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671.
附加回流的生物接触氧化工艺净化滇池大清河水质的示范工程研究 总被引:3,自引:0,他引:3
针对滇池流域污染最为严重的大清河,采用附加回流生物接触氧化工艺(IBCOP)开展河道水体的旁路处理示范工程研究。IBCOP示范工程的设计规模为1 000 m3/d,HRT为4.75 h,在2007年11月至2008年4月冬旱季期间,根据气候和进水水质条件调节回流比,示范工程运行了3种工况。研究结果表明:示范工程对COD和NH+4-N具有较高的去除效果,平均去除率为46.8%和48.8%,高回流比有利于去除NH+4-N;受到低温、低碳源、高进水DO和生物膜生长不佳等因素影响,示范工程对TN去除效果较低,平均去除率为10.2%,调节回流比不能显著改善碳源不足的情况;水绵的吸收和底泥的沉积是示范工程除磷的主要机理,TP平均去除率为17.9%,低TP浓度进水、生物膜的脱落以及高回流比不利于除磷。 相似文献
672.
水污染生态补偿是解决流域跨界水污染纠纷的重要措施。以行政单元为补偿主体,通过交界断面水质目标确立上下游政府间的水污染生态补偿责任,建立基于污染物通量的生态补偿量化计算方法,并提出了生态补偿运作模式。以钱塘江流域为例,根据2004年钱塘江流域水质状况,在75%保证率的水文条件下,基于COD通量估算了流域内各县(市)间水污染生态补偿量。结果表明,生态补偿量反映区域污染特点,上游地区基本上都是接受补偿者,而呈结构性污染的地区是生态补偿支付者,部分区域补偿强度超过当地经济发展水平,表明其发展不具有可持续性。钱塘江流域水污染生态补偿模式可以是政府层面上的财政支助,也可以通过项目支持、技术支持等形式实现区域间的补偿。通过生态补偿机制的实施,将对流域水环境保护起到积极的激励作用。 相似文献
673.
The USGS Water Availability and Use Science Program: Needs,Establishment, and Goals of a Water Census
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Ari M. Michelsen Sonya Jones Eric Evenson David Blodgett 《Journal of the American Water Resources Association》2016,52(4):836-844
Many reports have recognized the need for a national water census for the United States and have called upon the U.S. Geological Survey to undertake this challenge. For example, the National Science and Technology Council stated: “The United States has a strong need for an ongoing census of water that describes the status of our Nation's water resource at any point in time and identifies trends over time.” Responding to the need for this information, the U.S. Congress established the SECURE Water Act. The directives are to provide a more accurate assessment of the status of the water resources of the United States; determine the quantity of water available for beneficial uses; identify long‐term trends in water availability; assist in determination of the quality of the water resources; and develop the basis for an improved ability to forecast the availability of water for future economic, energy production, and environmental uses. This article provides summary and new information on the process and progress on work to estimate water budget components nationwide, involvement of stakeholder interests, efforts to examine water‐use characteristics throughout the Nation, studies of water availability in geographically focused areas and the initiation of methods to provide open access to existing and new water resources information contributing to Open Water Data Initiative (OWDI) efforts and objectives. 相似文献
674.
Effects of Land Use and Sample Location on Nitrate‐Stream Flow Hysteresis Descriptors during Storm Events
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Lawrence S. Feinson Jacob Gibs Thomas E. Imbrigiotta Jessica D. Garrett 《Journal of the American Water Resources Association》2016,52(6):1493-1508
The U.S. Geological Survey's New Jersey and Iowa Water Science Centers deployed ultraviolet‐visible spectrophotometric sensors at water‐quality monitoring sites on the Passaic and Pompton Rivers at Two Bridges, New Jersey, on Toms River at Toms River, New Jersey, and on the North Raccoon River near Jefferson, Iowa to continuously measure in‐stream nitrate plus nitrite as nitrogen (NO3 + NO2) concentrations in conjunction with continuous stream flow measurements. Statistical analysis of NO3 + NO2 vs. stream discharge during storm events found statistically significant links between land use types and sampling site with the normalized area and rotational direction of NO3 + NO2‐stream discharge (N‐Q) hysteresis patterns. Statistically significant relations were also found between the normalized area of a hysteresis pattern and several flow parameters as well as the normalized area adjusted for rotational direction and minimum NO3 + NO2 concentrations. The mean normalized hysteresis area for forested land use was smaller than that of urban and agricultural land uses. The hysteresis rotational direction of the agricultural land use was opposite of that of the urban and undeveloped land uses. An r2 of 0.81 for the relation between the minimum normalized NO3 + NO2 concentration during a storm vs. the normalized NO3 + NO2 concentration at peak flow suggested that dilution was the dominant process controlling NO3 + NO2 concentrations over the course of most storm events. 相似文献
675.
当前有关流域生态补偿的研究和实践探索,均倾向于从责任分配视角来设定流域生态补偿的适用条件。然而,从责任分配视角来界定流域生态补偿之适用条件面临着诸多困境。以水质控制目标作为适用条件的地方立法和以超过Ⅲ类水质标准作为流域生态补偿适用条件之观点,均限缩了流域生态补偿的适用范围,导致了补偿义务主体与受偿主体之间法律关系的混乱,并背离了流域生态补偿的本质和基本功能预设。无论从流域生态补偿的功能定位出发,还是基于该制度构建的正当性基础和可行性考量,均应从权利确认而非责任分配视角来明晰流域生态补偿之适用条件。首先,流域生态补偿的基本功能是流域生态利益正向供给激励,受偿主体的权利确认与保障是这一制度构建的重心。从责任分配的角度来界定流域生态补偿之适用条件,将导致其基本功能的偏离;其次,"最少受惠者的最大利益"原则是流域生态补偿制度构建的正当性基础,流域生态补偿的本质是对"最少受惠者"发展权的弥补。从责任分配视角界定流域生态补偿之适用条件遮蔽了流域生态补偿法律关系中的"最少受惠者";再次,受益主体的非特定性意味着从权利确认视角来界定流域生态补偿之适用条件将更具有可行性。从权利确认视角来看,流域生态补偿的适用条件应包括:有生态增益行为、非有责主体、不问主观动机与现实损害后果。 相似文献
676.
鄱阳湖流域基本特征、面临挑战和关键科学问题 总被引:2,自引:0,他引:2
鄱阳湖流域总面积占长江流域面积的9%,占江西省国土面积的939%,鄱阳湖流域的生态健康维系着流域内,特别是长江中下游的生态安全,是区域经济、社会、生态可持续发展的重要保障。在全面认识鄱阳湖流域基本特征和面临挑战的基础上,探讨了鄱阳湖流域面临的五大科学问题:“山 江 湖”的相互关系与流域的生态健康;全球变化背景下流域生态系统的响应;流域生物多样性地理格局与社会经济合理分区;长江流域环境演变对鄱阳湖流域的影响;流域科学管理的理论与实践。为鄱阳湖生态经济区的建设和全流域的综合管理提供科学的建议和对策 相似文献
677.
Carolyn T. Hunsaker Thomas W. Whitaker Roger C. Bales 《Journal of the American Water Resources Association》2012,48(4):667-678
Hunsaker, Carolyn T., Thomas W. Whitaker, and Roger C. Bales, 2012. Snowmelt Runoff and Water Yield Along Elevation and Temperature Gradients in California’s Southern Sierra Nevada. Journal of the American Water Resources Association (JAWRA) 48(4): 667‐678. DOI: 10.1111/j.1752‐1688.2012.00641.x Abstract: Differences in hydrologic response across the rain‐snow transition in the southern Sierra Nevada were studied in eight headwater catchments – the Kings River Experimental Watersheds – using continuous precipitation, snowpack, and streamflow measurements. The annual runoff ratio (discharge divided by precipitation) increased about 0.1 per 300 m of mean catchment elevation over the range 1,800‐2,400 m. Higher‐elevation catchments have lower vegetation density, shallow soils with rapid permeability, and a shorter growing season when compared with those at lower elevations. Average annual temperatures ranged from 6.8°C at 2,400 m to 8.6 at 1,950 m elevation, with annual precipitation being 75‐95% snow at the highest elevations vs. 20‐50% at the lowest. Peak discharge lagged peak snow accumulation on the order of 60 days at the higher elevations and 20 to 30 days at the lower elevations. Snowmelt dominated the daily streamflow cycle over a period of about 30 days in higher elevation catchments, followed by a 15‐day transition to evapotranspiration dominating the daily streamflow cycle. Discharge from lower elevation catchments was rainfall dominated in spring, with the transition to evapotranspiration dominance being less distinct. Climate warming that results in a longer growing season and a shift from snow to rain would result in earlier runoff and a lower runoff ratio. 相似文献
678.
679.
综合下垫面条件、气象与水文信息,对皖西大别山区的诸佛庵镇“05.9”小流域暴雨,进行暴雨重现期和洪水过程分析计算。结合灾害特征,探讨其成因。在小流域风险洪水预估的基础上,从防灾减灾的角度提出对策性建议。 相似文献
680.
Kahl JS Nelson SJ Fernandez I Haines T Norton S Wiersma GB Jacobson G Amirbahman A Johnson K Schauffler M Rustad L Tonnessen K Lent R Bank M Elvir J Eckhoff J Caron H Ruck P Parker J Campbell J Manski D Breen R Sheehan K Grygo A 《Environmental monitoring and assessment》2007,126(1-3):9-25
This paper is an overview of this special issue devoted to watershed research in Acadia National Park (Acadia NP). The papers
address components of an integrated research program on two upland watersheds at Acadia NP, USA (44° 20′ N latitude; 68° 15′
E longitude). These watersheds were instrumented in 1998 to provide a long-term foundation for regional ecological and watershed
research. The research was initiated as part of EPA/NPS PRIMENet (Park Research and Intensive Monitoring of Ecosystems Network),
a system of UV-monitoring stations and long-term watershed research sites located in US national parks. The initial goals
at Acadia NP were to address research questions about mercury, acid rain, and nitrogen saturation developed from prior research.
The project design was based on natural differences in forests and soils induced by an intense wildfire in one watershed in
1947. There is no evidence of fire in the reference watershed for several hundred years. We are testing hypotheses about controls
on surface water chemistry, and bioavailability of contaminants in the contrasting watersheds. The unburned 47-ha Hadlock
Brook watershed is 70% spruce-fir mature conifer forest. In contrast, burned 32-ha Cadillac Brook watershed, 4 km northeast
of the Hadlock watershed, is 20% regenerating mixed northern hardwoods and 60% shrub/rocky balds. Differences in atmospheric
deposition are controlled primarily by forest stand composition and age. The watersheds are gauged and have water chemistry
stations at 122 m (Cadillac) and 137 m (Hadlock); watershed maximum elevations are 468 and 380 m, respectively. The stream
water chemistry patterns reflect, in part, the legacy of the intense fire, which, in turn, controls differences in forest
vegetation and soil characteristics. These factors result in higher nitrogen and mercury flux from the unburned watershed,
reflecting differences in atmospheric deposition, contrasting ecosystem pools of nitrogen and mercury, and inferred differences
in internal cycling and bioavailabilty. 相似文献