Mohammadsaleh Ekhlasi, Dr. Somayeh Soltani-Gerdefaramarzi, Dr. Abolfazl Azizian, Morteza Gheysouri,
Volume 0, Issue 0 (3-1921)
Abstract
In this research, the effect of climate change on the amount of virtual water of some strategic crops was investigated in Kerman province for future periods. For this purpose, the climatic data of HadCM3 model was used under RCP4.5 radiative forcing scenario. In order to investigate the possibility of producing and simulating meteorological data in the future periods, was applied the LARS-WG microscale-representative model. For the basic period (1991-2011), was done calibration and validation of the model. Through the data of LARS-WG, the amount of precipitation and the maximum and minimum temperature of the selected stations were predicted for the periods of 2011-2070 and compared with the base period. Virtual water amount was calculated for selected crops including alfalfa, barley and wheat. The results of the current research indicate that the phenomenon of climate change significantly affects the evapotranspiration and the performance of the studied crops, and hence it will affect the agricultural water productivity in the future. While the average temperature of the growing season will increase in the future under the influence of climate change, the maximum temperature parameter will be affected by this phenomenon more than the minimum temperature, and parallel to this, the water requirement and plant evaporation-transpiration will increase in this period. Also, the surveys show a decrease in precipitation in the hot seasons and an increase in the cold seasons in all study stations. The amount of virtual water changes obtained for all studied plants is increasing, and this increase for barley and wheat crops shows a greater increase on average in the future period. The biggest increase in the virtual water compared to the base period in Kerman station is related to barley and alfalfa products by at least 30%.
Msc. Graduated Student Najmeh Daneshvar-Marvast, Dr Somayeh Soltani-Gerdefaramarzi, Dr Samaneh Poormohammadi,
Volume 19, Issue 55 (12-2019)
Abstract
The phenomenon of evapotranspiration causes water and moisture losses from water, soil and vegetation levels. Due to the small amount of atmospheric precipitation and water resource constraints in Iran, it is important to calculate it through a suitable method. The present research attempts to evaluate the evapotranspiration reference crop (ETo) and present it in the form of zoning map as a basic tool for water management. In this study, the long-term average of seven meteorological stations and evaporation pan data were used to determine the appropriate ETo estimation method. Evapotranspiration of reference crop was calculated to 14 methods the based on climatic information in each station. Computational methods including combinational methods Penman-based, radiation-temperature method, temperature method and radiation method. The most appropriate computational method was selected based on the R2 and Nash -Sutcliffe statistics. The zoning of evapotranspiration of reference crop was carried out based on the geographic information of the meteorological stations and the GIS software. The results of the research indicate that the best method for this region as the cold and moderate climate are FAO radiation and Blaney-Criddle. Also, the zoning result shows that west of the catchment has less evapotranspiration rather than its east. Sunshine hours, maximum temperature and wind speed were the most effective factors for evapotranspiration in this area by sensitivity analysis.
