CONJUNCTIVE WATER USE FOR IRRIGATION: GOOD THEORY, POOR PRACTICE (pp. 227-245)
aOverseas Development Institute, Regent’s College, Regent’s Park, UK; bNational Rivers Authority (Severn-Trent), UK
Abstract: There is growing interest in conjunctive water use in irrigation management. However, most systems are introducing ‘joint use’ of surface and groundwater to overcome problems of poor water delivery or quality, rather than systems which actually maximize water utility. This paper summarizes the findings of a literature review on conjunctive use research, including the variable objectives behind its promotion and the hydrological and agricultural planning models experimented with. Effective promotion and subsequent sound management of conjunctive use technologies in irrigation require interaction between a broad range of institutions, including rural development and agricultural support agencies as well as water management bodies.
ENVIRONMENTAL IMPACTS OF CLIMATE CHANGE AND WATER DEVELOPMENT IN THE INDUS DELTA REGION (pp. 247-261)
aDepartment of Geography, Pennsylvania State University, University Park; bDepartment of Geography, University of Colorado, USA
Abstract: The prospect of global warming raises particular concern in delta regions, many of which are already experiencing severe environmental strain as the result of human activity. This paper considers the potential environmental effects of climatic change and water development in the delta region of Pakistan’s Indus River Basin. The impact assessment is conducted using regional output from a river basin simulation model of the Indus Basin. Potential changes in river inflows to the delta, canal diversions and groundwater balance are evaluated under a range of climate change and water development scenarios. The paper also explores possible environmental impacts not included in the modelled evaluation, and discusses policy implications of the assessment results.
DEVELOPMENT IMPACTS ON GROUNDWATER RESOURCES IN BAHRAIN (pp. 263-279)
aAssistant Professor, Hydrology, Department of Physical and Engineering Sciences, Arabian Gulf University, Manama, Bahrain; bHead, Well Construction and Maintenance, (On assignment at Bahrain Center for Studies and Research) Water Resources Directorate, Ministry of Commerce and Agriculture, Bahrain; cAssociate Professor, Environment, Department of Chemical and Biological Sciences, Arabian Gulf University, Bahrain
Abstract: The development process in Bahrain has led to a continuous depletion of its groundwater resources. The unplanned, excessive pumping of groundwater caused a sharp decrease in groundwater storage and the lowering of the aquifer’s potentiometric levels by about 4 metres in the period from 1925 to 1991. As a result, more than half of the original groundwater reservoir has been completely polluted. Development activities will be hindered if the effects of these activities on the groundwater reservoir are not realized. In order to sustain the aquifer usefulness in the development process, the reservoir’s natural balance must be re-established. Therefore, the need for multi-objective planning aiming at integrating Bahrain’s limited water resources capacity and water demands is of paramount importance.
AN ANALYSIS OF MULTIYEAR DROUGHTS IN GREECE (pp. 281-291)
Abstract: A regional analysis was conducted regarding quantiles of the fundamental features of multiyear droughts, severity, magnitude and duration. Basin geomorphic and climatic characteristics were used as explanatory variables in multiple linear regression equations of the logarithmically transformed variables. Results of satisfactory accuracy were obtained, permitting their utilization in ungauged basins of the study area, which encompasses a significant part of the hydrologically important central and northern Greece. Finally, comparisons are made with a similar study in California and some observations advanced regarding the sensitivity of drought characteristics to climatic warming.
SIMPLE WEATHER-WATER DEMAND MODEL (pp. 293-304)
Abstract: To employ plain simulation instead of complicated correlation consumption models one has to utilize modern database facilities. Reciprocally, theoretical rules have to be built into the database as a criterion for the data import into this database and for debugging of previously imported data. Practical use of the model is very forthright; no special program is required. Its applications are: analysis of pricing policies impact, water demand planning, simulation of water demand for new cities and suburbs, etc.
INTERSTATE MULTIVALLEY MULTIRESERVOIR SIMULATION: A CASE STUDY (pp. 305-317)
aAssistant Professor; bFormer Graduate Student Department of Civil Engineering, Indian Institute of Technology, India
Abstract: Most of the water resources systems in India are operated with conventional approaches formulated several decades ago without much knowledge about the system behaviour. In the present study, the HEC-3 simulation model has been used to derive the operating policies for an interstate, multivalley-multireservoir system in India, to achieve optimal operational policies. Four different HEC-3 policies were analysed together with the standard operating policy. The results of the simulation runs were analysed and a suitable optimal operating policy for a multivalley-multireservoir system operation has been evolved. Trade-off analysis between the conflicting objectives of irrigation releases and hydropower production and the probability distribution for the annual average hydropower production were also arrived at to estimate the reliability of the system.
ROLE OF MAJOR DAMS IN THE INDIAN ECONOMY (pp. 319-336)
Abstract: Water resources in India are increasingly becoming scarce. Since rainfall occurs only for three months in a few spells, storage by dams is imperative to utilize waters. On account of topographic limitations, ultimate storage capacity is only 16% of average annual flows and utilizable water is only 38% of the available total. The Indian economy is predominantly agricultural. Irrigation and power have brought self-reliance in food production and economic prosperity but with an increasing population, demands for water are rising fast. By 2025, all utilizable waters will be consumed. This article presents the existing and future scenarios, answers criticisms and brings out the inevitable necessity of major dams.
THE THREE GORGES PROJECT AND MASS RESETTLEMENT (pp. 337-351)
Abstract. In April 1992, the National People’s Congress in Beijing approved the Three Gorges project. Once built, the dam will generate hydroelectric power, check flooding and improve navigation and water supply along the Changjiang (Yangtze). If the construction problems have been solved and investment funds are available, there remains concern about the potential environmental impact and the need to resettle compulsorily over one million people.
Nile 2002, Aswan, Egypt, 1-6 February 1993
International Symposium on Ecologically-Sound Resources Management in Irrigation, Berlin, Germany, 29-30 April 1993