نتایج جستجو برای: vegetation index
تعداد نتایج: 435690 فیلتر نتایج به سال:
This paper analyses monthly differences in drought impact on vegetation activity in a semi-arid region in the north-east of the Iberian Peninsula between 1987 and 2000. The study determines spatial differences in the effects of drought on the natural vegetation and agricultural crops by means of the joint use of vegetation indexes derived from AVHRR images, a drought index (standardized precipi...
Many algorithms have been developed for the remote estimation of vegetation fraction in terms of combinations of spectral bands, derivatives of reflectance spectra, neural networks, inversion of radiative transfer models, and several multi-spectral statistical approaches. The most widespread type of algorithm used is the mathematical combination of visible and near-infrared reflectance, in the ...
Drought Assessment using Standardized Precipitation Index and Normalized Difference Vegetation Index
Urban vegetation growth is vital for developing sustainable and liveable cities in the contemporary era since it directly helps people’s health well-being. Estimating cover biomass commonly done by calculating various indices automated urban management monitoring. However, most of these fail to capture robust estimation due their inherent focus on colour attributes with limited viewpoint ignore...
Spectral vegetation indices obtained from satellite sensors have been used to measure and monitor the Earth’s vegetative cover from local, regional, to global scales. The normalized difference vegetation index (NDVI) has been the most widely-used index and shown to correlate with green leaf area index, green biomass, and net primary productivity. The NDVI from the two sensors, National Oceanic ...
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...
In most habitats, vegetation provides the main structure of the environment. This complexity can facilitate biodiversity and ecosystem services. Therefore, measures of vegetation structure can serve as indicators in ecosystem management. However, many structural measures are laborious and require expert knowledge. Here, we used consistent and convenient measures to assess vegetation structure o...
extended abstract introduction the most important indicator of climate in a region is vegetation community. climate can be different over large areas, because of changes in vegetation community. vegetation influences weather and climate in its surrounding areas mostly by way of evapotranspiration and albedo so they play a role in the earth’s energy balance. these effects on the earth’s energy...
Background: Monitoring terrestrial vegetation cover condition is important to evaluate its current condition and to identify potential vulnerabilities. Due to simplicity and low cost, point intercept method has been widely used in evaluating grassland surface and quantifying cover conditions. Field-based digital photography method is gaining popularity for the purpose of cover estimate, as it c...
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