Document Type : علمی - پژوهشی
Authors
1
Associate Prof. of Geography and Climatology, Faculty of Earth Sciences, Shahid Beheshti University, Tehran
2
Prof. of Remote Sensing and GIS, Faculty of Earth Sciences, Shahid Beheshti University, Tehran
3
Professor of Physical Geography, Faculty of Human Sciences, Department of Geography, University of Zanjan
4
Assistant Prof. of Climatology, Faculty of Sciences, Dep. of Environmental Sciences, University of Zanjan
Abstract
Water vapor as one of the most important climate elements, plays an important role in decision-making, design and evaluation in hydrological models. Therefore, understanding the spatial changes of this important climate element have a significant effect on water management and planning. Accordingly, this study is tried to studythe spatial structureand estimation of watervapor pressurein south and south west of Iran, using by geostatisticsmethodand variography analysis. In this regard, the water vapor pressure data of 78 synoptic stations on 18 August 2007 as one of the sweeping days by the water vapor pressure was analyzed. The first step for this purpose was calculation of the spatial variable of water vapor pressure that were analyzed by plotting the variogram. After fulfilling this requirement, geostatistical methods such as simple kriging, ordinary kriging, Co-kriging with auxiliary variables, and circular, spherical, exponential, Gaussian and quadratic rational models were used and their performance were evaluated. The results of cross validation showed that the best method that being able to justify the amount of water vapor pressure is Co-kriging method with altitude. According to the drawn map with the optimum method it was found that near the Persian Gulf and Oman Sea and the North and North West of study area are the highest and lowest amounts of water vapor pressure, respectively. It was determined that three reasons 1. Far and near to the main sources of humidity, 2. Zagros Mountains and 3. The establishment of strong pressure has an important role in water vapor pressure distribution.
Keywords