The Three Gorges Dam Project in China : history and consequences

After several decades of planning and deliberations, the Three Gorges Dam (Sanxia Daba, ) in the upper reaches of the Yangtze River (Central China), is near to be completed. It is expected that this mega-dam, which will harbor the largest hydropower plant in the world, will contribute to flood control in the middle and lower reaches of the Yangtze River, will solve the energetic scarcity of the region, and will improve the river navigability. Its construction, however, would also imply a series of severe negative consequences, such as the loss and fragmentation of many habitats and other effects on the wildlife, the loss of many archaeological and cultural sites, and the forced displacement of more than 1 million people.Després de diverses dècades de planificació i deliberacions, l'embassament de les Tres Gorges (Sanxia Daba,), al curs alt del riu Iang-Tsé (Xina Central), és a punt de completar-se. S'espera que aquesta enorme presa, que comptarà amb la central hidroelèctrica més gran del món, pugui contribuir al control de les inundacions en el curs mitjà i baix del Iang-Tsé, solventi l'escassetat energètica de la regió, i millori la navegabilitat del riu. La seva construcció, no obstant, també significarà una sèrie de greus consequències, com ara la pèrdua i la fragmentació d'hàbitats i d'altres efectes negatius sobre la biodiversitat, la desaparició de nombrosos jaciments arqueològics i d'altres indrets d'interès històric, i el desplaçament forçós de més d'un milió de persones.Tras varias décadas de planificación y deliberaciones, el embalse de las Tres Gargantas (Sanxia Daba,), en el curso alto del río Yangtzé (China Central), está cerca de su conclusión. De esta enorme presa, que contará con la mayor central hidroeléctrica del mundo, se espera que pueda contribuir al control de las inundaciones en el curso medio y bajo del Yangtzé, solvente la escasez energética de la región, y mejore la navegabilidad del río. Su construcción, sin embargo, también significará toda una serie de graves consecuencias, como por ejemplo la pérdida y la fragmentación de hábitats y otros efectos negativos sobre la biodiversidad, la desaparición de numerosos yacimientos arqueológicos y de otros lugares de interés histórico, y el desplazamiento forzoso de más de un millón de personas

2000 USCID international conference

Presented at the 2000 USCID international conference, Challenges facing irrigation and drainage in the new millennium on June 20-24 in Fort Collins, Colorado.Includes bibliographical references.Sponsored by U.S. Committee on Irrigation and Drainage.Multicriteria strategic planning for rehabilitation of the Wind River Irrigation Project, Wyoming -- Environmental management plan for the Irrigation Improvement Project (IIP) - Tajan Subproject -- Organizational requisites of successful irrigation system rehabilitation: cases from Nepal -- Verification-based planning for modernizing irrigation systems -- Policy reforms for sustainable irrigation management in Indonesia -- Bench terracing - a cost effective alternative to traditional irrigation in the Philippines -- GIS-based management system for irrigation districts -- Capacity building for the practice of irrigated agriculture -- Planning of modern irrigation systems integrated with human settlement for enhanced reuse of water -- Drainage in the Aral Sea Basin: past and future -- Impacts and solutions to urbanization on agricultural water resources -- Improving subsurface drainage design and management to reduce salt loads from irrigation areas in southeastern Australia -- Evaluation and update of drainage water management options on the westside San Joaquin Valley, California -- Simulation studies on use of saline water for irrigation in a semi-arid environment -- Hydrodynamic modeling to optimize irrigation efficiency -- Planning to meet future water needs -- Tracing the history of the development and management of two irrigations systems in the Terai of Nepal -- Secondary water supply management for irrigation districts and canal companies -- Role of canal automation and farmer's participation in managing water scarcity: a case study from Orissa, India -- PIM: a reality in Asia? -- Private group irrigation projects in Manitoba: Central Manitoba Resource Management Ltd. - a case study -- Evaluation of dielectric soil moisture sensors for irrigation scheduling on farms -- Sensitivity of micro irrigation emitters to plugging using treated municipal wastewaters -- NCWCD irrigation scheduling program - converting to a web-based accessible program -- On-farm activities to promote irrigation scheduling - the South Kansas Irrigation Management Project

Weir management : challenges, analysis and decision support.

If humanity is to make the best of this planet then it is crucial that we develop the capacity to implement the most effective environmental management practices. Essential is a holistic approach to management, as is advocated by integrated catchment management (ICM), which proposes that catchment management issues will be best dealt with when interventions are planned together at the catchment scale and all stakeholder interests are given consideration during decision making. The issue of weir modification is a good example of a problem that would benefit from these principles. Many stakeholder interests are affected by weir modification, and if effective and fair weir modification decisions are to be made, all must be used to evaluate alternative weir modification options. So that decision makers can make the most of the synergies and avoid the conflicts that can occur between interventions, they need to know how multiple weir modifications interact. To do this decision makers must be able to manage and utilise a large amount of information and use it to help them make effective decisions. The objective of the research presented in this thesis is to develop an approach to the management of weirs in the Don Catchment that is holistic both a spatial sense and in terms of the assessment of alternative management options. An evaluatory framework for weir modifications is formulated by adapting published typologies of river ecosystem services (ESs). The prediction of how catchment interventions affect sociocultural ESs is recognized as a particularly challenging to the application of this framework because their qualitative and subjective nature makes them hard to predict. Bayesian Networks (BNs) are identified as a potential solution as they use probabilities to describe the relationships between variables. A BN was built to predict how weir modification affected weir danger and weir fun for canoeists by utilising the knowledge of canoeing groups. It is concluded that despite a number of caveats, BNs offer a potentially important method for allowing sociocultural ESs to be predicted in decision making processes. The consideration ofthe complex interdependencies multiple weir modifications can have is recognised as another of the challenges facing weir management decision making. A spatially explicit modelling approach is developed that can account for the interactive effect multiple weir modifications have on river connectivity for several river species in the Don Catchment. Expert judgement and hydrological modelling are used to discriminate between different levels of habitat quality for European eel (Anguilla anguilla) and Atlantic salmon (Safrna safar). Several strategies to increase connectivity in the Don Catchment were explored. It was found that each had its own set of winners and losers, indicating trade-offs between species need to be considered when planning connectivity enhancements. The modelling approach shows the interdependent effects of weir modifications are vet: important in determining habitat accessibility, particularly the cumulative effect of multiple fish passes. A decision support system (DSS) dubbed the Weir Tool was constructed through the integration of the canoeing BN and the river connectivity models. As it is generally assumed that if DSS are employed, improved decision making will result, this assumption was tested in a controlled experiment. In contrast to expectations, users of the Weir Tool learnt less about the environmental issue of weir modification compared to the control group, and did not make more effective decisions

Quantification of the cross-sectoral impacts of waterweeds and their control in Ghana

The Akosombo Dam on the Volta River in Ghana was built in 1963 to provide cheap energy to fuel industry and to accelerate the economic growth of the country. It provides hydroelectric power, enhanced fishing and water transportation upstream, and improved opportunities for irrigated farming, especially in the lower reaches, and their attendant economic multiplier effects. A few years after the construction of this major dam, a rapid expansion of industrialization took place in Ghana. This brought about an exponential increase in demand for more electrical power. This led to the construction of a smaller dam at Akuse, downstream of the Akosomho Dam in 1981 and the formation of a headpond at Kpong. The impoundment of the river at the two sites (Akosombo and Kpong) caused an alteration in the existing ecological and biophysical processes in the river basin, including a slowing of the flow of the river, upstream and downstream. Changes in the natural processes, such as a reduction in the flow of the river and an increase in nutrient status of the water, resulted in an invasion of aquatic weeds, increasing the density of aquatic snails (intermediate hosts of schistosomiasis), silting and closure of the estuary, as well as other more subtle effects. The invasion of the river's main course and the dams by aquatic plants led to a corresponding reduction of navigable water both upstream and downstream. The aim of this thesis was to quantify the impact and control of waterweeds, especially water hyacinth, Eichhornia crassipes (Mart) Solms-Laubach (Pontederiaceae), in Ghana. A floral survey on the Kpong Headpond recorded 49 emergent, 12 free floating and I submerged aquatic plant species, many of which were indigenous, but the exotic or introduced water hyacinth was recorded at most of the sampling sites, and was the most abundant and had the biggest impact on the utilization of the water resource. Mats of water hyacinth served as substrates for other, indigenous species to grow out into the main channel of the headpond, including the intake point of the Kpong head works of the Ghana Water Company Limited (GWCL) and landing sites for boats. These mats resulted in a reduction of the fish (fin and shell) harvest, reducing the annual production to far below demand. Water hyacinth was also shown to have severe health implications. A survey of the Ministry of Health records showed that the prevalence of both urinary and intestinal schistosomiasis had risen significantly over time as the abundance of waterweeds, most notably water hyacinth, increased, and ranged between 70% and 75% but up to 100% in some lakeside communities. Based on the work done by an NGO on board the medical boat ("Onipa Nua "), losses in terms of money due to the effect on health of the aquatic weed infestations on the Volta River in 2006 amounted to US$620,000. Economic losses due to invasive alien aquatic weeds were also calculated on the Oti River Arm of Lake Volta. It was estimated that about US$2.3 million per annum would be lost to the Volta Lake Transport Company and individual boat transport operators if this section of the river were 100% covered by aquatic weeds (water hyacinth and Salvinia molesta D.S. Mitchell (Salviniaceae)). It was also estimated that US$327,038 was spent annually in monitoring and managing the weeds in the Oti River. Control interventions for aquatic weeds have been implemented in river systems in Ghana. The biological control agents Neochetina bruchi Hustache (Coleoptera, Curculionidae) and Neochetina eichhorniae Warner (Coleoptera, Curculionidae) have been used on water hyacinth infestations in the Oti River Arm of Lake Volta, the Tano River and the Lagoon complex in the south-western part of the country. Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) has been used to control salvinia, and Neohydronomous affinis Hustache (Coleoptera: Curculionidae) to control water lettuce, Pistia stratiotes Lilmaeus (Araceae) in the Tano River and Lagoon complex. Although these projects have been regarded as successful, they have relied on research from elsewhere in the world and no postrelease quantification has been conducted. In evaluating the impact of the biological control agents Neochetina bruchi and Neochetina eichhorniae weevils on water hyacinth infestations in the Tano River, fresh adult feeding scars were recorded as well as the numbers of adult weevils on each water hyacinth plant sampled at six sites. Despite being released in 1994, weevil numbers and resultant damage to plants in the Tano Lagoon was low in comparison to other regions of the world where these agents have been used. The main reason for this is that this lagoon floods seasonally, washing weevil-infested plants out to sea. Water hyacinth then re-infests the lagoon from seed and the weevil populations are low. To resolve this situation, two courses of action are proposed. The first is to mass rear the weevils along the shore of the lagoon and release them when the first seedlings recruit. The second proposal is that additional agents that have shorter lifecycies and are more mobile than the weevils should be released. To this end, the water hyacinth mirid, Eccritotarsus catarinensis (Carvalho) (Hemiptera: Miridae) was imported from South Africa and released onto the Tano Lagoon in 2009. Retrospective laboratory host specificity trials were conducted on Neachetina eichharniae and Neachetina bruchi weevils 15 years after their release into Ghana to see if any variation in their host ranges had occurred. Considerable damage was inflicted on the E. crassipes leaves by the Neachetina weevils, while little feeding damage was recorded on both Heteranthera callifalia Kunth. (Pontederiaceae) and Eichharnia natans (P.Beauv.) Solms (Pontederiaceae). All the weevils introduced on H callifalia and E. natans died after the first week. This study served to confirm the host specificity and thereby the safety of these agents. Invasive alien aquatic macrophytes have negative impacts on the environment and economy of Ghana. The control of these weeds is essential to socioeconomic development and improved human health standards in riparian communities. Biological control offers a safe and sustainable control option, but requires diligent implementation. However, aquatic weed invasion is more typically a result of the anthropogenically induced eutrophication of water bodies, and this is the main issue that has to be addressed

Emerging Issues in Public Policy: The Environment, Water, and the Coast, 1977-1982

This collection, titled The Environment, Water, and the Coast, presents a selection of the Institute\u27s Public Affairs Report on these topics for 1977-1982

Assessing Economic, Social, Political and Environmental Issues Related to Mega-projects: A case study of Merowe Dam in Sudan

Contemporary global economic development has been undergoing a transition into multiple pathways aiming at sustainable development, poverty eradication and environmental protection especially in energy production to achieve socioeconomic development (Behera, 2006; Dunning, 2006). In developing countries, a shift from traditional development to modern economic development has begun since the 1970s (Amin & Thrift, 1995; Behera, 2006). Many developing countries have used mega-dams as a source of electricity generation and water supply for irrigation, urban and industrial uses. Dams are still preferred as the primary strategy to pursue economic development, which has been reinforced by increasing levels of urbanisation, industrialisation, agribusiness and diversification of income in rural economy (Rigg, 2007; Varma, 2003). Sudan has embarked on economic development for decades and the need for electricity and water for irrigation is becoming more important over time as the country has experienced political polarisation and rapid transition towards modernisation, industrialisation and urbanisation (Verhoeven 2011). However, in 1990s the country’s economy has faltered due to electricity shortages, and stagnation in industrials and agribusiness, which has reduced economic output (Askouri, 2014; Hashim, 2009). Many academics have focused on evaluations of the contribution of mega-projects primarily to economic development in the developing economies. But, less emphasis has been placed on the agency of society, economic structure, development stage and needs of the economy, its geo-politics, level of institutional development and socio-cultural factors (Dogra, 1992; Ersumer, 1999b; Flyvbjerg, Garbuio & Lovallo, 2009; Varma, 1999; Varma, 2003). Furthermore, in 1990s the processes by which development are governed have changed remarkably. Scholars are debating the conceptual and theoretical approaches concerning actual and potential impacts of mega-projects as a powerful force in shaping development and their position in development theories. Much of the focus has been on the consequences of dams, which increasingly do not have a consensus as a development tool (Behera, 2006; Dunning, 2006). Therefore, in order to address the gap in the literature, this thesis adopts an approach that combines socioeconomic, human development and social conflict theories to study the influence of mega-projects on the development and communities through a case study of the Merowe Dam located in northern Sudan. A multi-methods approach was used to collect data, including 300 questionnaires in seven locations, in-depth interviews of over 30 participants, participant observations and secondary data. The results suggest that the electricity produced by Merowe Dam together with the complementary projects implemented by the Dam Implementation Unit (such as educational, health facilities, infrastructures, new settlements and agriculture schemes) have increased social mobility in the region and driven positive economic, social and human development in the Merowe region. However, in the context of social and environmental aspects, the positive outcomes of the project have been overshadowed by social conflicts and mistrust between project authorities and local communities. This outcome suggests difficult interactions and negotiations between various stakeholders and political institutions. The social conditions in Merowe region are now no better than before the dam, and the environmental effects have been negative in some aspects. However, it should be noted that the arid nature of the region has also played an important role in reducing the negative influence of Merowe Dam on the environment. On the basis of the discussion of convergences and divergences arising from Merowe Dam, the thesis renders support for similar projects in other developing economies to pursue socioeconomic development. The two key policy implications are: long-term monitoring of the resettlement areas and strengthening of agricultural extension services. The empowerment of local communities in negotiation and consultation processes by establishing independent mechanisms and administrative bodies to oversee the process of future projects in Sudan is also recommended in developing economies facing similar development challenges