The catchment area of the Nile—the longest river in the world at 6695 km—links 10 African countries: Egypt, Sudan, Ethiopia, Eritrea, Uganda, the Democratic Republic of Congo, Kenya, Rwanda, Burundi, and Tanzania (Figure 1). A treaty regulating water use was signed in 1929 (revised in 1959) between Egypt and Sudan, which greatly favors Egypt. But more and more water is being claimed by countries upstream. Altogether, some 300 million people share the water of the Nile. The question of use represents an enormous potential for conflict, and water issues are now being addressed by the Nile Basin Initiative.

The signing of the Lesotho Highlands Water Project treaty in 1986 between Lesotho and the then apartheid government of the Republic of South Africa triggered mixed feelings. In Lesotho and several other countries in the region, the project was seen as a sellout that compromised the struggles of the oppressed, tantamount to Lesotho becoming a province of South Africa. Additional objections grew more vociferous during project implementation. These came especially from the communities affected, where people were removed from their original homes or their pastoral and agricultural lands were swallowed up by the immense water reservoir that now covers valleys and steep slopes of the Maluti Mountains. Lesotho has begun selling water to South Africa, earning about US$44 million annually (October 2001), and Lesotho is now self-sufficient in electricity. The present hydropower output is 72 MW. Major infrastructure has also been put in place, including roads, hydropower plants, administrative centers, and engineering masterpieces such as the 18-m-high Katse Dam and related tunnels through the mountains.

The Kullu District is a typical high-mountain environment with valley bottom elevation in the Manali area of about 2000 m and major summits that rise to 6500 m. This topography offers vast potential for hydroelectric development. In recent years the demand for power in India has exceeded supply, especially in the northern region, resulting in rapid exploitation of the hydropower potential of Himachal Pradesh (HP). The government of HP established the HP Energy Development Agency to encourage private sector investment in small hydro projects (3 MW and less) and to assist proponents by smoothing the process of project approval. The present study makes conclusions relevant to environmental asessment (EA) screening based on several cases in the Kullu District.

Water scarcity is a major issue in rural watersheds in the Middle Mountains of Nepal and in the entire Hindu Kush–Himalaya region. Dense population and heavy dependence on irrigated agriculture place immense pressure on available water resources, which have a distinct seasonality. New forms of management based on traditional and scientific knowledge must be introduced to solve problems of water supply, water demand, and water quality in these watersheds.

A related article in the Research section of this issue, Water: A Scarce Resource in Rural Watersheds of Nepal's Middle Mountains, by Juerg Merz et al, further explores the problem of water availability in Nepal. Ed.

Water scarcity is a serious problem in Koppal, a semi-arid district with barren rocky hills in northern Karnataka, India. The hills were denuded of forests and trees in the past. Resource depletion continues to occur because of rock blasting and stone cutting. This has led to low groundwater recharge, a problem further aggravated by the digging of bore wells to a depth at which only saline water is available. High-input agriculture combined with saline water has caused the soil to become unproductive. Farmers thus find it more profitable to leave the land uncultivated. As agriculture or other resources in the region do not provide a secure supply of food, people in the area face a severe livelihood crisis. Moreover, the local population and the government do not link the exploitation of rocks and hills to ground water depletion. There is an urgent need for solutions. People respond to their livelihood crisis at the household level and do not come together as a community to address issues. External facilitators are needed to generate a discussion of problems and alternative solutions. Short-term solutions only increase the predicament of the people. Long-term perspectives and investments are required to ensure sustainable management of natural resources as well as livelihoods in this semi-arid area.

Irrigation in general and pressurized irrigation in particular are at an early stage of development in Eritrea. Currently, there are only about 28,000 ha under surface irrigation systems. There is no proper assessment of the extent of pressurized irrigation systems, but it has been estimated at less than 1000 ha. Smallholder irrigation technologies developed by International Development Enterprises (IDE) and consisting of bucket, drum, and micro-sprinkler kits were introduced in several villages in the highlands at the beginning of 2001 by the Center for Development and Environment (CDE). Joint research has been conducted by CDE and the Asmara College of Agriculture and Aquatic Science since March 2001 to assess the social, economic, and technical preconditions for successful implementation of the technology. As used here, the term “smallholder” refers to farmers who manage farms smaller than 1 ha entirely on their own, with little or no input from external government resources.

Mountains and highlands are often called the world's natural “water towers” because they provide essential freshwater for populations both upstream and downstream. Despite this, knowledge about the significance of mountains in the hydrological cycle is still uncertain. The present article takes a regional approach, using case studies to assess and compare the hydrological significance of mountains. Methods are developed based on the experience gained in the Rhine River catchment and then applied to 19 additional selected catchments worldwide, with the river Euphrates serving as an example. The resulting comparative assessment serves as an elaboration on the hydrological significance of the world's mountains and underscores their function as sources of large, reliable, and compensatory discharge. The mean annual mountain contribution to total discharge in the river basins included in our case studies is disproportionately high, at 63%, with a mean relative mountain area of only 32%. Furthermore, distinctions can be made according to climatic regions, clearly highlighting the vital role of mountain runoff in lowlands in arid and semiarid areas. This means taking mountains and highlands more carefully into account in terms of monitoring and scientific research and especially in terms of watershed management and conflict management.

Water remains one of the major issues in the Middle Mountains of the Hindu Kush–Himalayas. This most populated region of Nepal depends mainly on rainwater supply, which is highly variable: around 85% of annual rainfall is expected during the monsoon, which lasts about 4 months from June to September. During this season, the major concern in many parts of the region is flooding and surface erosion due to too much water. During the remaining 8 months, water shortage for domestic and agricultural use is a persistent problem.

This article discusses water availability considerations in 2 watersheds in the Middle Mountains of Nepal. A survey of the water need and supply situation was carried out in both watersheds. The survey revealed the most needy regions within the watersheds and local residents' major concerns. Their main apprehension is water availability for both agricultural and domestic purposes, and increasingly, water quality concerns are mentioned in villages. A comparison between the 2 watersheds is particularly interesting because of their location in relation to Kathmandu, a major market opportunity for vegetable farmers. This study concludes that with the increasing pressure on available water resources, new forms of water resources management at watershed scale have to be introduced. They must be based on the social background of the area and on the technical possibilities in terms of both locally available knowledge and scientific information.

The shortage of water in Iran and most countries in the arid and semiarid zones is approaching the critical stage. Because about 60% of the water used in Iran is supplied by underground resources and natural recharge cannot replace the amount of water exploited, artificial recharge of groundwater (ARG) is actively pursued in this country. Desiltation of turbid floodwaters in sedimentation basins is a prerequisite for ARG. It is executed close to the heads of alluvial fans on an extensive area in Iran. Because the sediment removal efficiency of sedimentation basins is not 100%, downward migration of some clay particles, both in sedimentation basins and recharge ponds, causes the gradual impermeability and eventual clogging of the vadose zone and reduces the economic life of the recharge systems. Coarse-grained alluvium beneath 2 sedimentation basins, one in operation for 13 years and the other for 11 years, was sampled down to a depth of 7.5 m. Sampling was repeated in a control area outside and adjacent to the ARG system. X-ray diffraction patterns clearly show the presence of illite, chlorite, kaolinite, smectite, and sepiolite. Single laths and bundles of laths of palygorskite–sepiolite, a well-formed 6-sided and a pseudohexagonal flake of kaolinite, and smectite particles with smooth, wavy edges are clearly seen in the transmission electron micrograph. The order of clay mineral accumulation at a depth of 7.5 m was as follows: sepiolite > palygorskite > chlorite. The relatively high concentration of sepiolite may indicate its neoformation in the rooting zone of river red gum (Eucalyptus camaldulensis Dehnh.).

Analysis of seasonal water discharge and sediment load data for major tributaries of the Upper Yangtze indicates significant changes from 1957 to 1987. Discrimination between land use–induced and climatic variation–induced changes was attempted using the systematic shift in the seasonal sediment load relative to the seasonal water flow. Available evidence suggests that most of these changes were caused by human activities such as deforestation, water use, and construction of reservoirs rather than by decadal climatic variations. The changes identified in water flow and sediment flux in both wet and dry seasons for some tributaries had significant implications with respect to flooding and water shortages.

Mountain lakes, an important mountain resource in China, are increasingly faced with degradation through pollution, eutrophication, and sedimentation. This article reviews the environmental situation of Qionghai Lake in Sichuan Province, China, and presents an analysis of the causes of its degradation. Regulations have been adopted for ecological restoration of Qionghai Lake, and a management bureau has been established. Although some positive results have been achieved, institutional and technical weaknesses and gaps remain. Degradation of mountain lakes is closely linked to degradation of their watersheds. Management of a mountain lake may extend beyond the body of water to overall improvement of its watershed, including livelihood improvement and development for all stakeholders along the lake or in upstream mountain areas. Environmental protection programs need to be integrated within development programs and involve active collaboration among various government agencies. Participatory planning and implementation of programs to restore degraded mountain lakes are also desirable. A multidimensional approach may help provide an in-depth, comprehensive understanding of the environmental problems of mountain lakes.

Drawn by the rich pre-Columbian legacy of the region, we studied the prehistoric groups of peoples who have settled in the high canyons of Atacama (above 3000 m), on the western slopes of the South-Central Andes, for the past 30 years. The traditional culture of the present-day indigenous Andean population enabled us to interpret the material remains left by pre-Columbian peoples, especially their particular way of understanding and occupying the land, knowledge of its flora and fauna, beliefs related to the sacredness that permeates all aspects of their lives, and their way of inhabiting the landscape that surrounds them. Ethnographic research is a priority in the highlands of northern Chile because the harnessing of water for industrial and urban use has dramatically reduced extensive areas of pastureland, springs, and streams. This progressively restricts the possibility for flora, fauna, and humans to survive in traditional settlements and stimulates gradual, forced migration toward the urban enclaves of the desert. Our research aims to present some aspects of our archaeological and ethnographic work and, especially, to explore ideological aspects related to the mountains in this region, from pre-Hispanic to the present.