نتایج جستجو برای: river ecosystem

تعداد نتایج: 162076  

Journal: :Journal of environmental quality 2013
Helen P Jarvie Andrew N Sharpley Paul J A Withers J Thad Scott Brian E Haggard Colin Neal

This commentary examines an "inconvenient truth" that phosphorus (P)-based nutrient mitigation, long regarded as the key tool in eutrophication management, in many cases has not yet yielded the desired reductions in water quality and nuisance algal growth in rivers and their associated downstream ecosystems. We examine why the water quality and aquatic ecology have not recovered, in some case a...

Journal: :Marine pollution bulletin 2014
K E Fabricius M Logan S Weeks J Brodie

Changes in water clarity across the shallow continental shelf of the central Great Barrier Reef were investigated from ten years of daily river load, oceanographic and MODIS-Aqua data. Mean photic depth (i.e., the depth of 10% of surface irradiance) was related to river loads after statistical removal of wave and tidal effects. Across the ∼25,000 km(2) area, photic depth was strongly related to...

2017
Chamara P. Liyanage Koichi Yamada

Human activities pose a significant threat to the water quality of rivers when pollution exceeds the threshold limit. Urban activities in particular are highlighted as one of the major causes of contamination in surface water bodies in Asian countries. Evaluation of sustainable human population capacities in river watersheds is necessary to maintain better freshwater ecosystems in a country whi...

Journal: :caspian journal of environmental sciences 2014
m. pourafrasyabi z. ramezanpour

phytoplanktons are the first bio- indicators of pollution in aquatic ecosystems. phytoplankton assemblage and aquatic ecosystems are always influenced by environmental factors therefore these environmental changes and threats must be understood in any ecosystem. phytoplankton are inexpensive and readily available bio- indicators. in the present study, phytoplankton were used to study the sefid ...

Journal: :Ambio 2009
Chongyun Wang Peter van der Meer Mingchun Peng Wim Douven Rudi Hessel Chenlin Dang

In the Langcang (Upper-Mekong) watershed, degraded watershed ecosystems in upland areas threaten cultivation practices, water resources, and dam development downstream. Assessment of ecosystem services and the factors that threaten them is an important first step to support watershed management. This, however, requires detailed information that is often missing in mountainous regions. To overco...

2009
Brian Deal

Sustainable management of a region’s critical and valued ecosystem resources requires an understanding about how these resource systems might function into the future. In urbanized areas, this requires the ability to frame the role of resources within the context of urban dynamics and the implications of policy and investment choices. In this paper we describe a three-step approach to assessing...

Journal: :Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research) 2014

Journal: :Aquatic Sciences - Research Across Boundaries 2003

Journal: :Environmental management 2014
Mattia Trabucchi Patrick J O'Farrell Eduardo Notivol Francisco A Comín

Semi-arid Mediterranean regions are highly susceptible to desertification processes which can reduce the benefits that people obtain from healthy ecosystems and thus threaten human wellbeing. The European Union Biodiversity Strategy to 2020 recognizes the need to incorporate ecosystem services into land-use management, conservation, and restoration actions. The inclusion of ecosystem services i...

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