An adequate and reliable supply of energy is a prerequisite for development. In Nepal, forests and water are the two major indigenous energy resources. Forests are being overexploited in many parts of the country, mainly for fuelwood, whereas water resources are underutilized with regard to their capacity to generate hydroelectricity. Nepal might be able to control forest degradation by adopting a differentiated approach to hydropower development. The prospects and the risks of such development are discussed here, and three scenarios that have received increasing attention in recent years are presented for implementation in a wider South Asian context.

Honduras is predominantly mountainous; its highest peaks are close to 2800 m. The country has a population of approximately 6 million and an area of 112,000 km². In a bid to solve its energy problems and achieve greater self-sufficiency in energy production, Honduras turned to its abundant water resources. El Cajon Reservoir, the largest civil engineering project ever undertaken in the country, was a result of this approach. At the same time, Honduras is very prone to hurricanes. The present article describes the effects of Hurricane Mitch (1998) on El Cajon dam and examines the extent to which the reservoir was able to mitigate the hurricane's impact in downstream areas. It concludes with a series of recommendations for preventive action in the event of future hurricanes.

Beginning in the second half of the 19th century, large areas of West Java's mountainous rainforests were transformed into tea gardens. The volcanic soils, high rainfall, and cool climate of this region proved the perfect environment for such plantations (Figure 1). During this period, many tea factories were powered by small hydropower plants (SHPs). The location of the factories on tea estates was often determined by the availability of a suitable site for the SHPs. This renewable form of energy was the perfect match for the moderate power requirements of tea factories. However, after the peak in tea production at the beginning of the 20th century, a gradual decline in production took place in West Java. Unfortunately, this period also saw the degradation of the many SHPs that formerly powered the factories. Today most of the plants in the old factories have been destroyed, dismantled, or replaced by Diesel gensets. Rising fuel costs and increased consumer awareness are now providing the right environment for a revival of indigenous hydraulic resources.

Hydropower is a renewable source of energy of which ecological benefits include very low average greenhouse gas emissions. As a result of dams, however, more than 20% of all freshwater fish species are now considered threatened or endangered. Such negative ecological impacts are a focus of broad public concern in Alpine regions where hydropower production is most intense. The liberalization of electricity markets now provides an economic rationale for selling hydropower as green energy. This offers an opportunity to improve the ecological performance of hydropower plants. The lessons learned from this large-scale economic and ecological experiment in the industrialized world might be important in other mountain regions where hydropower production is being developed or needs ecological upgrading. As a step in this direction, the present paper gives an overview of recent developments in Europe concerned with the ecolabeling of hydropower. Different initiatives for green hydropower in liberalized electricity markets are discussed, followed by analysis of the shortcomings of simplistic ecolabels. Finally, a new method for ecological assessment of green hydropower plants is outlined. This is currently being implemented in Switzerland along with ecolabeling.

Special difficulties and high costs are frequently incurred when sources of energy such as kerosene or dry-cell batteries are transported to mountain areas. Moreover, use and disposal of these sources of energy pose risks to health and the environment. On the other hand, the use of local, renewable sources of energy such as wind, water, or solar power ensures that mountain communities can enjoy both greater independence and safety with respect to energy supply. In mountain regions worldwide, local hydropower produced by small water turbines is important for irrigation, grain milling, and other purposes. Water turbines have also long been used to produce electricity to illuminate houses or operate radio and television devices, while direct solar energy has traditionally been used to dry food and clothing. Recently, however, a variety of solar energy systems including special house construction, use of cooking devices such as the well-known cooking boxes and reflector systems, and electricity supplied by photovoltaic (solar-electric) systems have been introduced. Some of these systems are especially suitable for areas with intense sunlight and low temperatures. Solar-electric stand-alone systems have proven useful in the European Alps and the Pyrenees, where there is evidence that they are an important source of sustainable energy (Figure 1).

A new classification of 15 relief patterns at the global scale combines a relief roughness indicator and the maximum altitude at a resolution of 30′ × 30′. Classical geographic terms have been retained but assigned to fixed relief roughness (RR = maximum minus minimum elevation per cell divided by half the cell length in meters/kilometer, or ‰) and altitude boundaries. Plains (33.2 Mkm² of currently nonglaciated land surface) correspond to subhorizontal terrain (RR < 5‰). Lowlands (19.2 Mkm; 0–200 m) have a very low degree of roughness (5 <RR <20‰). Platforms and hills (30.5 Mkm²) correspond to the 200–500-m mean elevation class and have a greater degree of roughness (RR > 20‰). Plateaus (16.8 Mkm²), with mean elevations between 500 and 6000 m, have a medium degree of roughness (RR from 5 to 40‰). Mountains (33.3 Mkm²) are differentiated from hills by their higher mean elevation (>500 m) and from plateaus by their greater roughness (>20‰ then >40‰) in each elevation class. Accordingly, Tibet and the Altiplano are very high plateaus, not mountains. These quantitative definitions of relief patterns were divided into 15 classes, then clustered into 9 main types and mapped at the global scale at a resolution for which water runoff depth and population were previously determined. We also differentiated between exorheic areas (115.6 Mkm² globally) and endorheic areas (17.36 Mkm² globally) of potential runoff. Mountains thus account for 25% of the Earth's total land area, 32% of surface runoff, and 26% of the global population. The presence or vicinity of a rough and elevated landscape is less limiting to human settlement than water runoff.

In many Western European mountains, ancient irrigation practices have been the basis for sustainable subsistence-based mountain agriculture, especially up to the beginning of the 20th century. These mountain zones have proved popular sites for the development of hydroelectric power (HEP). Few attempts have been made to measure the impact of HEP on traditional indigenous irrigation systems dependent on the same resource base. This article examines the physical and socioeconomic impact of HEP development on the bisse irrigation system in the Valais, Switzerland, and discusses new water resource issues, conflicts, adaptations, and innovative responses. The study shows that a two- to three-tier consultation process has led to communes and autonomous collective irrigation institutions (consortages) signing and ratifying long-term conventions that ceded water to HEP companies at the scale of watersheds. Water supplies for irrigation are protected by these conventions at the same time as changed hydrological regimes improve water security in economically viable bisses. Conventions also improved the economic security of some consortages, while at the level of individual households, HEP development allowed diversification of income generation strategies.

A study of high-elevation catchments in the San Miguel River Basin of southwest Colorado was conducted during the summer of 1997 to develop a scientifically based tool for water resources management. The authors mapped landscape types and associated water quality parameters with those types, enabling sensitivity assessment at the landscape unit scale, thus addressing catchment heterogeneity. Landscape-type maps and derived sensitivity maps were entered into a geographic information system (GIS). They proved effective visual tools for use in policy decisions and public presentations. Water quality issues addressed were sensitivity to acidification and nutrient enrichment. Landscape types associated with surface waters having growing season acid neutralizing capacity (ANC) < 50 μeq/L were considered sensitive to acidification and included talus and mining-related areas. Types sensitive to nutrient enrichment were those having average growing season NO₃⁻ concentrations > 9.0 µeq/L, and included tundra, talus, and rock glaciers. Using the results of this study, San Miguel County commissioners adopted regulations for restricting development in sensitive high-elevation areas, including limits on building footprints and bans on septic systems. The adoption of these regulations lays the foundation for future application of this approach to headwater catchments in other western US locations.

The Yaluzangbu River, the largest river on the Tibetan Plateau, becomes the Brahmaputra when it flows into India. New fieldwork and map analysis show that the fluvial landforms and landform evolution of the river are controlled by the tectonic structures of the southern plateau. The history of the Yaluzangbu River since the Eocene is established here based on geomorphological and tectonic studies. It includes the formation of the main course along the suture before the Miocene and establishment of downstream course and major tributaries along strike-slip faulting in the Miocene. Also noted are the formation of alternations of wide sections and gorges, gentle and steep hydraulic gradient intervals, and deposition and erosion channel stretches along the river by normal faulting and grabens since the Pliocene.

Since the 1950s, the Spanish Mediterranean mountains have become a marginal territory, with few inhabitants and limited economic activity. As a consequence, significant land use changes (farmland abandonment, development of extensive cattle rearing, and reforestation) have taken place, resulting in landscape degradation and new hydromorphological processes. In this article, the process and impact of farmland abandonment in the Camero Viejo (northwestern Iberian System) are described. The authors also studied the geomorphological evolution of terraced fields after cultivation was given up. Runoff rates and sediment yield in abandoned and grazed terraces were measured using a rainfall simulator. Results show that the speed and intensity of the hydrological and erosional response increased if plots were grazed intensively. The study demonstrates that new land management systems in the Camero Viejo, in particular extensive cattle grazing, have generated additional source areas of sediments.

Accelerated soil erosion is a common and environmentally destructive consequence of development, especially in mountain regions. Soil erosion is of special concern in agricultural lands, but agriculture is only one of many development activities that greatly accelerates soil erosion processes. Road building, trail use, excavation, extractive activities, and construction also can cause severe soil erosion. Soil conservation technologies are relatively simple and well known, but often they are not applied where they could be most effective because the connections between different elements of the landscape (eg, roads and cultivated fields) are not well understood. This paper reviews two previous soil erosion research projects in the Ecuadorian Andes involving field observations and small-plot rainfall simulation experiments and provides examples of erosion-related landscape connections at the drainage basin scale. In light of the important influence of roads, trails, and abandoned farmlands on soil erosion processes on Andean slopes, sustainable management of the soil resource requires both looking across and managing across conventionally delineated boundaries in the natural and altered landscapes of mountain regions.