based on spi and rdi indices, changes in droughts in the semi-arid areas of west golestan province was assessed in the gis environment by incorporating data from hashemabad synoptic station and 11 climatic stations. after evaluating the ability of lars-wg5 in the simulation period (1984-2010), downscaling of hadcm3, ipcm, and gfc models was done as a group under scenarios of a1b, a2 and b1 to e...

abstract use of empirical competition models is one of approaches in integrated weed management strategies. in order to investigation of this approach in simulation of yield loss of bean (phaseolus vulgari. l.) caused by jimson weed (datura stramonium l.) interference, an experiment was conducted in national bean research station, in khomein, in 2007. the experiment design was randomized comple...

the present research focuses on the changes of urmia lake level. for this purpose, two timescales have been considered. the trend changes of temperature, precipitation rate and quantitative values of climate type for the observational period from 1968 to 2011 (past scale) and from 2011 to 2100 (future scale) have been analyzed. general circulation model (gcm) is considered for simulating the va...

the present research focuses on the changes of urmia lake level. for this purpose, two timescales have been considered. the trend changes of temperature, precipitation rate and quantitative values of climate type for the observational period from 1968 to 2011 (past scale) and from 2011 to 2100 (future scale) have been analyzed. general circulation model (gcm) is considered for simulating the va...

the yield loss simulation (yls) and the macros liq.csm models were used to simulate the effect of stem borer damage at a detillering rate of 5, 15, 30, 60% at vegetative, panicle initiation and grain filing stages, on yield of rice cultivar?s ratna. this stem borer damage during vegetative and panicle initiation stages was not simulated appropriately by both the models. relatively macros simula...

application of agent based model in simulation of stakeholder’s behavior is slightly a new method for modeling of complicated systems that include autonomous agents interacting with each other. recent numerical achievements have made the applications of agent based models possible in various fields. these applications range from modeling of human progress and destruction of past civilizations t...

nowadays protecting land cover, quality and quantity of water resources are important. surface runoff is one of most important reasons of soil erosion which causes sediment in reservoirs and reduction of land’s fertility and also quality reduction water of rivers. so the main issue is exact prediction of basin runoff to raining events. the hydrologic models are simplified models of real hydrolo...