فهرست مطالب samad fotohi

The subsidence phenomenon is considered one of the most frequent hazards occurring worldwide and imposing irreparable damages every year. This phenomenon affects the ground’s surface and its layers and causes the ground deformation. It can be referred to as a morphological phenomenon that is associated with the gradual sinking of the ground and the vertical movement of materials. Among the various methods used to study the land subsidence pattern, the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique has provided more accurate results. Therefore, this technique was used to investigate the subsidence rate in Mashhad plain from 2003 to 2010 and the Envisat ASAR (C-band) and Sentinel-1 ASAR (C-band) satellite images were employed during the year 2019. The results show that the highest subsidence rate of about 44 cm occurred in Qasem Abad and Kalateh-ye Barfi lands from 2008 to 2010. A subsidence rate of about 37 cm was also observed in the same area from 2007 to 2009. The interpolation results using piezometer well statistics show a decrease in groundwater levels in this area and confirm the accuracy of the results.

Undoubtedly, the first step in tackling drought and its consequences is to understand and understand this phenomenon and its implications in different dimensions so that effective strategies and strategies can be formulated and applied. Since Heshivar village of Darab County is known as a village with good agricultural potential, the economy of these villages appears to be directly dependent on rainfall and water resources. The purpose of this study is to investigate and explain the effects of drought on rural economy and migration in Heshivar village of Darab County. The present study is descriptive-analytical and in nature it is a kind of applied research that the method of data collection is library and field. The statistical population of the study is 17 villages of Heshiwar village (8403 out of 10 villages with population of this village). The sample size was 286 according to Cochran formula. Inferential statistics (T-test) and validated standard precipitation (SPI) and percentage of normal precipitation (PNPI) were used for data analysis. The results based on the Spi index show that the study area has experienced moderate drought during the years of 2003, 2005 and 2008, and in the year of 1995 there has been a very severe wet season. Also according to PNPI index in the years 2001 and 2003 the region was experiencing poor drought and in the years of 1999, 2000, and 2007, there was severe drought and in 2005, 2008, there was a very severe drought. Droughts during this period have reduced the cultivation levels in the villages of Heshiwar and have led to the instability of development in the economic and social areas, especially the reduction of income and migration. According to a questionnaire, the effect of drought on the social and economic dimensions of the rural population in the study area, 73% believed very high impact, 25% high impact and 2% believed it to be less effective.

The need for management of the coastal of the Oman Sea and the Makran as a vast stretch of the Iranian territory with great development potentials in various areas. One of the most important areas for progress in this region is the enhancement of the tourism industry. One of the effective and potential capabilities that can be utilized for enhancing tourism is the geodiversity and the geomorphodiversity in the region. These diversities have been emphasized as the main bases for tourism in the region and steps have been taken to analyze and evaluate them. The study area, extends from the shorelines of Jask Bay to those of the Gwadar Bay and its land area stretches for approximately 120 kilometers from the coastline to the conical fold in the Makran zone. This research used quantitative, statistical and remote sensing methods to study the roles of active geological and tectonic factors, climate and proximity to the sea as the main parameters in the formation and expansion of geomorphological relief. It also evaluated the capability of each one, based on priorities, in the development of tourism in the area covered by the main drainage basins. The results show that geomorphodiversity with PRD of 0.0009, SHDI of 3.3529, SHEI of 0.9329, SIDI of 0.9578, and SIEI of 0.9774, is more importance and valuable than the geodiversity. Therefore, it is essential that the responsible authorities build the infrastructures required for the development of the Geomorpho-tourism industry in order to develop the coastal in southeastern Iran.

Lake basins have spatially and temporally index patterns and represent valuable maps of physical and chemical history. According to this point, that direct survey of climate changes has only been available as machinery in the past few decades, so past’s climate changes indexes can give a better understanding of climate changes in the past era and its causes. Of these, lake sediments have an extraordinary ability to record climatic and environmental events with high sensitivity and resolution and very high- resolution amounts. Therefore, lake sediments can be considered as regions for detecting paleontological environments. Abzalou Lake formed in the northeast of Khuzestan province on the hillsides of folded Zagros and under the Izeh unit in a pit. This study has been tried to by sedimentary examination, identification of sedimentary facies, identification of sedimentary environments and changes of these environments set to the reformation the climatic and environmental conditions of Abzalou wetland in the end Holocene.

The steps of this research include book studies, field works, laboratory works, data processing and then interpretation and conclusion. To investigate the paleontological climate and conditions of the sedimentary environment, 8 intact sediment cores with a maximum depth of 7.5 m and total of 35 m collected with using Auger corer. In this regard, tried to the position of the core be in a way that makes it possible to collect the maximum thickness of wetland bed’s sediments, give maximum coverage to wetland’s sedimentary environments and at least collect one sample in each homogenization work unit as much as possible. Based on field observations, core’s description and lab results, the cores separated into sedimentary units and their stratigraphy columns drew and determined under each sedimentary unit. Also, 3 sediment samples sent to ETH Zürich Institute of geology to age/ date measurement analyzing by the radiocarbon method of organic matters.

in the studied cores, 8 major sedimentary facies identified. The facies often contains clay, silt, sand, gravel, and interstitial sediments along with vegetation and shell fossils which in most cases frequency and interference in the mentioned sediments are often seen. Changes were in particle size between clay to gravel due to process type changes, environmentchr('39')s energy and river inputchr('39')s amounts and sediment color variations concerning sedimentation conditions, presence of organic matter, pH amount, salinity and temperature variations, and drought occurrence, throughout the cores. Three wetland sedimentary, river and alluvial environments identified. According to the age measurement, the average sedimentation rate in the Abzalou wetland is 1.22 mm / year, which this amount is different for various depths. Due to the type of sediments, the Abzalou wetland has undergone human changes for about 600 - 500 years ago. The high water period of the Abzalou wetland has been established between 1800 and 500 years ago. The study of the facies bed sediments of the wetland shows that climate change occurred gradually (not suddenly) about 1800 years ago and this trend has taken at least 200 years. The relatively dry period lasted about 700 years from 2500 years to 1800 years ago and is confirmed with the reported dry periods in the Maharlou lake about 1800 years ago, in the Mir Abad lake about 1500 years ago and in the Urmia lake between 2500 and 1500 years ago. From 4400 years ago to about 2500 years ago, stable and slow wetland conditions prevailed. The conditions for creating a peatland environment have been provided in the wetland and were associated with increasing the amount of organic matter, vegetation and shell fossils and consequently increasing sedimentation rate. This period which lasted for about 1900 years, has been accompanied by extremely humid conditions, high groundwater level and activity of springs feeder in the region. The existence of light brown mud which has the age ranges from 4400 to 4700 years ago, indicates a dry period (300 years). This dry period shows suitable approximate conformity with a dry event of 4200 years ago in the northern hemisphere. This period in the studied region appeared with at least 200 years of temporal delay. After this dry period, we see again a gray sequence with plant and shell fossils that continue to a depth of 7 meters (about 5300 years ago). At depths of 7 to 7.5 m, the existence of brown-muddy sediments along with coarse-grained sediment in size of gravel, pebble and rubble, strengthen the possibility of very strong flood in the region that sent the coarse-grained sediments of around formation to bed of the wetland or maybe has hit to the area of wetland sediments bed in the region.

According to the results of surveys in the Abzalou wetland, at least 3 high water periods with humid climate and at least 2 dry periods during the Late Holocene were identified.  Dry periods appear more suddenly and with more intensity and shorter duration than humid periods in the region and gradually lead to from very dry periods to semi-arid, semi-humid, and eventually humid periods.

Studies show that 14 provinces are impacted by wind erosion and the movement of sand dunes. The sand originated from the shores of Oman Sea is the most important environmental hazards that threaten the already large number of rural settlements. Sands of marine origin are available on the beach and away from the sea of dunes in addition of marine origin, Predictive models for planning sustainable use of land use and land cover in a country like Iran that land use is changing rapidly, there is an urgent need; To detect and predict changes in land cover changes overview to better manage natural resources and protect marginal lands beaches and is very effective long-term policy measures. The aim of this paper is modeling and prediction of changes in land-use in 2035 by using CA Markov model and Landsat satellite images in the West of Zarabad,( The coasts of Makran). Then to determine the changes in the movement of sand dunes in the study area ranged from twenty-three years (1991-2014), satellite imageries from Landsat 7 and 8(ETM+ sensor) with 15 and 30 meters spatial resolution , was used. The 1991, 2001and 2014 month August images were used, this images from website of the US Geological Survey (USGS) have been prepared. Finally, these images by using Geographic Information System (GIS), ENVI and IDRISI softwares were analyzed. The results showed that the changes in the region the largest increase in the interest of sand dunes in the year 1991 (25.561) km², in 2001 (10 . 568) km², and in 2014 (45.578), and the increase of (17.198) km², has experienced. The results also estimated that in future (2035) sand dunes area increase to 592.45 km².This increase in area of sand dunes occur in the absence of proper and efficient management is done in order to stabilize the sand. This increase resulted from changed moorland 162 km²of land area (27%) and 12 kilometers of vegetation (2%) and 23 km² of fluvial (3.4%). These changes makes heavily exposed about 6 villages (Karti,Gnjk, Sohroki, Pyvshk, Vanak and Kalirak) to the movement of running sands.

Has been stated in various sources, soil as one of the most important natural resources has a major, role on the lives of humans. Today soil erosion and sediment production, a problem that is increasing day to day process and loss of surface soils and sediment accumulation in dam reservoirs, canals and also sedimentation damage to the country's economy. One of the most important types of water erosion, gully erosion or (Galli formation). This type of erosion and loss of soil due to sediment production and enormous damages to land, roads and infrastructures, is of great importance. Soil erosion is one of the most important factors that threatens large areas of Iran annually and decreases or eliminates the quality of agricultural lands and rangelands. Due to highlands of Iran in comparison with the grounds and surrounding plains (mean elevation of 1250 m), it has been affected by water erosion. So it is very important to study erosion and present management strategies to reduce the impacts of erosion in basins of Iran. This study to Target morphometry gullies and the influencing factors on gully erosion in the South West sub-basin of ILAM (Cham Fusel).
The average height in the area between 50 and 1,200 meters above sea level and has a dry climate with an average annual rainfall of less than 200 mm and the average annual temperature is above 25 degrees C°. In terms of the main geological formation of this area is affected by gully erosion, Aghajari formation (red mudstone, siltstone and sandstone) are related to Miocene period. Basin area of over 150 hectares affected by gully erosion and slope threshold for gully erosion in the area between 8-2 percent.
The research method in this study is field research, library study and morphometric measurements of gully erosion forms. Besides, on the basis of the geological maps of 1/100000 and topographic 1/50000 and DEM 30 meter area, the software of GIS Arc has been used to make the required maps. Furthermore, the GPS device and a camera has been used in the field to harvest. o
The average height in the area between 50 and 1,200 meters above sea level and has a dry climate with an average annual rainfall of less than 200 mm and the average annual temperature is above 25 degrees C°. In terms of the main geological formation of this area is affected by gully erosion, Aghajari formation (red mudstone, siltstone and sandstone) are related to Miocene period. Basin area of over 150 hectares affected by gully erosion and slope threshold for gully erosion in the area between 8-2 percent. The study, which the sub basin in Cham Fusel ILAM province is located in the South West, with the aim of gully morphometric including deep, height, length, height from sea level, and geographical location as well as classification criteria in three sample gully gully of area, In order to identify factors affecting the development of erosion in the basin plain Cham Fusel was evaluated. The results of morphometric and field visits to the region, factors such as climate factors, slope and aspect, geology (Land genus), tectonic activity and faulting, land use, overgrazing of amount plants, including the most important factors recognized were identified in the development of gully. Which layers to extract some of these factors in Arc GIS software designed and based on creation of maps and data to analyze each of these parameters and their impact on Gully Erosion percent has been paid.
According to the morphometric data, it can be concluded that the gullies basin largely toothed and clawed, permanent, of medium to large gullies, which have expanded continuously. Below you can see images of morphometric gullies sample was collected during the field visit of the area. The results show that due to the widespread earthquake in the region in recent years and local faults can be concluded that one of the most important factors in the formation Galli uplift of the Earth. Also overgrazing by cattle ranchers in the area Tuesday Abdanan city, murmury, Dahlgren and ranchers outside the province of Hamedan and Kermanshah provinces such as ranchers who use the area as Qishlaq, Another important factor in the development of gully erosion in the area. Due to the climatic amount of rain, sleet, snow, ice, temperature and wind could be the climate factors in the rise of water erosion. As the geographical location and local climatological data suggests, the study area is influenced by the Mediterranean winter rains. Which are imported to Country from the West in winter and more in the form of showers and hail rainstorm conditions caused severe erosion gully in the area easy. Lack of growth of vegetation and bare Land is another contributing factor is considered in the development of gully erosion in the area. That is because the rainy season in the winter when the soil in the area is almost devoid of vegetation. The lack of vegetation in the region as one of the important factors, has caused soil erosion, its most destructive erosion of the gullies show. Also according to the map slope and aspect of the region was marked within the range of between 2-8 percent and Create Gully and aspect with the West and the South West and North West are more affected by gully erosion. Finally, all factors except factors of land use, all other factors were named among the important factors affecting the development of gully erosion are the region. It was also found other factors in the evolution of land use contrary to gully erosion region. That is because of the lack of culture in this area and dropping land by farmers as wasteland, and also because of the recent drought in the region has caused more and more extend of gully erosion and land with the ability crop damage and destroy all. The results obtained showed that the study area in terms of of gully erosion in critical condition.

Fluctuations in the meteorological variables such as: temperature, precipitation, is one of the atmospheric circulation characteristics. Meanwhile, the sharp decrease of precipitation and dry periods caused by that has many negative effects on water resources. Climatic fluctuating in a region has severe effect on soil and water resources. Nowadays, generally it has been accepted that any change in climate system is important in the water and soil resources management. Among the climate elements, precipitation has the most fluctuation; this matter especially in Iran that the average rainfall is 250 mm is more importance. Drought and wet periods, especially drought period has been affected the Kaju watershed for a long time; and because of its long durability has been exposed to a lot of damages and injuries. The purpose of this article is Investigation of temperature, precipitation and discharge change trend the basin watershed a period of 20 years. Mann-Kndall parametric test was used to determine trend parametric. The results show precipitation decrease trend, temperature is ascendant trend and discharge River region is decrease trend.

Iran is among 10 top potential countries of occurrence of natural hazards in the world and from among 35 natural hazards, so far about 30 hazards have occurred in Iran(Negaresh and Latifi,2009). One of the different types of natural hazards which every year causes a lot of damage particularly in arid and arid regions of the world is the existence of sandy hills(Omidwar,2006); sandy hills are mostly created in coastal regions of most seas and oceans. These hills are the result of mutual effects of waves, marine currents, wind and sediments available in coastal regions. They are implemented with components of the coastal environment and construct the eco-systemic bases in which there are valuable collection flora and fauna(Kidd, 2001). The studied region is among the deserts near Gulf of Oman coasts. Sand on the coast are with marine origins and by getting far from the sea, sandy hills, in addition to having marine origins, have land origins. In some seasons of the year, particularly in summers and falls in which Monsoon winds start blowing up, the range of the movement of running sands is more towards rural regions in such a way that annually, a large part of sands covers residential areas, farmlands, road & building facilities, and infrastructural facilities in the rural areas of the west of Zarabad and left behind heavy damages and losses. The aim of this study is the detection of temporal-spatial changes in sand dunes in the Gulf of Oman coastal region. In addition, trend and severity of this hazard and the effects of climatic and environmental factors that intensified dimensions of risk were considered.
The present study, to achieve the mentioned objective is an applied study and in terms of research, a method is a descriptive-analytical one. To collected data, it uses library-documentary as well as survey studies in the rural areas of the west of Zarabad. After that, to investigate the changes of the degree of displacement in dunes of the studied region in the 23 year time period (1991-2014), GPS and the Enhance Thematic Mapper Plus (ETM) images of the Landsat Satellite 7 and 8 with the spatial resolution of 15 and 30 m were used. The satellite images were used in this study with time intervals of 10 and 13 years were related to years of 1991, 2001, and 2014 in August respectively and they were extracted from USGS.The ENVI software and Geographic Information System were used for images processing and interpretation. The geometric and radiometric corrections were applied on images according to standard procedures. Finally, classification and related calculation were performed.
The conducted studies in the region based on the interpretation of satellite images and survey studies indicated that changes in the available users in the region, the top increases for dunes occurred in 1991 as 561.25 km2, in 2001 as 568.10 km2, and in 2014 as 575.45 km2. In fact, it has experienced a growth as 17.198 km2. The vegetation whose area covers 32 km2 in 1991, in 2014 has reached an area with 45km2 and increased as 1.6% compared to the previous period. In 1990 to 2014, the area of the user which has been changed in favor of dunes, includes 0.108 km2 vegetation, 10.60 km2 stream sediment, and 264.35 km2 arid lands. Therefore, dunes move with high speed after each storm and during these displacements, a lot of damages are imposed on farmlands, facilities, and rural settlements. Investigating the degree of imposed damages indicates that annually, a large area of regions such as villages, roads, and facilities are influenced by running sands, which this trend can cover more regions in future years. The degree of displacement of dunes, according to the analyses conducted during the research period(1990-2014), has been so great that it has caused the burial of a large number of villages, infrastructure, farmland and roads and resulted in the unemployment of a large number of farmers in the region. Imposed damages to rural settlements have not been less than agricultural sectors and facilities. Therefore, due to the movement of running sands during recent years, 15 villages have been at the exposure of damages in such a way that compensation of these damages has imposed heavy costs, and consumed a lot of time on the shoulder of the society. As a result, the movement of dunes towards studied villages, i.e. Biahi, Mashkouhi, Abd, Rig Mostafa, Kalirak, Kerti, and Gati which are in the coastal regions, and Sohraki, Ganjak, Tanban, Zahrikar, and Kaidar which are located at far distances from the coast suffer from the highest amount of dunes and are considered as the most critical regions in terms of the movement of sand dunes. The results also showed that the important factors on severity and development of these critical regions are: a shortage of precipitation , loose and fine-grained sediments, low slope, no obstructions against the marine winds and high frequencies of winds and storms in this region.On the other hand, the lack of any varieties of vegetation on dunes, as well as the drought of recent years confirms spatial-temporal changes in the sand dunes towards the study area.
In this research, the hazards due to running sands in the West region of Zarabad (Baluchestan) were studied. The results from satellite image interpretation and field works were showed that the greatest change of land cover in recent years was related to sand hills. The total areas of sand dunes in 1990 are 561 km²,in 2001 these area increases to 568 km² and finally in 2014 reached to 578.5 km².The average growth rate is about 0.76 km² per year. The landcover change from river sediments and barren land to sand dunes, during this period are estimated 10 and 264 km².
The storm and marine winds moving sand dunes and running sands from coastal regions to rural settlements,farmland,Roads and other Infrastructures of the region. This hazard was just too much damage like buried villages, the destruction of roads and unemployment and migration of farmers. The number of evacuated villages are 15 cases that some of these villages is located in the coastal region(Biahi,Mashkohi,Abd,Kalirak……..) and others in inland(Soharaki,Ganjak,Tanbalan,…..).
This is the manifestation of crisis and instability in the rural communities that creating important obstacles to development and it is triggered vulnerable rural development was decreased.

Geological phenomena and sights are among the most attractive tourist areas, which can be considered in geotourism as the vision of future economy. Geotourism is the sustainable form of nature-based tourism, which mainly focuses on experience and perception of nature and learning about it, is defined based on comprehensive and sustainable development, and is managed such that its resulting negative outcomes are few and its benefits are maximal for local societies, providing their welfare causes. Iran has a beautiful nature with climatic variety and regions full of unique geological phenomenon and the investigation of these attractions is necessary for gaining more knowledge about them. Mazandaran Province which owns beautiful landscapes, unique geomorphological phenomena, animal diversity, and vegetation is Iran's one of the most important tourism sources. Maintaining and preserving these valuable sources, especially unprecedented geological phenomena which are the result of millions of years of change and evolution of the earth in this region, require fundamental measures and planning at international and regional levels in order for this global legacy to be preserved based on principles of sustainable development and commitments of present generation to the generations to come. To this end, it is necessary to identify motivations of geotourists for visiting a natural attraction in order to present a planning for the protection of natural resources and tourism development. In this research, the selection motivation of geotourits for visiting Badab-e Soor region in Mazandaran Province is investigated. The research method was descriptive-analytical. In order to proximate the ranking to reality and obtain better results, a combination of correlation coefficient and AHP Delphi method which is called synthesis Delphi AHP correlation (SDAC) was used. Results showed that the most frequent motivation of tourists visiting Badab-e Soort geotourism region was its natural attractions.

Identification of areas susceptible of landslide is one of the primary measures in managing and reducing the damage caused by such phenomena. In this regard, according to the goal and environmental conditions, different zoning models have been proposed. In order to zone and study the areas susceptible of landslides in the north of Neyshaboor, AHP method was applied. Thus, factors causing landslides including slope, lithology, land use, rainfall, the distance from river, the distance from the fault and the distance from the road were analyzed as the main factors for the occurrence of landslide. Layers of information related to each of the factors effective in the occurrence of landslides were prepared by the means of GIS analysis, and effective factors were evaluated using the AHP and paired comparisons. Finally the landslide hazard zonation map was prepared. Considering the final weight of each of the factors, it was concluded that the slope of the landslide and lithology in this area are the first and second most important factors influencing the landslide degree. Also the results of this zoning and the existing distribution of landslides confirmed that places susceptible of landslide in this region are based on landslide areas.

Tourism as the largest industry service in the world has a special role in the development of geographic areas. When the dimensions and aspects related to tourism are known well, this situation will be more and more objective. Today, there are many theoretical and executive experiences in the world for the study, program planning and management of tourism areas, which along with the progress in technology are increasing trends. In this research, Geomorphologic landforms of Bisotun tourism regional sample have been identified and assessed their status of Geomorphotourism capabilities have been assessed. For assessing the regional landforms, geological and topographic maps as well as fieldwork data and have been used the degree of the capabilities of Geomorphotourismy landforms have been assessed and ranked based on prolong method. Accordingly, Bisotun mountain landform because of historical and archaeological, geomorphologic phenomenon and beautiful natural landscapes with a mean tourism value of 0.79 and average efficiency value of 0.81 and is of the highest value of Geomorphotourismy.