نشریه تحلیل فضایی مخاطرات محیطی
سال هفتم شماره 1 (بهار 1399)

Forest fire in recent years has paid great attention to climate change and ecosystems. Remote sensing is a quick and inexpensive way to detect and monitor forest fires on a large scale. The purpose of this study was to identify forest and rangeland fire hazards using NOAA / AVHRR in Kayamaki Wildlife Refuge. For the purpose of this study, the history of the fire-burns occurred in MODIS products. Then, the sensor images were prepared based on the date of fire burning. After preprocessing the images, Giglio and IGBP developed algorithms that detected fire. The results of fire detection detection algorithms were evaluated with MODIS products. The results showed that fire detection using the IGBP algorithm is better than the developed algorithms and Giglia. In this way, the IGBP algorithm with the detected fire number of 6 pixels from the 7-pixel fire detection detected by the MODIS product, the Giglio algorithm with the detected fire number is 5 pixels from the 7-pixel fire detection detected by The MODIS and extended algorithm detected the detected fire detected firefight number of 3 pixels from the 7 pixels of fire detection detected by MODIS products. Also IGBP algorithm with error rate of 14% and with fire detection number of 86%, Giglio algorithm with error rate of 28% and number of fire detected 72%, and developed algorithm with 57% error rate and detected fire number 43%.

Dust is influenced by the interaction of the atmosphere-Earth system and, by changing radiation energy, atmospheric chemistry and physics, affects the climate of an area. Due to the necessity of the role of dust and its spatial-dynamic distribution in the atmosphere of a region, as well as the existence of advanced remote sensing techniques and modeling in the field of dust simulation, the present study attempts to compare, quantize and simulate dust using aerosol optical depth (AOD) of MODIS and MACC products. Pearson correlation showed that there is a significant relationship between the sensor and the model in the west of the interested area. The lowest correlation was observed over Hamadan province. The results showed that simulated dust was more than satellite observations. The annual dust revealed that dust have two active (2000-2010) and inactive from 2010 onwards. In addition, monthly distributions of Dust in MODIS and MACC showed that the interested area had the highest dust concentration in the months of April to August; it was high overlaps of AOD between MACC and MODIS in the wet months (December to March) than dry month (April to November). In general, the spatial distribution of dust in the study showed that the dust pattern in both the sensors and the model has increased from south to north in Kurdistan, Kermanshah and Ilam, but the spatial variation of dust in the MODIS is more regular than the MACC. In general, the spatial distribution of dust had the South-North trend and northward decreased

Seasonal lakes or playas are considered as a major source of wind sediments and dust storms due to locating in post-topographic areas in dry and desert areas with strong winds system and also the presence of fine-grained and separated particles. Sediments and wind deposits in Sistan have caused the lives of thousands of people in these areas and especially the students to be at risk. The volume of wind sediments in this county has been multiplied in the last ten years; therefore the purpose of this research is to identify the effective factors on the volume difference of accumulated wind sediments in the schools of the villages of Nimroz County. The research method in this study is quite field and as direct observation, besides library resources has also been used. After the initial investigations, it was found that the geographical location, type of soil and topography have little effect on the volume difference of accumulated sediments in the studied schools. The findings of the study show that the three factors in Bash Delbar area, Hamoon Lake and lack of agriculture and the lack of vegetation in Deh Isa area are the most important factors in increasing or decreasing the volume of wind sediments.

 Considering that water resources are at risk from climate change, the study of temperature and precipitation changes in the coming years can lead to droughts such as droughts, sudden floods, high evaporation and environmental degradation. To this end, global climate models (GCMs) are designed to assess climate change. The outputs of these models have low spatial accuracy. In order to increase the spatial accuracy of this data, downscaling methods are used which are divided into statistical and dynamic methods. One of the reasons for using these models is their quick and easy operation compared to other methods. Our study area consists of Kurdistan, Kermanshah and Hamedan provinces in the west of the country. In this study, observational data of minimum temperature, maximum temperature, precipitation and radiation of 6 synoptic stations in the studied area in the statistical period of 1961 until 2005. In this study, the LARS-WG model was used for downscaling of HadCM3 global model data. The LARS-WG model is one of the most popular weather generator models that which to generation for maximum and minimum temperature, rainfall and radiation are used daily under current and future climate conditions. This model as a downscaled version of the same process less complex and simulated data input and output, high ability to predict climate change. The HadCM3 model is also a type of atmospheric- oceanic circulation model developed at the Hadley Center for Climate Prediction and Research, which has a 2.5 degree latitude network at 3.75 degrees longitude. Also, three climate change scenarios A1B, A2 and B1 have been used, each of which reflects the characteristics of the world's economic growth, the world's population and social awareness. The methodology is that the model receives the monitored data of the basic course; by examining them the statistical characteristics of the data are extracted. Then, in order to validate and ensure the model's capability for the basic statistical period, the model is implemented to re-establish a series of artificial data in the base period. Then the outputs to evaluate the performance of the model in the reconstruction of the data, the statistical characteristics of observations to test and compare various criteria. MAE, MSE, RMSE and R2 criteria were used to evaluate and analyze the performance of the downscaling model.

The population of Rudbar in northern Iran, is due to Steep slopes of topography, Sloping Loose Materials, active tectonic phases, Construction of roads and railways, from areas prone to landslide events .In this reaserch, in the first phase, based on ground surveys, a geologic map of 1: 25,000, satellite images and  other data of Rudbar region, range and status of landslides of the region were identified. Structural and weight factors (Slope loading) had the greatest impact on the occurrence of this incident, and the main motive for most of them is the structural factor. This important requirement of the determination of how tectonic activities are necessary to predict and control the phenomenon of landslide in the substructure of Developmental and environment in Rudbar region. therefore, in the second phase of the study, the geomorphic indicators of the mountain front sinuosity (Smf), ratio of valley floor width-valley height (Vf),  stream Length (SL), basin shape (Bs) and asymmetric factor (Af) were used. Then, the results of the indices, as an indicator of the relative tectonic activity (LAT), showed that most sub-basins have high and moderate tectonic activity.  In terms of  width, the high class with an area of 195.55 square kilometers (67.21%) covers total of the area. The spatial integration of the identified landslide zones in the first part of the research with the tectonic zones extracted in the second part shows the adaptation of this zone in the two class. Occurrences zone The landslides of the Fatalak, Lavie, Rudbar, Filde are located in zones with intense tectonic activity, and the landslides of Dashtegan, Talabar, Taklim, Nesfi, Dolatabad, Herzvil are located in moderate tectonic active zones. Detailed studies on engineering and geological in larger scales should be undertaken to prevent future landslides and more detailed reports for any developmental and environmental activities in the Rudbar region.

understanding the behavior of extreme events is one of the main aspects of climate change. In this research, we used network data from interpolation daily rainfall observation of 823 meteorology stations from January 1st up to December 31st, 2016 by using Kriging interpolation method and by separating 6×6 km spatial. The results formed matrix interpolation process by dimension of 18993×6410. This matrix has the rain status of 6410 points of west of Iran for every day rainfall(18993). Extreme rain falls are identified in terms of threshold of 95 percentile in each point and each day of year. for studying extreme rain fall portion in total yearly rainfall, the total of equal rainfalls and more than 95 percentile is calculated for each year and each of pixel and, it is divided to total of the same pixel rainfalls in that year. We used the least squarely error for understanding temporal- spatial behavior of regression. By increasing geographical latitude in Iran's western provinces, it is decreased both of total extreme rainfalls and portion of such rainfall out of total yearly rainfall. Total extreme rainfall trend shows a frequency in a domain with 16 mm in each year. The negative trend of total rainfall with the area of 74.72 percent consists of three quarters of Iran's west. The narrow strip of the west of Kurdistan and south-west of west Azerbaijan have the highest amount of positive trend which is meaningful in certainty level of 95 percent. The study of process showed the ratio of extreme rainfalls portion to total yearly rainfall, which is increasing about 60.7 percent of west area of  this country extreme rainfalls in total yearly rainfall and the greatest part of this area is located in southern half of the studied area. The negative trend also is located in northern half and they have consisted of 39.29 percent of studied area of these, only in 29.81 percent of region, the trend ratio of extreme rainfalls to total yearly rainfalls are meaningful in certainty level of 95 percent.

The geographical location of Yazd province has greatly influenced the creation of spatial and climatic diversity and the provision of appropriate facilities for the formation of various natural and cultural attractions. Nevertheless, these areas need more attention in terms of the potential of tourism development for social sustainability. This research is done with the aim of spatial analysis of tourism capacity of desert areas and its role in social sustainability, and according to its nature, it is an applied type. The research method is descriptive-analytic. Documentary and field data are used to collect data. The data were analyzed quantitatively (one-sample T-test, Pearson test and AHP and Barda methods). The findings show that according to the experts' opinion, the effective indicators in identifying tourism capacities are distance from roads, distance from historical attractions, distance from residential centers, distance from natural attractions, type and soil suitability, distance from water resources , Elevation, direction of gradient, slope, land use and precipitation. The results show that 24 percent of the total area of the area has relatively good capacity and is located in the central, eastern and northeastern parts of the province. The most important criteria that have made these areas selected as optimal areas are the density of natural-ecological elements such as the existence of diverse deserts and deserts, geotops, glacier cirques, and historical-cultural elements such as traditional water reservoirs, markets, shrines and temples And so on. Also, 26% of the area has average power, which is mostly located in the east and northeast of the province. Finally, areas with inappropriate and relatively inappropriate power are found in parts of the eastern province of Karshra that occupy 51% of the total area of the zone. The results of measuring the social sustainability status of desert and desert areas based on indicators (population distribution, transport infrastructure, immigration status and deprivation rate) show that Yazd city has the highest ranking and Ardakan, Bafgh, Mehriz , Taft Meybod and Abarkuhh moderate sustainability, and finally Khatam, Saduj and Bahabad are among the unstable and less developed cities of Yazd province. The results of Pearson correlation coefficient showed that there is a significant relationship between tourism development and social sustainability in different regions of Yazd province at 99% level. This means that areas with demographic, demographic, and low levels of social sustainability have lower attraction and tourism capabilities than other Yazd province cities.

One of the major issues in hydrology engineering is the prediction of the flood routing or rising and falling limb river hydrograph, in which the importance of the climate is very evident due to the high volatility and is therefore one of the most important factors to be carefully studied. The main objective of this research is to investigate the past and future potential of climate change and its impacts on the hydrologic response of the basin. In this study, the Taleghan watershed of the Sefidrood basin was selected as a case study due to its socio-economic significance. At first using weather data and meteorological data with a daily step in a 21-year period and three base maps information, flow hydrograph was simulated using WetSpa model in Taleghan watershed. Results show that there is good agreement between simulation and observations in the base period. Then, the future climate change (precipitation, temperature and evaporation) based on CanESM2 model from the fifth report the Intergovernmental Panel on Climate Change (IPCC) on emission scenario RCP8.5 was used for simulating the flow hydrograph during the next period (2016-2029) and its comparison with the base period (1995-2015). The results showed that in the considered scenario, the average runoff watershed will increase Up to 45% by the climate in the future. Also, the average of runoff will increase in all months of the year (except in October) compared to the base period. This increase is more pronounced for April.

In this study, a randomized complete block design with 36 plants in Shiraz vineyard with simulated peeler, washing and control treatments was used to study the effect of microgravity on grape varieties. After applying the treatments, chlorophyll a and b, branch length, leaf relative water content, dry weight and leaf area as vegetative and biochemical traits, fruit formation, number of cubes per panicle, panicle weight, sugar percentage in cabbage and yield as traits Productivity of grapes was measured. Data analysis was done by analysis of variance and comparison of the meanings with Tukey test. The results showed that desert racecrine reduced the vegetative and reproductive traits of grapevine. Chlorophylls a and b were decreased 13.6% and 34.5%, respectively. Branch length and leaf relative water content did not change under threshing stress, but dry weight and leaf area decreased by 61.6% and 34.4%, respectively, and the difference between treatments was significant at 5% probability level. The leaves were washed out to eliminate the effect of the microtubules on plant growth and there was no difference between the treatment and the control. Formation of fruit is the most important phonological stage of garden trees, which is a significant reduction in insemination and formation of cabbage in grapevines. Reducing cabbage formation reduced the weight of the cluster and eventually decreased the yield by three times the plant yield and the difference was significant at the probability level with washing and control at 1% probability level. Washing the plant after spraying the thimble removed it from the leaves and the flowers opened the grapes and increased the yield of the plant, and with the control in one floor. The occurrence of reindeer phenomenon at pollination and inoculation stage can reduce fruit and yield formation.

A subsidence is the collapse of land surface that may have a small horizontal displacement vector. This movement is not limited by magnitude, scope and extent of the areas involved. The Urban region 18 in South West of Tehran megalopolis has been developed. This study is conducted on radar interferometry, geotechnical analysis, piezometer wells analysis, and geomorphological effects. In the first step, images taken by Sentinel-1 data related to the years 2015 and 2017 were collected. size of subsidence obtained from radar interferometry was about 430 mm around Yaftabad and showed an increase from West to East and from North to South. Maps showing the distribution of gravel, sand were prepared using the geotechnical data within the depths of 5, 10, 15, 20, 25, and 30m. Study results show that the Particle size gets smaller in the region under study from North to South. in the Continuation, Examination of geomorphological effects revealed that as the urban region 18 is located on young alluvial fan of Kan, which contains high gravel distribution and porosity in lower depths, and as the depth of wells in the area indicate thick alluvium, water table decline, emptied pore space and as a result increased alluvium weight along the direction of gravity may increase the compression force and justify the subsidence phenomenon. next a map of phreatic surface was first prepared and then water table of area under study was compared over a period of 14 years. The phreatic surface map indicated that its level has been decreased from North to South. It also showed that the  water level of piezometric wells has been declined from West to East. Comparison of the water table over a period of 14 years revealed an average decline of 13 meters. The maximum water table decline in the area under study was related to the Northern part with 33 meters fall. The Eastern part of the urban region 18 is highly influenced by the subsidence phenomenon. Study results showed a relationship between the size of subsidence and areas with fine-grained soil. About 30 Km of main roads in the region are highly influenced by the subsidence phenomenon. railway of Tehran-Tabriz and the subway line 3 are important elements of transportation in region 18 which Length more than 12 Km over zones influenced by the subsidence phenomenon.

The purpose of this research is to identify the relationship between different types and configurations of the jet stream with heavy and pervasive rainfall southern half of Iran. For this purpose, daily rainfall data of the cold season (December to March) during the 1970 to 2014 period was obtained from the country's meteorological organization. Then, considering the two conditions of learning over 50% and the rainfall of more than 95% percentile of each station, 61 days of heavy and pervasive rainfall were selected for the synoptic analysis. upper tropospheric data also includes zonal and meridian wind, Geopotential Height, sea level pressure, omega, and specially humidity, which was obtained with a spatial resulotion of 2/5 * 2/5 arc of the center of the American Weather Forecast. Then, by using the principal component analysis on geopotential height data of 500 hPa in the 61 days of selected precipitation, 12 factors, which explain more than 90% of the data diffraction, were extracted. By applying the cluster analysis with Ward method on the factor scores, the four patterns influencing the arrangement of the jet streams were identified. The results showed that subtropical jet stream with Reinforcement surface Convergence and divergence field at high levels And consequently the development of surface low pressure And mid-tropospheric trough levels, It plays an important role in the incidence of heavy and heavy rainfall in the southern half of the country And its interactions with the polar jet stream lead to the most severe and widespread rainfall days in the region. In the studied patterns, the jet stream deployment from northern Arabia to northern part of Iran with zonal and meridian curvature And the equilibrium of the left-hand side of the output of the jet stream with low pressure sea level and half-eastern troposphere middle level trough, The hot and humid air brings the Red Sea, Persian Gulf and Arabian Sea to the southern half of the country.

Wind erosion occurs in many arid, semiarid and agricultural areas of the world. Sadobist-roz-e winds are common phenomena in arid and semi-arid areas. In recent years, Sadobist-roz-e winds frequencies and intensities have increased significantly in Iran. A research on Sadobist-roz-e winds sources is important for understanding the mechanisms of dust generation and assessing its socio-economic and environmental impacts. Deserts are the main sources of emitted dust, and are highly responsive to wind erosion. Low content of soil moisture and lack of vegetation cover lead to fine particle’s release. The wind in the eastern part of Iran, Sistan, is one of the most important phenomena in the ecological studies. The intensity and velocity of the wind, has caused environmental problems. This population is distributed in more than 1000 cities, villages and nomadic settlements. Sadobist-roz-e winds is the most significant wind in the region which starts every year at the end of the spring and lasts all through the beginning of autumn, with a mean velocity of 100 km/h. Architecture and urbanization of the Sistan region have been built with the focus on reducing the amount of sand. The orientation and placement of buildings can be effective in reducing the damage to these winds. Sadobist-roz-e winds has increased in zabol since 1999. The average annual number of dust Storm events increased from 10 d during 1990–1998 (before the drought) to 54 d during 1999–2004 (after the drought). The frequency of dust storms also increased 5-fold after 1999 in the region. This shift is associated with an increase in wind speed, rainfall reduction, drying of Hamoun Lake and drought occurrence. The purpose of this paper is to determine the type of obstruction, orientation and enclosure level of the central courtyard so that it can be useful in two areas: wind speed reduction and reduction of dust contamination in the building area. Modeling of buildings is done using 3D software; and simulation of airflow using “Flow3D” Fluid Simulation software has been investigated.  Each time the flow of air was tested in different models. First, two main patterns that were expected to be appropriate to the behavior of the wind were selected. Both of them were simulated and it was found that the concave shape has a better performance. Because in addition to reducing the wind speed, it also causes rotational movement