In this article, the sediment transport processes in the Khuran Strait between the mainland Iran and Qeshm Island at North Central Persian Gulf are studied in regional scale in a comprehensive manner. The objectives o...In this article, the sediment transport processes in the Khuran Strait between the mainland Iran and Qeshm Island at North Central Persian Gulf are studied in regional scale in a comprehensive manner. The objectives of this study include defining the type and origin of the sediment, the influencing factors, and the dominant mode of sediment transport. Four possible scenarios of sediment processes in terms of sediment sources and influential environmental forces are examined. The results of the conceptual and 2D numerical model of MIKE21 applied for this purposes indicate that the sediment sources in the transport processes are mainly provided by the sediments suspended from the central and eastern zones of the strait bed. Other sources including input from rivers do not have direct influence on the processes. The results are applied to the study of morphological changes for engineering applications including the pattern and amount of deposit in the Rajaee port approach channel and harbor basin. The pattern and amount of annual sediment deposits in the approach channel predicted by the model is satisfactory, compatible with annual dredging records.展开更多
Fire,especially wildfire,which can be considered as one of the main threats to vegetation cover and animals’life,has attracted lots of attention from environmental researchers.To better manage the fire crisis and tak...Fire,especially wildfire,which can be considered as one of the main threats to vegetation cover and animals’life,has attracted lots of attention from environmental researchers.To better manage the fire crisis and take the necessary measures to compensate for its damages,it is essential to have detailed information about the burn severity levels.Accordingly,satellite images and their spectral indices have been widely considered in the literature as powerful tools in producing burn severity information.Despite the efficiency of the previously proposed methods,the necessity of ground reference data for their thresholding step faces them with serious challenges.To address this problem,in this study,an automatic procedure based on the change-point analysis is presented for thresholding differenced normalized burn ratio(dNBR)and its another version,dNBR2.In this procedure,a mean-shift based change-point analysis is performed on the dNBR and dNBR2 images for classifying them into burn severity levels.Experiments,conducted on some parts of Alaska and California in the United States,illustrated the high efficiency of the proposed method.Moreover,as an applied experiment,the severity of the fires,occurred in 2020 in the Khaeiz protected area in Iran,was estimated and compared with local reports.展开更多
文摘In this article, the sediment transport processes in the Khuran Strait between the mainland Iran and Qeshm Island at North Central Persian Gulf are studied in regional scale in a comprehensive manner. The objectives of this study include defining the type and origin of the sediment, the influencing factors, and the dominant mode of sediment transport. Four possible scenarios of sediment processes in terms of sediment sources and influential environmental forces are examined. The results of the conceptual and 2D numerical model of MIKE21 applied for this purposes indicate that the sediment sources in the transport processes are mainly provided by the sediments suspended from the central and eastern zones of the strait bed. Other sources including input from rivers do not have direct influence on the processes. The results are applied to the study of morphological changes for engineering applications including the pattern and amount of deposit in the Rajaee port approach channel and harbor basin. The pattern and amount of annual sediment deposits in the approach channel predicted by the model is satisfactory, compatible with annual dredging records.
文摘Fire,especially wildfire,which can be considered as one of the main threats to vegetation cover and animals’life,has attracted lots of attention from environmental researchers.To better manage the fire crisis and take the necessary measures to compensate for its damages,it is essential to have detailed information about the burn severity levels.Accordingly,satellite images and their spectral indices have been widely considered in the literature as powerful tools in producing burn severity information.Despite the efficiency of the previously proposed methods,the necessity of ground reference data for their thresholding step faces them with serious challenges.To address this problem,in this study,an automatic procedure based on the change-point analysis is presented for thresholding differenced normalized burn ratio(dNBR)and its another version,dNBR2.In this procedure,a mean-shift based change-point analysis is performed on the dNBR and dNBR2 images for classifying them into burn severity levels.Experiments,conducted on some parts of Alaska and California in the United States,illustrated the high efficiency of the proposed method.Moreover,as an applied experiment,the severity of the fires,occurred in 2020 in the Khaeiz protected area in Iran,was estimated and compared with local reports.
