Sustainability of Water Quality and Ecology最新文献

The conservation and management of military training lands has long evolved around the unique criteria for maintaining a viable fighting force. In lieu of this primary mission, landscapes have often experienced accelerated degradation and loss of structural and functional capabilities for providing desired ecosystem services (including the basic training mission). In an effort to aid military land managers as well as anyone who makes and implements decisions for natural resource management; we support an innovative approach towards the integration of evidence and the application of diagnosis and prognosis for the decision-making process through the use of Bayesian Networks. Illustrated below is an example for utilizing Bayesian Networks in the decision support process. We utilized data and experience from ongoing efforts at the Fort Hood Military Installation to build the initial network; then integrate expert input from authors and engineers in propagating the node relationships. Through this approach, we demonstrate how military land managers can integrate varying streams of evidence, including empirical, model generated or expert opinion, into a network for decision support. The example below is developed based upon land management issues within the U.S. Army, but the process can be adapted and implemented across most all ecosystems under some form of land management.

Water pollution remains a challenging issue for the sustainable development of Kathmandu Valley despite several infrastructural, awareness-raising and policy measures. The paper assesses the sustainability of the surface water resources of Kathmandu valley by analyzing the water quality parameters such as Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD). The case study of Bagmati River pollution is analyzed for current and future wastewater production and treatment scenario based on the two important indicators of aquatic health. The DO and BOD were simulated to assess river pollution along a 25 km stretch between Sundarijal and Chovar. Water Evaluation And Planning (WEAP) model was used to simulate the current (year 2014) and future (year 2020 and 2030) river water quality conditions. The results showed that the water quality of the Bagmati River is relatively better during monsoon season due to higher river flow in comparison to the dry season. A comparison of simulated DO and BOD values for 2020 and 2030 with 2014 values indicated that the water quality of the Bagmati River within Kathmandu Valley will not significantly improve as a result of the planned wastewater treatment plants requiring additional countermeasures. The study pointed out the inefficiencies of the current practice of discharging untreated sewage into the surface water and causing largely in the river water and unsuitability of river water of water from the Gaurighat to the Chovar area. It is recommended to integrate river water pollution management and maintain ecologically to achieve the healthy urban development.

While much has been done to reduce conventional pollutants in watershed systems, emerging contaminants (ECs) are posing a major threat to health and environment. These contaminants pose a threat to humans and to ecosystems. There is a critical need for comprehensive strategies that aim at watershed system-wide abatement (source-transfer-fate levels) using both structural and nonstructural approaches. In this study, we review sources, occurrence and harmful impacts of ECs with an eye toward watershed-scale mitigation strategies at source, transfer, fate, and organismal response levels. The use and efficiency of activated carbon, ozonation, photocatalysis, photo fenton, reverse osmosis and constructed wetlands are useful in mitigation. Management priority is needed for pharmaceuticals, personal care products, pesticides, and industrial contaminants that are increasing in frequency and concentrations. Structural approaches at source level can include best management practices like buffer strips, riparian management, natural and constructed wetlands. These natural strategies are cost-effective for small communities due to low operational cost and energy consumption. Non-structural approaches can include dissemination of information, education, outreach, incentives for mitigation, and policy mechanism for compliance. A comprehensive, watershed-based, systems approach with multi-level strategies at source, transfer and sink level for efficient abatement of ECs and sustainability of watershed systems.

Given the complexity and urgency of future governance, the beneficial use of historic evidence for decision-making is examined. Considering the megatrends and the objective of sustainable development, environmental governance has become subject of a global policy and local (in particular urban) management. The ongoing shift from a technology-driven to a governance-driven society will define the need and kind of future technological improvements and innovations. Mainly based on the industrial and sanitary revolution, it is illustrated lessons can be drawn from facts and storylines, suitable for decision-making and technological applications. Water technology provides part of the solutions for water-related issues, in the sense techniques from the past may still offer opportunities for future applications. But historic evidence on the process of decision-making becomes of higher value in supporting future governance. The cases of London (UK) and Ghent (Belgium) show successes and failures of technological developments related to the process of decision-making. At the same time, they provide an example of deriving a storyline from facts.

Riparian land supports multiple ecosystem services that are essential for good water quality and aquatic biodiversity, providing habitat and hydrological connectivity, and retaining pollutants and sediments. Riparian land reduces sediment fluxes in the freshwater systems by trapping sediments generated on the hillslopes before they reach the stream network, and by stabilizing stream banks. The aim of this study was to assess the impact of current riparian land in reducing sediment fluxes in the stream network of the Danube River Basin. The Soil and Water Assessment Tool (SWAT) model was used to assess sediment yields across the basin and quantify sediment retention by riparian vegetation. Europe-wide spatial information on riparian land type and extent was used to set up agricultural to riparian land ratio and the streambank reach vegetation cover. SWAT sediment simulations for current conditions, i.e. including riparian land parameterization, were calibrated and validated for the period 1995–2009. The impact of riparian land was quantified by analyzing differences in mean annual specific sediment yields between scenarios without riparian land and current conditions. Sediment yield reductions and efficiency of riparian land were quantified at several spatial scales across the basin, considering hillslopes, stream order, and administrative regions. The impact of riparian filtering in reducing sediment fluxes to the stream network at the hillslope scale was always positive, with median efficiency of 50%. Efficiency was higher where incoming sediment and water yields per unit of area were larger, and in smaller HRUs (areas lower than 10 km²). Sediment filtering in riparian buffers was more efficient in smaller reaches, and decreased from about 17% to 5% with Strahler’s order. Streambank protection was important locally in about 8% of reaches characterized by high stream power, where current streambank protection reduced potential sediment yields by more than 5 t/km²/y, and in large reaches, like in the Sava and Danube Rivers. At the Danube outlet to the Black Sea, the reduction in sediment yield attributable to current riparian land was estimated at 480 kt/y. Although riparian efficiency declined with spatial scale in terms of sediment yield reduction, filtering of sediments in riparian buffers abated in-stream sedimentation substantially. While occupying only about 2% of the Basin, current riparian land in the Danube Basin reduces sediment fluxes in river networks by about 8% regionally, and contributes to the improvement of the ecological conditions of freshwater ecosystems.

Nonpoint source pollution (NPS) resulting from agricultural production is one of the major causes of impaired natural resources, adversely affecting the provision of ecosystem services. Best management practices (BMPs) are commonly implemented in watersheds to mitigate agricultural NPS. Appropriate selection of BMP type and its placement in agricultural watersheds are crucial for successful mitigation efforts. In this study, an integrated modeling system was developed to identify scenarios of best management practices such as nutrient management, constructed wetlands and filter strips that provide downstream water quality improvements. The modeling system is a coupling of Soil and Water Assessment Tool (SWAT) for simulating watershed responses and impacts of BMPs, with cost evaluation model solved using Archived Micro-Genetic Algorithm (AMGA2) for generating optimal reduction strategies of NPS pollution at a watershed scale. Its application was demonstrated using tributary watersheds of Lake Decatur – a water supply reservoir located in Illinois, which is listed as impaired for nitrate-nitrogen (N) and total phosphorus (P) in the 2004 Section 303(d) List of Clean Water Act. Study results indicate that nutrient management is the best alternative practice to provide water quality benefits with annual nitrate-N loss reduction of 14.9 percent and cost savings of $6.42 per kg of nitrate-N reduction per hectare (ha). In contrast, constructed wetlands and filter strips were found to incur implementation costs of $10.89/kg N/ha and $1.74/kg N/ha, respectively, including associated land revenue losses. The effectiveness of the filter strips was very limited because of extensive tile drainage in the study watersheds. The integrated modeling system generates valuable information for developing sound watershed management plan and its framework can be adapted to investigate other environmental challenges detrimental to sustainability of water resources.