Quantification of vegetation-site relationships is often required in biogeographic research. Methods linking species to particular sites typically assess evaporative demand and soil moisture availability at the site, though methods differ in how these factors are assessed. This study compares three approaches—a water-budget approach, and field-based and map-based moisture scalars—in their abili...

abstract evapotranspiration (et) determination is a key factor for irrigation scheduling, water balance, irrigation system design and management and crop yields simulation. therefore many scientists have tried to estimate evapotranspiration in different spatial and temporal scales. remote sensing is a one of new technique in estimation of et in regional scales. so, in this study it’s tried to e...

ABSTRACT- Overgrazing accelerates soil and vegetation degradation in rangelands. This study aimed to assess livestock pressure on natural resources of Khuzestan province, located in the south western part of Iran, using Geographic Information System (GIS) tools and a model-based procedure. FAO/UNEP Model which uses a ratio of potential carrying capacity of region to current liv...

in this study, we applied classification methods and geographic information system(gis) techniques to identify vegetation structures in andevar rangelands. homogenous work unit maps were produced by overlaying the layers of slope, aspect and digital elevation. totally 95 homogenous units were determined in which the field studies were carried out. vegetation sampling was done in 69 transects an...

We developed a new world natural vegetation map at 1 degree horizontal resolution for use in global climate models. We used the Dorman and Sellers vegetation classification with inclusion of a new biome: tropical seasonal forest, which refers to both deciduous and semi-deciduous tropical forests. SSiB biogeophysical parameters values for this new biome type are presented. Under this new vegetat...