摘要:

ABSTRACT:The last decade has seen accelerated interest in international hydropolitics. Yet, the international politics of the world's fresh water are highly complicated, some might even say byzantine. This paper discusses some of these complications, the background to them, and the place of fresh water in recent environmental initiatives, particularly in UNCED. It proposes a way forward for the future in order to improve international cooperation to assist in averting the coming water crisis.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03358.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:Because of its importance and the perceived inability of private sector sources to meet water demands, many countries have depended on the public sector to provide water services for their populations. Yet this has resulted in many inefficient public water projects and in inadequate supplies of good quality and reliable water. Decentralization of water management, including the use of water markets, cannot solve all of these water problems, but it can improve the efficiency of water allocation. When given adequate responsibility and authority, water user associations have effectively taken over water management activities at a savings to tax payers. Moreover, water markets add the potential benefit of improving water efficiency within a sector as well as providing a mechanism for reallocating water among sectors. The key question involves developing innovative mechanisms for reducing the transaction costs of organizing water users and of making water trades. Water rights need to be established which are recorded, tradable, enforceable, and separate from land if markets are to operate effectively. Also, institutions are needed that effectively resolve conflicts over water rights, including third party impacts and water quality concerns.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03359.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:A study was initiated to examine the effects of wind speed, wind direction, freshwater inflow, and tide height on suspended solid concentration and distribution in the Loxahatchee estuary, Florida. Recent efforts to increase freshwater flows in this system raised concerns that suspended solid concentrations would increase as well, which might result in negative impacts for the estuary. The data indicated that total suspended solids (TSS) in the estuary are derived primarily from the inlet and not from freshwater tributaries. In addition, total suspended solids and volatile suspended solids were correlated strongly with salinity, suggesting that suspended sediments act conservatively throughout this system. No one environmental factor had an overwhelming influence on suspended solid concentration throughout the estuary; different regions of the estuary were influenced by different factors. Freshwater inflow was negatively related to TSS in the upper reaches of the estuary but was positively related to TSS in the central embayment region of the estuary. We attribute this latter finding to the fact that extremely high inflows both prevented the normal transport upstream of tidal borne suspended sediments and promoted mixing when the freshwater front moving downstream confronted the tidal front moving upstream. Wind speed, wind direction, and tide height had relatively small effects on TSS concentration but were most influential in reaches upstream of the central embayment, where tidal velocity begins to diminish.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03360.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:The use of artificial recharge in Saskatchewan and the rest of Canada to improve rural community and farmstead domestic water supply has great potential. Approximately 75 percent of the people in rural Saskatchewan and 26 percent of all the people in Canada are dependent on ground water for their domestic water supply. Typically, this water is highly mineralized and is often unpalatable due to odor and taste. A source of readily available, high quality water to eliminate expensive chemical treatment of available water and long distance hauling would be of significant value to rural residents. Storage of high quality water in aquifers by injection through wells has been documented and has been shown to depend on the use of a surface water catchment system to provide the high quality water. Since air entrainment or formation clogging can occur in poorly operated recharge schemes, development of proper design and operation of recharging procedure is required. This can be accomplished by using an injection response computer model and a properly designed injection system. Small scale artificial recharge projects will provide a valuable commodity to rural water users and will promote sustainable and conjunctive use of surface and ground water resources.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03361.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:One‐hundred‐and‐sixty step pools were examined that have developed in andesitic, basaltic, or dacitic lavas or in glaciofluvial sediments along several reaches of Soda Creek in the Three Sisters Wilderness of the Oregon High Cascades to determine whether such systems exhibit similar morphology. Pool shapes, sizes, and spacing were measured, and the hydraulic head loss calculated for each pool surface. Lithologic variations among 15 shape categories were not significant, but size attributes ‐ length, depth, and area ‐ of pools were systematically different by rock type. The energy lost at hydraulic jumps did not differ significantly among the four lithologies, suggesting that perhaps step pools represent similar stream channel adjustments in stee

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03362.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:A study was conducted to derive a simple procedure for estimating the tributary drainage area that may potentially develop at the base of a uniformly graded, steep slope. Data were extracted from a nil development flume study in which 112 rills and their tributary drainage areas were documented. The tributary drainage area for each rill was correlated to the slope length and the slope gradient. The findings are considered applicable to planar, convex, and divergent slopes with lengths of up to 130 m. Field verification is needed to extend the applicability of the relation.

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03363.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:The development of a nondegradation policy for high quality waters is a complex and often controversial process. This paper discusses the development of a nondegradation policy for two components of the National Wild and Scenic Rivers System. Water quality in these reaches of the Delaware River is threatened by rapid growth and development and the cumulative impacts from numerous wastewater discharges and nonpoint sources of pollution. The Delaware River Basin Commission, with assistance from its member states and the National Park Service, conducted a highly public, six‐year planning process to develop a nondegradation policy that protected existing water quality without impinging upon local and state economic development objectives. The resulting non‐degradation policy includes such features as numeric definitions of existing water quality and measurable change; stringent point source requirements; nonpoint source requirements including watershed planning requirements; and other water quality management polic

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03364.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:The RIVMOD hydrodynamic model was used to route upstream flows through a 115 km section of the Carson River and Lahontan Reservoir, Nevada. RIVMOD results will later be used to predict sediment movement and ultimately to determine mercury transport within the river/reservoir system. Significant modifications to the model computer code were necessary to represent the narrow, steeply sloping rectangular channel and relatively shallow sloping floodplain of the Carson River and its confluence with the Lahontan Reservoir. These changes include expansion of the continuity and momentum equations to account for rapidly changing channel widths along with the characterization of a complex cross‐sectional shape. This modified version of the RIVMOD model can handle shallower side slopes and much more severe flood flow simulations than the original version. A 0.25 km spatial increment was required in the zone of confluence between the river and reservoir. Model predictions show excellent agreement with observed downstream flow and reservoir stage for the entire 1986 water year, which includes one of the most severe flood events of recent record. (KEY TERMS: hydraulics; modeling; simulation; surface water hydrology

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03365.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:Both catchment experiments and a review of hydrologic processes suggest a varying effect of forest harvest on the magnitude of peak flows according to the cause of those peak flows. In northwestern Montana and Northeastern Idaho, annual maximum flows can result from spring snowmelt, rain, mid‐winter rain‐on‐snow, or rain‐on‐spring‐snowmelt. Meteorologic and physical data were used to determine the cause of annual maximum flows in six basins which had the necessary data and were smaller than 150 mi2. Rain‐on‐spring‐snowmelt was the most frequent cause of annual maximum flows in all six basins, although there was a strong gradient in the magnitude and cause of peak flows from southwest to northeast. Less frequent mid‐winter rain‐on‐snow events caused the largest flows on record in four basins. Mid‐winter rain‐on‐snow should be distinguished from rain‐on‐spring‐snowmelt because of differences in seasonal timing, the relative contributions of rain vs. snowmelt, and the projected effects of forest harvest. The effects of mixed flood populations on the flood‐frequency curve varied from basin to basin. Annual maximum daily flows could not be reliably pred

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03366.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

ABSTRACT:A one‐layer decreasing‐availability monthly water balance model is used to estimate monthly surplus that flows into the Lake Pontchartrain Basin from the Amite, Tickfaw, Natalbany, Tangipahoa, and Tchefuncte Rivers for water years 1949 through 1990. The modeled annual surplus for each drainage basin is compared to gauged annual discharge obtained from the United States Geological Survey. This provides an estimate of the differential success of the model over watersheds of various sizes, and also suggests appropriate adjustment factors to be used in future water balance analyses of similar basins in humid subtropical climate regions. Results show that annual surplus values agree well with the USGS values, after an annual adjustment of about 140 mm (11 to 28 percent of the basin surplus) is subtracted from the annual modeled totals to compensate for overestimation by the model. However, inter‐annual variability is high in the annual cycles. Winter and spring discharges can also be modeled success

ISSN:1093-474X    

DOI:10.1111/j.1752-1688.1995.tb03367.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY