In uncon®ned aquifers ¯owing under topographic gradients, the water table is a subdued replica of the ground surface above. This principle is the basis for using detailed collateral or secondary information from digital elevation models to supplement sparse observations from water wells in the mapping of phreatic surfaces. Data from DEM-derived secondary variables are incorporated into the esti...

this study was carried out in sorkhdeh rangeland in semnan province in order to determine the ecological species groups and their relationships with environmental factors as a tool for better management. vegetation sampling was performed in 230 plots under equal random classification method and soil samples were taken in 0-15 depth. climatic and topographic data were extracted by overlaying sam...

The objective of this analysis was to identify topographic and bioclimatic factors that predict occurrence of forest and grassland patches within tropical montane forest-grassland mosaics. We further investigated whether interactions between topography and bioclimate are important in determining vegetation pattern, and assessed the role of spatial scale in determining the relative importance of...

This research conducted to evaluate spatial pattern of some biological variables (mean diameter, density, richness index and biodiversity index) of forest by linear regression models using terrain analysis in the Kheiroud-Kenar forest located at the Nowshahr, north of Iran. To obtain these parameters, sampling was performed on a systematic grid (250× 400 m) in 193 plots with one ha area. Densit...

The influence of topographic and temporal variables on cetacean distribution at a fine-scale is still poorly understood. To study the spatial and temporal distribution of harbour porpoise Phocoena phocoena and the poorly known Risso's dolphin Grampus griseus we carried out land-based observations from Bardsey Island (Wales, UK) in summer (2001-2007). Using Kernel analysis and Generalized Additi...