ADAPTATION TO ARIDITY: WATER DEVELOPMENT IN SOUTH AFRICA1

ABSTRACT The Republic of South Africa, legatee of a three-century history of recurring drought, is firmly committed to a program of the optimum use of its water for the national benefit. Its water law encourages centralized planning in that water is held to be the property of the state and is assignable without requiring acquiescence by the basin or province of origin. Interbasin diversions from the Tugela River to the Vaal River Basin, from the Orange River to the Fish and Sundays River Basins, and from several basins to Cape Town are under construction as are facilities for water importation from Lesotho and Angola. For satisfaction of demands beyond the year 2000 the nation may depend increasingly on a shift of its power production and water-using industry from the coal fields of the central plateau to nuclear power development with associated desalination along its coasts. Alternatively, and preferably, it may cooperate in a co-prosperity bloc in Southern Africa aiding the economies of its neighbors by development for mutual advantage of the water and power resources of the Okavango and other northern rivers.     

POTENTIAL BENEFITS AND COSTS OF INGROUND STORAGE OF IMPORTED WATER1

ABSTRACT: In the near future, groundwater storage of imported water may become increasingly important as sites for surface storage are less available. This article explores the potential economic costs and benefits of groundwater storage. The costs include capital outlays, maintenance costs, land costs, legal costs, energy costs, and opportunity costs. The benefits include land cost savings, prevention of subsidence, aquifer protection, and higher economic use of surface lands that might be covered by a reservoir.     

Sustainable use of water in the Aegean Islands

Water demands in the Aegean Islands have increased steadily over the last decade as a result of a building boom for new homes, hotels, and resorts. The increase in water demand has resulted in the disruption of past sustainable water management practices. At present, most freshwater needs are met through the use of the limited groundwater, desalinated seawater, and freshwater importation. Wastewater reclamation, not used extensively, can serve as an alternative source of water, for a variety of applications now served with desalinated and imported water. Three alternative processes: desalination, importation, and water reclamation are compared with respect to cost, energy requirements and long-term sustainability. Based on the comparisons made, water reclamation and reuse should be components of any long-term water resources management strategy.     

ASSESSMENT ANALYSIS FOR WATER SUPPLY ALTERNATIVES1

ABSTRACT Providing adequate water supplies of good quality is becoming a serious problem in many areas of the United States. Some of the alternatives proposed for meeting the growing shortage of clean-water or cheap-water are reallocation, reuse, and importation. This paper outlines a methodology to assess all of these water supply alternatives by examining the amount and time-staging for development of water sources. In conceptualizing the problem, sources of supply are classified in three categories: primary or base supplies, secondary or effluent supplies, and supplementary or imported supplies. A model of the water system is formulated as a “transportation problem” in linear programming depicting the possible sources of supply which can be used to satisfy the requirements of various water users. The optimizing objective in the model is to minimize the cost of water under various assumptions for operating the system. A case study of the Salt Lake Qty, Utah, area is used to illustrate the application of the model in obtaining optimal water supply allocations for projected future demands. Assessment of alternatives in the study include redistribution of supplies, time-staging of supplies and related treatment facilities, and sensitivity of allocations to changes in costs.     

中国固体废物进出口格局演化分析——以废纸为例

固体废物进出口是影响我国生态文明建设及区域可持续发展的重要因素,也是最近环境管理关注的焦点。为了认识我国固体废物的进出口形势和全球固体废物贸易的格局,本文以进口量最大的固体废物——废纸为例,系统总结梳理了近年来我国废纸进出口情况的演化,绘制了2016年国际废纸贸易的流向地图,从2015年以来的废物管理政策调整出发探讨未来废纸产业的发展和转变。研究发现:(1)作为主要的造纸原材料,我国废纸进口量从1996年的137万t增加到2016年的2850万t,增长了近20倍。(2)当前全球废纸贸易突出表现为发达国家出口、发展中国家进口的格局,我国作为最大的废纸进口国,进口约占全球总量55%的废纸,美国则为最大的废纸出口国,出口约占全球总量36%的废纸。(3)应对洋垃圾入境的挑战,未来我国应在进口管控、再生资源产业发展等多个方面继续加强政策的引导和调控作用,激励国内的再生资源市场,促使废纸利用企业调整产业布局,加快产业转型。