EFFLUENT FEES,AN ALTERNATIVE SYSTEM FOR ACHIEVING WATER QUALITY: A CASE STUDY1

This paper reports the findings of a case study of the relative costs of a uniform standards system and an effluent fee system of water quality control. A 30-mile stretch of the Black Warrior River in Alabama is considered. The analysis demonstrates that the dischargers could reduce total pollution abatement costs by 33 percent under the suggested effluent fee system.     

THE MILWAUKEE POLLUTION CASE - IMPLICATIONS FOR WATER RESOURCES PLANNING1

ABSTRACT: The Illinois v. Milwaukee Federal District Court decision is the most far reaching application yet of the federal common law of nuisance to interstate water pollution conflicts. Although a Federal Appelate Court recently rescinded part of the district court decision, Milwaukee must still upgrade its metropolitan sewage system to a level beyond that required by federal and state regulations. The improvements must be completed with or without federal aid. The case points out the apparent inability of the Clean Water Act, the most comprehensive federal legislation affecting the nation's water quality, to deal with certain interstate water quality conflicts. The Milwaukee decision could set a precedent for similar settlements elsewhere which may in turn affect the U.S. Environmental Protection Agency's water quality clean up program. A more integrated, ecosystem conscious approach to management of shared water resources (e.g., the Great Lakes) would help reduce the need for court decisions like Illinois v. Milwaukee.     

HYDROLOGIC EFFECTS OF THE TONKAWA CREEK FLOOD ABATEMENT PROGRAM1

ABSTRACT: Floodwater-retarding impoundments, controlling 68 percent of the drainage area of Tonkawa Creek, a Washita River tributary in southwestern Oklahoma, have reduced the total flow volume about 36 percent over a 5-year period. Analyses showed the reduction occurred primarily in the less-than-2.5-cfs flow range, indicating the base flow regime has been altered. However, channelizing the downstream, mild-sloped, 3.6 miles of Tonkawa Creek that flows across a Washita River terrace increased the flow volume fourfold at the outlet. A double-masscurve analysis of water yield from a 1,127-square-mile Washita basin segment versus an untreated tributary showed the yield has not changed after 25 percent of the tributary area had been treated. Therefore, the flow reduction caused by structures is being offset by increased yields from channelization.     

ESTIMATING THE SUSPENDED SEDIMENT LOAD IN RESERVOIRS1

ABSTRACT: The total suspended sediment loads of four north Mississippi reservoirs were determined from measurements of concentrations of suspended sediment in a vertical profile at several locations on each reservoir made during the year. These data were combined with the stage-height and known stage-volume relationships for each reservoir in a numerical integration to determine the total suspended sediment in the water body. Total suspended sediments were estimated using the product of the suspended sediment concentration in the surface water by the appropriate reservoir volume. The averaged ratios of the estimated to measured suspended sediment loads for each reservoir exceeded 0.90. Since the concentration of suspended sediments in surface waters of north Mississippi reservoirs has been shown as highly correlated with spectral reflectance, estimating the total suspended sediment of these reservoirs using remotely sensed spectral reflectance data is possible.     

FLOOD HAZARD STUDIES IN THE MISSISSIPPI RIVER BASIN USING REMOTE SENSING1

ABSTRACT. The Spring 1973 Mississippi River flood was investigated using remotely sensed data from ERTS-1. Both manual and automatic analyses of the data indicate that ERTS-I is extremely useful as a regional tool for flood management. Quantitative estimates of area flooded were made in St. Charles County, Missouri and Arkansas. Flood hazard mapping was conducted in three study areas along the Mississippi River using pre-flood ERTS-1 imagery enlarged to 1:250,000 and 1:100,000 scale. The flood prone areas delineated on these maps correspond to areas that would be inundated by significant flooding (approximately the 100 year flood). The flood prone area boundaries were generally in agreement with flood hazard maps produced by the U. S. Army Corps of Engineers and U. S. Geological Survey although the latter are somewhat more detailed because of their larger scale. Initial results indicate that ERTS-1 digital mapping of flood prone areas can be performed at 1:62,500 which is comparable to some conventional flood hazard map scales.     

EVAPOTRANSPIRATION DYNAMICS AT AN ECOHYDROLOGICAL RESTORATION SITE: AN ENERGY BALANCE AND REMOTE SENSING APPROACH1

ABSTRACT: Little work is reported where spatial methods are employed to monitor evapotranspiration (ET) changes as a result of vegetation and wetland restoration. A remote sensing approach with the Surface Energy Balance Algorithm for Land (SEBAL) for estimating ET at The Nature Conservancy's Glacial Ridge prairie‐wetland restoration site in northwestern Minnesota is presented. The calibrated 24‐hour ET from SEBAL was estimated with an average error of prediction of ?4.3 percent. Monthly, interseasonal, and seasonal ET for the period of June to September (2000 to 2003) from three adjacent land‐uses: a hydrologic control preserved wetland; a treated or restored site; and a nontreated or impacted wetland, were used in the study. Results from comparing ET behavior to the preserve suggest restoration efforts have affected monthly and seasonal ET within the treated site. Spatial average standard deviations of the seasonal ET within the preserve, treated, and nontreated sites give 47.3, 75.7, and 109.9 mm, respectively, suggesting hydrologic stabilization within the treated site. Monthly and interseasonal comparisons show similar behavior to that of the seasonal data, where monthly correlations suggest increasing agreement within the treated site, approaching those within the preserve.     

城市绿色空间及对城市热岛效应的影响

采用遥感技术结合实地测定的研究方法,利用1987年至2001年遥感卫星影像数据,建立了北京市不同年份的城市绿色空间专题图和热岛分布图,分析了13年中北京城市绿色空间及热岛效应的演变特点,评价了城市发展及城市绿化对热岛效应的影响。结果表明:受城市化的影响,14年中北京城市绿色空间变化明显,城市热岛效应也随之发生明显变化;随着城市建设范围的扩大,原有自然植被不断减少,热岛影响范围随之扩大;随着市区内的绿化建设,绿色空间总量增加,热岛效应有缓解的趋势。     

吉林省农业病虫害发生规律与防治效果的定量分析

本文以定量分析为主要手段，详细研究了吉林省农业病虫害发生的时间过程规律和空间分布规律，深入探讨了环境因子对农业病虫害的影响，综合评价了病虫害防治工作的效果。     

喀斯特石漠化治理区农户适应能力研究

喀斯特石漠化治理区生态环境脆弱,经济发展水平低,该区域农户生计适应能力不仅关系到自身的利益,更影响其与生态环境可持续协调发展。以贵州省安顺市花江示范区为例,通过引入农户适应感知及可持续生计框架构建农户适应能力评价指标体系,采用主成分分析法,对509户农户适应能力进行定量评价及对比分析,探究其影响因素,并提出相应改进策略。结果表明：石漠化治理下花江农户对治理变化的感知能力表现为纯农户>农兼户>非农户>兼农户;花江农户适应能力整体呈现较低水平,兼农户和农兼户比纯农户和非农户适应能力强;影响花江农户适应能力的因素主要有物质和经济能力、人力和自然能力、石漠化治理考虑感知能力和生计多样化程度。通过改善农户的生计资本,增强其物质经济能力,提升受教育程度等措施,可提高喀斯特石漠化治理区农户适应能力。

     

基于控制网络的输送机运行故障智能诊断

对煤矿井下胶带输送机运行过程中容易出现的故障,在计算机监控系统的基础上,研究了智能化的检测和判断方法。与传统的胶带机综合保护系统相比,减少了误报和漏报现象,既提高了故障诊断的可信度,又提高了胶带机运行的效率和可靠性。