GROUND WATER OF THE ISLAND OF MONTREAL,CANADA1

ABSTRACT: The geochemistry and nature of the flow of ground water not only control the supply potential but constitute clues to the whole geology of an area. A study has been made of the largest available assemblage of data from 161 wells for the Island of Montreal collected by the Geological Survey of Canada in 1951–53. Data indicated that the system is generally subartesian, flowing from the principal topographically high areas towards the shores of the Island. As the probable use is about 13% of the estimated recharge of 140 million liters per day, most wells could be supplied by local recharge. The study has confirmed the predominance of calcium bicarbonate ground water from the carbonate sequence. The waters appeared to be saturated with respect to CaCO₃ in all but 10 wells. The presence of other types of waters suggests the effects of the igneous intrusions of the area, the post-glacial marine submergence and the upward movement of waters from deep sources through fault and other structural zones. Confirmation of the significant variations in chemical composition in some neighboring wells indicated the future need for repetitive sampling from specific horizons for chemical and isotopic analyses.     

AN EX POST ANALYSIS OF THE UNCOMPAHGRE PROJECT1

ABSTRACT: The national and regional economic impact of the Bureau of Reclamation's Uncompahgre Project which was authorized in 1903 is assessed. Benefit-cost ratios for the project are calculated for a range of production cost estimates and discount rates. An economic base approach is used to estimate the project's regional economic impact. Although the project has been marginal in terms of an economic efficiency rationale it has been an important impetus to regional economic growth in the Uncompahgre Region over time.     

STRATEGIES TO CONTROL NONPOINT SOURCE WATER POLLUTION1

ABSTRACT: Strategies for controlling nonpoint sources of water pollution are discussed in terms of three representative states and eighteen regional agencies. The programs in Virginia, New York, and Wisconsin are seen to exhibit control options which range from voluntary action to strict regulation. Four conclusions are drawn from the analysis. First, nonpoint sources of pollution are a major component of the overall water pollution problem in the three states. Second, technical controls are generally available to solve the problems. Third, existing controls programs are not necessarily technologically sound or cost effective. Finally, existing control programs are capable of instituting solutions to the problems if and only if specified actions take place within the respective states and regions in the future. Critical research needs are identified which will assist states and regions in developing cost effective programs to control nonpoint source pollution.     

论水资源格局与可持续发展

以可持续发展理论为指导,分析了我国水资源自然格局及利用格局的现状与问题,提出了作为可持续发展重要支撑的水资源,其可持续利用的根本途径是建立可持续发展的水资源格局,即流域经济系统格局,并实现流域基础上的区域竞争与协作一体化     

区域农业资源开发与可持续发展——以江苏为例

我国系典型的人多地少国家,自然资源特别是农业资源对经济高速发展的支持能力相当薄弱,农业资源开发社会经济可持续发展中起着十分重要的作用。以江苏为例,探讨了农业资源开发与区域共同发展,经济国际化及科教兴省等战略实施之间的关系,对该区域主要农业资源开发前景进行分析,在此基础上提出了可持续发展战略下农业资源开发的途径与措施。     

MATHEMATICAL GENERALIZATION OF STREAM TEMPERATURE IN CENTRAL NEW ENGLAND1

ABSTRACT: The empirical fit of an annual harmonic function to stream temperature measurements in central New England can be improved by considering a harmonic period of less than 365 days instead of 365 or 366 days. Generalized equations, developed using periodic temperature data from 27 streamflow stations, allow predictions of stream temperature at any site given (1) the mean basin altitude (E), in meters above mean sea level, and (2) station latitude (LAT), in degrees. Stream temperature t, in degrees Celsius, on day number d, in days starting with January 1, is estimated as: in which, M = 31.48 – 0.0025 (E) ? 0.4635 (LAT) with standard error of estimate of 0.62°C, and τ= 1228.88 – 21.01 (LAT) with standard error of estimate of 14.1 days.     

ON THE MISMATCH BETWEEN DATA AND MODELS OF HYDROLOGIC AND WATER RESOURCE SYSTEMS1

ABSTRACT: Many difficulties exist in the matching of models with data. This paper identifies elements of this problem and discusses considerations involved in model evaluation. The well known multivariate linear regression model is used to illustrate the distinctions between accuracy and precision and between estimation and prediction (because the model is commonly misused.) No amount of additional data will improve the accuracy of a poor model. A high R², while indicative of a good matching between the observed data and model estimates, is a poor criterion for judging adequacy of the model to make good predictions of future events. Model evaluation also includes the problem of introducing secondary data and proxy variables into a model. Secondary data frequently enter, for example, the mass, energy and water budget equations because of difficulties in measuring the primary variables. Proxy variables arise because of a desire to collapse a vector of incomparable values, say, of water quality into a single number. Review of the above issues indicates that model evaluation is a multi-criterion problem, often imbedded in a larger framework where models are intended to meet multiple objectives. The mismatch of models and data has increasing legal and social consequences.     

MODELING ACTUAL EVAPOTRANSPIRATION FROM FORESTED WATERSHEDS ACROSS THE SOUTHEASTERN UNITED STATES1

ABSTRACT: About 50 to 80 percent of precipitation in the southeastern United States returns to the atmosphere by evapotranspiration. As evapotranspiration is a major component in the forest water balances, accurately quantifying it is critical to predicting the effects of forest management and global change on water, sediment, and nutrient yield from forested watersheds. However, direct measurement of forest evapotranspiration on a large basin or a regional scale is not possible. The objectives of this study were to develop an empirical model to estimate long‐term annual actual evapotranspiration (ART) for forested watersheds and to quantify spatial AET patterns across the southeast. A geographic information system (GIS) database including land cover, daily streamflow, and climate was developed using long term experimental and monitoring data from 39 forested watersheds across the region. Using the stepwise selection method implemented in a statistical modeling package, a long term annual AET model was constructed. The final multivariate linear model includes four independent variables—annual precipitation, watershed latitude, watershed elevation, and percentage of forest coverage. The model has an adjusted R² of 0.794 and is sufficient to predict long term annual ART for forested watersheds across the southeastern United States. The model developed by this study may be used to examine the spatial variability of water availability, estimate annual water loss from mesoscale watersheds, and project potential water yield change due to forest cover change.     

区域经济开发中的生态建设——以天山北坡经济带昌吉州为例

昌吉州区域经济开发在新疆地方经济发展中占有重要地位，在发展区域经济时也对生态环境造成了影响或污染，加强生态建设,做好区域环境保护的规划十分必要。昌吉州在石油勘探开发、土地资源开发中重视生态建设，在保护耕地、保护森林、野生动、植物方面制定出台了一系列措施，行至有效，取得了一定的实效。     

HYDRAULIC GEOMETRY RELATIONSHIPS FOR URBAN STREAMS THROUGHOUT THE PIEDMONT OF NORTH CAROLINA1

ABSTRACT: Hydraulic geometry relationships, or regional curves, relate bankfull stream channel dimensions to watershed drainage area. Hydraulic geometry relationships for streams throughout North Carolina vary with hydrology, soils, and extent of development within a watershed. An urban curve that is the focus of this study shows the bankfull features of streams in urban and suburban watersheds throughout the North Carolina Piedmont. Seventeen streams were surveyed in watersheds that had greater than 10 percent impervious cover. The watersheds had been developed long enough for the streams to redevelop bankfull features, and they had no major impoundments. The drainage areas for the streams ranged from 0.4 to 110.3 square kilometers. Cross‐sectional and longitudinal surveys were conducted to determine the channel dimension, pattern, and profile of each stream and power functions were fitted to the data. Comparisons were made with regional curves developed previously for the rural Piedmont, and enlargement ratios were produced. These enlargement ratios indicated a substantial increase in the hydraulic geometry for the urban streams in comparison to the rural streams. A comparison of flood frequency indicates a slight decrease in the bankfull discharge return interval for the gaged urban streams as compared to the gaged rural streams. The study data were collected by North Carolina State University (NCSU), the University of North Carolina at Charlotte (UNC), and Charlotte Storm Water Services. Urban regional curves are useful tools for applying natural channel design in developed watersheds. They do not, however, replace the need for field calibration and verification of bankfull stream channel dimensions.