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841.
842.
ABSTRACT: The 26-mile man-made beach bordering part of Mississippi's Gulf Coast and the contiguous Mississippi Sound waters provide an important recreational and tourist attraction for that area. Being the tourist nucleus for the State, announcements in September 1973 by the Mississippi Air and Water Pollution Control Commission and the State Board of Health that Sound waters had reached a level of pollution that made them potentially dangerous for body contact was met with a myriad of responses. The resulting multi-governmental, multi-agency interface that resulted in trying to deal with the situation highlighted the type of problems that can arise when social, economic, political, and legal forces come to bear on a sensitive area. Questions of jurisdictional and legal authority to act, tourist industry economic pressures, and water quality testing and monitoring procedures were representative of the type of problems that arose during this period. A retrospective analysis of this problem served to isolate the type of articulation that is essential between federal, state, and local agencies vested with responsibilities such as monitoring water quality, protecting public health, etc. This paper develops some of the interface complexities that emerged in dealing with this problem and makes selected recommendations for other areas that may potentially face similar situations.  相似文献   
843.
ABSTRACT: In the past, researchers have applied a variety of analytical techniques for maximizing the present value of a stock resource - simulation, calculus of variations, stochastic dynamic programming, and optimal control theory. This paper presents a more operational approach - linear programming. A simplified, broadly drawn example from Southwest agriculture is used for demonstrating the model's structure and output. The method is based on a set of state transformation operations that prevent the additivity assumption of linear programming from being violated.  相似文献   
844.
The EPA Storm Water Management Model was used to model the effects of urban and agricultural development on storm water runoff from uplands bordering a Louisiana swamp forest. Using this model, we examined the effects of changing land use patterns. By 1995 it is projected that urban land on the uplands bordering the swamp will increase by 321 percent, primarily at the expense of land currently in agriculture. Simulation results indicate that urbanization will cause storm water runoff rates to be up to 4.2 times greater in 1995 than in 1975. Nutrient runoff will increase 28 percent for nitrogen (N) and 16 percent for phosphorus (P) during the same period. The environmental effects of these changes in the receiving swamp forest are examined.  相似文献   
845.
Modeling hydrology and eutrophication in a Louisiana swamp forest ecosystem   总被引:2,自引:0,他引:2  
The EPA Storm Water Management Model (1971) was used to model hydrodynamics, nutrient dynamics, and eutrophication in a Louisiana swamp forest ecosystem. The present system of canals and spoil banks in the swamp causes impoundment of swamp areas and does not optimize discharge from the swamp forest. Simulations showed that hydraulics could be managed to increase discharge rates to the lower estuary (22 percent), to increase productivity of the swamp forest (100 percent), and to decrease lake eutrophication (43 percent). This could be done by removing spoil banks in the swamp and allowing upland runoff to pass through the backswamp.  相似文献   
846.
ABSTRACT: The concepts of inertia and elasticity were applied to existing fish data from Conowingo Creek. It was determined that these two concepts could form the foundation for a stream classification system based on the structure and function of fish communities. Inertia appears to be more useful for predicting the effects of potential stress than elasticity (a stress must first occur before elasticity can be fully evaluated). The relationship between structural and functional redundancy and their influences on the inertia index is discussed.  相似文献   
847.
Lake Holiday, a human-made recreational lake in northern Illinois, was threatened with closure due to high bacterial levels. A factorially designed experiment with multivatiate responses was developed to study and identify the main sources of pollution. Data on total coliform, fecal coliform, fecal streptococci, dissolved oxygen, pH, ammonia-N, total phosphorus, nitrate/nitrite-N were analyzed using regression models describing dam spillway loads as a function of source loads and time. The results suggest that the relationships among source, time, and load are complex, even though only two sources account for most of the lake's loading Stevens Brook, which receives the discharge from the Somonauk Sewage Treatment Plant, and Somonauk Creek, which is the major drainage, contribute high loads of bacteria and nutrients to the lake. The influent loads contributed to the lake are discharged at the dam over about 4 weeks  相似文献   
848.
ABSTRACT: The salinity of the lower South Platte River in Colorado is characterized by plotting the average annual flow, total dissolved solids, and salt mass flow against distance along the stream. The plots show that salts are being leached from the irrigated lands above Greeley and are being deposited on the irrigated lands below Greeley. The salt deposition on the lower lands will result in their salination. The plots show also that fall and winter stream flows carry most of the salt loads. These fall and winter flows are stored in off stream reservoirs for use during the irrigation season. Therefore these salts are transferred to the lower irrigated lands where they accumulate. The salt balance for these lands can be improved by permitting the fall and winter flows to leave the basin, or by providing adequate land drainage coupled with supplemental irrigation water.  相似文献   
849.
ABSTRACT: A pilot study, which was conducted in the Southern Blue Ridge geographical province of the Southeastern U.S., demonstrated the feasibility of a probability-based regional synoptic design for the National Stream Survey, which is a project aimed at estimating the number and percentage of streams in various regions of the U.S. that are acidic or at risk from acid deposition. Estimated population distributions for key chemical variables were not appreciably affected by week-to-week variability in stream chemistry during the spring index period chosen for the study. Differences were observed in estimated acid neutralizing capacity (ANC), nitrate, and pH frequency distributions between spring and summer. Observations made at the downstream node did not represent the chemistry of the entire reach for some variables (ANC and nitrate) as indicated by differences in chemical concentrations between upstream and downstream sampling locations. Coefficients of variation in chemical species were low enough to provide a reasonably stable classification of streams based on ANC. Although median ANC, sulfate, and nitrate concentrations were quite low in the region, the probability of finding streams with ph < 6.3 is less than 1.3 percent at the α= 0.05 confidence level.  相似文献   
850.
Siting a geologic repository for isolating highlevel nuclear waste up to 10,000 years is a controversial undertaking never before attempted in the United States. The Nuclear Waste Policy Act of 1982 exempted repository siting from important requirements for environmental review under the National Environmental Policy Act. In December 1987, the Nuclear Waste Policy Amendments Act identified Yucca Mountain as the first site to be characterized for a high-level nuclear waste repository. In light of the unproven nature of the technology being evaluated, the scientific uncertainties associated with Yucca Mountain, and the lack of proven methods for risk evaluation, the environmental policies for repository siting represent a significant departure from more traditional, comprehensive, and interdisciplinary environmental review for siting nuclear projects. The policies warrant further study by those interested in how present as well as future decisions about complex technologies may be made.  相似文献   
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