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This study is designed to analyze the trend and pattern of the urban growth in Karaj City applying the landscape ecology approach. Accordingly, monitoring changes in land use/ land cover (LULC), synoptic analysis is conducted. Change detection is conducted applying three TM satellite images taken in 1989, 2001 and 2013 and the post classification comparison method. For implementing synoptic analysis, some composition and configuration-based metrics including Number of Patches, Percentage of Landscape, Largest Patch Index, Landscape Shape Index, Patch Density, Edge Density, Contagion and Shannon’s Diversity were then calculated at two class and landscape levels and their changes were detected. The results indicated that man-made areas increased by 63.91 % and this degraded 2413 hectares of agriculture land and 658 hectares of green cover during the past 24 years. The results of the synoptic analysis indicated that the landscape has become more fragmented, more complex and irregular in shape, more disconnected in continuity of patches and less diversified in terms of land use/ land cover types at the end of the 1989- 2013 period. In addition, the results revealed that sprawl of the man-made areas has caused an increase in fragmentation, irregularity and complexity of agriculture patches and decrease in total area of agriculture class

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High temperature extremes are a serious threat to society, the environment and the economics of countries. High extreme temperatures are important features of weather events. Human and natural physical caused climate change can affect climate extremes, as well as maximum temperatures. Heat waves and super-hot days occurrence was increased in recent years due to global warming phenomena. Since south east of Iran is in subtropical location, it is exposed to this extreme climate frequently. In the present study, statistical analysis and identification of synoptic pattern of extreme high temperature in south east of Iran were investigated. In order to do this, firstly temperature data of nine synoptic stations in south east of Iran were collected, and then Normalized Temperature Deviation output data were calculated and by using these data, summer days were categorized into hot, sever hot and super-hot days. Increasing of hot days was concluded. Twenty seven super-hot days were chosen for synoptic analysis. Gang thermal low pressure on earth surface and 850 HPa level and subtropical high pressure on two levels including 700 HPa and 500 HPa cause super-hot days. Ward cluster analysis shows no variation in these patterns. Advection of temperature on hot days shows that maximum temperature was occurred in south east of Iran and not originated from abroad.

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Synoptic analysis of the structure of heat waves in Khuzestan province is the main purpose of the present study. Statistical and synoptic analysis and dynamic downscaling technique were used to identify the atmospheric circulation structure in the time of the emergence of a heat wave in the area. To this end, daily maximum temperature during the warm period (June to September) for 13 synoptic stations in the southwest of Iran with different statistical length were taken from the Iran Meteorological Organization. Based on the statistical analysis results, 1 July 2000 was identified as the hottest day in the selected hottest heat wave in the period of study, and therefore this day was selected for exact investigation and dynamic downscaling. The results of synoptic analysis showed that the intense subsidence heating that occurred in the selected day had two causes: At the surface of the earth, a low pressure situation with the origin in thermal low pressures of the Gange, Arabian Peninsula and Persian Gulf and West Asians independent subtropical high pressure at 500 hpa level; and warm air advection fluxes to the study area, both in low latitudes and Iran dry areas. The RegCM4 dynamic downscaling results indicated that at the earth surface, there is a strong low pressure on the Zagros and there exists a strong typical ridge at upper levels. This strong typical ridge caused dry adiabatic subsidence and created intense heating. This study revealed that the Zagros high Pressure (ridge) has obvious role in the emergence of heat waves and intensification in Khuzestan.