the destructions caused by many recent earthquakes shows that the subsurface structure directly affects the ground motions. especially in areas with possible seismic hazard expectation, expansion of cities has come up with detailed vulnerability analysis. therefore, site response investigation is a key step in every microzonation study. one of the best approaches for understanding the geologica...

introduction the average annual precipitation in iran is about 250 mm that is not regularly distributed spatially and temporally. more than 70 percent of total precipitation is not accessible due to evapotranspiration. total renewable water resources of the country are estimated to be around 130 billion cubic meters. in spite of limitation in water resources, they are not used properly. agricul...

introduction: market power is an important factor affecting welfare. existence of market power on the purchase side reduces supplier welfare. however, existence of market power on the sales side reduces supplier welfare. some believe that the agricultural market structure is a monopoly. in fact, most of the agricultural products can be purchased by small firms and then delivered to consumers be...

1. introduction thunderstorms or lightning storms are kinds of storms that generally are associated with the convective clouds and usually are resulted in hailing, strong winds, and flash floods. clouds of convective storms are observed in most regions, but a small percentage of the convective storms can produce severe weather conditions and flash floods that cause damages. a flash flood is a d...

introduction geographically risk of an area determines the nature of disasters, their magnitude and spatial distribution. geographically risk is been controlled by several environmental variables such as geographical situation, climatic characteristics, topography, landform processes, land changing and human impacts. in many countries environmental crises generally is under influences of inabil...