mahin pireh

Landslides are one of the environmental hazards that are always associated with a lot of damage. Landslides are a common danger in mountainous areas that have a high potential in the western regions of Iran, including the Sanandaj County. Due to the importance of the issue, in this study, the effective factors in the occurrence of landslides in Sanandaj County have been analyzed. In this study, in order to achieve the desired goals, a 30 m high digital model of landslides occurred in the region (prepared by the Rangeland and Watershed Management Organization of Kurdistan Province), 1: 100000 geological map and 1: 5000 topographic map of the region Has been. The most important tool used in the research was ArcGIS and also in this research the combined model of fuzzy logic and AHP was used. This research has been done in two stages in the first stage, in the first stage of landslide analysis in relation to various environmental factors and in the second stage, areas prone to landslides have been identified. Based on the results, a large part of the landslides occurred in the direction of the northern slope (51 landslides), slope floors between 40 to 60% (51 landslides), altitudes 1500 to 2010 meters (112 landslides), nearby areas Fault lines, rivers and roads, conglomerate floors, sandstones and shales (78 landslides) as well as classes related to combined cover of pastures and agriculture and poor pastures (respectively, 64 and 36 landslides) occurred. Also, the results indicate that the southern, southwestern and southeastern regions of Sanandaj County have a high potential for landslides due to high altitude and slope, type of lithology and use, as well as northern slope directions.

In recent years, the increasing trend of the population has caused urban areas to face a lot of physical development, the share of developing countries has been higher than that of developed countries. Physical development in many areas has caused rapid changes in land use and increased environmental degradation. Therefore, the physical development of cities is considered as one of the main factors that change the surface of the earth. Studies have shown that the urban areas of Iran, due to their unlimited and unplanned expansion, have encroached on the natural environments and destroyed them, which has increased the potential for natural hazards such as floods in these areas. Has been considering the mentioned cases, more supervision should be done on the physical development of cities, especially flood-prone cities. Saghez city in Kurdistan province is one of the flood-prone cities that have faced a lot of physical development in recent years. Due to its economic and social situation, this city has faced a large population growth in recent years, which has caused the significant physical development of this city and as a result, the development of residential areas into flood-prone areas. Considering the importance of the topic, in this research, the physical development of Saghez city towards flood-prone areas has been investigated.

In this research, in order to achieve the desired goals, descriptive-analytical methods have been used. The research data includes topographic maps 1:50000 and geological maps 1:100000, a digital elevation model of 30 meters, as well as Landsat satellite images (Table 1). Research tools include Arc GIS, ENVI and IDRISI. The models used in the research also include the integrated model of fuzzy and AHP (in order to identify flood-prone areas) as well as the LCM model (in order to evaluate the physical development process of Saghez city towards flood-prone areas). This research has been done in two stages. In the first stage, in order to prepare the flood potential map of the study area, 6 parameters of height, slope, slope direction, distance from the river, and type of lithology and land use have been used. In the second stage, in order to evaluate the process of physical development of Saghez city towards flood-prone areas, the LCM model has been used. At this stage, after preparing the land use maps, the prepared maps were entered into the IDRISI software and using the LCM model, the trend of land use changes in the study area was evaluated.

The results of the flood zoning of Saghez city have shown that the middle areas of the range have the highest flood potential due to the proximity to the Saghez River, low altitude and slope. Also, the results obtained from the satellite images have shown that the city of Saghez had an area of about 6.5 square kilometers in 1369, which increased by 1.1 square kilometers to 7.6 square kilometers in 2000. In continuation of the physical development process of this city, the area of residential areas increased to 10.2 and 16.6 square kilometers by 2019 and 2019, respectively. Based on this, the maximum amount of physical development with 5.5 square kilometers was related to the time period of 1389 to 1399. Also, the results of the physical development of cities towards flood-prone areas show that in 1369, 3.8 square kilometers of residential areas were exposed to the risk of flooding, and from this amount to 1379, 1389 and 1399, respectively, 3 It has increased by 4.1, 5.1 and 2.7 square kilometers. Based on this, the highest amount of development towards flood-prone areas with 1.9 square kilometers was related to the time period from 2010 to 2020

The increasing trend of population and physical development of urban areas has caused a large part of population areas to move towards flood-prone areas in recent years. The results of this research have shown that the middle parts of the study area have a high flood potential due to their proximity to the river, low altitude and slope. The results of the evaluation of the physical development of the city of Saghez also indicate that this city has faced a lot of development during the years 1369 to 1399, and based on the results, the city of Saghez had an area of about 6.5 square kilometers in 1369, which is 2019 has increased to 16.7 square kilometers. The results of the evaluation of the physical development process of Saghez towards flood-prone areas indicate that in 1369, about 3.8 square kilometers were exposed to floods, which increased to 2.7 square kilometers in 1399. Also, the results of the evaluation of land use changes indicate that during the studied time period, 8.8 square kilometers of pastures, 0.6 of agricultural lands and 0.8 of pastures have been converted into residential areas, the highest amount of which is related to It was the eastern areas of Saghez city. According to the mentioned cases, a large part of the city of Saghez has moved towards flood-prone areas in recent years, which indicates the lack of monitoring of the physical development of this city.

Karst landscapes are of great importance due to their role in providing vital water resources. However, these areas face a high risk of resource pollution, which is a significant concern. This study aimed to identify pollution-prone zones within the Tekab Catchment. The research utilized topographic maps (1:50,000 scale), a 1:100,000 geological map, and a 12.5-m digital elevation model derived from Landsat satellite imagery. Key analytical tools included ArcGIS and ENVI software. The study was conducted in two stages. First, the (Concentration, Overlapping, and Protection (COP) method was employed to delineate areas vulnerable to pollution. Second, the trend of residential expansion towards these vulnerable zones was assessed. The COP model results indicated that approximately 33% of the catchment area, primarily the northwestern and southern regions, exhibited high to very high pollution vulnerability. This was attributed to the underlying lithology, land cover type, hydroclimatic conditions, and geomorphological characteristics. Furthermore, evaluation of land use changes revealed that the built-up area had increased from 8 km2 in 1990 to 19 km2in 2019. Consequently, the southern and northwestern parts of the Tekab Catchment were facing heightened vulnerability due to both their inherent pollution potential and the ongoing expansion of human settlements. These findings underscored the critical need for targeted management strategies to protect the valuable water resources within the Tekab Catchment, particularly in the identified high-risk zones, and ensure the long-term sustainability of this important karst landscape.

How the first human settlements came to be is an important issue, and from different scientific perspectives, different answers can be given; because the creation or degeneration of these settlements is not the choice of individuals; it depends on countless human and natural conditions. Studies show that the establishment of human societies on the ground has always been done in order to achieve maximum natural resources such as water resources, adequate vegetation and access to arable land, this effort is undoubtedly based on the principles that today It is interpreted as the science of location. At the beginning of human life, natural hazards were unknown to humans until their occurrence. Natural are also safe. Natural disasters are born of natural elements and factors, but human profiteering intervention in nature affects the quantity and quality of many natural disasters. Considering the mentioned cases, environmental factors, especially geomorphology, have played an important role in locating residential areas throughout history. Accordingly, in this study, environmental factors affecting the distribution of ancient settlements in Piranshahr have been investigated.

In this research, in order to achieve the desired goals, a 30-meter-high digital model, a layer of ancient sites identified in the region (Masoumian, 2021), a 1: 100000 geological map and a 1: 50,000 topographic map of the region have been used. The most important tool used in the research was ArcGIS and also in this research the combined model of fuzzy logic and AHP has been used. This research has generally been done in two stages. In the first stage, after preparing the layer of ancient sites in the region, the location of ancient sites in terms of slope, slope classes, elevation classes, distance classes from the river, lithology units and geomorphological units are analyzed and thus the distribution status of sites Ancient has been analyzed in relation to environmental conditions. In the second stage, in order to identify areas prone to ancient settlements, the results of the previous stage have been used and using the integrated model of AHP fuzzy areas, a map of areas prone to ancient settlements has been prepared.

In this study, in order to investigate the effects of environmental conditions on the distribution of ancient settlements, first the location of 67 ancient sites in Piranshahr city has been determined. According to the results, a large part of the ancient settlements are located in the slope classes less than 10%, so that 32 ancient sites (equivalent to 47.8% of the identified sites) are located in this class. In terms of slope, a large part of the ancient settlements are located in the northern directions so that 36 ancient sites (38.8% of the identified sites) are located in the northwest to northeast. In terms of height, a large part of the ancient sites are located in the altitude classes of 1250 to 1650, so that in this category there are 56 ancient sites (equivalent to 83.6% of the identified sites). In terms of distance from the river, a large part of the ancient sites are located near the river, with 48 ancient sites (equivalent to 71.6% of the identified sites), located less than 500 meters from the river. They had. Lithologically, a large part of the settlements are located on Quaternary alluvial sediments, so that 37 ancient sites (equivalent to 55.2% of the identified sites) are located in this unit. Also, in terms of geomorphology, a large part of the ancient sites are located in the alluvial plain unit, so that 37 ancient sites (equivalent to 55.2% of the identified sites) are located in this unit.

Environmental conditions have played an important role in the settlement of residential areas in the past and today. Considering that the knowledge of the effective factors in location selection has an important role in various planning, in this study, the effective environmental factors in the establishment of ancient sites in Piranshahr city have been analyzed. Based on the results, the distribution of ancient sites was directly related to environmental conditions, so that the highest density of ancient sites in low-slope areas, low-lying areas, areas near the river, north slope directions, unit Quaternary alluvium as well as unit of alluvial plains. According to the results obtained at this stage, areas prone to the establishment of ancient settlements in Piranshahr city have been identified that based on the results, the middle areas of Piranshahr city due to the conditions, are prone to the development of ancient settlements. The results of this study have shown that environmental conditions in the past have played a major role in the distribution of residential areas and by examining the environmental conditions of each area to a large extent can be found the existence of ancient sites in that area.

Desertification is a type of land degradation that often occurs in semi-humid, semi- arid, arid or hyper-arid areas. It becomes drier and loses its original structure, water, plants, and wildlife as a result of a variety of factors such as climate change, soil over-exploitation, and human activities.Common to all definitions of desertification is the severe destruction of the environment and the reduction of biological production of ecosystems due to desertification. Desertification of arid and semi-arid ecosystems is one of the most critical issues studied in ecosystems, which have severe economic and ecological impacts on a wide range of geographical areas with the potential risk of desertification. Desertification has many consequences that directly and indirectly affect human life, the most important of which are mass migration, poverty, water and food shortages, and conflicts over land and water resources. According to studies by the International Fund for Agriculture, desertification threatens 40 percent of the planet and directly affects 12 million hectares of land annually. Different regions have different potentials for desertification development depending on their hydro-climatic conditions. Iran's hydro-climatic situation has caused many parts of it, especially the eastern regions of the country, to be prone to desertification. Considering the direct effects of desertification on human life and its important environmental effects, in this study, vulnerable areas against desertification in Kerman province have been studied.

In this study, in order to investigate the vulnerability of the study area, the DVI vulnerability index has been used. The information used in the research includes climatic information, a digital model of 30 m altitude, information about the type of soil in the area, and also some demographic information. The most important tool used in research has been ArcGIS. This research has been done in several stages. In the first step, the required information is collected. In the second step, in order to identify vulnerable areas, initially, the intra-layer weight of each parameter is determined and, subsequently, based on that, vulnerable areas are identified. In the third stage, using the DVI relationship and in ArcGIS software, a map of vulnerable areas against desertification has been prepared and then the status of desertification potential in Kerman cities has been evaluated.

In this study, in order to identify the vulnerable areas of desertification, factors including climatic indicators, topographic indicators, soil characteristics and also demographic indicators have been used. Climatic indicators are one of the effective factors in determining the vulnerability of desert areas, so that areas with less rainfall, high temperature and drought index and more evaporation have a high potential for vulnerability. Soil status and slope are also effective factors in aggravating the vulnerability of areas. Land slope is one of the effective factors in permeability, erosion and runoff. Typically, steep areas have greater potential for vulnerability. Sand fields and salt marshes are also prone to desertification. Demographic indicators are also effective factors in desertification. Demographic indicators used in this study include population density, population growth and illiteracy. Typically, areas with high population density, high illiteracy rates, and high growth rates have greater potential for vulnerability and are prone to desertification.

In this study, using DVI vulnerability index, the extent of desertification has been investigated in Kerman province. The results of the research indicate that a large part of the area of ​​Kerman province is covered by areas with high and very high vulnerability, so that 61722 square kilometers (equivalent to 34.7%) of the area of ​​the province is a class with high vulnerability potential and 32381 square kilometers (equivalent to 18.2%) of the province's area is covered by floors with very high vulnerability potential. The study of spatial distribution of vulnerable areas indicates that the southern regions of Kerman province have the highest potential for vulnerability due to climatic and demographic conditions. In this study, the level of vulnerability in different cities has been evaluated. Based on the results, the cities of Manojan, Qaleh Ganj and Anbarabad have the highest potential of vulnerability with 97, 96 and 91% of the areas, respectively. The results of the study also indicate that Kerman province has a high potential for vulnerability and the southern regions of the province are at risk of erosion, so it is necessary to plan for conducting measures to prevent desertification, especially in the southern regions of the province.

global surface temperatures to a wide variety of scientific studies of climatology and meteorology and hydrology, ecology, geology, medical science, design and optimization of transport network and locating fires is required This study aimed to investigate the temperature on Earth Its digital elevation models using geostatistical environment (GIS) in Yazd province is the research of DEM (13M) and meteorological data were used to assess temperature with a 20-year period beginning on the regression equation for each May be then prepared for analysis of the collected data at the end of rastercalculator tool for disorders F Oscillation all months of the tool was used cellstatistics software used in this study include: Arc Gis and Excel are the results of this study revealed that parameter H in accordance with the temperature of the surface of the earth in order to agree with each other such that in areas with high temperature on low ground, and Balksh evaluated the results of this study showed that in the months months (June- July_ August) compared to the other months of the swing high temperature fluctuations belong to the city of Tabas, PA; Ardakan, Bafg, gets; Tabriz.