the objective of this study is evaluation of topographic wetness index (twi) using attraction model in northern of fars province. the first attraction model was used to enhance the spatial resolution of digital elevation model (dem). in this research to estimate of value of sub-pixels neighboring pixels, touching and quadrant neighboring models were used. after manufacturing output images for s...

We present a scale-space with separate scales in the greyscale and spatial dimensions, using ideas from mathematical morphology. Dynamics are used for greyscale (luminance) filtering and openings or closings with scaled disks for spatial scaling. Dynamics cater naturally for the inclusion relationships between regions and give a very good measure of the salience (scale) of a region in greyscale...

scale analyses are essential for revealing how the infl uence of specifi c ecological factors changes with scale (Wiens 1989). In this study, we present a novel methodology that can be broadly-applied to assess the scale-dependency of species ’ distributions. Distribution changes – such as those that occur in response to species introductions or climate change – provide ecological experiments t...

Many numerical models for weather prediction and climate studies are run at resolutions that are too coarse to resolve convection explicitly, but too fine to justify the local equilibrium assumed by conventional convective parametrizations. The Plant–Craig (PC) stochastic convective parametrization scheme, developed in this paper, solves this problem by removing the assumption that a given grid...

Inference mechanisms about spatial relations constitute an important aspect of spatial reasoning as they allow users to derive unknown spatial information from a set of known spatial relations. When formalized in the form of algebras, spatial-relation inferences represent a mathematically sound definition of the behavior of spatial relations, which can be used to specify constraints in spatial ...

Maps of fire frequency, severity, size, and pattern are useful for strategically planning fire and natural resource management, assessing risk and ecological conditions, illustrating change in disturbance regimes through time, identifying knowledge gaps, and learning how climate, topography, vegetation, and land use influence fire regimes. We review and compare alternative data sources and appr...

Emergent vegetation covering floodplains and wetlands has an important role in fluvial ecosystems. Since natural systems are not homogeneous, the flow within the stem array is influenced by several space scales, determined by the number-density of stems and its spatial modulation. The aim of this study is to characterize experimentally the spatial variation of the flow at the smallest spatial s...

urban large-scale projects have always been a controversial topic of debates. these projects are time- and money-consuming and the rejection or approve of their functionality is based on political intentions. in the last hundred years, each of them costed billions of dollars from private or public budgeting, used technical and human resources. these risky-complex creatures are built to fulfill ...