Several studies have shown a close relationship between vegetation fertility and different vegetation indices extracted from satellite data. The vegetation fertility in Arctic is at overall scales highly related to temperature. At lower scales surface material, snow cover, hydrology and anthropogenic effects (geese, reindeer) are determinant in constituting the different vegetation communities....

هدف: کارآفرینی یکی از عوامل کلیدی در توسعه اقتصادی و شاخص اساسی جوامع روبه‌رشد است. آنچه که کارآفرین را به آغاز فعالیت ترغیب می‌کند، انگیزه فرایند تبدیل یک فرد عادی است می‌تواند فرصت‌هایی ایجاد کند حداکثر رساندن ثروت کمک کند. هدف این پژوهش شناسایی طبقه‌بندی انگیزه‌های کارآفرینان می­باشد.طراحی/ روش‌شناسی/ رویکرد: با رویکرد مرور نظام­مند استفاده ماتریس شش سلولی دو مؤلفه جهت (کشش یا فشار) منبع (اق...

We analysed the Normalized Difference Vegetation Index (NDVI), calculated from biweekly NOAA Advanced Very High Resolution Radiometer (AVHRR) images for northern Alaska at both regional (latitudinal gradients) and site scales. Our objectives were to determine if tundra types and arctic subzones could be differentiated in terms of intra-seasonal patterns of greenness, and to construct the relati...

Fire scars in Kalimantan, Indonesia were mapped using optical and thermal data from the NOAA-AVHRR satellite sensor. Forty-four high-resolution picture transmission images mapped at 1 km spatial resolution were selected for a period immediately after intense biomass burning from October–December 1997. Composite images of the Normalized DiŒerence Vegetation Index (NDVI), surface temperature (ST)...

Information about forage productivity and its interactions with cultural practices or climatic variation is necessary to plan livestock management and to increase production without damaging the environment. Remote sensing provides a valuable data source to achieve these goals. Here we characterize forage production over a large region (92 million hectares) by analyzing spatial, seasonal, and i...

The Normalized Difference Vegetation Index (NDVI) is widely used for Leaf Area Index (LAI) estimation. It is well documented that the NDVI is extremely subject to the saturation problem when LAI reaches a high value. A new multi-angular vegetation index, the Hotspot-darkspot Difference Vegetation Index (HDVI) is proposed to estimate the high density LAI. The HDVI, defined as the difference betw...

This study aimed to evaluate the response of the Normalized Difference Vegetation Index NDVI derived from Terra MODIS sensor to soybean phenology, in a grain producer region of Parana State, Brazil. Landsat TM and ETM+ images were selected to analyze the spatial distribution of soybean fields for this region from 2000/01 to 2006/07 crop seasons. Then pure pixel samples (250 x 250m) that contain...

We analyzed geographic patterns of richness in both the breeding and winter season in relation to a remotely sensed index of seasonal production (normalized difference vegetation index [NDVI]) and to measures of habitat heterogeneity at four different spatial resolutions. The relationship between avian richness and NDVI was consistent between seasons, suggesting that the way in which available ...