Of the many climatic events that influence the Earth’s environment, drought is perhaps the one that is most linked with desertification. Drought is the consequence of a natural reduction in the amount of precipitation received over an extended period, usually a season or more in length. Drought monitoring is an essential component of drought risk management. It is normally performed using vario...

Gastropod assemblages were investigated along intertidal rocky shore in the Qeshm Island in the northern Persian Gulf. Monthly sampling was undertaken from May 2007 to April 2008. Environmental factors were also measured in each site. A total of 28 gastropod taxa belonging to 15 families were identified and Cerithiidae was the most abundant family and Cerithium caeruleum was the most abundant...

The spatial model of Levene (1953) was examined in a finite population and compared to a temporal model. The spatial model was much more effective in retaining genetic variation in a finite population. Furthermore, the haploid spatial model was more effective in retaining genetic variation than the analogous diploid absolute dominance model. This is the opposite from that found for the temporal...

Understanding population dynamics requires spatio-temporal variation in demography to be measured across appropriate spatial and temporal scales. However, the most appropriate spatial scale(s) may not be obvious, few datasets cover sufficient time periods, and key demographic rates are often incompletely measured. Consequently, it is often assumed that demography will be spatially homogeneous w...

precipitation regime refers to distribution of seasonal- monthly precipitation. by studying this character, it could be find out about the most important parts of mechanism(s) dominant in temporal distribution of precipitation. precipitation regime can have positive or negative effects on other environmental components performance. in the present research, the monthly data in 73 stations during...

there is a need to analyze and map rainfall erosivity to assess soil erosion at the regional scale. the objectives of this study were to develop a regional model to estimate seasonal erosivity from seasonal rainfall data and to study temporal and spatial distribution of rainfall erosivity for the gorganrood drainage basin in the northeast of iran. six gauging stations with a high temporal reso...

Abstract Spatiotemporal variation in fish assemblage structure was conducted from January to December 2015 in order to know the impacts of sanctuary on ichthyo-faunal diversity with its indices and major hydrological factors from six sampling stations of Karatoya fish sanctuary sectioned in the river Karatoya. A total of 69 fish species was obtained from this sanctuary including 21 threatened ...