نتایج جستجو برای: river ecosystem

تعداد نتایج: 162076  

2002
Michael T. Coe Marcos Heil Costa Aurélie Botta Charon Birkett

[1] A terrestrial ecosystem model (integrated biosphere simulator (IBIS)) and a hydrological routing algorithm (HYDRA) are used in conjunction with long time series climate data to simulate the river discharge and flooded area of the Amazon/ Tocantins River basin over the last 60 years. Evaluating the results of this modeling exercise over the entire basin yields three major results: (1) Observ...

The study of benthic macroinvertebrate communities is one of the most common methods for assessing the effects of stresses on the biological conditions of aquatic ecosystems and water quality monitoring. This research was conducted to study the changes in the macroinvertebrate communities in the Shanbeh-Bazar River, Anzali International wetland and the effects of environmental factors. Sampling...

Journal: :Ecotoxicology 2012
Luke R Iwanowicz Vicki S Blazer Nathaniel P Hitt Stephen D McCormick David S DeVault Christopher A Ottinger

The use of fish as sentinels of aquatic ecosystem health is a biologically relevant approach to environmental monitoring and assessment. We examined the health of the Ashtabula River using histologic, immunologic, and endocrine biomarkers in brown bullhead (BB; Ameiurus nebulosus) and largemouth bass (Micropterus salmoides) and compared fish collected from a reference site (Conneaut Creek). Sea...

2006
Jonathan D. Phillips

Submitted to the Texas Water Development Board 2 PREFACE This report is submitted in fulfillment of contract no. 2005-483-564 between the Texas Water Development Board and Jonathan Phillips (doing business as Copperhead Road Geoscience). The report is presented in two more-or-less independent parts, reflecting the Scope of Work for the project. The first is a review and evaluation of geomorphic...

2010
L. N. Mikhaylovskaya I. V. Molchanova V. N. Pozolotina

The Techa river was contaminated in 1949-1956 from the nuclear enterprise "MAYAK". The investigations were carried out in flood plain of the Techa river in 1992-1999. In the upper and middle parts of the river the basic contaminator is I 3 7 Cs; downstream more active is 9 0 Sr. Density of contamination of soils with 9 0 Sr down the river changes from 600 to 200 kBq/m , and that with 1 3 7 Cs f...

2017
Wietse I. Van De Lageweg Aimée B. A. Slangen

The world’s largest deltas are densely populated, of significant economic importance and among the most valuable coastal ecosystems. Projected twenty-first century sea-level rise (SLR) poses a threat to these low-lying coastal environments with inhabitants, resources and ecology becoming increasingly vulnerable to flooding. Large spatial differences exist in the parameters shaping the world’s d...

2010
Brian D. Richter Sandra Postel Carmen Revenga Bernhard Lehner Allegra Churchill

The World Commission on Dams (WCD) report documented a number of social and environmental problems observed in dam development projects. The WCD gave particular emphasis to the challenges of properly resettling populations physically displaced by dams, and estimated the total number of people directly displaced at 40-80 million. Less attention has been given, however, to populations living down...

2014
Shuhong Peng Xi Chen Jing Qian Shuguang Liu

To restore declining species, including Populus euphratica and other riparian communities, in the river ecosystem of the lower Tarim River, the ecological water conveyance project (EWCP), as a part of an integrated water resource management plan, was implemented in 2000. The EWCP aims to schedule and manage the water resources in the upper reaches and transfer water to the lower reaches by a se...

2015
Uyen Nguyen Edward P. Glenn Pamela L. Nagler Russell L. Scott

The Upper San Pedro River is one of the few remaining undammed rivers that maintain a vibrant riparian ecosystem in the southwest United States. However, its riparian forest is threatened by diminishing groundwater and surface water inputs, due to either changes in watershed characteristics such as changes in riparian and upland vegetation, or human activities such as regional groundwater pumpi...

Journal: :Journal of environmental monitoring : JEM 2012
Syed Ali-Musstjab-Akber-Shah Eqani Riffat Naseem Malik Athanasios Katsoyiannis Gan Zhang Paromita Chakraborty Ashiq Mohammad Kevin C Jones

Concentrations in surface waters (including particulate phase) of the River Chenab ranged from 27-1100 ng L(-1) and 25-1200 ng L(-1) for OCPs and 7.7-110 ng L(-1) and 13-99 ng L(-1) for PCBs during summer and winter, respectively from 2007-2009. DDTs exhibited the highest concentration, followed by HCHs > chlordane > ∑(24)PCBs > ∑other OCPs. Different indicative ratios for organochlorines sugge...

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