مقالات رزومه دکتر مجتبی رحیمی

Today, climate change and its anomalies, one of the important issues raised in the world. Detection of changes on temperature and precipitation as the most important climatic elements, is used as primary evidence of climate change in many parts of the world. This paper investigates the temperature trend of Iran of annual, monthly and seasonal scales. For this purpose minimum, average and maximum temperature data of 38 synoptic stations, over the period of 50 years (1960-2010) with good distribution, were obtained from Iran meteorological organization.  Then the temperature trend parameters were investigated (studied) by Mann Kendall nonparametric test. The results showed that the general temperature trend is increased in most of the stations for different time scales; however this intensity of increase decreases from the minimum to maximum temperature. On monthly, in June and July, and on seasonal, in summer, the increase of temperatures are higher than other time. Although the most frequency positive trend of the maximum and average temperature observed in the winter, but for a few of the stations was significant. While in warm seasons especially in the summer, the frequency of station with positive significantly trend is higher. In terms of spatial, the stations that located in the Alborz Mountains, South West and South East of IRAN have experienced higher temperatures than other areas of the country and in some station such as SHAREKORD, URIMA, KHORRAMABABD AND BANDAR ABASS trend of temperature in different scale is mostly decreasing.

The goal of this study is to determine the temperature on time scales of years, seasons, months, and its relation to the rate of evapotranspiration and crop water requirement of cotton in Sabzevar city. The minimum climatic data of temperature, the mean average and maximum temperature, wind, solar radiation, relative humidity and rainfall from the archives of meteorological synoptic stations Sabzevar 56-year period (2010-1956), was received. In order to investigate the thermal parameters of the test I was Man Kendall and Sen Stimstor. For estimating evapotranspiration and water requirement of the crop watts were used. The results showed that the rate of increase of temperature trends in Sabzevar city is strong and it’s maximum to minimum temperature, because in all three scale annual, seasonal and monthly maximum increase in this parameter is observed. Behavior similar to the behavior of the minimum average mean temperature. Seasonal temperature trends follow the trend of the increasing trend in annual minimum temperature is remarkable. Evaluation of evapotranspiration rates for the study period may indicate a trend in this parameter. Maximum amount on monthly evapotranspiration due to the occurrence of maximum temperature in July and August and the lowest was in January. Cotton crop irrigation requirements estimated using a model W for each year showed that over the period studied, the average irrigation requirement is 1371.83 mm. Meaningful verification process to increase the water requirement by 95% for the tests I Man Kendall and age of the plant, respectively. Maximum water requirement was estimated at flowering and boll development. In general we can say at this station increasing the temperature increases the rate of evaporation and transpiration. The cotton crop irrigation requirements are calculated based on the estimated evapotranspiration during the study period in the time scale, long-term and short-term increased.