نتایج جستجو برای: forest watershed
تعداد نتایج: 121015 فیلتر نتایج به سال:
Effects of dispersed recreational activities on the microbiological quality of forest surface water.
The microbiological quality of forest surface waters in the Greenwater River watershed was examined to investigate the influence of heavy motorized camping in an area with no sanitary facilities. Indicator densities increased during weekend human-use periods when compared to weekdays. Increases in indicator densities were also noted downstream from heavily used camping areas when compared to up...
Emissions of methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) from a forested watershed (160 ha) in South Carolina, USA, were estimated with a spatially explicit watershed-scale modeling framework that utilizes the spatial variations in physical and biogeochemical characteristics across watersheds. The target watershed (WS80) consisting of wetland (23%) and upland (77%) was divided ...
the control of biological, hydrological and geochemical cycles of soil is the key part of the earth system. the objective of this research was to evaluate changes in soil chemical properties due to deforestation occurred in the gazafolya village, merek watershed, kermanshah province, iran. toward this attempt, 35 soil samples were collected from top soil layer using auger in early june, 2013. s...
The land-use change, cutting forest trees and the grasslands conversion to agricultural lands destroyed natural ecosystems and also current or future production capacity reduce and these are harmful effects on the soil physicochemical characteristics. This study taken with aim, checking the role of forest-land change on some soil physical-chemical characteristics and then identify some effectiv...
The aim of this study was to evaluate the impact of forest on erosion and runoff variables and compare it with rangeland and agricultural in part of Mereg watershed located in Kermanshah province. At first, three forest mass were identified and divided into three density categories (low, medium and Many), then Soil and hydrological parameters were measured in each forest density area and also i...
[1] Watershed export of phosphorus (P) from anthropogenic sources has contributed to eutrophication in freshwater and coastal ecosystems. We explore impacts of watershed urbanization on the magnitude and export flow distribution of P along an urban-rural gradient in eight watersheds monitored as part of the Baltimore Ecosystem Study Long-Term Ecological Research site. Exports of soluble reactiv...
This paper describes estimation of stream channel geometry with multiple regression analysis of GISderived watershed characteristics including drainage area, catchment-averaged precipitation, mean watershed slope, elevation, forest cover, percent area with slopes greater than 30 percent, and percent area with north-facing slopes greater than 30 percent. Results from this multivariate predictor ...
There is ever-increasing competition for the many uses and natural resources of forests in the eastern United States. Multiple-use management has long been a stated goal for these forests, but application has been problematic and seldom satisfactory to all users. There is a need to incorporate more science into management decisions for Eastern forests, and thereby convincingly demonstrate to fo...
The National Phosphorus Project rainfall simulator was used to quantify overland flow and P transport from nine sites distributed throughout the watershed of a New York City Watershed Agriculture Program collaborating dairy farm. Observed concentrations of total dissolved phosphorus (TDP) were low (0.007-0.12 mg L(-1)) in flow from deciduous forest, extensively managed pasture, and hillside see...
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