نتایج جستجو برای: forest roads
تعداد نتایج: 119097 فیلتر نتایج به سال:
soil is known as the base material for many structure, on the other hand, some soils cause problems for some structures such as roads. some types of soils absorb moisture and swell then they may shrink when losing water. the changes of moisture in these soil samples cause changes their volume and pressure to layers of the pavement and eventually leads to destruction of roads. therefore, it is n...
During the construction of road networks large area of forests and rangelands will be destroyed in the road path and its margins. This process causes massive amount of soil and rock move from its site and on adjacent lands will be accumulated, that causes increasing environmental degradation. One of the most important problems due to forest roads making is increasing of different erosion forms ...
The magnitude, seasonality, and duration of peak discharge responses to forest removal and regrowth and roads in 10 pairs of experimental basins in the western Cascade Range of Oregon are consistent with fundamental water balance and routing concepts in hydrology. Hypothesized effects of forestry treatments on evapotranspiration, cloud water interception, snowpack dynamics, and subsurface flow ...
Debate over repealing the ivory trade ban dominates conferences of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Resolving this controversy requires accurate estimates of elephant population trends and rates of illegal killing. Most African savannah elephant populations are well known; however, the status of forest elephants, perhaps a distinct spe...
land use change may influence many natural phenomena and ecological processes, including runoff, soil erosion, sedimentation and soil conditions. decreasing of forest area in the north of iran is one of the critical problems in recent years. the aims of this study are to detect land use changes between 1967 to 2002 using satellite images of land sat 7 etm+ (2002), aerial photos and digital topo...
In this research, sediment production and delivery amount by Darabkola forest roads was estimated using the SEDMODL model. To evaluate the model results, the sedimentation rate in the above roads was directly measured using rainfall simulator. Also, the paired t-test, BIAS, RE and RMSE were used to assess the results. The analysis showed that the rate of sediment production from study roads' su...
In order to evaluate the effects of forest road on vegetation and some soil properties was selected a road with the length of 400 m. Type and number of regeneration species of trees and shrubs in plot area of 100 m2 and type and cover percentage of herbaceous species using minimal area method were recorded in plot area of 64 m2 and herbaceous species was classified into two groups using Two-W...
Industrial logging has become the most extensive land use in Central Africa, with more than 600,000 square kilometers (30%) of forest currently under concession. With use of a time series of satellite imagery for the period from 1976 to 2003, we measured 51,916 kilometers of new logging roads. The density of roads across the forested region was 0.03 kilometer per square kilometer, but areas of ...
Forest degradation in the tropics is often associated with roads built for selective logging. The protection of Intact Forest Landscapes (IFL) that are not accessible by roads is high on the biodiversity conservation agenda, a challenge for logging concessions certified by the Forest Stewardship Council (FSC). A frequently advocated conservation objective is to maximise the retention of “roadle...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید