitors, and more often their wild relatives, still occur in natural ecosystems.
From page 73...
... Conflicts Between Water Resource Development and Ecosystem Goods and Services All species of realized or potential economic benefit to humans, globally and in the study area, are land users, and this type of land use competes with irrigated cropland. Improved water supplies for the study area may reduce not only the economic benefit of any expanded agriculture, but also the sustainability of existing irrigated and rain-fed agricultural production.
From page 74...
... Water Supplies, Biodiversity, and Desertification There is a critical relationship between ecosystems, desertification, loss of biodiversity, and climate change in the context of sustainable water supplies. Desertification is land degradation in drylands caused by mismanagement and overexploitation.
From page 75...
... The preceding sections explained how environmental quality depends on the goods and services provided at no cost by natural ecosystems and explained how economic well-being, quality of life, and maintenance of water supplies depend on environmental quality. This section describes some of the specific consequences that follow from failure to maintain ecosystem goods and services by losing the land that is needed for ecosystems to persist.
From page 76...
... Effects of Water Use on Regional Biodiversity and Ecosystem Services It is clear from the preceding that biota and ecosystem services depend on water. Water-resource development in the study area usually entails six major practices: transportation of water from lakes and river sources; pumping from sources of springs as well as impounding springs by enclosing them in concrete structures; drainage of wetlands and large ponds; drainage of ephemeral ponds; pumping from aquifers; and damming floodwater courses to construct floodwater reservoirs.
From page 77...
... As Appendix C shows in greater detail, a watershed-management approach for the whole Jordan River Basin could be essential to achieving overall sustainability of water-resource development in the area. This approach could achieve a sound balance between providing water supplies to the study area, and maintaining and promoting ecosystem services related to water quality those of both the Hula wetlands and Lake Kinneret/Lake Tiberias/Sea of Galilee as well as the biodiversity of the lower Jordan River and around the Dead Sea coasts.
From page 78...
... The most important ecosystem services of these pools are recreational, educational, and scientific, given the unique nature of their biodiversity and their dynamic ecology. The interest in Israel's ephemeral ponds has generated surveys and plans for rehabilitating and constructing ephemeral ponds, rather than permanent artificially maintained water bodies (Gazith and Sidis, 1981~.
From page 79...
... Finally, the reservoirs enrich the desert with water bodies that dramatically affect the behavior, population dynamics, and structure of the desert's annual-plant communities. These changes may be exacerbated since the development of aquatic biota in the reservoirs often leads to introducing predatory fish to control mosquitoes.
From page 87...
... Two other effects are restricted to agriculture: the damage to species in adjacent and nearby ecosystems caused by airborne pesticides, and the contamination of aquatic ecosystems and aquifers by pesticide and fertilizer runoff. Loss of Natural Ecosystems and Biodiversity The millions of dunams of agricultural land in the study area, much of it under intensive cultivation, means the loss of millions of dunams of natural ecosystems.
From page 88...
... The reduction of natural ecosystems also causes local extinction of populations and species, that is, reduction of biodiversity, regardless of the loss of ecosystem services. The persistence of a population is a function of its size, among other things.
From page 89...
... To conclude, the appropriation of land by agricultural and urban development impairs at least one water-related ecosystem service recharge and also jeopardizes regional biodiversity. A troubling example of the loss of biodiversity is the loss of natural ecosystems in the Negev desert.
From page 90...
... Mitigation activities are of four types: restoration of damaged aquatic ecosystems; securing allocation of water for aquatic ecosystems, thus guaranteeing their ecosystem services for the future; development and implementation of a system for environmental impact assessment of planned major water-management projects in the study area; and development of regional planning policies that integrate water-resource development, agricultural development, and the functioning of natural ecosystems, to promote overall sustainability.
From page 91...
... Balancing Water Resource Development with Biodiversity and Ecosystem Services Regional Planning Using Advanced Technologies Intensifying water-resource development puts the study area's biodiversity and ecosystem services at risk. It is therefore necessary to evaluate the benefits of the development against the lost biodiversity and services.
From page 92...
... For highly developed sections of the study area, the biodiversity areas will be scattered patches of natural ecosystems within a matrix of development, with the size of each patch and its distance from adjacent patches contributing significantly to its relative value. In nondeveloped areas, patches of development will be interspersed within a matrix of natural ecosystems, and the relative value of each type of patch will be less affected by size and distances to similar patches.
From page 93...
... Water-related ecosystem services depend on the property of the ecosystem and its placement within the watershed. Concerning properties, working hypotheses are that the larger the number of vegetation layers, the greater is the infiltration potential and the smaller the risk of soil erosion and intense surface runoff; and the larger the number of species, the greater the number of vegetation layers.
From page 94...
... Hence, in the study area, which as a whole is small, the larger the area allotted to natural ecosystems, the better. Rehabilitation of biodiversity and ecosystem services following disturbance is faster when there are sources of immigrants.
From page 95...
... With respect to species' economic value, the category of forage species in the previous list of terrestrial ecosystems should be replaced by species of fisheries significance. Special features of aquatic ecosystems that confer resistance and resilience, apart from features described for terrestrial ecosystems, are the distance of the ecosystem from polluting sources, which should be great, and the existence of corridors, such as streams, between isolated water bodies.
From page 96...
... of current and potential economic significance, especially in aquatic habitats and climatic transition zones inhabited by peripheral populations, and determine the water allocation and the land area and configuration required for their conservation.
From page 97...
... Operational Recommendations 1. The sustainability of water supplies requires that the area's natural ecosystems be treated as one of the legitimate users of the study area's water resources.
From page 98...
... 1992. The Influence of Mankind on Aquatic Ecosystems.
From page 99...
... 1993. Constructed Wetlands for Wastewater Treatment and Wildlife Habitat.


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