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911.
利用常州市6个环境空气质量评价点PM2.5、PM10、SO2、NO2、CO和水溶性离子数据,结合后向轨迹、激光雷达探空资料、气象资料等,分析了2018年1月29日—2月2日长三角区域一次持续重污染过程。结果表明,重度污染时次高达94 h,PM2.5最高值达235 μg/m3,由外来输送污染物与本地排放的污染物叠加而成,在不利气象条件影响下,污染物在长三角区域长时间滞留;重污染期间,污染物日变化规律显示,PM2.5受外来源影响更显著,而SO2、NO2受本地污染源影响更显著,水溶性粒子组分与常州市本地源存在较大差异,其中NO3-、NH4+、K+、Mg2+和SO42-值增加最为明显,较污染前分别增加了9.1,5.9,4.3,4.2和4.1倍;K+值升高较快,说明污染期间也受到了生物质燃烧的影响。此外,NO3-和SO42-在空气质量较好时,在水溶性离子中的占比日变化幅度较大,而在重污染期间,NO3-和SO42-日变化幅度明显减小。 相似文献
912.
AbstractWater is a key resource for all life. Recent droughts have also exemplified the importance for manufacturers to understand their impact on water resources. While most manufacturers typically know the amount of water they use in their facilities, they have little knowledge about the indirect effects they have on water resources. In this paper, the indirect impact from the automakers’ electricity use and work force on water resources is examined. Water withdrawal and consumption from electricity use by hypothetical but representative facilities around the world is quantified and analysed. Water withdrawal by the workers is also quantified and analysed. The results indicate that the water withdrawal and consumption by the workforce and caused by the use of electricity is larger than the direct water use and consumption in the facilities themselves. 相似文献
913.
Impact of climate factors on cyanobacterial dynamics and their interactions with water quality in South Taihu Lake,China 总被引:1,自引:0,他引:1
Shams Ali Baig Linglin Huang Tiantian Sheng Xiaoshu Lv Zhe Yang Muhammad Qasim 《Chemistry and Ecology》2017,33(1):76-87
Cyanobacterial bloom events in South Taihu Lake cause serious water quality problems and disturb aesthetic view of lake’s environment. In this study, correlations between cyanobacterial blooms and hydro-meteorological factors, including water quality, temperature and precipitation were investigated. Results demonstrated that South Taihu Lake was heavily affected by cyanobacteria and the proliferation of cyanobacteria due to variations in hydro-meteorological factors and water quality conditions. Water quality parameters, including COD, NH3-N, TN and TP improved significantly since 2008 even at an elevated cyanobacterial bloom situation. Correlation analyses have shown that the development of cyanobacterial density and chlorophyll a concentration was sensitive to a wider temperature variation. The optimum temperature for cyanobacteria was 20°C, while extremely low and high temperatures were found to suppress their growth. Moreover, unusual rainfall patterns were measured during the study period (2003–2009), which showed an adverse impact on cyanobacterial development. Findings from this study suggested that seasonal lake’s water quality monitoring; suitable treatment of cyanobacterial blooms and strict policy implementation can solve the water quality issues in highly eutrophic lakes like Taihu. 相似文献
914.
The monitoring of surface water quality of rivers is crucial to protect aquatic life and receiving water bodies of economic importance. The aim of the current study was to examine selected physicochemical parameters of River Tajan due to its ecological importance in Iran. Water samples from nine points covering the entire Tajan River and Caspian Sea estuary were collected and analyzed for pH, electrical conductivity (EC), total dissolved solids (TDS), carbonates, chlorides and selected heavy metals including zinc, cadmium, lead and chromium. The pH and levels of EC, TDS, chlorides, carbonates and all metals were within the USEPA reference guidelines for surface water quality standards. Although these water quality parameters are considered safe, continuous monitoring and assessment is recommended in order to protect the coastal receiving waters of Caspian Sea which serves as a tourist attraction in northern Iran. 相似文献
915.
Development and Testing of a Physically Based Model of Streambank Erosion for Coupling with a Basin‐Scale Hydrologic Model SWAT 下载免费PDF全文
B. Narasimhan P.M. Allen S.V. Coffman J.G. Arnold R. Srinivasan 《Journal of the American Water Resources Association》2017,53(2):344-364
A comprehensive streambank erosion model based on excess shear stress has been developed and incorporated in the hydrological model Soil and Water Assessment Tool (SWAT). It takes into account processes such as weathering, vegetative cover, and channel meanders to adjust critical and effective stresses while estimating bank erosion. The streambank erosion model was tested for performance in the Cedar Creek watershed in north‐central Texas where streambank erosion rates are high. A Rapid Geomorphic field assessment (RAP‐M) of the Cedar Creek watershed was done adopting techniques developed by the Natural Resources Conservation Service (NRCS), and the stream segments were categorized into various severity classes. Based on the RAP‐M field assessment, erosion pin sites were established at seven locations within the severely eroding streambanks of the watershed. A Monte Carlo simulation was carried out to assess the sensitivity of different parameters that control streambank erosion such as critical shear stress, erodibility, weathering depth, and weathering duration. The sensitive parameters were adjusted and the model was calibrated based on the bank erosion severity category identified by the RAP‐M field assessment. The average observed erosion rates were in the range 25‐367 mm year?1. The SWAT model was able to reasonably predict the bank erosion rates within the range of variability observed in the field (R2 = 0.90; E = 0.78). Editor's note : This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series. 相似文献
916.
An Open Source GIS‐Based Decision Support System for Watershed Evaluation of Best Management Practices 下载免费PDF全文
Hui Shao Wanhong Yang John Lindsay Yongbo Liu Zhiqiang Yu Anatoliy Oginskyy 《Journal of the American Water Resources Association》2017,53(3):521-531
Economic costs, water quantity/quality benefits, and cost effectiveness of agricultural best management practices (BMPs) at a watershed scale are increasingly examined using integrated economic‐hydrologic models. However, these models are typically complex and not user‐friendly for examining the effects of various BMP scenarios. In this study, an open source geographic information system (GIS)‐based decision support system (DSS), named the watershed evaluation of BMPs (WEBs), was developed for creating BMP scenarios and simulating economic costs and water quantity/quality benefits at farm field, subbasin, and watershed scales. This DSS or WEBs interface integrated a farm economic model, the Soil and Water Assessment Tool (SWAT), and an optimization model within Whitebox Geospatial Analysis Tools (GAT), an open source GIS software. The DSS was applied to the 14.3‐km2 Gully Creek watershed, a coastal watershed in southern Ontario, Canada that drains directly into Lake Huron. BMPs that were evaluated included conservation tillage, nutrient management, cover crop, and water and sediment control basins. In addition to assessing economic costs, water quantity/quality benefits, and cost effectiveness of BMPs, the DSS can be also used to examine prioritized BMP types/locations and corresponding economic and water quantity/quality tradeoffs in the study watershed based on environmental targets or budget constraints. Further developments of the DSS including interface transfer to other watersheds are also discussed. Editor's note : This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series. 相似文献
917.
Based on the national database of 28,104 water rights (concessions) granted in Colombia, this paper presents an analysis of how the principles of equity and sustainability are reflected in water allocation. Concessions appear to be an exclusionary mechanism since only a minority of small water users have concessions and the distribution of water volumes among those who have them is extremely inequitable. The 2009 Gini coefficient calculated for water concessions granted for agriculture was 0.90 compared with the rural land Gini of 0.88 (both indicators grouping holdings under the same entity). More than half of the Colombian departments have a higher Gini coefficient for water than for land, suggesting that water rights are at least as unequally distributed as land, in one of the most inequitable countries in Latin America. Water allocated to domestic, agriculture and hydropower use indicates a lack of consistency of water allocation criteria across regions. The volumetric and administrative attributes of water allocation in Colombia do not account for environmental flows or the concerns of marginalised groups of society that have limited access to the mechanism. Water allocation as a technical task, with limited transparency and secluded from public scrutiny, does not contribute to the solution of increasing water-related conflicts. 相似文献
918.
东莞运河水环境容量优化研究 总被引:3,自引:0,他引:3
本文根据东莞运河的特点,建立了适用运河特点的水环境容量优化模型,求解运河在不同的运行规律下最大的水环境容量值。建立的模型简单,易于求解,求解方程可以直接引用线性规划软件,计算得到的结果正确。 相似文献
919.
920.