Tayebeh Mesbahzadeh; Farshad Soleimani Sardoo; Ali Salajeghe; Gholamreza Zehtabian; Abbas Ranjbar; Mario Marcello Miglietta
Volume 27, Issue 4 , December 2020, , Pages 752-762
Abstract
The dust phenomenon is of particular importance because of its close association with public health. Many researchers are looking for ways to reduce the harmful effects of this phenomenon. To this end, having information about the nature of the spatial and temporal pattern of this phenomenon is of particular ...
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The dust phenomenon is of particular importance because of its close association with public health. Many researchers are looking for ways to reduce the harmful effects of this phenomenon. To this end, having information about the nature of the spatial and temporal pattern of this phenomenon is of particular importance to all researchers. Dust is one of the natural hazards of the central Iranian plateau. In this study, statistical analysis was performed on a yearly and monthly basis in the period 2006 to 2018 using codes 06 and 07 obtained from 50 synoptic stations located in the study area. Also the spatial pattern of dust days with horizontal views less than 1000 m, 1000 to 1500 m and 1500 to 3000 m in the study area was plotted. The results also showed that Tabas synoptic stations with 661 days, Arak with 528 days and Zahedan with 511 days with 1500 to 3000 m horizontal view were more important in the study period. Also, the results of seasonal survey of dust days in the statistical period showed that spring with more than 42% had the highest occurrence of dust. The results showed that in the horizontal view of less than 1000 m, Zahedan station with 113 days and Tabas station with 91 days of dust had higher frequency. Meanwhile, Zahedan and Shahreza stations with 91 and 55 days of dust with a horizontal view of 1000 to 1500 meters also had the highest frequency of dust days in the study area. Monthly statistical analysis revealed that most of the dust events were recorded in June and May. The results of spatial variation of dust days showed that there is no regular spatial pattern due to the extent of the area but in general in all three classes of horizontal view the focus of this phenomenon is most of the southeastern part of the study area.
Farshad Soleimani Sardoo; Ali Azareh
Volume 26, Issue 1 , June 2019, , Pages 131-142
Abstract
Over the past few decades, there have been many global efforts to combating and mitigating desertification, and one of the most important actions is the United Nations Convention on the combating desertification. The present study aimed to assess the severity of desertification and identify the most ...
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Over the past few decades, there have been many global efforts to combating and mitigating desertification, and one of the most important actions is the United Nations Convention on the combating desertification. The present study aimed to assess the severity of desertification and identify the most important factors affecting land degradation in the Jazmurian basin. In this study, the IMDPA model was used to assess the desertification severity. Due to the time and cost limitations, two criteria for water and climate were selected. At first, by determining the geometric mean of the indices and then the criteria, the total desertification was calculated and the quantitative value of the indices and criteria and the final desertification were divided into four classes: low, moderate, severe and very severe. Then, using GIS, the desertification intensity map of the area was drawn up in the study periods. The results showed that in the study area, the water criterion was dominant and classified with a weighted mean of 3.2 in the sever class. Subsequently, the climate criterion with a weighted mean of 2.4 was in the next rank. The results indicated that the most important desertification indices in the study area were groundwater drop, electric conductivity of water, precipitation, TRANSO Drought Index, Drought Continuity Index and SPI index.
Tayebeh mesbah Zadeh; Farshad Soleymani Sardoo
Volume 25, Issue 2 , August 2018, , Pages 366-377
Abstract
Changes in temporal and spatial patterns of droughts are always a pivotal element of water resource planning, and the necessary strategies for policy-making and integrated water resources management are considered based on this parameter. Drought is a phenomenon degrading the lands and sometimes causes ...
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Changes in temporal and spatial patterns of droughts are always a pivotal element of water resource planning, and the necessary strategies for policy-making and integrated water resources management are considered based on this parameter. Drought is a phenomenon degrading the lands and sometimes causes irreparable damages. In this research, SPI and GRI indices were used to study the spatial and temporal patterns of meteorological and hydrological droughts in Bam Plain. The results of this study showed that the most severe meteorological drought and the most severe wet occurred in 2002 and 2014 in the study area, respectively. Also, the most severe hydrological wet (SHW) and the most severe hydrological drought (SHD) are related to 2002 and 2014, respectively. Meanwhile, the hydrological drought temporal pattern occurs with a one-year delay as compared with meteorological drought in the study area. According to the results of the spatial pattern analysis, the moderate and normal drought classes covered most of the region. In addition, as moving from east to west, the severity of drought is increased and wet periods are mostly observed in the northeast of the region.