Annexes

1. Abstract of background papers^[100]

Land use impacts on water resources

Author: Ian Calder

Abstract

This paper aims to provoke discussion on land use and water resource impacts, particularly in relation to rural watersheds in developing countries, with a view towards surfacing key issues, identifying research needs and, ultimately, towards developing guidelines on instruments to distribute costs and benefits arising from land-use impacts on water resources amongst upstream and downstream stakeholders in a watershed. The paper is in three parts which address and question: (i) The adequacy of our scientific knowledge in relation to the environmental processes (biophysical/climate) which determine land use impacts on water resources. (ii) The (often poor) connection between scientific knowledge and policy; the adequacy of the decision-making and policy-making processes of national and international organisations in relation to land use and water resources management; the self sustaining nature of pseudo science myths in relation to land use and water resources and the interdependence and interrelationships of stakeholders in relation to land use and water resources. (iii) The adequacy of current management approaches and the need for consistent policies towards land-use and water resources management, development and poverty alleviation, which are applicable from the local to the global scale.

Water quality degradation effects on freshwater availability: Impacts of human activities

Authors: Norman E. Peters, Michel Meybeck

Abstract

The quality of freshwater at any point on the landscape reflects the combined effects of many processes along water pathways. Human activities on all spatial scales affect both water quality and quantity. Alteration of the landscape and associated vegetation has not only changed the water balance, but typically has altered processes that control water quality. Effects of human activities on a small scale are relevant to an entire drainage basin. Furthermore, local, regional, and global differences in climate and water flow are considerable, causing varying effects of human activities on land and water quality and quantity, depending on location within a watershed, geology, biology, physiographic characteristics, and climate. These natural characteristics also greatly control human activities, which will, in turn, modify (or affect) the natural composition of water. One of the most important issues for effective resource management is recognition of cyclical and cascading effects of human activities on the water quality and quantity along hydrologic pathways. The degradation of water quality in one part of a watershed can have negative effects on users downstream. Everyone lives downstream of the effects of some human activity. An extremely important factor is that substances added to the atmosphere, land, and water generally have relatively long time scales for removal or clean up. The nature of the substance, including its affinity for adhering to soil and its ability to be transformed, affects the mobility and the time scale for removal of the substance. Policy alone will not solve many of the degradation issues, but a combination of policy, education, scientific knowledge, planning, and enforcement of applicable laws can provide mechanisms for slowing the rate of degradation and provide human and environmental protection. Such an integrated approach is needed to effectively manage land and water resources.

Community-based water quality monitoring: from data collection to sustainable management of water resources

Authors: William G. Deutsch, Jim L. Orprecio, Allison L. Busby, Janeth P. Bago-Labis, Estela Y. Cequiña

Abstract

The paper is an account of how a rural community in the Philippines worked side by side with researchers, non governmental and governmental workers over a five-year period to develop science-based indicators of water quality that proved relevant for developing environmental policy. The case focuses primarily on the early stages of implementing a municipal-level, natural resource management plan in Lantapan, Bukidnon Province, Mindanao. The setting and background of the project are briefly described, followed by the nature of specific indicators and how they were chosen and refined. The paper presents the process by which these indicators influenced policy and concludes with lessons learned throughout the process. The paper emphasizes the methods, results and applications of the biophysical data collected by the citizen monitors.

Valuation of water-related services to downstream users in rural watersheds: determining values for the use and protection of water resources

Author: Marta Echavarría

Abstract

Although water is critical to life and to most resource management activities by humankind, water has a very low price world-wide and, surprisingly, even in areas facing serious water constraints. The costs that a mismanaged upstream landholding can generate for users downstream are rarely accounted for. Or, vice-versa, water quality and flow benefits that a well-preserved watershed area can generate are generally not recognized. This is a definite market failure. Attempts to internalize watershed protection benefits and costs are few. In general, there is a gap between economic theory and actual practice in regard to water resource appraisal, planning, conservation, management and use. Therefore, there is a need to innovate and promote policy and institutional changes in water resources management at local and national levels. This paper aims to give insights into economic instruments that can effectively support the wise use and management of watersheds and the protection of hydrological services. It briefly reviews the economic valuation methods commonly used focusing on water related goods and services. It highlights actual cases in Latin America where efforts have been made to link water uses and watershed protection activities and therefore conserve water resources.

Downstream effects of land degradation and soil and water conservation

Author: Jan de Graaff

Abstract

This paper gives an overview of the downstream effects of soil conservation and watershed development (SCWD) activities, and an outline for the assessment and valuation of the downstream impact of these activities in situations with multiple function reservoirs. For many watersheds insufficient attention is given to erosion control. Thus, reservoirs are fast losing their functions through siltation and changes in streamflow. This may eventually lead to much lower irrigation and hydro-electricity capacities, or to very high costs of dredging and other correcting measures. Since many SCWD projects are initiated to safeguard these reservoirs and other infrastructure, more attention should be paid to the appraisal and valuation of their effects on downstream users.

2. Abstract of case studies^[101]

Optimizing soil fertility and plant nutrition to prevent groundwater pollution

Country: Austria
Authors: Peter Cepuder, Volker aus der Schmitten
Language: English

Abstract

The objectives of this case study were to quantify groundwater pollution through measurements of percolation and nitrate leaching, to compare results with those obtained from a simulation model of leaching and percolation, to determine the effects of crop cover on these variables, and to consider possible recommendations for a sustainable combination of fertilizers and cover crop. A good agreement was found between measurements and simulated results. The simulation model, used to compare percolation and leaching with and without cover crops, found no direct relationship between them. In a comparison of different soil groups, low water storage capacity was found to be associated with significantly higher percolation, nitrogen leaching, and concentration of nitrates in the percolation water. The minimum contamination of groundwater was associated with the soil group that had higher water retention capacity and cover crops. An extension of the results to the entire area suggests that percolation and nitrogen leaching is higher with no cover crop but that lower nitrogen leaching and higher percolation can be obtained by using cover crops only on the soil group with the highest water retention capacity, and not using them on the other two soil groups. No definitive conclusions could be reached regarding the best combinations of soil, crop rotation, cover crop and weather conditions.

Inter-relationships between agriculture and hydrology in lowland areas. The case of the Kangura watershed

[Interrelations entre agriculture et hydrologie en zone de bas-fond. Exemple du bassin versant de Kangura]

Country: Burkina Faso
Authors: C. Cudennec, Y. Sinaré, Daurensan
Languages: English, French

Abstract

Hydraulic projects have been used to manage hydrometeorological hazards in the lowland areas in order to extend agriculture, which had traditionally only been practised on the hillslopes. This paper describes a study in progress, designed to better understand the functional relationship between hillslopes and lowlands, and between stream, overland and groundwater within the lowlands, by identifying the main processes for each geomorphologic entity. Surface flows are measured where the stream enters the lowland area which would only reflect the influence of hillslope processes, and in the lowland, where it would also reflect influences of groundwater and submersion. This data is intended to be combined with piezometric transects, topographic mapping, and geographic diagnosis. The data will be used in the development of a physically-based model of lowland functioning, intended to provide results of relevance for hydraulic engineering and agriculture at the event scale. This will in turn provide the basis for developing a decision-support system based on simulated scenarios of hillslopes and lowland anthropic modification, including series of hydraulic projects on a single stream.

Impact of upstream irrigation dams on surface hydrology. The case of the Yvel watershed

[Impact de retenues collinaires agricoles sur l'hydrologie de surface. Exemple du bassin versant de l'Yvel]

Country: France
Authors: C. Cudennec, M. Sarraza
Languages: English, French

Abstract

In this case study, dams have been located in the downstream area of an upstream watershed, to store winter flows so that they can be available for irrigation during the period of low stream flows, when water is most needed. A modelling tool is proposed for considering and quantifying their hydrological impacts. Application of the model to this case study shows that downstream modifications reduce upstream hydrographic peaks and also affect the shape of the whole hydrograph. These effects are localized and have a relationship to geographical patterns.

Can participatory land use planning at community level in the highlands of northern Thailand use GIS as a communication tool?

Country: Thailand
Author: Oliver Puginier
Language: English

Abstract

This case study describes a village level participatory process of land use classification and mapping used to inform mediation and conflict resolution between hill tribes and the government. Hill tribes, whose populations have quadrupled over the past 40 years, are in transition from shifting cultivation to permanent residence and long-term agroforestry, and seek land security to insure they can meet their subsistence needs prior to changing traditional farming systems. The government has conflicting interests of forest preservation and integration of ethnic minorities. As a result of the participatory process, villagers changed and strictly follow rules and regulations for natural resource management, organizations within the same watershed improved management capabilities, and integration of natural resource conservation with traditions and cultural practices increased community involvement. The mapping shows that forest cover goals were met in this area and that the watershed classification needed to be revised to account for permanent settlements. The maps are being used to petition for recognition of highland farming systems. Although the new government has been hostile to this, participatory mapping has gained greater acceptance in development agencies even if not in policy. A case in which government and village representatives signed written land use agreements may serve as a model in that it provided highland farmers confidence that their management system was endorsed by the government.

Agricultural practices and water quality in Saskatchewan, Canada: A sociological perspective

Country: Canada
Author: Randall Kehrig
Language: English

Abstract

The purpose of this case study is to provide social insights into policy associated with rural water quality. People who live in rural areas, be they farmers or indigenous populations, have unique relationships with the natural environments around them. Although water is a basic requirement of human, livestock and crop life, the quality of rural water is often overlooked until it raises immediate human health concerns. The intensification of agriculture practices including livestock in controlled environments and the use of commercial fertilizer and farm chemicals has the potential to drastically alter rural water quality. However, water policies designed to ensure water quality are often compromised by the structural conditions of the economy and of the state. This case study examines agriculture practices and water quality in rural Saskatchewan, Canada. It presents exploratory data with a social analysis and several suggestions for more effective policy.

Economic effects of changing water quality on an irrigation scheme: a case study from South Africa

Country: South Africa
Author: Jack Armour
Language: English

Abstract

Irrigation agriculture contributes to non-point source water pollution through nutrients, salts and chemicals in return flows, for which farmers are not held accountable. It is expected to expand in South Africa, although irrigation water prices will also be forced up because of increased competition with industrial and municipal uses as water becomes scarcer. The practice of leaching salts out of the soil, is necessary to sustain irrigation agriculture, but has downstream impacts. A model was constructed to allow farmers to consider the potential consequences of various combinations of management options and crops under different water quality situations. Data generated by the model that can be used in impact assessment include the volume of salt loaded return-flows, each farmer’s contribution to non-point source pollution, economic effects of constraining return flow, and effect of water pricing policy on volume of return flows. It is suggested that different rates should be charged for irrigation waters of different qualities. Greater incentive for efficiency could be achieved by allocating water on a volumetric rather than a per hectare basis. Under the current water pricing system, returns from leaching more than compensate for pumping costs. The trade-off between leaching and downstream effects remains to be quantified.

Development de small watersheds

[Desarrollo de pequeñas cuencas hidrográficas]

Country: Cuba
Authors: Miguel Hernández Bauzá, Nilo Alfonso González
Language: Spanish

Abstract

This case study discusses the development of small water projects in Cuba. In this particular case, the problem was to provide sufficient water for a new ranching development greater than 100 000 ha for which there are no secure sources or sufficient reserves. Management of the catchment area was regarded as key to development, and allowed agriculture to be organized within the geography of the basin.

Integrating biophysical, ecological and social research for catchment-scale management of water resources: the Motueka river initiative

Country: New Zealand
Author: Breck Bowden
Language: English

Abstract

This case study describes a research programme designed to integrate technical knowledge with social learning, in a framework of integrated catchment management (ICM) for the Motueka river. Main concerns in this catchment are consequences of land and water management on the coastal fishing industries, impacts on trout habitat quality, and conflicts over water allocation. These are associated with steep slopes, seasonal dryness, low-flow and sediment impacts, and transport of nutrients and pathogens. Through a process of stakeholder consultations, involvement of international experts in review and design, and input from research staff, a research plan was agreed upon that is focused on helping to achieve specified national outcomes. Expected project outcomes are to increase awareness of cumulative impacts, the need for catchment scale management, and to provide new knowledge and tools that will provide common ground for decision-making with reduced conflict.

Tracing sediment transport with Cs-137 isotopes: The Chasovenko catchment case study, Central Russian Federation

Country: Russian Federation
Authors: Valentin Golosov, Vladimir Belyaev
Language: English

Abstract

Chernobyl-derived 137Cs deposits were used to examine the distribution of sediment within the Chasovenkov Verh catchment. Eroded sediments were found to be primarily deposited within the catchment, in the dry creeks or "balka" in the valley, which serve as a sink. These contaminated sediments are therefore not expected to enter the rivers unless there is a change in climate or land use that leads to active incision. It is suggested that this approach can be used to better understand environmental processes in areas of high contamination, and also to assess upstream and downstream interactions.

Southern highlands irrigation infrastructure refurbishment project

Country: Australia
Author: Stephen Arnold
Language: English

Abstract

This case study describes a cooperative approach to natural resource management, which increased the incomes of farmers, enabled them to diversify, and led to more efficient water usage. Downstream benefits were lowered water tables that otherwise dissolve salt and bring it to the surface, and reduced salt accessions into the river system. Measures adopted were reforms to water pricing and allocation which included user fees and tradable water entitlements, provision of economic incentives for efficiency of use; legislative reforms regulating the water industry, investment in public infrastructure to increase efficiency, retirement of agricultural land unsuited to irrigation, and farmer training programs. On-farm water savings of up to 30 percent have been reported and further efficiency gains are expected. Involvement of farmers in the planning and design phase was critical.

Land-water linkages in the upper Niger watershed

[Relations terre-eau dans le bassin versant de Niger supérieur]

Country: Guinea
Author: Sény Soumah
Language: French

Abstract

The case study describes the general situation of the upper Niger in Guinea in which there are dry areas dependent on irrigation, and where wild fires are a common environmental calamity. A management plan is needed to harmonize resource conflicts in the region.

Watershed development - or should it be watershed management? The Kawad project, Karnataka

Country: India
Authors: C. Batchelor, M. Rama Mohan Rao, K. Mukherjee
Language: English

Abstract

As part of the Karnataka Watershed Development Project (KAWAD) in northern India, a water resources audit study was conducted to consolidate existing data from a wide range of sources, assess the status of land and water resources, and provide a starting point for identifying options. Among the key findings were that groundwater extraction is increasing and its levels are falling. Although local perception attributes this to cutting down of trees, it is driven by higher profitability of irrigated agriculture, grants or cheap loans for well construction, and policies of free electricity for pumping. Although extraction is about equal to recharge, since wells are pumped until they fail every year, some villages extract it at 2.5 times the average recharge rate. Because of this situation, there is no groundwater "buffer" that can be relied on in a drought, and shortages have disproportionate impact on the poor, particularly women and children. Among the conclusions are that water resources are fully developed and emphasis is needed on management, for which over 40 options were identified, that could increase productivity and/or improve equitable access. This implies giving highest priority to drinking water supplies and then allocating it to uses with the highest social and economic value. Village level planning needs to take place within a wider planning framework to facilitate consideration of issues such as upstream-downstream equity, flood protection, drought preparedness, pollution, and biodiversity protection.

Indo-german watershed development programme Gujarat: A baseline survey

Country: India
Authors: Andreas Groetschel, Ingrid Müller-Neuhof, Ines Rathmann, Hermann Rupp, Ximena Santillana, Anja Söger, Jutta Werner
Language: English

Abstract

This case study describes a recently initiated programme for improving agricultural potential and living conditions in the semi-arid drought-prone state of Gujarat, to be implemented by villagers with guidance from a Project Implementing Agency that is preferably a local NGO. Types and combinations of physical measures to be implemented in each watershed will be decided through an intensive participatory resource and land use planning process. Another objective is to develop and strengthen social coherence through the establishment of Village Watershed Committees, and to open income generating opportunities for the weaker groups. A baseline survey is to be conducted by a multidisciplinary team of junior experts, to identify issues, stakeholders, potential capacity building institutions, existing government-funded rural development programmes, and to analyze needs of target groups.

Combating drought in Rajasthan through the watershed approach

Country: India
Author: B.K. Kakade
Language: English

Abstract

The paper describes impacts of a watershed development programme that enabled the particular communities involved to maintain increased productivity even during a drought that was devastating to the surrounding districts. The programme was carried out through village level institutions, and the initial assessment blended indigenous with scientific knowledge, which led to the development of innovative measures that were effective for water harvesting. A mid-term survey, at the end of the third year of the project, which was also a drought year, reveals significant increases in particular crops, less use of firewood because of improved cooking devices, reduction in the amount of time needed for women to fetch drinking water, increases in stream flow, and increases in the water tables.

Environmental impacts and vulnerability of water resources in the Berdawni rural watershed, Bekaa

Country: Lebanon
Authors: T. Darwish, M. Khawlie, I. Jomaa, R. Chihny
Language: English

Abstract

This case study presents an assessment of downstream water impacts in the Berdawni watershed, where pollution of surface water has led to increased exploitation of less polluted groundwater for irrigation purposes, and to the uncontrolled development of private wells. The watershed is significant both for industrialization and agriculture and is under increased demographic pressure. Chemical analysis of the Litani river and its branches reveals pollution levels in excess of international norms and levels of tolerance for nickel and chromium that accumulate with irrigation water from the Litani, and also in well water. It concludes that regulatory measures are urgent and that these should be developed and implemented through a participatory process involving stakeholders. Priority should be given to establishing water and instream values and developing strategies needed to assure quality of living, monitoring and updating of databases, and institutional capacity building through a continuous Impact Assessment Program. Environmental impact assessments should also be done for large scale projects, and there should be focus on quality, and on total watershed management.

Water quality and management in peri-urban Kumasi

Country: Ghana
Authors: D.F.M. McGregor, D. A. Thompson, D. Simon
Language: English

Abstract

In order to determine effects of urban and peri-urban pollution, measurements were taken at two sites, upstream and downstream from Kumasi, and show significantly higher levels at the downstream site. The main pressure on land use in this area is conversion of agricultural land to housing development. Associated with this are problems with various forms of waste disposal. To improve community awareness, water quality testing kits were provided to selected schools. Ten months following the start of this aspect of the project, the junior high school participants were disseminating knowledge of water quality issues to their communities, in some cases in the form of plays. Following feedback from the schools, improved water quality test kits were provided that enabled them to conduct a wider range of tests and provide a more systematic description of watershed conditions. Their intent is to report any measurements of concern to environmental authorities for verification and follow-up. A more thorough investigation of stakeholder attitudes is planned.

Agriculture and nitrogen pollution of water in Brittany

[Agriculture et pollution azotée des eaux en Bretagne]

Country: France
Author: Séverine Gibet
Language: French

Abstract

In western France, Brittany has developed its economy mainly through agriculture. The agricultural revolution has displaced all traditional cultivation but fodder crops have continued. Nowadays, animal husbandry predominates. Over the last 30 years, plant production has increased by 25 percent, while animal production has been multiplied by five.

The input of nitrogen on fields to increase yields from the spread of manure originating from animal husbandry accounted for 56 percent, and from fertilizers for 42 percent. During many years, the input of nitrogen was exceeding the need of cultures. Among the consequences of this over-fertilisation, an important nitrogenous pollution has appeared. Since 1972, nitrate concentration in running water increased fivefold, reaching 40mg/L in 1998 and leading to problems for the supply of drinking water.

Small Hydraulic structures and their impact on farmers' lives, streamflow, soil and water conservation and downstream water resources: The cases of the Siliana and Kef watershed

[La petite hydraulique et son impact sur la vie de paysan, les eaux de ruissellement, la conservation des eaux et des sols et les ressources en eau vers l'aval dans un bassin versant: cas des deux bassins versants de Siliana et du Kef]

Country: Tunisia
Author: Mohamed Mechergui
Language: French

Abstract

The objective of this case study is to present the results of research conducted in Tunisia in two main semi-arid zones dealing with the implementation of small hydraulics for water catchment in the upland and big dams downstream. It was shown that the relationship between upstream and downstream land use is directly related to the rain intensity. When the rain intensity is low, the upstream catchment hydraulic reservoirs makes profit from water and solid transports which gives a bigger life for big dams and the farmers can improve their cereal production by supplement irrigation. However, when the rain intensity is high, the upstream dams collect small quantities of rain but big solid transports and let clear water going downstream to the big dams; the strategic runoff water resource is improved and downstream irrigation is maintained. The mechanism between upstream and downstream in the watershed increases profit for the big dams (clear water downstream, smaller life for upstream reservoirs) and so for the downstream farmers because the national strategy is based on collecting surface runoff in big dams to stabilize or increase production on fertile soils downstream. The question that can be raised is what will be the optimum number of small hydraulics reservoirs upstream and what will be the optimum capacity of downstream reservoirs to minimize the runoff to the sea.

The Romwe catchment study - the effects of land management on groundwater resources in semi-arid Zimbabwe

Country: Zimbabwe
Authors: P.B. Moriarty, C.J. Lovell
Language: English

Abstract

Two crucial parameters that control land management and groundwater interactions in the Romwe catchment and that are external to the farming system, are climate and geology. Extreme variability in rainfall follows a pattern, reflected in groundwater levels, of nine years above and nine years below average, found in much of Southern Africa. The pattern is also found in the development of herds during wet periods, and their collapse at the onset of dry periods. The relevant geological characteristic is that groundwater is relatively close to the surface because shallow soils are found on top of impervious rocks or crystalline basement areas, and is therefore always within the root zone of vegetation and therefore constantly in use. Deforestation of the valley bottom increased the water supply, which could be significantly reduced in the event of reforestation or woodlot development. In-field structures that create ponding effects increase groundwater recharge. The implications of these observations are that there is a trade-off between forestry and other land uses, and between management for soil moisture to support rain-fed crops, and groundwater recharge, to support irrigated crops. Groundwater is therefore highly localized and is best managed locally. Downstream effects in this case will be minimal.

The influence of a headwater wetland on downstream river flows in Sub-Saharan Africa

Country: Zimbabwe
Author: Matthew McCartney
Language: English

Abstract

This paper reports on a study conducted to provide insight into the hydrology of dambos, a type of seasonal wetland, common in the headwaters of many major river systems in southern and central Africa. Although largely based on conjecture, dambos have been attributed an important role in the regional hydrological cycle in the form of dry season flows, and their disturbance is perceived to conflict with their function as a source of downstream flow. Results obtained in this study suggest instead that, although they store significant amounts of water during the wet season, its depletion is dominated by evaporation, with only a small portion contributing to stream flow. Also, that they may reduce floods at the start of the wet season but once the soils are saturated, they generate flood runoff. This suggests that shallow rooted crops could be grown in dambos with little impact on dry season flows.

A quantitative treatment on the influence of catchment features, based on GIS, on fish production in Sri Lankan reservoirs

Country: Sri Lanka
Authors: Sena S. De Silva, U.S. Amarsinghe, C. Nissanka
Language: English

Abstract

Sri Lankan reservoirs are the mainstay of an important inland fishery as it is the main source of protein for the rural poor. Fisheries and limnology data were collected at nine perennial reservoirs, and land use patterns were digitized from land use maps. Statistical analysis of catch statistics and reservoir catchment land use features suggest that the extent of forest cover and shrub land in relation to reservoir surface area, were the most determining factor on fish yield. In addition to demonstrating the importance of land use pattern in fish production, the study suggests GIS can be used to formulate yield predictive models in inland waters and can be an effective management tool.

The Goulburn broken water quality strategy

Country: Australia
Author: Pat Feehan
Language: English

Abstract

This catchment is a priority catchment for developing a strategy to address algal and nutrient problems. Water quality, as indicated by nitrogen and phosphorus, shows a progressive decline upstream to downstream and algal blooms have been increasing, although total nutrient export to the basin varies with stream flow. Irrigation water is particularly problematic because it is high in nutrients and is released during the summer when most algal blooms occur. The strategy is expected to reduce phosphorus loads by 65 percent over a 20 year period through specific measures to reduce nutrient loads from irrigation drains, sewage treatment plants, fish farms and new developments, by installing filter strips along streams, and through monitoring and evaluation. Cost contributions from downstream beneficiaries are made through the state and federal governments (17 percent each), while catchment stakeholders are expected to cover the remaining 66 percent, specifically to cover works and the full cost of ongoing operations and maintenance of these works. A number of uncertainties in the science made it necessary to make some basic assumptions about whether and to what extent phosphorus reductions will reduce risks of algal blooms, and about how it behaves in the ecosystem. The community recognizes these uncertainties and accepts that the strategy may require modification as more information becomes available.

Integrated land and water management in the upper watersheds of the Aral Sea basin

Country: Tajikistan
Author: S. Aslov
Language: English

Abstract

The five Central Asian states affected by the Aral Sea crisis have cooperated to develop a system of interventions to promote efficient use of land and water resources and also improve environmental and socio-economic conditions. Key aspects of the program are assessment of the status of land and water resources as well as living standards, and to identify actions that can be taken to restore degraded ecosystems. The main causes of deteriorating water quality are excessive withdrawal for irrigation and drainage of saline irrigation water containing pesticides, and pollution from domestic and industrial wastewater. Soil erosion is associated with both irrigated and rainfed agriculture and with pasture, and has led to intensive gully formation. More needs to be known about the dynamics of soil erosion and its spread, as a basis for identifying urgently needed control measures. In a pilot project proposed for Tajikistan, where the main problem is unavailability of drinking water, in addition to all of the above, expected benefits to the local population include construction of a complete drinking water tap system, development of sanitary systems, construction of structures to prevent damages from mudflows, erosion control and reclamation of degraded lands, multipurpose land uses that include small enterprises, small power plants based on renewable energy sources, and socio-economic studies to evaluate and guide the project.

Collective action to fight soil erosion in Réunion

[Action concertée de lutte contre l'érosion des sols à la Réunion]

Country: Réunion
Authors: Denis Groene, Alain Hébert, G. Benoit
Language: French

Abstract

Situated in the Indian Ocean, the island of La Réunion is a part of France. It is inhabited since the 16th century. Nine tenths of the total area (2512 km²) are covered by a volcanic mountain. The population is 700 000 people (density 280/km²). The climate is tropical with heavy rains and annual cyclones. Landscapes are very impressive, with huge abysses. The social and economic background is tense, with an unemployment rate about 37 percent.

The paper presents a programme of action in progress since 1988, to mitigate the soil erosion. This action started with small land use improvements planned, implemented and monitored by farmers. Now, in 2000, 18 projects involve 250 farmers working on a total area of 1 200 ha. The programme is continuing by focusing on training and building a public awareness of soil as an limited natural resource. The Environment Chart (1996) of La Réunion has included the erosion as one of its four main topics.

Micro-dams for rainfall water retention in central-west Brazil: Pilot project on water and soil conservation in the micro-basin of the Paiol

Country: Brazil
Author: Luciano Cordoval de Barros
Language: English

Abstract

The accelerated and disorganized deforestation in Central Brazil and the transformation of these natural ecosystems into crop land or pastures, without adequate technologies, resulted in irrecoverable damages to the environment, especially with respect to water and soil conservation, with particular mention to compaction. As a consequence, the soil intake rate decreased and surface runoff increased, thus causing laminar erosion, low soil quality, silting up of rivers, floods and decreased sustainability of family properties. With the objective of reverting this scenario, a demonstrative unit was implemented in Sete Lagoas, MG (1 350 mm rainfall per year), in 1995. On a property of 70 ha, 30 micro-dams ("barraginhas") were built to contain surface runoff damages. These micro-dams also retain pollution sources carried by the waters and favour the recharge of good quality water tables, by means of improving soil intake rate, recovering water sources and alleviating droughts. Due to the success of this demonstration unit, by means of field visits by farmers, NGOs and publication of articles in journals and national/international congresses, a decision was taken to extend the experience and build 960 low-cost micro-dams, in 1998, in 60 small properties covering all the micro-basin of the Paiol stream, comprising a total area of approximately 40 km², in the village/community of Estiva, Sete Lagoas county. That was only possible because of the active participation of small farmers in the indication of existing degraded sites and the support provided in terms of food and lodging for the working teams. As a result, it is now possible to hear the farmers testimonials on the effects observed in elevation of water tables observed in their domestic reservoirs ("cisternas"), better utilization of the water and drought alleviation, that have increased their yields.

The impact of drainage of agricultural soils on annual runoff: an example from the Brie region

[Rôle du drainage agricole enterré sur les écoulements annuels: un exemple en région de grande culture (Brie)]

Country: France
Authors: Claude Cosandey, Marie-Josée Penven, Tatiana Muxart
Language: French

Abstract

On the Brie plateau, as in numerous places in France, agricultural soils are drained by pipes, in relation to new agricultural practices. In order to study the role played by this drainage network in the transfer of water from the soil surface to the stream, three small hydrological bodies (6.4 ha, 4.6 and 30.6 km²) with pipe drains, are monitored. Three hydrological winters are considered here, under contrasting rainfall conditions. The answers of the three hydrological bodies are similar in terms of rhythms, but quite different in terms of runoff coefficient. When the soil water content is at field capacity, the total amount of effective rainfall is very quickly transferred by the pipes to the stream in the drained parcel. In the two small watershed, only about 60 percent of effective rainfall appear as surface runoff during winter. The results raise the question about the role of drainage on flood magnitude.

Water quality and rural society: Potential health risks in the lower Rio Colorado watershed. The case of the Mexicali Valley

[Calidad de agua y sociedad rural, riesgos potenciales de salud en la cuenca baja del río Colorado: el caso del Valle de Mexicali]

Country: Mexico
Author: Alfonso Cortez Lara
Language: Spanish

Abstract

This study evaluated levels of nitrogen pollution in the eastern Mexicali Valley. 68 rural wells were sampled, a survey of households interviews with key actors were conducted to identify relationships between socio-economic conditions and health, and technical information was reviewed. Based on a nitrogen budget, it was estimated that the amount reaching the aquifer is 22.9 mg/L, over twice the limit established by the United States Public Health Service, and therefore represents a health risk to the local population. Nitrogen contamination was not found in the regional aquifer during the first phase but a large portion of the population has been using latrines for over 20 years, fertilize with nitrogen, and have shown some signs of water related illness including cancer among children, although there has not been sufficient evidence to link this to water consumption. 69 percent believe that water consumed is of good quality, based on personal experience. The low level of awareness of causes of potential contamination of the aquifer limits the capacity to implement preventative measures. The government has done little to disseminate information about the problem and, according to consumers, there was insufficient government action and little or no coordination among government agencies.

Estimation of basin sediment flux in the Pang Khum Experimental Watershed in northern Thailand: The contributions of roads and Agricultural Lands

Country: Thailand
Authors: Alan D. Ziegler, Thomas W. Giambelluca, Ross A. Sutherland
Language: English

Abstract

Stream sediment load and sediment contributions from roads, paths, and agricultural lands are estimated for a one-year period in an upland watershed in northern Thailand. Total road sediment input to the stream was only slightly higher than that from agricultural lands (30-41 versus 25-40 Mg), but corresponding erosion rates were substantially greater (65-88 versus 2-4 Mg ha-1 y-1). The results emphasize that basin sediment yield is not a reliable indicator of the existence of severe erosion within a watershed. Rather, sediment budgeting approaches are needed to uncover important sediment sources that occupy small percentages of the total basin area (e.g., roads). Finally, the trend of focusing solely on impacts of agricultural practices on erosion, ignoring impacts associated with unpaved roads, is not a sustainable conservation strategy for managing upland watersheds in southeast Asia.

Influence of land use on the hydrological properties of volcanic soils: the case of catchment providing water to Andean cities

Country: Ecuador
Authors: W. Buytaert, B. De Bièvre, J. Deckers, G. Dercon
Language: English

Abstract

In the catchment of the Rio Paute in the southern Andes of Ecuador, soils have a high water retention and regulation capacity because of the presence of allophane clay in which hollow spheres are formed which show microscopic pores that store water. However, it is not clear which phenomena control the retention and release of water (e.g. retention in soil, in vegetation, in organic matter layers, in swamps, lakes, forests...) The case study analyzes effects of land use on retention capacity. Cultivation affects hydrophysical properties but traditional methods do not seem to apply as they are based on concepts of equilibrium between gravity, capillary and hygroscopic forces - other forces are active in the andosols. So it is not clear what actions of stakeholders will affect downstream water availability, which makes negotiation difficult.

The watershed protection fund (FONAG) as a mechanism for the conservation of the cayambe-coca and antisana reserves in Ecuador

[El fondo para la protección del agua y las cuencas (FONAG) como mecanismo para la conservación de las reservas cayambe-coca y antisana en Ecuador]

Country: Ecuador
Author: M. Echavarría
Language: Spanish

Abstract

The case study describes a proposed financing mechanism for water and watershed protection activities in the upper watersheds of the city of Quito, Ecuador. Local (e.g., the water supply company) and international sources will be contributing to the fund. The fund will be governed by a board consisting of representatives from the local water and electricity companies, water users, the regional and local government, communities, and non-governmental organizations. It will finance conservation activities with the aim of ensuring a clean, dependable water supply.

Impacts of irrigation development on small-scale aquatic resources: a case study of southern Laos

Country: Laos
Authors: Sophie Nguyen Khoa, Kai Lorenzen, Caroline Garaway, Robert Arthur, Bounthanom Chamsingh, Douangchith Litdamlong, Nick Innes-Taylor, Darrell Siebert
Language: English

Abstract

In southern Laos, where there is heavy livelihood dependence on aquatic resources, irrigation was found to have moderate but significant impacts, which need to be considered in cost-benefit analysis and environmental assessments of small and medium scale irrigation schemes. Proliferation of these schemes may lead to even greater cumulative impacts. Although there were no significant effects near new reservoirs, these are not accessible to those impacted downstream and only provide partial compensation.

3. List of interventions

* Administrative messages by the team are not included in this list, thus, the numbering is not consecutive.

4. Workshop programme