饮马河流域水环境综合风险时空分布

为评价饮马河流域水环境综合风险,从水环境风险的危险性、暴露性、脆弱性及区域治理能力4个方面构建了饮马河流域水环境综合风险评估体系.选取2000年、2005年、2010年和2015年的水环境数据进行分析,采用水环境污染风险指数法和层次分析法对饮马河流域水环境综合风险进行评估,并绘制了各年度饮马河流域的风险空间分布图,分析了饮马河流域水环境风险空间变化特征.结果表明:2000—2015年,各危险性指标的量化值不断减小;暴露性指标中,耕地面积不断扩大,工业企业个数不断增加,人口密度变化不明显;各脆弱性指标的量化值不断减小;水环境区域治理能力各指标的量化值不断增大.研究显示,2000—2015年,流域内水环境危险性和脆弱性不断降低,暴露性和区域治理能力逐渐升高,水环境风险逐渐降低;其中,长春市一直处于水环境高风险水平,伊通县一直处于低风险水平.      

POTENTIAL ECONOMIC IMPACTS OF CHANGES IN WATER AVAILABILITY ON AGRICULTURE IN THE TRUCKEE AND CARSON RIVER BASINS,NEVADA, USA1

ABSTRACT: Effects of climate change are likely to be detected in nearly all sectors and regions of the economy, with both winners and losers. One of the consequences of climatic changes could be altered regional water supplies. This paper presents an investigation of regional agricultural implications of changes in water availability. Specifically, using a profit maximization approach, the economic consequences of altered water availability in the Great Basin of Nevada are analyzed in terms of the effects on net returns of agricultural producers. Under the scenarios analyzed in this paper, it is found that with adequate water systems, increase in streamflow and consequent increase in water availability could significantly benefit agricultural producers of this region. Net returns to irrigators could increase by 8 to 13 percent, not taking into account the possibility of changes in crop yields and prices. It is also shown that the benefits from increased water availability are sensitive to likely crop yield and price changes. The potential for adverse effects of climatic changes on water supply is also considered by analyzing the effects of decreased water availability. Under decreased water availability scenarios, farmer net returns decrease substantially.     

REAPPRAISAL OF WATER SUPPLY RESOURCES IN DELAWARE RIVER BASIN USING SYNTHETIC HYDROLOGY1

ABSTRACT The 60's drought (1961 1966) which hit the Northeastern United States, had its center over the Delaware River Basin and caused water supply shortages to New York City, Philadelphia, and many other towns and industries in the Basin. Until this event occurred, the existing water supply sources and those planned for the future had been considered adequate, as they were designed for the worst drought of record (usually the 1930-31 drought). In view of this “change in hydrology,” the Delaware River Basin Commission authorized a study (DRBC Resolution 67-4) to re-evaluate the adequacy of existing and planned water supply sources of the Delaware River Basin and its Service Area (New York City and northern New Jersey). Synthetic hydrology is a tool which can be used to overcome many of the limitations of the traditional approach. By analyzing generated streamflow traces in this study, it has been determined that there is a definite relationship between the accumulated rainfall deficiency during the drought and the return periods associated with various durations of runoff in the drought. This indicated that generated traces can be used to standardize the hydrology over an area where the intensity of drought varied. This represented an important facet in the study, because it provided a means to equalize the effects of this drought over the study area, and gave the Delaware River Basin Commission more information so that it could better plan and manage its water resources equitably, not only for the people within the Basin, but for the New York City and northern New Jersey areas as well. Synthetic hydrology was used to determine yield-probability relationships for 50-year periods, and storage-yield-frequency relationships for existing and planned water-supply reservoirs. It was also used to determine yield-probability relationships for reservoir systems within the Basin. In the study, it was determined that monthly streamflow traces and uniform draft rates could be used in yield analysis because of the magnitude of the reservoirs and because seasonal variations of draft rate are small in the study area. Although it was found that with the streamflow generating models (first order Markov) in common use today, it is not possible to definitely determine the actual frequency of a very severe historic drought, it is possible to place a drought in perspective by using synthetic hydrology. The study showed that it is a useful tool in determining water availability over a basin and is useful in studying water management problems such as interbasin transfers, and reservoir systems operations.     

REASONABLY FULL HYDROLOGIC DEVELOPMENT OF RESERVOIR SITES1

The size of multipurpose reservoir development is usually determined by an economic analysis of reservoir capabilities and the present and projected water resources needs which can be satisfied. This analysis is referred to as project formulation, wherein optimum conditions are sought. In responding to multiple objectives, i.e., national economic development, regional development and environmental quality, which are being considered in river basin planning in recent years, reservoirs should provide for reasonably full hydrologic development. Additional storage will be needed to provide opportunities for economic development, as well as meet unexpected development. Also, it provides more flow regulation capability for quality of environment considerations. An analysis has been made on twelve reservoir sites in the New York State portion of the Susquehanna River Basin to determine the so-called “reasonably full hydrologic development of reservoir sites.” Hydrologic, economic, environmental and physical characteristics of the sites are taken into consideration. For normal conditions, it can be concluded that a yield equivalent to about 80 percent of the average discharge (runoff) can be considered as reasonably full hydrologic development for reservoir sites in the Susquehanna River Basin in New York. The same technique can be applied elsewhere to determine reasonably full hydrologic development of reservoir sites.     

MATHEMATICAL MODELS: PLANNING TOOLS FOR THE GREAT LAKES1

The Great Lakes Basin Commission has initiated a Framework Study to assess the present and projected water- and related land-resource problems and demands in the Great Lakes Basin. Poorly defined objectives; incomplete and inconsistent data arrays; unknown air, biota, water, and sediment interactions; and multiple planning considerations for interconnected, large lake systems hinder objective planning. To incorporate mathematical modeling as a planning tool for the Great Lakes, a two-phase program, comprising a feasibility and design study followed by contracted and in-house modeling, data assembly, and plan development, has been initiated. The models will be used to identify sensitivities of the lakes to planning and management alternatives, insufficiencies in the data base, and inadequately understood ecosystem interactions. For the first time objective testing of resource-utilization plans to identify potential conflicts will provide a rational and cost-effective approach to Great Lakes management. Because disciplines will be interrelated, the long-term effects of planning alternatives and their impacts on neighboring lakes and states can be evaluated. Testing of the consequences of environmental accidents and increased pollution levels can be evaluated, and risks to the resource determined. Examples are cited to demonstrate the use of such planning tools.     

河南省境内淮河流域历史时期旱涝等级序列的重建

本文根据旱涝史料，运用旱涝等级评定法，对河南省境内淮河流域１４７０～１９４９年逐年的旱涝状况进行了评定；并采用“区域综合法”，重建了河南省境内淮河流域１４７０～１９４９年的旱涝等级序列。     

长江流域可持续发展的环境支持系统研究

可持续发展取决于智力、资源、环境、动力、过程五大支持系统的正常协调运转１。其中环境支持系统是一个重要方面。但目前长江流域的环境支持系统较为脆弱,生态环境问题比较严重,若不积极研究采取有效措施加以解决,对长江流域的持续发展极为不利。本文根据有关资料,对持续发展的可利用空间及其五大支持系统作了较为系统的论述,并对长江流域环境支持系统面临的主要问题和对策作了较深入的分析。研究认为,长江流域环境支持系统面     

改良模糊综合评价法在水质评价中的应用

基于传统模糊综合评价法原理,通过对评价指标选择、权重确定、模糊运算分析三个环节进行改良,建立了一种分辨率高、简便有效的地表水质量评价模型,并将其应用于辽河流域的水质评价中。改良后的模糊综合评价法能够更实际、更客观地反映多指标共同作用下的地面水环境质量状况,这为制定水环境宏观决策提供了必要的科学参考。     

Distribution and origin of polycyclic aromatic hydrocarbons in surface sediments from an urban river basin at the Metropolitan Region of Curitiba, Brazil

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in surface sediment samples from nine sites located at the Iguac?u River Basin in the Metropolitan Region of Curitiba, Brazil to evaluate their distribution and sources. The total concentration of the PAHs was greater for sediments from highly urbanized areas, while the sediments from the Ira′? Environmental Protection Area (Ira′? EPA) showed significantly low concentrations. The sediments from the Iguac?u and Barigui rivers were classified as highly contaminated, while those from the Cercado and Curralinho rivers were classified as moderately contaminated. The predominance of PAHs containing two to four aromatic rings in most of the samples suggested the direct input of raw sewage into the water resources evaluated. Benzo[g,h,i]perylene, dibenzo[a,h]anthracene and indeno[1,2,3-cd]pyrene were predominant in sediments from the areas under the greatest urban and industrial development. The correlation between thermodynamic stability and the kinetics of evolution presented by the isomeric pairs indicated that combustion is the predominant source of PAHs in the sediments because the combustion of fossil fuels affected most of the points evaluated, followed by combustion of biomass and eventually combustion of oil product inputs. In general, the results showed that areas under strong urban influence, as well as the Ira′? EPA, receive contributions of PAHs from similar sources.     

Spatial and temporal distribution of acetochlor in sediments and riparian soils of the Songhua River Basin in northeastern China

The Songhua River Basin is a burgeoning agricultural area in the modern times in China. Particularly in recent years, increasing chemical fertilizers and pesticides have been applied with the development of agricultural production. However, the situation of non-point source pollution (NSP) from agricultural production in this basin is still obscure. In order to solve the problem, the occurrence and distribution of acetochlor in sediments and riparian soils of the Songhua River Basin before rain season and after rain season were investigated. In addition, total organic carbon was analyzed. The result showed that the concentration of acetochlor ranged from 0.47 to 11.76 μg/kg in sediments and 0.03 to 709.37 μg/kg in riparian soils. During the high flow period in 2009, the mean concentration was 4.79 μg/kg in sediments and 0.75 μg/kg in riparian soils, respectively. Similarly, the mean concentration was 2.53 μg/kg in sediments and 61.36 μg/kg in riparian soils, during the average flow period in 2010. There was a significant correlation between the concentration of acetochlor and total organic carbon in surface sediments. Moreover, the distribution of acetochlor in sediments of the Songhua River was significantly correlated to land use and topography of the watershed. The investigated data suggested that the concentration of acetochlor in the Songnen Plain and the Sanjiang Plain was higher than that in the other areas of the basin, and riparian buffering zones in these areas had been destroyed by human activities. The optimal agricultural measures to alleviate the contamination of pesticides should be adopted, including controlling agricultural application of acetochlor and ecological restoration of riparian buffering strips.