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11.
ABSTRACT: The use of the Ohio River for recreational purposes is increasing. While documentation of the real-time use of the river for recreation is sparse, inferences are made from the availability of mooring facilities. The location of the facilities, the economic advantages of Ohio River recreation, and the hazards to such recreation coincide at the four major urban centers. Future use plans for the Ohio River must consider recreation among the multiple uses of this river.  相似文献   
12.
ABSTRACT: Monthly water use for the period 1960–1984 for the Columbus, Ohio, metropolitan area is analyzed to identify differential monthly trends in growth of water use. By associating water use activities with the identified trend months, inferences may be made as to the possible underlying causes of the observed trend in overall water use. Three methods were found useful in determining monthly trends: 1) regression analysis on the monthly percentage of annual use, 2) regression analysis on the monthly water use data itself, and 3) analysis of the slope of the monthly water use regression line. Agreement between the three methods is strong, but each provides some insight not found in the others. All three should be used in drawing final conclusions. For the case study, usage in the Winter months January-April has grown considerably relative to the other months, while the Summer-Fall months of June, August, September, and October show a relative decline. A possible explanation for the trend is aging of the distribution system, with consequent general leakage and increased water main breakage caused by freeze/thaw conditions. More research needs to be carried out linking water use activities to particular months or groups of months.  相似文献   
13.
Land classification systems can be useful for assessing aquatic ecosystems if relationships among them exist. Because the character of an aquatic ecosystem depends to a large extent upon the character of the landscape it drains, spatial patterns in aquatic ecosystems should correspond to patterns in the landscape. To test this hypothesis, the US state of Ohio was divided into four aquatic ecoregions based on an analysis of spatial patterns in the combination of land-surface form, land use, potential natural vegetation, and soil parent material. During the period July–October 1983, fish assemblages were sampled in 46 streams that were representative of the ecoregions, and that had watersheds relatively undisturbed by human activities. Spatial patterns of the fish assemblages were examined relative to the ecoregions; distinct regional differences were identified. The assemblages differed most between the Huron/Erie Lake Plain region and the Western Allegheny Plateau region; assemblages in the Eastern Corn Belt Plains and the Erie/Ontario Lake Plain-Interior Plateau regions were intermediate. This pattern also reflects the gradient in landscape character as one moves from the northwest to the southeast of Ohio.  相似文献   
14.
The net agglomeration and disamenities approaches to the measurement of agglomeration economies are merged. The net agglomeration view is represented by a labor demand function derived from Segal (D. Segal, Rev. Econ. Stat. 48, 339–350 (1976)). The disamenities view is represented by an upward-sloping labor supply function derived from Izraeli (O. Izraeli, Urban Stud. 14, 275–290 (1977)). Three cases are simulated. Case I is the benchmark case and assumes a linear homogeneous production function, no agglomeration economies, and no perceived environmental quality differences between cities. Cases II and III combine Segal and Izraeli by introducing agglomeration economies, an upward-sloping labor supply function, and a change in the level of air pollution. The results demonstrate the feasibility of isolating the output of market goods and environmental goods within a common framework.  相似文献   
15.
The Ohio River Basin (ORB) is responsible for 35% of total nitrate loading to the Gulf of Mexico yet controls on nitrate timing require investigation. We used a set of submersible ultraviolet nitrate analyzers located at 13 stations across the ORB to examine nitrate loading and seasonality. Observed nitrate concentrations ranged from 0.3 to 2.8 mg L−1 N in the Ohio River's mainstem. The Ohio River experiences a greater than fivefold increase in annual nitrate load from the upper basin to the river's junction with the Mississippi River (74–415 Gg year−1). The nitrate load increase corresponds with the greater drainage area, a 50% increase in average annual nitrate concentration, and a shift in land cover across the drainage area from 5% cropland in the upper basin to 19% cropland at the Ohio River's junction with the Mississippi River. Time-series decomposition of nitrate concentration and nitrate load showed peaks centered in January and June for 85% of subbasin-year combinations and nitrate lows in summer and fall. Seasonal patterns of the terrestrial system, including winter dormancy, spring planting, and summer and fall growing-harvest seasons, are suggested to control nitrate timing in the Ohio River as opposed to controls by river discharge and internal cycling. The dormant season from December to March carries 51% of the ORB's nitrate load, and nitrate delivery is high across all subbasins analyzed, regardless of land cover. This season is characterized by soil nitrate leaching likely from mineralization of soil organic matter and release of legacy nitrogen. Nitrate experiences fast transit to the river owing to the ORB's mature karst geology in the south and tile drainage in the northwest. The planting season from April to June carries 26% of the ORB's nitrate and is a period of fertilizer delivery from upland corn and soybean agriculture to streams. The harvest season from July to November carries 22% of the ORB's nitrate and is a time of nitrate retention on the landscape. We discuss nutrient management in the ORB including fertilizer efficiency, cover crops, and nitrate retention using constructed measures.  相似文献   
16.
ABSTRACT: The HEC-4 monthly stream flow simulation model, developed by the Hydrologic Engineering Center, Davis, California, is used to extend the available historical stream flow records in the Central Ohio area. The principal objective of this paper is to examine the effectiveness of the HEC-4 model in generating synthetic monthly flows. Important statistical parameters are evaluated in order to relate the statistical properties of the historical and generated flows. In doing so, it is observed that the mean, standard deviation, and skewness of the generated flows are consistently larger than the corresponding estimates based on historical flows. However, results show that these statistics, as well as the lag-1 serial correlation, are generally well maintained by the generated sequences. The degree to which any statistical dissimilarities would be critical, from an engineering design point of view, is demonstrated by utilizing their low flow characteristics. Estimates of reservoir safe-yields, based on a nonsequential mass-curve analysis of the historical and generated low flows, indicate a nominal difference in this particular study.  相似文献   
17.
ABSTRACT The role of water resources in the urban economic and social environment, particularly in the inner city, has never been established to the degree necessary for making informed decisions on investments in urban waterway and shoreline improvements. The basic tools for measuring psychological and social impacts of waterway and shoreline developments in the inner city have not been fully developed and utilized to date. However, through a detailed analysis of the water resources in the urban core area of Cleveland, it appears that deliberate development of water-based recreation and other environmental resources can lead to improvement in some of the social problems of the inner city. In recreation analysis, there is currently a great gap between methodologies that are conceptually sound and those that have been applied by urban and water-resources planning agencies. New tools and methodologies can only be used successfully when public agencies are given the institutional and policy means for using them equitably in light of social needs. Present urban-water planning practices have been found to be biased against the inner city, often unintentionally.  相似文献   
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