نتایج جستجو برای: vegetation cover percentage
تعداد نتایج: 280240 فیلتر نتایج به سال:
the study of the exclosure effects on the vegetation changes undergrazing and non-grazing conditions in the rangeland areas has particularimportance in the rangeland improvement and revivification projects. theresearch was accomplished in semi-steppe khoybilehvar area, from 1999 to2005. vegetation cover was annually measured within fixed plots during transact.the results showed that during nine...
In this study, different indices of vegetation cover variations and different physicochemical properties of soil in three treatments of flood spreading, enclosure and grazing (control) were investigated and compared in in the region of Peshert in Mazandaran province. In order to measure different soil characteristics, 18 soil samples (six withdrawals at any treatment) from a depth of zero to 30...
Introduction: One of the ways of restoration and reclamation of damaged rangeland is to use different methods of rain harvesting such as pitting, counter furrowing, flood spreading, small arc basins system and etc., along with the reduction of runoff, it increases the soil moisture content and thus increases vegetation cover. Biodiversity is most commonly used to describe the number of species....
Seasonal changes over 2 years (2004–2006) in soil moisture content ( v) of frozen alpine frost meadow soils of the QinghaiTibet plateau permafrost region under three different levels of vegetation cover were investigated. Vegetation cover and air temperature changes had significant effects (synergistic effect) on v and its distribution in the soil profile. During periods of soil freezing or tha...
To investigate land use changes, Qale Shahrokh basin (15098.1 ha area) was selected. Satellite images of Landsat sensors (MSS, TM and ETM+) were used. After improvement and different enhancement analysis of images such as FCC, PCA, the study area was checked using GPS and topographic maps (1:50000) and other information. Land use units were determined using classified random sampling method. Ma...
As an alternative to the traditional approach of using prede ned classi cation schemes with discrete numbers of cover types to describe the geographic distribution of vegetation over the Earth’s land surface, we apply a linear mixture model to derive global continuous elds of percentage woody vegetation, herbaceous vegetation and bare ground from 8 km Advanced Very High Resolution Radiomete...
rangelands encompass 55% of iran's territory. monitoring of such resources is inevitable due to dynamic behavior and extremely high extension. scanning of land resources data by satellites facilitates monitoring the rangelands. this research was carried out to study the relationships of vegetation indices derived from irs liss-iii data with vegetation cover of tange sayyad region in the ch...
The rangeland in the Khangai mountain region in Mongolia has degraded for the last decades mainly because of overgrazing and climate change. Livestock production is important part of the economy and is based on natural rangeland. In this research we seek to elucidate the influence of five years (2004-2009) of protection from grazing on vegetation cover of different degradation levels of Fes...
To investigate land use changes, Qale Shahrokh basin (15098.1 ha area) was selected. Satellite images of Landsat sensors (MSS, TM and ETM+) were used. After improvement and different enhancement analysis of images such as FCC, PCA, the study area was checked using GPS and topographic maps (1:50000) and other information. Land use units were determined using classified random sampling method. Ma...
Using accurate and low-cost methods to monitor quantitative changes in vegetation cover play an important role in the efficient and sustainable management when the area is too large. In this study, the changes of vegetation cover were investigated using satellite data of TM (Landsat_5) and oli (Landsat_8) sensors for a 30-year period (1988-2018) in Chaharbagh rangeland of Golestan province. T...
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