physical geography
sayyad asghari saraskanroud; mehdi Faal Naziri
Abstract
in this study, the effects of land use changes with surface temperature of karaj cityand spatial autocorrelation have been discussed using the moran index. for this purpose, landsat OLI- TM satellite imagery has been used in 2000 and 2018. first, the images were taken and the required images were applied. ...
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in this study, the effects of land use changes with surface temperature of karaj cityand spatial autocorrelation have been discussed using the moran index. for this purpose, landsat OLI- TM satellite imagery has been used in 2000 and 2018. first, the images were taken and the required images were applied. then classification using object orinted method and nearest neighbor algorithm was developed and the earth surface temperature was extracted with split window algorithm (imagery). The results showed that the arid land has the highest temperature in 2000 and 2018, respectively, due to the lack of vegetation, the high capacity of absorption of heat by barren soil, and the use of blue zones in 2000 and 2018 respectively, has a temperature of 38 - 25 (° C), which is دفع and has lower heat temperatures. also, the results showed strong relationship between land use and temperature. finally, the hot and cold clusters of karaj city heat islands were extracted using the hot spots analysis index (hotspot). Space autocorrelation analysis with global Moran's indices showed that the Earth's surface temperature was cluster - like. the analysis of hot spots confirmed the focus and cluster of the heat islands of karaj city in space with increasing periods of time.Keywords
Climatology
vahid safarian zengir; Broumand Salahi; Roghayeh Maleki Meresht; MohammadKia Kianian
Abstract
The aim of this study was to analyze rainfall drought indices to predict and reduce their negative effects in Ardebil province, which involved a descriptive-analytical study in terms of research type. Data were collected using documentary method. Accordingly, the information of mean rainfall and mean ...
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The aim of this study was to analyze rainfall drought indices to predict and reduce their negative effects in Ardebil province, which involved a descriptive-analytical study in terms of research type. Data were collected using documentary method. Accordingly, the information of mean rainfall and mean temperature on a monthly basis in synoptic stations of Ardebil, Germi, Parsabad, Meshkinshahr and Khalkhal were received from the Meteorological Organization in Ardebil province for the period (1996-1996). Dip and Dic software were used to analyze the SPI and CZI indices data in each of the 5 synoptic stations of the province. Drought zoning was then performed in two scales of 6 and 12 months, from IDW interpolation, in ArcGIS software. The innovation of the present study was the use of if-then rules in MATLAB software in combining drought indicators in the field of climatology. The results showed that very severe droughts at the 12-month scale were less than at the 6-month scale, and in all 5 stations studied, the number of moderate droughts was more than severe and very severe ones. Also, the highest frequency of drought was observed in Ardebil city and the lowest in Germi station. Similarly, a comparison of the two indicators displayed that their performance did not differ much; but it turned out that the SPI index, could reveal the number of droughts better than the CZI index.
