BIOME-BGC is a general ecosystem model designed to simulate hydrologic and biogeochemical processes across multiple scales. The objectives of this investigation were to compare BIOME-BGC estimates of hydrologic processes with observed data for different boreal forest stands and investigate factors that control simulated water fluxes. Model results explained 62 and 98% of the respective variance...

for determination of irrigated sugar beet crop evaporation (etc) and water consumption a field experiment was conducted for three years (1991 to 1993)  in kabotar-abad agricultural experiment station. the climate was semi-arid according to gossen method with mean annual precipitation of 90 to 110 mm. the soil was esfahan series with a silty clay loam texture. the crop evapotranspiration was mea...

Evapotranspiration (ET) is the movement and transfer (i.e., flux) of water as a liquid at the Earth’s surface to the atmosphere as a gas. ET is a combination of open water evaporation and plant transpiration ( , which is the Sublimation transition of solid water (i.e., ice, snow) to vapor due to low atmospheric pressure (i.e., high altitude), dry air and high sunlight, is generally considered s...

Available energy (often expressed in terms of potential evaporation) and precipitation largely determine annual evapotranspiration and runoff rates in a region. The ratio of annual potential evaporation to precipitation, referred to as the aridity index by Budyko, has been shown to describe the evaporation ratio (the ratio of annual evapotranspiration to precipitation) of catchments from a rang...

food security in the world that water shortages are faced is very important, especially in arid regions. effects of climate change on agricultural water requirement have doubled this importance. in this study, the risk of water demand has been assessed for a wide range of products under climate change. aogcm models have been used to simulate climate variables. the climate change scenarios of cl...