Saeed Jahanbakhsh; Majid Rezaee Banafshe; Marziyeh Esmaeelpour; Masoomeh Tadayoni
Volume 16, Issue 40 , September 2012, , Pages 25-46
Abstract
Accurate estimating of potential evapotranspiration is essential for many studies related to agriculture and water balance. This study was carried out with the aim of surveying models for estimating potential evapotranspiration in the southern basin of Aras river. For this purpose, the monthly data of ...
Read More
Accurate estimating of potential evapotranspiration is essential for many studies related to agriculture and water balance. This study was carried out with the aim of surveying models for estimating potential evapotranspiration in the southern basin of Aras river. For this purpose, the monthly data of 6 stations including mean air temperature, minimum and maximum temperature, wind speed, sunshine hours, mean and minimum relative humidity were used in the statistical period of 20 years (1986-2005).
After reconstruction missing values and controlling stations for being reference (well irrigated) or non reference, potential evapotranspiration values were computed applying 9 methods (FAO- Penman- Monteith, Blanney-Criddle, Hargreaves-Samani, Makkink, Turc, ASCE standardized method, Kimberly- Penman, Penman and Priestly-Taylor) in REF-ET software. For determining best method, calculated potential evapotranspiration values were compared with evaporation pan values by using correlation coefficient and root mean square difference. Results indicated that there was significant correlation between Blanney-Criddle and pan evaporation values. Therefore, Blanney-Criddle model was selected as the best model for the study area. Afterwards, based on the above mentioned model and also the use of interpolation technique, the potential iso-evapotranspiration map was drawn for the southern basin of the ArasRiver.
Saeed Jahanbakhsh; Majid Zahedi; Khalil Valizadeh Kamran
Volume 16, Issue 38 , February 2012, , Pages 19-42
Abstract
In a wide variety of scientific climatology studies earth surface temperature, is important, Astronomy, meteorology hydrology, ecology, geology, medical science, design and optimization of transportation network and site selection of fire extinction and particularly cases required. In the calculation ...
Read More
In a wide variety of scientific climatology studies earth surface temperature, is important, Astronomy, meteorology hydrology, ecology, geology, medical science, design and optimization of transportation network and site selection of fire extinction and particularly cases required. In the calculation of the actual evapotranspiration also we consider these.. Considering the earth's surface temperature monitoring in a limited number of meteorological stations to the distribution point and the need to place the surface temperature in a wide area and at the same time the surface temperature were estimated. To access the earth's surface temperature and classification SEBAL algorithm and decision tree were used. Using ETM + image dated 31 August 2000 and pre- process, files became ready for implementation. For processing of SEBAL method. the above mentioned software Envi4.5 and ArcGIS9.3 were used. This paper estimates the difference less than 5.57° C, temperature difference between a satisfactory level was estimated through remote sensing and statistics. Temperature measured from ground level 12 years (1993 - 2005) in Maragheh meteorological station was achieved. Temperature was estimated through remote sensing and studies applicable in earth sciences research and the environment.
