Third World Centre for Water Management

Journals

Volume 16, Issue 3

ONLINE ACCESS TO THIS ISSUE

EDITORIAL
World Water Forum—A Personal Reflection

REPORT
The World Commission on Water


OPERATIONAL PLANS AND PERFORMANCE IN THE PHITSANULOK IRRIGATION SYSTEM, THAILAND (pp. 321-342)

M. Mainuddin, R. Loof and C.L. Abernethy, Water Engineering and Management Program, School of Civil Engineering, Asian Institute of Technology, Thailand

Abstract: Key performance aspects of a 92 000 ha rice irrigation system in central Thailand are reviewed, with reference to water-distribution performance, agricultural performance and plan-implementation performance. Farmers have invested heavily in recent years in pumps, principally for access to shallow groundwater. This allows independent agricultural decision making by farm households. It is shown that tail-end farmers, who have the highest intensity of pumps, achieve the best agricultural performance. The performance in terms of canal water distribution and plan implementation is erratic. Absence of appropriate water-measurement facilities, insufŽcient information ows concerning water quantities and wide variations of farmer strategies seem to be signiŽcant reasons for these difŽculties.


PREDICTION OF DOWNSTREAM GEOMORPHOLOGICAL CHANGES AFTER DAM CONSTRUCTION: A STREAM POWER APPROACH (pp. 343-367)

Sven Anders Brandt, Institute of Geography, University of Copenhagen, Denmark

Abstract: A literature survey on methods of computing stable river-channel geometry, demanding a small amount of work effort and few input data, has been made and is presented. Besides the use of empirical regime equations and the use of an extremal hypothesis in conjunction with a sediment-transport and a ow-friction theory, new regression equations have been formulated which are used together with a sedimenttransport equation. These methods may prove efŽcient when predicting changes, such as after dam and reservoir construction, on an alluvial river. Calculations using the different methods have been exempliŽed on a natural river.


IMPACTS OF IRRIGATION ON SHALLOW GROUNDWATER IN EASTERN PROVINCE, SAUDI ARABIA (pp. 369-390)

Walid A. Abderrahmana, M. Rasheeduddinb and Jamal K. Nejemc

aManager, bEngineer I, cEngineer-II, Water Section, Center for Environment and Water, Research Institute, King Fahd University of Petroleum and Minerals, Saudi Arabia

Abstract: The Kingdom of Saudi Arabia has witnessed rapid and comprehensive developments during the last two decades in the social, industrial, agricultural and construction sectors. Expansion of agricultural areas and excessive use of irrigation water has resulted in the formation and continuous rise of a shallow water-table and waterlogging in some parts of the Kingdom such as the Eastern Province. This is due to the absence of an effective drainage network and the presence of an impervious layer at shallow depths. Landsat images and crop-water demand models have been utilized to investigate the history, causes and extent of this problem in the west of Al-Awjam area of the Eastern Province as an example of waterlogged areas in the Province and in the Kingdom. The shallow groundwater has continued to rise with the expansion of the irrigated agriculture. Chemical analyses of water samples indicate that the shallow groundwater table is contaminated with high concentrations of salts in addition to trace elements. The continuous rise of the shallow groundwater table and its contamination have caused negative impacts on the environment, agriculture, groundwater resources, human health and engineering facilities. To overcome such problems, an effective solution through the introduction of a drainage system is required to lower the water table. Sound irrigation development should always consider necessary actions to drain the excess irrigation water to avoid shallow water table formation and rise. This is necessary to protect environmental resources and human health in the Kingdom and worldwide.


WATER MANAGEMENT IN THE INDUS BASIN OF PAKISTAN: A HALF-CENTURY PERSPECTIVE (pp. 391-406)

James L. Wescoat JRa, Sarah J. Halvorsonb and Daanish Mustafaa

aDepartment of Geography, University of Colorado at Boulder, Boulder, USA; bDepartment of Geography, University of Montana, Missoula, USA

Contact: James L. Wescoat JR, e-mail: wescoat@spot.colorado.edu

Abstract: This paper surveys the past half-century of water management experiments and experience in the Indus River basin in Pakistan as a way to identify principles for long-term water planning. The survey focuses on three variables: (1) spatial scales of water management; (2) geographic regions of water management; and (3) substantive water problems. These variables help assess changes during the post-colonial transition (1947–60); Indus basin development (1960–75); and management and environmental movements (1975–2000). Taken together, these periods point toward a model of Articulated Adaptive Management, which stresses planning for economic, political and environmental crises; dynamic changes in governance; multiple scales of water management; regional diversity and innovation; and broader scientiŽc experimentation and monitoring of water management alternatives.


PERFORMANCE EVALUATION OF URBAN WATER SUPPLY IN TANZANIA: THE CASE OF DAR ES SALAAM CITY (pp. 407-421)

W.S.J. Reweta and R.K. Sampath, Department of Agricultural and Resource Economics, Colorado State University, Fort Collins, USA

Abstract: Despite its importance, performance evaluation of urban water supplies in the developing countries is very inadequately dealt with in the economic literature. This paper is an attempt to draw attention to this topic. We analyse the equity and efŽciency aspects of performance evaluation of urban water supplies in the city of Dar Es Salaam in Tanzania in terms of between and within the three administrative districts in the city, and the Žve Dar Es Salaam Water and Sewerage Authority (DAWASA) branches and wards. The results show a very serious water supply problem for the city. Currently, water is unevenly distributed at all levels and it is expected that inequality between and within districts will increase over time.


CENTRAL ASIA’S WATER RESOURCES: CONTEMPORARY AND FUTURE MANAGEMENT ISSUES (pp. 423-441)

Sarah L. O’hara, School of Geography, University of Nottingham, University Park, Nottingham, UK

Abstract: The collapse of the Soviet Union in 1991 meant that overnight the newly independent Central Asian Republics (CARs) had to assume responsibility for the management and maintenance of a huge, poorly managed and maintained water distribution and irrigation system. Problems emerged almost immediately with a lack of funds virtually halting maintenance programmes. The decline of the system has been marked and it is likely that major failures will occur in the near future. Tension over access to water is also increasing and despite public assurance regarding regional cooperation over water-resource allocation a number of recent incidents suggest this is more political rhetoric than reality. The situation is likely to deteriorate as governmentbacked policies coupled with predicted population increases mean that water resources will become stressed and demand will far outstretch supply. This paper presents a brief review of past water-management strategies, outlines current problems and highlights the challenges which Central Asia’s leaders face as they strive to develop a water-management strategy to ensure the economic and social well-being of the region into the 21st century.


CONFERENCE REPORTS
FIDIC 1999 Conference ‘Expanding the Boundaries’, The Hague, The Netherlands, 19–24 September 1999

Xth World Water Congress, International Water Resources Association, Melbourne, 13–16 March 2000

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