PAST AND FUTURE OF ANALYSIS OF WATER RESOURCES TIME SERIES1

ABSTRACT: water resources supply and demand time series consist of several or all of the four basic characteristics: tendency, intermittency, periodicity and stochasticity. Their importance changes from one type of variables to another. Historic developments of analysis of time series in hydrology have varied significantly over the past, from the stress on search for periodicities and persistence in annual series to the emphasis on the series stochastic properties. Supply and demand series are often highly interrelated, which fact is most often neglected in planning water resources systems in general, and water storage capacities in particular. The future of series analysis in water resources will likely be by a joint use of physically-based structural analysis and the use of advanced methods of treating data by stochastic processes, statistical estimation and inference techniques. The most intriguing challenge of the future of this analysis may be the treatment of nonnormal, nonlinear and in general nonstationary hydrologic and water use time series. The proper treatment of complex multivariate processes will also challenge the specialists, especially for the purposes of transfer of information between data on variables at given points, or between data at several points of a given variable, or both.     

CULTURAL ASPECTS OF WATER RESOURCE DEVELOPMENT PAST,PRESENT, AND FUTURE1

ABSTRACT Attitudes toward the development of the American West have undergone important changes over the past century just as the nature of water resources as factors in development have changed. Viewing these changes processually, stages for water resources definition and use can be identified in the total process of western cultural development. The first stage involves the value of water resource development as a stimulus to population and economic growth in the West. The second stage, still in process', adopts a dominant cultural norm which sees water resource development as inevitable if not necessary to keep up with growth. A third stage to this evolutionary process is incipient. Future cultural values and thinking with respect to water resource development will be to look at development as a means for controlling or managing both the location and quantity of population and economic growth. To this end planners will have to become concerned with the questions of human adaptation. Concern will have to be given to the problems of getting a living which enables individuals to meet the subsistence needs of self and family, to establishing community which provides for cooperation among individuals and the management of conflict, to establishing improved communication which promotes interpersonal interaction, and for fostering innovation which provides the new ideas necessary to adapt to new environmental situations.,     

EFFECTS OF CLIMATE CHANGE ON HYDROLOGY AND WATER RESOURCES IN THE COLUMBIA RIVER BASIN1

ABSTRACT: As part of the National Assessment of Climate Change, the implications of future climate predictions derived from four global climate models (GCMs) were used to evaluate possible future changes to Pacific Northwest climate, the surface water response of the Columbia River basin, and the ability of the Columbia River reservoir system to meet regional water resources objectives. Two representative GCM simulations from the Hadley Centre (HC) and Max Planck Institute (MPI) were selected from a group of GCM simulations made available via the National Assessment for climate change. From these simulations, quasi-stationary, decadal mean temperature and precipitation changes were used to perturb historical records of precipitation and temperature data to create inferred conditions for 2025, 2045, and 2095. These perturbed records, which represent future climate in the experiments, were used to drive a macro-scale hydrology model of the Columbia River at 1/8 degree resolution. The altered streamflows simulated for each scenario were, in turn, used to drive a reservoir model, from which the ability of the system to meet water resources objectives was determined relative to a simulated hydrologic base case (current climate). Although the two GCM simulations showed somewhat different seasonal patterns for temperature change, in general the simulations show reasonably consistent basin average increases in temperature of about 1.8–2.1°C for 2025, and about 2.3–2.9°C for 2045. The HC simulations predict an annual average temperature increase of about 4.5°C for 2095. Changes in basin averaged winter precipitation range from -1 percent to + 20 percent for the HC and MPI scenarios, and summer precipitation is also variously affected. These changes in climate result in significant increases in winter runoff volumes due to increased winter precipitation and warmer winter temperatures, with resulting reductions in snowpack. Average March 1 basin average snow water equivalents are 75 to 85 percent of the base case for 2025, and 55 to 65 percent of the base case by 2045. By 2045 the reduced snowpack and earlier snow melt, coupled with higher evapotranspiration in early summer, would lead to earlier spring peak flows and reduced runoff volumes from April-September ranging from about 75 percent to 90 percent of the base case. Annual runoff volumes range from 85 percent to 110 percent of the base case in the simulations for 2045. These changes in streamflow create increased competition for water during the spring, summer, and early fall between non-firm energy production, irrigation, instream flow, and recreation. Flood control effectiveness is moderately reduced for most of the scenarios examined, and desirable navigation conditions on the Snake are generally enhanced or unchanged. Current levels of winter-dominated firm energy production are only significantly impacted for the MPI 2045 simulations.     

DEVELOPMENT OF KARST WATER RESOURCES IN TURKEY WITH EMPHASIS ON GROUND WATER

About one third of the area of Turkey is underlain by carbonate rocks that are relatively soluble, and this has produced large areas of karst in the country. The economic implications of karst hydrology in Turkey are immense, considering its effects on water resource development. An ongoing project in Turkey, assisted by the United Nations, is undertaking a comprehensive and interrelated approach to solving hydrogeological problems in a karst polygon region of over 13,000 km². The area chosen for this project has one of the most complex karst circulation systems, not only in Turkey, but probably in the entire Mediterranean basin. Demand for water in this polygon region is high. The project personnel have applied both the classical methods, such as geological mapping, geophysical research, aerial photo interpretation, drilling, and observation of piezometric boreholes to the problem, as well as more modern techniques such as quantitative fluorometry, processing of remotely sensed data, time bombs and environmental isotopes. Several examples of applied methods and of results obtained are presented. Un tiers environ de la surface de la Turquie recouvre des roches carbonatées relativement solubles où se sont formés des systèmes karstiques très étendus. Les implications économiques de l'hydrologie des karsts en Turquie sont considérables si on considère ses effets sur l'aménagement des ressources en eau. Dans un projet en Turquie, exécuté avec l'assistance des Nations Unies, une approche compréhensive et intégrée est en cours en vue de résoudre des problèmes hydrogéologiques dans un polygone karstique de plus de 13.000 km². La zone choisie pour ce projet possède l'un des systèmes de circulation karstique les plus complexes qui existent non seulement en Turquie mais probablement dans tout le bassin méditerranéen. Dans ce polygone, la demande d'eau est très élevée. Pour étudier ce problème, le personnel du projet a appliqué deux méthodes classiques comprenant la cartographie géologique, l'exploration géophysique, l'interprétation photoaérienne, les sondages, l'observation des tubes piézométriques et des techniques plus modernes telles que la fluorémetrie quantitative, le traitement des données de la télédétection, les bombes à action retardée et le dosage des isotopes. L'article discute de plusieurs méthodes utilisées et des résultats qui en ont découlé. Cerca de una tercera parte del territorio de Turquía está sobre rocas carbonatadas. Las implicancias económicas de hidrología kárstica en Turquía son immensas si se consideran las posibilidades de desarrollo de sus recursos hidrológicos. En un proyecto en ejecución bajo la asistencia de las Naciones Unidas en Turquía se está haciendo un enfoque integral de la solución de los problemas hidrológicos en una región poligonal kárstica de mas de 13,000 km². Esta región tiene uno de los sistemas mas complejos de circulación kárstica de no solamente de Turquía sino también probablemente de Mediterraneo. La demanda de agua en este polígono kárstico es muy alta. En el proyecto se está aplicando tanto los métodos geológicos, investigación geofisica, interpretación de fotografia área, perforación, y observación de sondajes piezométricos, asi como también técnicas modernas tales como fluorometría cuantitativa, procesamiento de datos obtenidos por satélite, bombas de acción retardada e isótopos de medio ambiente. Varios ejemplos de los métodos aplicados y de los resultados obtenidos se presentan a este artículo.     

CURVE NUMBER HYDROLOGY IN WATER QUALITY MODELING: USES,ABUSES, AND FUTURE DIRECTIONS1

ABSTRACT: Although the curve number method of the Natural Resources Conservation Service has been used as the foundation of the hydrology algorithms in many nonpoint source water quality models, there are significant problematic issues with the way it has been implemented and interpreted that are not generally recognized. This usage is based on misconceptions about the meaning of the runoff value that the method computes, which is a likely fundamental cause of uncertainty in subsequent erosion and pollutant loading predictions dependent on this value. As a result, there are some major limitations on the conclusions and decisions about the effects of management practices on water quality that can be supported with current nonpoint source water quality models. They also cannot supply the detailed quantitative and spatial information needed to address emerging issues. A key prerequisite for improving model predictions is to improve the hydrologic algorithms contained within them. The use of the curve number method is still appropriate for flood hydrograph engineering applications, but more physically based algorithms that simulate all streamflow generating processes are needed for nonpoint source water quality modeling. Spatially distributed hydrologic modeling has tremendous potential in achieving this goal.