نتایج جستجو برای: vegetation cover
تعداد نتایج: 148562 فیلتر نتایج به سال:
Assessment process of vegetation cover by remote-sensing images should be based on understanding of the vegetation indices. Vegetation indices are widely used for assessing and monitoring ecological variables such as vegetation cover, above-ground biomass and leaf area index. The aim of the present research was to study of the ASTER data capabilities to estimate the vegetation cover percentage ...
abstract. the purpose of this study was to investigate vegetation dynamics and range conditions considering the climatic conditions and soil properties in haftooman, khoor and biabanak deserts, iran. for this purpose, after determining vegetation types and the associated species, the type of rangeland utilization, grazing season, the livestock type, the other relevant information, vegetation da...
because soil moisture condition affects vegetation changes hence, monitoring of drought and vegetation changes are among valuable management tools in these ecosystems. nowadays, satellite images are used as a low-cost and fast method for vegetation study in different scales. vegetation change is assessed using vegetation spectral characteristics. this study aimed to analyze and monitor the vege...
SUMMARY Operational monitoring of vegetative cover by remote sensing currently involves the utilisation of vegetation indices. Vegetation indices are widely used for assessing and monitoring ecological variables such as vegetation cover, above-ground biomass and leaf area index. This study reviewed and evaluated different vegetation indices for estimating vegetation cover in rangelands in Cente...
Gully erosion is one of the most significant erosion types. This type of erosion is one of the most important sources of sediment in different regions of the world. Gullies often have different dimensions and complex characteristics and these characteristics may affect the distribution of vegetation. Topographic characteristics of gullies provide complex ecosystem for vegetation establishment. ...
Soil and water resources management of rivers has an important role because of direct relation withdifferent systems such as earth, life, social and people. Although the use of vegetation cover inbioengineering and biological stabilization and also soil and water resources management projects hasmany advantages, but improper methods of design and implementation cause hydraulic specificationsof ...
The objective of this study was to assess the relationship betweenvegetation, landform and physicochemical properties of soil. At the first terrainmap unit were provided using the landsat thematic mapper (TM) satellite images,aerial photograph, topographical and geology map. Field sampling was done in therepresentative area using plot sampling. 104 plots 100 m2 were sampled in eachplot landform...
the purpose of this research is investigation of relationship between vegetation cover and soil characteristics and determination of the most important soil factor that effects on quantity variations and kinds of vegetation cover in the study area. the study area is located in west of tehran province and south eastern of hashtgerd, next to najm-abad village. after field study, the index vegetat...
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...
Knowledge of rangeland vegetation characteristics as well as factors affecting it in environmental planning, land management and sustainable development is very important. However, regional and up-to-date maps of pasture vegetation cover are not always available. In this study, in order to plot the vegetation cover percentage of the rangelands and monitor its changes in drought and wet periods,...
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