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1.
New concerns with African drought and famine have redirected attention to the great potential of African rivers dramatically to increase food production. The recent history of irrigation, however, has proved otherwise. This is partly due to policy makers' failure systematically to consider the socio-economics of land/water use in river basins in their development plans. This paper focuses on the socioeconomic dimensions of African river basin development and argues that a better incorporation of such systems in development plans will aid African countries more effectively to achieve their food production and development goals.  相似文献   

2.
可回收式锚索试验研究   总被引:9,自引:0,他引:9  
在城市建筑基坑支护中.常规锚索由于不回收而侵犯到临近地下空间的产权.其应用将会逐步得到限制,可回收式锚索将是解决这一问题的有效手段.在其使用功能完成后可以将锚索体顺利地从钻孔内全部回收,在今后的城市建设中将会有着广阔的应用前景。在综合国内外相关研究成果的基础上,开发出压力分散型回收式锚索和压力型回收式锚杆,并通过现场试验对其结构型式的合理性、承载力以及回收性能进行了验证。  相似文献   

3.
Urbanization and the groundwater budget, metropolitan Seoul area, Korea   总被引:3,自引:1,他引:3  
The city of Seoul is home to more than 10 million people in an area of 605 km2. Groundwater is abstracted for public water supply and industrial use, and to drain underground facilities and construction sites. Though most tap water is supplied from the Han River, the quantity and quality of groundwater is of great concern to Seoul's citizens, because the use of groundwater for drinking water is continuously increasing. This study identifies the major factors affecting the urban water budget and quality of groundwater in the Seoul area and estimates the urban water budget. These factors include leakage from the municipal water-supply system and sewer systems, precipitation infiltration, water-level fluctuations of the Han River, the subway pumping system, and domestic pumping. The balance between groundwater recharge and discharge is near equilibrium. However, the quality of groundwater and ability to control contaminant fluxes are impeded by sewage infiltration, abandoned landfills, waste dumps, and abandoned wells. Electronic Publication  相似文献   

4.
Water for sustainable development in the 21st century: a global perspective   总被引:2,自引:0,他引:2  
Many arid and semi-arid countries are feeling water crisis already at present, and the problem will become more serious in the 21st century. Global water consumption will increase, 10-fold during this century, and the increasing trend will continue well into the 21st century. This Presidential Address to the International Water Reserves Association discusses the reasons for the water crisis, and the major water issues of the 21st century. Among those issues are water conservation and efficient use of water, water pricing and cost recovery, social and environmental considerations, institutional responses to better management, management of international water bodies and proper analytical frameworks.  相似文献   

5.
This paper analyses groundwater resources use and management in the socio-economic context of the Amu Darya River Basin which covers a part of the following landlocked Central Asian countries: Afghanistan, Tajikistan, Turkmenistan and Uzbekistan. These agrarian nations for sustaining their vital agricultural productions started to use groundwater during the recent drought years (1998–2001) because of its relatively good quality and quantity and as an alternative to highly mineralized surface waters. Present extent of groundwater resources use is discussed with consideration to their reserves, quality, and institutional management and transboundary aspects within the basin. After the collapse of the centralized water resources management system and infrastructure of the former Soviet Union, new underdeveloped systems are being practiced over the whole Amu Darya River Basin. The critical situation of groundwater management in Afghanistan is also discussed. This work attempts to document the management and use of groundwater in the Amu Darya Basin and present time management realities, with fragmented and weak national and regional regulation on groundwater. Special attention is given to groundwater resources in irrigated agriculture, which increased use in all countries of the basin is due to quick access to underground resources and relatively good quality and quantity.  相似文献   

6.
J. A. Allan Dr. 《GeoJournal》1992,28(3):375-385
Evident mismatches exist between the demand and supply of water in many countries particularly in the semi-arid and arid worlds. The resulting food gaps which concern both the national governments of these countries as well as the international agencies which extend assistance to them, appear at first sight to pose challenges beyond the economic and political capacity of peoples and institutions to make the necessary adjustments. The institutions with responsibility for the allocation and planning of water use at international, national and local levels do not seem to be robust enough, or informed enough, to provide the necessary leadership to ensure that scarce water is used sustainably.It will be argued that despite the great difficulties which governments and users face in coping with the need to manage water so that it brings a sound return, as well as according to principles of equity, safety, and ecological sustainability, everywhere there are examples of conflict over water being avoided. And while the avoidance of conflict can in many cases be calculated to have been at a cost to the environment, nevertheless, to date conflict of a hot nature has been avoided. Case studies from a region seen to have the worst water resource future outside the industrialised world, the Middle East and North Africa, will be discussed which exemplify the numerous strategies adopted by countries in their various ecological, economic and political circumstances. A fortunate few governments have substituted oil capital for water while others have filled the food gap, which is generally an expression of the water gap, by ceding economic and political autonomy.  相似文献   

7.
我国城市地质调查研究现状及发展方向   总被引:3,自引:0,他引:3  
城市化是世界各国发展的共同趋势,是人类文明和进步的标志。论文简述了国内外城市环境地质工作的发展历史,着重论述了城市地质工作的现状及发展方向,指出我国城市环境地质中存在的问题。如地面沉降,地裂缝,岩溶塌陷等地质灾害及水资源短缺,城市废弃物处置以及特殊岩土环境问题。  相似文献   

8.
Groundwater is an important and readily available source of fresh water in the Mekong-Lancang River Basin. With a rapid population growth and increasing human activities, an increasing number of countries in the Mekong-Lancang River Basin are experiencing depleted and degraded groundwater supplies. In transboundary river basins, such as the Mekong-Lancang River, prioritizing the use of the shared aquifer by one riparian government may affect the opportunities of other riparian governments and lead to potential water conflicts between neighboring countries. To promote the sharing of strategies and information for the sustainable and equitable use of water resources of the shared basin, international collaborative workshops on groundwater resources have been organized for all Mekong-Lancang River countries. These workshops provide an opportunity to communicate and discuss nationally sensitive issues on groundwater by the associated countries, with topics covering multiple aspects of groundwater, such as the groundwater status in the basin, quality issues, water use conflicts, hydrological information gaps, management policies and capacity building for successful water resource management. Consensus has been reached by all countries on the importance of catchment-based groundwater management and the need for close communication among the countries. Strategies for managing transboundary aquifer issues must foster international collaboration based on the regional network, influence national networks and enhance the capacity to building maps and monitoring systems based on associated databases. The sustainability of water resources cannot be achieved without the integrated involvement and contributions by multiple countries and various stakeholders. Therefore, collaborative workshops provide a great opportunity to further our understanding of the hydrologic processes of the Mekong River Basin, share the benefits of the aquifer and provide a strategy and vision for sustainable water resource management in the Mekong-Lancang River countries.  相似文献   

9.
河西地区城镇体系特征及未来发展构想   总被引:8,自引:0,他引:8  
张志斌  张小平 《冰川冻土》2002,24(4):463-469
河西地区城镇体系在空间地域结构上,表现出绿洲城镇的特点;在职能类型结构上,以综合性城镇为主;在规模等级结构上,具有经济不发达地区城镇体系的共性. 未来城镇体系建设,必须从区域整体发展的宏观思路出发,统一构建与绿洲环境相协调的城镇体系格局,使水资源能够支持重点城镇的发展,围绕酒泉市、张掖市、武威市和敦煌市4个区域中心城市,有意识地利用"点-轴"结构,积极培育次级中心,形成空间分布合理、职能类型多样、规模等级协调的城镇体系网络,促进河西地区社会经济的持续发展.  相似文献   

10.
Phu Le Vo 《GeoJournal》2007,70(1):75-89
The management of water resources is an unfinished effort of the international community. Rapid urbanization has transcended the management capacity of governments in developing countries. Since the renovation policy launched in 1986, Ho Chi Minh City, Vietnam, has experienced the fastest urbanization and industrialization process. This has placed severe constraints on the use of water resources and management capacity of the local government. The abstraction of groundwater has exceeded the limiting volume (520,000 m3/day) and the annual drawdown of water table is 2–3 m. In addition, the quality of urban water bodies is increasingly exacerbated by a huge volume of untreated industrial and domestic wastewater. These are hampering water demand, use and the capacity of the municipal authority in managing water resources. The purpose of this paper is to analyze the impact of urbanization on water resources. Current issues and challenges in the management practices of water resources are discussed. It will propose a new paradigm of water management in Ho Chi Minh City.  相似文献   

11.
With the rise in the number of applications using geospatial data and the number of GIS applications, the number of people who come into contact with geospatial data is increasing, too. Despite many attempts to introduce standardized formats in this area, they are often ignored by software developers as well as the users themselves for various reasons. When creating or exporting geographical data, users choose the format with regard to the software they use, or for which the data are intended. Users then have to deal with conversion of data formats, and considering its use also the issue of their transformation to the appropriate spatial reference system. This work presents findings related to this issue, obtained from several years of operation of an online service for the conversion and transformation of geographical data which is heavily used by users from all over the world. It presents statistics of individual formats use and spatial reference systems of geospatial data use from the point of view of both input and output data. The results, besides other things, are shown in the form of a pie chart map in which various needs of users from a variety of countries can be seen. The results of this work can be used especially by developers of applications which use geospatial data; it will allow them to quickly understand current user needs.  相似文献   

12.
South Asia is the subregion of Asia with the most neighbors of China. Although the high mountains in the Great Himalayas spatially separate South Asia from East Asia along the border of China’s autonomous region of Tibet, the geographical items such as mountains and rivers link the countries in South Asia with China, resulting in a special and complex geopolitical environment and relationship. In this geopolitical relationship, the transboundary rivers are becoming a key issue of this region in an era of increasing water stress. Depleted and degraded transboundary water supplies have the potential to cause social unrest and spark conflict within and between countries in South Asia, and complicate the geopolitical relationship among them. In addition, the increasing impacts from climate change and human activities will definitely bring many transboundary eco-environmental issues in this region, projecting a big challenge to regional stability and development. The key issues related to the water resources supplement and exploration require the transboundary rivers to be a positive role in regional water resources utility and exploration, and the result will definitely affect regional relationship and water security. How to handle these issues and challenges will be a question for the countries in this region with a long time. Currently, the “Belt and Road” Initiative represents an opportunity to build a shared vision for common prosperity through regional cooperation and is a way to inject new positive energy into world peace and development. In the light of this, the countries with transboundary rivers in South Asia must come together to construct a cooperative mechanism of water security, and adopt a win-win cooperation for the use of transboundary rivers under the principles of “equal”, “equitable” and “reasonable”.  相似文献   

13.
中国的用水何时达到顶峰   总被引:10,自引:1,他引:9  
从中国实际用水增长业已放慢的趋势、已经开始启动的供水价格的大幅上升趋势和水价与用水的关系、经济增长方式由粗放型向集约型转变(高耗水行业已经接近顶峰)和用水与产业结构的关系、日益严格的环境立法和执法对用水的影响、中国水资源本身的限制等5个方面,分析中国的用水变化趋势,提出中国的农业用水量、工业用水量和总用水量目前均已接近顶峰,可望在10年内达到顶峰,最大用水量不大可能超过6500×108m3。  相似文献   

14.
在城区化过程中,由于人口快速成长且集中,随之而来的建筑物、道路等不透水面密度增加,导致地下水补给减少及破坏水文循环。为了解土地利用方式改变对长期水文量影响,建立一个适宜的城区水循环模式是非常重要的。选定台湾台北的六馆抽水站集水区进行分析,模式参数经过敏感度分析、率定与验证。采用改变不同透水铺面设置比例的方案,评估其对径流量、入渗量、蒸发散量的改变。并分析设置不同比例屋顶雨水贮集系统对地表径流量及供水量的改变。所建立的城区水循环模式是评估土地利用改变造成水文量的改变的一个有效工具,并可提供决策者做为城区土地利用决策的参考。  相似文献   

15.
降雨是区域水资源的主要来源,水资源是控制城市发展的主要因素。对青岛市降雨特性进行分析,研究青岛市水资源现状,对未来用水量进行预测并提出对策。研究表明:青岛市多年平均降雨量705mm,没有显著趋势变化;多年平均水资源总量为21.5×1-8m3,多年平均入海径流量10×10-8m-3;到2015年青岛市用水量将达到12.66×10-8m-3,呈现缺水趋势,并且将逐渐成为制约经济发展的主要因素,控制城市规模和提高用水效率是科学发展的必由之路。  相似文献   

16.
The Basin of the Valley of Mexico is a closed basin of 9600?km2, where average annual precipitation (1980–85) is 746?mm (226.7?m3/s). Calculated actual evapotranspiration is 72–79% of the precipitation. The surrounding mountain ranges of the Sierra de Las Cruces, Sierra Nevada, and Sierra Chichinautzin are the main recharge areas for the enclosed Basin, in decreasing order. Calculated recharge rate is a maximum of 19?m3/s in the Metropolitan Zone, whereas a recent estimate of the groundwater exploitation rate indicates that 51.35?m3/s is being withdrawn from the Basin aquifer systems, resulting in a deficit of more than 30?m3/s. Taking into account infiltration processes by leaking water-supply systems, the calculated deficit is reduced to 20.5?m3/s. Overexploitation of the natural aquifer systems is also indicated by an average annual decline of 1?m of the potentiometric levels of the shallow groundwater systems. Possible solutions include: (1) the use of surface runoff water (unused amount in 1995?:?17.6?m3/s) for consumption purposes, which is currently pumped to areas outside the Basin; (2) an increased number and capacity of treatment plants; (3) the renovation of the leaky water-distribution network; (4) the reinjection of treated water; and (5) possible exploitation of deep regional aquifer systems.  相似文献   

17.
This paper considers the question of how sensitive inertially guided systems are to variations in the gravity field. There are systems which use other kinds of information for guidance, such as terrain. But, they will not be considered here.  相似文献   

18.
Trends of water resource development and utilization in arid north-west China   总被引:12,自引:0,他引:12  
 From an analysis of the current water resources and their development and utilization in arid north-west China, the authors conclude the extent of channelled water accounts for only 56.0% of the total, exploitable surface-water resources of arid north-west China. The utilization ratio of canal systems is 42%, and farmland use is 0.8. When the ground and surface waters of river basins in the region are comprehensively developed, the channelled water will reach its climax, accounting for 80% of the total, exploitable surface-water resources, which would constitute a 91% increase over current levels in surface-water resource development. In the future, the utilization ratio of canal system as well as the utilization ratio of farmland water will reach 0.9 with the help of scientific and technological advancements. The channelled water is the same as the comprehensive development and utilization stages, but the total water use will be increased by 247×108 m3, and will reach 756.8×108 m3, accounting for 88.2% of the total, exploitable surface-water resources in arid north-west China. Also, the authors suggest that the scientific and technological measures to increase the water-use ratio include improving management, strengthening protection of water resources and the environment, and increasing studies of water saving techniques. Received: 11 January 1999 · Accepted: 6 July 1999  相似文献   

19.
J.A. Allan 《Geoforum》1983,14(3):243-247
The development of agriculture is recognised to be an essential preliminary and on-going element in the economic development strategies of most developing countries. The contribution of agricultural production to gross domestic product, food self-sufficiency and export income are amongst the major development goals exercising the governments of such countries. In addition, in many countries the agricultural sector is regarded as one with a potential for generating a surplus to sustain other economic activities and to have an important stabilising role in reducing the movement of population from rural areas. This article discusses renewable natural resources, soil and water, as the basis for agricultural development and especially of irrigated farming. A number of case studies will be referred to which illustrate the idea that many national governments attribute quite unreal qualities to soil and water resources. Once development schemes were launched appropriate rhetoric was mobilised to invest the reclamation of ‘virgin lands’ and ‘new lands’, with the character of ‘green revolutions’. These ventures have been sustained not because of their success but because the ‘fantasies’ have been circulated amongst ill-formed urban populations, remote from the arduous realities of land reclamation. Case studies in the Soviet Union and the Middle East are discussed.  相似文献   

20.
Important as water is to man's manifold activities, a significant percentage of mankind still do not have access to clean water for drinking and personal hygiene. According to a WHO survey of facilities available in developing countries to the end of 1975, 75 % of urban population and 20 % of rural population have access to potable water. Studies carried out by the UN system estimate that investment necessary to provide clean water and sanitation by 1990 to both rural and urban areas is on the order of $ 132,940 million in constant 1977 dollors. Furthermore, provision of clean water alone is unlikely to eliminate all water-borne diseases, since it is only one of several complex factors affecting human health.The situation in developing countries on water requirements for agriculture, industry and generation of hydroelectric power also requires attention because of large amounts of water involved. Effectiveness and efficiency of the supply and distribution systems must be given top priority. There is a considerable potential for improving the efficiency of water use in virtually every developing country and in every sector.  相似文献   

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