فصلنامه پژوهش های جغرافیای طبیعی
پیاپی 118 (زمستان 1400)

In semi arid regions,gully and rill erosion are main types of water erosion.In recent time these erosion is very intensive ,due to climatic changes.The surfaces of slopes is disturbance, due to creation new channels or make loose old channel by incision runoff .When channel made on slope ,slope materials are delivered into rivers in short time, that these materials are cultivated soils .Surface erosion and soils delivery into flow can be damages to cultivated area .Drainage networks are experience intensive liner erosion that are located on eastern slopes of Sahand ,special Ojan chay basin ,as a semi arid region .The storm occurrence is creating runoff that have erosion power, just before plants is covering slopes surface. Deep channels that there are created on up slopes and foot slopes are suggested which erosion is very accreted .Range cultivated lands on slopes is play important role on quick concentrated runoff in study area. Soils is delivery into water at lower sites in during storm ,in these conditions. In study area ,liner erosion is intensive ,because surface material ,topographical property and climatic condition is suitable for liner erosion. Anthropologic factor is play main role on gully and rill erosion. In this paper for threshold liner erosion start determination, is used climatic data, topographic maps(1 :50000) and EXCELL ،SPSS وARCVIEW .Because that climatic factors is play main role on liner erosion ,is take care of in this paper .HTK is climatic coefficient that is used. HTK=ΣR/Σt.10,HTK is climatic threshold liner erosion , ΣR,is precipitation , Σt.10,is temperature (upper 10).Slope and area are play main role in rate of erosion. To attention of this role ,threshold of erosion is estimated by use of two parameters(A≈6As/10000 and r =SAs0.4(6/10000)0.4› 0.025).In final is zoned from an liner erosion ,all part of study area by using of statistical methods and by data that they gathering from study area . Gully and rill erosion are main reasons for increase and delivery of sediment into river in semi arid area .These forms of erosion are delivery huge of slope materials into water flow .Store of these material on foot slopes and washing they by floods ,is reason for increase of sediment into water flow in Ojan chay basin. Soils are deep in study area .These soils that liner erosion is active ,without salty in somewhere and are salty in other site .Study on soil horizons is suggested that silt and clay percent is high on upper part of horizon .These texture is sensitive to opposed to water erosion. The presence of sand on upper part of horizon is cause for gully walls instability. In study area ,slope ,surface materials and area of upper site are main parameters on slope disturbance .Thresholds of erosion on slope is determined by use of these parameters. Yearly average of precipitation is decrease and this is one reasons for suitable site for gully erosion. The results of study show that HTK is high in some months .This suggested that slopes is advanced to erosion in these months .This result show that runoff have power erosion in all parts of Ojan basin and soil is lose by water erosion. Field study show that when slopes is gentle , gully and once slopes is steep ,rills are created on slopes. Up walls of gully is very instable .Investigation slope of by using of A coefficient show that potential of erosion is high in many parts of study area .Liner erosion is main problem on slope of study area. Ojan chay basin is important farmer land that is main site for dry and water farming in Sahand mountain 3qu1cai8l8. This suggested that slopes is advanced to erosion in these months .This result show that runoff have power erosion in all parts of Ojan basin and soil is lose by water erosion. Field study show that when slopes is gentle , gully and once slopes is steep ,rills are created on slopes. Up walls of gully is very instable Liner erosion is main problem on slope of study area. Ojan chay basin is important farmer land that is main site for dry and water farming in Sahand mountain. In this study area lose of soil and disturbance of farmland by runoff ,have prejudicial for farmland and is increased sediment. The results of study show that this basin have high potential for liner erosion . The main reason for intensive liner erosion is quick concentration runoff, as natural or anthropologic .These cause is active on slope of study area and delivered high volume of soils into lower channel .Walls of gullies is unstable and many materials delivery in to water flow .Development of gully is very quick .For these reasons ,cause of gully creation must be investigated and slope management . Liner erosion is main problem on slope of study area. Ojan chay basin is important farmer land that is main site for dry and water farming in Sahand mountain. In this study area lose of soil and disturbance of farmland by runoff ,have prejudicial for farmland and is increased sediment. The results of study show that this basin have high potential for liner erosion . The main reason for intensive liner erosion is quick concentration runoff, as natural or anthropologic .These cause is active on slope of study area and delivered high volume of soils into lower channel .Walls of gullies is unstable and many materials delivery in to water flow .Development of gully is very quick .For these reasons ,cause of gully creation must be investigated and slope management .Liner erosion is main problem on slope of study area. Ojan chay basin is important farmer land that is main site for dry and water farming in Sahand mountain. In this study area lose of soil and disturbance of farmland by runoff ,have prejudicial for farmland and is increased sediment. The results of study show that this basin have high potential for liner erosion . The main reason for intensive liner erosion is quick concentration runoff, as natural or anthropologic .These cause is active on slope of study area and delivered high volume of soils into lower channel .Walls of gullies is unstable and many materials delivery in to water flow .Development of gully is very quick .For these reasons ,cause of gully creation must be investigated and slope management .

Air pollution is measured using the air quality index and by air quality measuring stations. The purpose of this study is to investigate the temporal-spatial changes of air pollution in December and January and during ten years from 1389 to 1398 using the average data of air quality index in Tehran. For this purpose, first air quality data were extracted from 21 air quality control stations in Tehran and then the average air quality data in the two months were calculated and IDW interpolation maps were drawn for both months during the ten years studied. In the drawn interpolation maps, the trend of temporal-spatial changes of air pollution during ten years can be observed, then the percentage of air pollution zones in the city of Tehran for both months during the study period have been calculated. Finally, the maps of December and January of the ten years studied were put together separately and analyzed. Thus, spatial and temporal analysis of air quality was performed in December and January for 10 years. The results show that during December and January of 1389 to 1398, the largest area of Tehran, respectively, in the areas, Relatively healthy (54%), unhealthy for sensitive (23%), healthy (20%) and clean (1.5%) and unhealthy (0.5%) groups. In other words, less than 2% of the city of Tehran is located in a clean area, and even in some years in Tehran, there has been no clean air in these two months. In terms of time, December 2010, January 1991 and January 1995 with more than 70% of unhealthy zones for sensitive groups were among the most infected years. Also, Sharif and Shadabad industrial stations without having a clean zone and with AQI 75 and above have been among the most polluted stations in the ten years studied. Therefore, the problem of air pollution in Tehran, in addition to the spatial dimension (being located in a large area of the city in an unhealthy area), is also a matter of time (high pollution in a long period of time).IntroductionTehran is one of the 8 most polluted cities in the world and although it has only 1.2% of the total area of the country, but 20% of the total population, 40% of industry and 85% of all professionals live and work in it (Ahmadi Moghadam, Mahmoudi. 1390). The importance and necessity of research stems from the fact that the political center of the country with a population of tens of millions of people today has more than 200 days of air pollution (Seidaei et al., 1998). In this study, temporal and spatial changes of air quality index by IDW interpolation method in December and January and during 10 years from 1389 to 1398 are investigated. According to the intensity of this index during these ten years, first two months, December and January, were selected as the most polluted months in this year, and then to continue the work of air quality data, 21 air pollution measuring stations of Tehran Municipality were calculated and produced inside The search took place.MethodologyAccording to the purpose of this study, which is to study the temporal-spatial changes of the average air quality index in Tehran during the ten-year period from 2010 to 2017, the following steps were performed. Air quality data were extracted from 21 air quality control stations affiliated to Tehran Municipality that are scattered throughout Tehran. Then, the average of each month of December and January in each year was calculated. Then, IDW interpolation maps were drawn. Then, from the maps drawn in each year, the percentage of the area of air pollution in the city of Tehran was calculated. Finally, to identify changes and air pollution zones during this ten-year period, ten-year maps were stacked separately and analyzed each month, thus spatial and temporal analysis of air quality in two months. December and January were studied during 10 years.DiscussionAccording to the calculations made during December of the ten years under study, on average, about 3% of the city of Tehran was in the area of clean air. Most of Tehran is located in a relatively healthy area, which during the study period, an average of 58% of Tehran is located in this area. The next area of air pollution in Tehran is a healthy area with an average of 22%, the highest area of this area with an average of 75% is in 1390. Unhealthy zones for sensitive groups with an AQI value above 100, cover an average of 18% of the area of Tehran. In just one year, an unhealthy area with an AQI value above 150 can be seen in Tehran, which in 2010 with an average of 0.5% of the city area.The results of the table and maps show that in January of the ten years under study, on average, only 2% of the area of Tehran was in the clean air zone, and the healthy area, on average, included only 20.5% of the area of Tehran. Becomes. Most of the city of Tehran is located in a relatively healthy area, which during the ten years under study, this amount is 52.5 on average. The unhealthy zone, with about 27% of the city, is in second place.. In the drawn maps, the trend of pollution changes during December can be seen. According to these maps, the highest range of air pollution was recorded in December 2010 and the lowest in December 1990. In the drawn maps related to January, the highest air pollution zone is related to January 2016 and the lowest pollution zone is related to January 2010.The results of the two-month maps of the temporal and spatial analysis of the air quality index are very similar, and there is not much difference between December and January in terms of spatio-temporal distribution of air pollution. The only slight difference is in some stations, such as the Sharif University of Technology station, where more pollution was recorded in December than in January.Conclusion and SuggestionsThe results of the research show that during the months of December and January of 1389 to 1398, the largest area of Tehran in the areas of relatively healthy (54%), unhealthy for sensitive groups (23%), healthy (20%), respectively. ) Are clean (1.5%) and unhealthy (0.5%). In other words, less than 2% of the city of Tehran is located in a clean area, and even in some years in Tehran, there has been no clean air in these two months. In terms of time, December 2010, January 1991 and January 1995 with more than 70% of unhealthy zones for sensitive groups were among the most infected years. Also, Sharif and Shadabad industrial stations without having a clean zone and with AQI 75 and above have been among the most polluted stations in the ten years studied. Therefore, the problem of air pollution in Tehran, in addition to the spatial dimension (being located in a large area of the city in an unhealthy area), is also a matter of time (high pollution in a long period of time)..

Iran is located in an arid region, so planning to adaptably cope with drought consequences in this arid climate regions is essential and a constitutes important water-resources/water-demands managerial program at country level. In order to compile a drought plan, we need to carefully study the historic rainfall period using a appropriate drought indices. Drought is a climatic phenomenon that is statistically random and is studied by several indicators. One of these indicators that has triggered a major paradigm change is the one proposed by McKee et al. (1993) known as Standardized Precipitation Index (SPI). The index was developed to define and monitor drought and determine rainfall intensity anomalies in time scales of 3 to 48 months in Colorado. In the calculation of SPI, the total precipitation of a cumulation period consisting of several consecutive months are compared with its counterpart during the studied years. Based on the appropriate statistical distribution, the probability of similar precipitation is calculated. The index number is obtained after normalizing the corresponding cumulative probability distribution function value using standard normal distribution. In this method, the rainfall of different months is included in the calculation without considering the distance or proximity to the present time and using a uniform weight. It has been observed that extreme monthly rainfall events, several times heavier than long-term a verge keeps the index value high for several consecutive months. The dry periods that follow the such a wet month are hidden from the SPI, and this index mistakenly show that period as wet, even though we know that these precipitations, especially in arid areas, are mostly in the form of showers and are quickly out of reach and will not have much effect on the wet season.

In this study, SPI drought index in12 provinces with26 synoptic stations located in the center, south and east of Iran with a dry climate (determined by Domarten method) has been calculated and analyzed over a period of 34 years (1364-1397) for a cumulation period of twelve months. The most abundant and the least precipitated stations were Safiabad-Dezful and Nehbandan, respectively. To calculate the SPI index, gamma distribution was used to fit long-term precipitation data. Since the SPI index does not take into account the effect of precipitation timing by definition, it is likely that in the period under review to estimate unreal wet period. Therefore, in this study, for the first time, the a new EP-SPI correction index is presented, in which the effective precipitation data obtained by damping the effect of precipitation with the time factor, as used as input to SPI Generator software, developed in2018 by The National Drought Mitigation Center was used. In this way, the effect of precipitation in the first month close to the event is 12 times, in the second month 11 times and also in the previous months compared to 12 and the farthest month. As far as the twelfth month is concerned, in practice it has not had much effect on the current drought, and only once it has been included in the calculation in the ratio of 1/12. Thus, the effect of older rainfall is reduced and the index provides a better estimate of drought.

Since the two methods used have the same logic, the regression of EP-SPI versus SPI values shows a significant correlation at the5% level with a coefficient of determination of 0/673 and a slope of 0/82. To compare the two methods SPI and EP-SPI, we need to perform statistical tests. If the data has a normal distribution, it is possible to use a parametric test, otherwise we must use a non-parametric test. Using the Kolmogorov-Smirnov test, we determine the normality of the data distribution. According to the result of this test with error α=0.05, the distribution of normal SPI and EP-SPI values and the difference between the two methods were not normal. In reviewing the studied stations, out of 9895 events, the cases in which SPI was positive and EP_SPI negative included 880 cases, of which 277 were differences in the values of SPI and EP-SPI index more than 1. In 67 cases, the degree of drought was 2 to 4 levels of difference with SPI, which indicates the presence of drought in the study areas. Three acute incidents occurred in Qom, Mehrabad and Omidiyeh stations in January and February 1996 and December 1998. In these three stations at least 4 levels of drought have been shifted. According to the study, the lowest number of disputes was related to Safiabad station (Dezful) in Khuzestan province with 6 incidents and the highest number was related to Omidieh (Aghajari) stations in Khuzestan province and Minab in Hormozgan province with 18 incidents. it is arrived 86% of the incidents were seen with a difference of more than one in the months of November to February and the highest difference between the two methods was equivalent to four levels of drought index shift from very severe to mild drought. Also, in terms of average, the difference between the two methods was more severe in December and January.

The monthly pattern of more than one difference between SPI and EP_SPI twelve months in the rainy months of December to February and low rainfall in June to October was in accordance with the rainfall regime in the region. In general, the difference in precipitation from year to year, more at the beginning or end of the rainy season, greatly affects the SPI values, while in the EP-SPI method, their effect dampens over time and a better understanding of the real state of drought/wet period has provided in the area. In this study, it was found that8.9% of the twelve-month drought events in dry climate were hidden from the SPI index. This was consistent with a comparison of NDVI maps that were typically received from NOAA satellite AVHRR sensors on5 dates. In these 5 dates, the difference between SPI and EP-SPI index has been observed in more than ten stations. Therefore, it can be said that the efficiency of EP-SPI method for detecting droughts in a period of twelve months is confirmed. Although no similar study has been found to date, Nadi and Sheikhi Soghanloo (2020) observed that the difference between SPImod and SPI indices is more obvious in stations with drier climates. Therefore, they concluded that using SPImod instead of SPI provides more accurate results due to the elimination of seasonal rainfall effects. It can be concluded that the results of this study were consistent with the result of this study.

Locating temporary settlement based on flood hazard in ShirazExtended AbstractIntroductionNatural hazards, especially floods, as recurring and destructive phenomena, have always existed throughout the life of the planet and have always been a danger to humans. The experiences of developing countries in this field indicate that they are more vulnerable to natural hazards. Due to its natural and human characteristics, Iran has suffered many crises and is one of the most vulnerable countries to natural hazards.Rivers are one of the vital arteries in attracting population and creating urban and rural settlements, especially in arid and semi-arid regions. The Khoshk and Rahdar River in the metropolitan area of Shiraz has been one of the dangerous geomorphic areas of the city in recent years. The location of Shiraz urban area due to the location of a significant part of it on the geomorphological field of floodplains of rivers is associated with the threat of flood risk, which is evidenced by floods in 1986, 2001 and 2019 and the damage caused by them. Therefore, the necessary environmental management in this field before, during, and after the flood in the urban area of Shiraz is essential. This study aims to help by locating temporary settlements based on flood risk in the urban area of Shiraz, which is doubly important with a population concentration (population of 1.5 million people) and significant economic capital.Materials and methodsIn this research, digital topographic maps of 1: 25000, geological 1: 100000, digital model of altitude 10 meters, detailed study map, aerial photographs, and satellite images have been used. Statistics of hydrological stations were provided by the Regional Water Organization. To calculate the average annual discharge of stations in the 25-year index period (1989-2014), at first, the statistics of stations with a statistical period of more than 10 years have been reconstructed by establishing a correlation between the annual discharge of these stations and the reference stations. Annual discharge statistics in stations with a statistical period of 10 years or more have been reconstructed and supplemented using the correlation between them and base stations.The research method used in this research is descriptive-analytical. First, flood zoning was done for the study area and then suitable places for temporary settlement were determined. Flood zoning was determined using Hec_GeoHMS and HEC_GeoRAS models for Khoshk and Rahdar Rivers.To select suitable neighborhoods for temporary settlement, first the necessary criteria for this location are prepared and after preparing these criteria, in the location stage, according to experts, scoring frameworks are determined based on these criteria. Determining suitable places for temporary settlement during flood risk in the study area has been done using multi-criteria decision-making models and the AHP model using ArcGIS software.Results and DiscussionFlood zoning was performed using HecGeoHMS and HECGeoRAS models for Dry River that flows seasonally. Due to the lack of information on the flow of the river, the flood zone of the Rahdar River has been determined by field visits and the opinion of the experts of the Water Regional Organization (average radius of 150 meters).According to studies, the main criteria for locating temporary settlement are: 1) distance to the flood zone, 2) distance to the border of mountains and plains, 3) distance to empty spaces (land without construction, garden, park and space Green, and agricultural lands), 4) building density, 5) distance to waterway and river, 6) distance to fire station, 7) total population, 8) vulnerable population (less than ten years and over 65 years) 9) compatibility of land uses, 10) distance to main thoroughfares, 11) distance to health centers, 12) distance to military-law enforcement points, 13) ground level, 14) land slope, 15) slope direction and 16) distance To the entrance of waterway and river.The steps for analyzing the data are as follows:1- Preparation of raster layers of criteria2- Reclassify the raster layers of the criteria3- Converting raster layers to vector layers4- Calculation of relative weights of sub-criteria by Analytic Hierarchy Process (AHP)5- Calculating the relative weights of sub-criteria the use compatibility 6- Preparation of raster layer of relative weights of sub-criteria7- Determining the relative weight of criteria8- Combining the layers of relative weights of the sub-criteria and determining the spatial utility index9- Determining the average spatial utility index in empty spaces10 - Determining the best areas for the construction of emergency settlementConclusionsShiraz has seen heavy and torrential rains 5 times in the last century. The water flowed out of the dry river and flowed in the passages and streets, causing major damage to houses and commercial places along the river. Many people needed a place to live temporarily. The uncontrolled expansion of the city, especially in the northwest axis, and the loss of natural areas absorbing runoff and precipitation and reducing vegetation in the region has caused that in high rainfall (more than 70 mm in 24 hours) and intermittent, water can not penetrate the soil. Slow and eventually flow in the path due to lack of drainage and proper disposal system. Among the effective human factors are land-use change, commercial, recreational and residential constructions, tampering with waterways or blocking these waterways completely, construction in the area of canals, construction of communication bridges on canals and narrowing of waterways.Locating temporary settlement before the hazard occurs and in the planning stage can help managers have a written action plan after the hazard occurs .One of the differences between this research and other researches is the type of criteria considered and that so far no comprehensive study has been conducted on the subject of research for Shiraz. Suitable places for temporary settlement during flood risk in the study area were determined using multi-criteria decision- making models and the AHP model using ArcGIS software. The combination of criteria for locating suitable areas for temporary settlement in Shiraz (Figures 9, 10 and 11) shows that areas in the southeast and central areas are among the areas with high potential for temporary settlement.

The temporal and spatial distribution of precipitation in Iran is affected by the distribution of global and regional atmospheric circulation systems which the slightest change in its pattern leads to severe climatic anomalies. Therefore, it is important to know more precisely the mechanism and operation of effective atmospheric circulation patterns in the occurrence of precipitation, especially action centers. Arabian anticyclone is one of the components of atmospheric circulation affecting Iran's winter precipitation. The anticyclone that is located on the Arabian Sea, transfer humidity to sublatitudes over the Middle East and Iran by clockwise motion. Hence, the spatial behavior of the mentioned atmospheric conditions has been studied in the form of the frequency of its centers spatial distribution with light, medium and heavy precipitation in Iran in the cold period (October to March).

For this study, re-analyzed precipitation data of the ERA Interim of the European Centre for Medium-Range Weather Forecasts (ECMWF) with 1o*1o spatial resolution and atmospheric data of the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) with spatial resolution of 2.5o*2.5° were used. So, in the first step to achieve the research aim, rainy days for the statistical period of 1981-2010 were extracted in three categories; light (1-10 mm), medium (10-30 mm) and heavy (More than 30 mm). Base on the average spatial location of the Arabian anticyclone, for proper division of the range to identify and analyze the temporal and spatial behavior of this anticyclone, the area was considered from 30 to 80 degrees East longitude and 0 to 30 degrees North latitude. The geographical location of anticyclone center was extracted by defining the maximum criterion of geopotential height in all rainy days within its activity range. 20 sub-areas were defined to better represent the position of the anticyclone. Finally, the frequency and dispersion of the geographical location of the Arabian anticyclone at the desired level is plotted and displayed based on the number of closed centers in each sub-areas. Also, for those sub-areas which had more number of anticyclone centers, the daily average geopotential height and daily average precipitation maps were drawn and analyzed.

Rainy days 1-10 mm From 2023 days with precipitation of 1-10 mm, 1622 days (80.2%), Arabian anticyclone has had an independent closed center at the level of 850 hPa. Among these, the highest frequency of anticyclone centers has been observed on the southeast of Arabian Peninsula, the Arabian Sea, the Indian subcontinent and the eastern coasts of the Arabian Sea in the range of 40 to 80 degrees east and 10 to 30 degrees north, respectively. The highest frequency of centers (sub-ranges of expansion) (spatial distribution of precipitation in Iran) in the range of 8 with 675 (southeast of the Arabian Peninsula) (western half, northeastern, eastern and region in central Iran), 9 with 213 (northern part of the Arabian Sea) (all of Iran but concentrated in the western half to the south and northeast), 10 with 197 (Indian subcontinent and the eastern coasts of the Arabian Sea) (almost all of Iran), 3 with 172 (southern Iran and Persian Gulf) (western Iran) and 4 with 99 (Pakistan and southeast) (almost all of Iran and concentrated in the west) have been observed.Rainy days 10-30 mmFrom 167 days of 10-30 mm of precipitation, 67.3% (104 days) of the independent closed center of Arabian anticyclone was observed. In other cases, the extension of a trough from the Siberian and Tibetan anticyclones on the study area and its integration with the Arabian anticyclone has been observed. The frequency of anticyclone centers in this part has been on the southeast of the Arabian Peninsula and the northern part of the Arabian Sea and in the range of 50 to 75 degrees east and 17 to 27 degrees north. The highest frequency of centers (sub-ranges of expansion) (spatial distribution of precipitation in Iran) in the range of 8 with 35 (southeast of the Arabian Peninsula) (west half to south of Iran but concentrated in the west, southwest and Zagros mountains), 9 with 25 (northern part of the Arabian Sea) (almost all of Iran but concentrated in the southwest), 10 with 17 (Indian subcontinent and the eastern coasts of the Arabian Sea) (all of Iran but concentrated in the west, southwest and south) have seen, respectively.Rainy days more than 30 mm Throughout the statistical period, 55 days were accompanied by heavy precipitation, of which 23 days (less than 50%) the Arabian anticyclone had a closed center. 32 days were observed on the study area along with Tibetan and Siberian anticyclones trough. The frequency and spatial distribution of anticyclone centers has been scattered. It covers 50 to 74 degrees east longitude. Its maximum concentration was in the two southeastern regions of the Arabian Peninsula and the Arabian Sea. The highest frequency of centers (sub-ranges of expansion) (spatial distribution of precipitation in Iran) in the range of 8 with 8 (southeast of the Arabian Peninsula and Oman Sea) (western half of Iran but focus on the southwest), 9 with 7 (Arabian Sea) (northwest to south of Iran but concentrated in the west), 10 with 17 (Indian subcontinent and eastern coasts of the Arabian Sea) (all of Iran but concentrated in the west, southwest and south) center is observed, respectively.

The results showed that on light, medium and heavy rainy days 80.2, 67.3 and 41.8%, respectively, the Arabian anticyclone has an independent closed center and on other days, it is combined with a trough of Siberian and Tibetan anticyclones at the level of 850 hPa. There is a high correlation between the location of position centers at level 850 hPa on the sea, and the distribution and amount of precipitation in Iran. As with the occurrence of precipitation in Iran, the frequency of anticyclone centers is concentrated on the southeastern coast of the Arabian Peninsula and the Arabian Sea. But the maximum precipitation (heavy precipitation) in Iran is when anticyclone is located in the Arabian Sea. In general, moving east towards anticyclone and settling on the Arabian and Oman Seas, according to the prevailing atmospheric circulation mechanism, is the most suitable model for transferring moisture to the incoming precipitation systems to Iran. It can be said that the position of this anticyclone and its displacement, especially to the east and northeast, is directly related to the amount and position of the maximum precipitation zone in Iran.

Caves play an important role in human habitation, geotourism and groundwater supply. In addition, they have biodiversity, tectonic evidence, fossil artifacts and archaeological significance. Caves have also been used for fun and worship. Unique phenomena, fossils, archeological artifacts and unique wildlife in the caves have made them important tourism attractions with high economic value. Caves are also considered as one of the oldest geotourist sites. Today, cave tourism encompasses a wide range of activities, from watch the scenery to see the wildlife, professional exploration and caving.

Research materials was books, articles, reports and visual documents. The research method was based on field study, direct observation, measurement and to some extent library. Mathematical, relative and elevation position, distribution, distance and access, geological status, genetic characteristics, topography and geomorphology condition, spatial dimensions, geohydrological aspects, biological characteristics, geotouristic status, stone caves and existing dissolution forms, archaeological aspects, existing fossils and their safety and protection aspects of the studied caves were investigated. Based on the instructions for protection and exploitation of caves, how to protect and exploit each of them was determined and graded each from a protection perspective and their privacy were introduced. In order to accurately measurement the geological structures and geometry of caves, a compass device and to estimate the distance and dimensions of the interior space of the caves laser meter was used. For sampling the water accumulated in the caves a water test tube and to place samples of rocks, fossils, etc zipped plastic was used. A questionnaire, checklist and identity card were used to record the characteristics of each caves.

A total of 16 caves were surveyed, most of which are located in Bojnourd and Esfarayen due to geological and climatic conditions, and 19 new caves were discovered in North Khorasan Province; Who need field visits and study10 caves have formed in the middle part of the province, which has more rainfall and lower temperature; Which indicates the effect of the climatic factor of altitude in the formation of some caves in this province. Also, 10 caves have been created in the eastern half of the province, which shows the superiority of the fault tectonic role than dissolution in this part.Due to the often calcareous lithology, mountain topography and mechanical destruction, finding the mouth of most caves is difficult. For this purpose, their mathematical and altitude coordinates were obtained and recorded with GPS.The mouths of caves have not developed in a specific direction of the slope. In shady slopes (ubac), the process of physical destruction and in sunny slopes (adret), mechanical degradation and tectonic fault processes have played a role in creating and expanding the mouths of caves. 9 caves are located at an altitude of 1000 to 1500 meters, which often matches with the limb of the anticlines, and tectonics has caused the greatest pressure and shearing stress to occur on the limb of the folds.8 caves have horizontal entrance corridors, that 7 cases have been formed and developed on the fault surface and in 7 of the caves without horizontal entrance corridors, the mouth corresponds to the fault surface. 7 caves have halls, that 6 cases have been formed and developed on the fault plate.6 caves of the province have been formed and developed in the light orbitolina limestone called Tirgan. Limestone and dolomitic limestone known as Lar Formation in the eastern Alborz zone (Binalood), is in second place. Marbled rocks, crushing, displacement and discontinuity in the vicinity of the fault plate, having aragonite rock, presence of breccia (It) and fault gouge, occurrence of main fault in the interior space of the cave, presence of transverse faults perpendicular to the main fault and presence of alternating faults along the length of most of the existing caves, indicate the superiority of the fault tectonics than dissolution process in the formation and development of caves. In terms of antiquity of the formations, dissolved spaces and evolved dissolution forms, the Gomnamane-Salug, Armadloo, Kaftarake-Daragh, Gesk and Ganjkooh caves are old and other caves are young.In the formation and development of most caves in North Khorasan province, fault tectonics and dissolution have played a role with the superiority of faulting; Which corresponds to the tectonic position of Kopet-dagh zone and the northern Khorasan region.There are 10 wet caves and 6 dry caves without dissolution process.There is water only in the caves of Siahkhaneh and Ganjkooh. Parameters affecting the chemical quality of drinking water such as PH, EC, temperature, nitrate, sulfate, chloride, total hardness, calcium, magnesium, total alkalinity, carbonate and bicarbonate were tested. The water of the Siahkhaneh cave is relatively light and suitable for good drinking. The water PH of Ganjkooh cave is neutral and is around 7.6 and it is generally known as a light water and very suitable for drinking.The caves of Gomnamane-Salug, Poostinduz, Honameh, Kafar Ghaleh, Siahkhaneh, Babaghodrat and Noshirvan have no bats and the rest have bats.The investment is done in the handmade collection caves of Honameh and Babaghodrat, but it needs more investment while preserving these natural and historical heritages. Bidak, Gomnamane-Salug, Armadloo, Kaftarake-Daragh, Gesk, Konehgarm and Ganjkooh have typical dissolution forms and need more protection.The entrance of Bidak, Yayjat, Armadloo, Kafar Ghaleh, Gesk, Konehgarm and Ganjkooh caves is in the form of wells or looks like a natural well; and must be entered with a static rope and harness.Apart from Babaghodrat and Noshirvan caves, there is a possibility of wild animals in other caves, of which wolves and leopards are the predominant animal species, respectively. In Armadloo cave, due to its proximity to Golestan National Park, the presence of bears is possible.Kafar Ghaleh and Konehgarm caves are completely unstable and are not suitable for nature tourists, and Konehgarm cave is 1st degree type with forbidden access.The caves of Gesk and Konehgarm have a high great depth of movement and the caves of Bidak, Armadloo, Poostinduz and Kafar Ghaleh have a great depth of movement.Bidak, Gomnamane-Salug, Armadloo, Kaftarake-Daragh, Honameh, Babaghodrat, Gesk, Konehgarm and Ganjkooh caves have a very protective value due to their beautiful dissolution forms and their vulnerability and fragility.

Honameh and Babaghodrat caves are handmade, Siahkhaneh and Noshirvan are natural-handmade and 12 other items are natural, the role of fault tectonics is more prominent than the dissolution action. Chemically, the accumulated water in Ganjkooh cave is light and very suitable and in Siahkhaneh cave is similar to surface waters, good, relatively light and suitable for drinking. These caves are formed in Tirgan, Mozduran, Shurijeh, Lar and Pliocene conglomerate. The caves of Honameh, Kafar Qaleh, Babaghodrat and Gesk have archeological importance. 9 of them have bats. Gesk and Konehgarm caves are the deepest and most technical, Konehgarm cave is 1st degree type with forbidden access.

The effect of wind cooling in combination with temperature, which is expressed as a special feeling, is called Wind Chill, and the Wind Chill index is used to show the effects of cold. Wind Chills Apart from their beneficial effects on agriculture, they, as one of the natural disasters of atmospheric damage, sometimes cause a lot of financial and even human losses. Since temperature, precipitation and wind are the main elements of climate formation in any region, changes in their behavior can change the climate structure of any region. Therefore, the study of the past trends and behaviors of these climatic elements in the form of various indicators and scales of time and space, is very important and has been a large part of climate research. Researchers' past research shows that temperatures and changes are noticeable in many parts of the world. A review of these valuable sources shows that, so far, many efforts have been made with different approaches and perspectives on the quantitative and qualitative status of temperature and wind speed and related indicators. But what is certain is that no scientific and comprehensive study has been done in Kurdistan province regarding Wind Chills in Zarrineh Obato high plain. Therefore, conducting this study is a special necessity and can be a small step and a starting point to study and explain the specific environmental phenomena of this geographical area in the cold period of the year. One of the questions that arises is whether the behavior of Wind Chills in the Zarrineh Obato Plain has changed over the last three decades.

The main purpose of this study is to study climatic elements and changes in atmospheric phenomena, especially wind chills indexing and their classification in order to study and model the past behavior of Wind Chills during the last three decades using Mann-Kendall graphical statistical method and polynomial regression. To help decision-makers manage and reduce the effects of wind chills.Research MethodsIn order to investigate the past behavior of Wind Chills in Zarrineh Obato plain, after collecting and summarizing daily data on temperature and wind speed of stations around the plain during the statistical period of 32 years (1989-2020), the status of data in terms of quantity and quality control The normality and homogeneity of the data were assessed using the Run Test. Then, according to the latest model of the Canadian Meteorological Organization, the Wind Chill index was defined by establishing temperature conditions of at least 2 degrees Celsius and wind speeds above 4.8 meters per second on a five-point Likert scale. After that, the frequency and intensity of wind chills were calculated and used as the basis for descriptive statistics analysis in SPSS and Excel software. Then, to identify the linear and nonlinear behavior and fit the trend line and calculate its slope, polynomial nonlinear polynomial regression was used based on the least squares size method. In addition, Man-Kendall test and T statistic of Man-Kendall were used to investigate the possible deviation and to determine the type and time of change in the time series of mean temperature, wind speed and wind chill index for the station closest to Zarrineh plain.

The results showed that in February, Wind Chills first (zero to -9 C˚) and second (-10 to -27 C˚) had the highest frequency of occurrence, and although based on the fit of the linear regression equation, The frequency of Wind Chills has been increasing overall, but unlike the second floor Wind Chills, this upward trend has been more related to the frequency of first floor Wind Chills and the significant increase in their number. The frequency of days with Wind Chill on the first floor was about 64% of the total Wind Chills and the frequency of Wind Chills on the second floor was about 36%. In the middle of the study period, there was a clear discrepancy and inconsistency between the frequencies of Wind Chills of the mentioned classes. This means that, in the years when the incidence of Wind Chills increased, the frequency of Wind Chills decreased relatively severely, both in number and severity. Although due to the mountainous nature of Kurdistan region and statistical limitations and lack of automated meteorological stations in the region, it is not easy and reliable to talk about climate and its changes, but the results of Mann-Kendall model analysis on the frequency of wind chills and The average annual temperature intensity of Wind Chills in the plain showed that, so far, there have been several jumps and the beginning of sudden changes in the frequency of Wind Chills during the 1990's. However, since the intersections of the two components U and U' related to the Man-Kendall statistical-graphic diagram within each other within the critical ±1.96 range intersected, so no significant jump was proven, but there are clear signs and signs of a decreasing trend. Wind chills are common in the time series, especially in the two decades of 2010-2020. The changes of the mentioned components for the annual average temperature of Wind Chills of different classes with the frequency of their occurrence have been completely different and vice versa. Thus, although the average temperature of Wind Chills has decreased in the two decades of 2000-2010, but as can be seen from the U' component diagram, the increasing annual average temperature of Wind Chills for the first and second temperature classes and the average temperature of total Wind Chills during the 2010's Shows an upward trend. This means that the average temperature of Wind Chills in the Zarrineh Obatovo Plain has increased significantly since the early 2020's. This issue was also emphasized by the field study and the statements of the villagers in the study area. The result of this research, with a slight difference in the study area, is consistent with the valuable work of many researchers on the beginning of the increasing trend of temperature in different regions of Iran during the last two decades.In general, the winter temperature in the region has increased, and as a result, both the coldness of Wind Chills and the frequency of their occurrence have changed. Thus, the cooling temperature of Wind Chills has been decreasing and in 1990 it has experienced a significant jump. Since the mid-1990's, the annual frequency of the first floor of Wind Chills has been declining, showing several significant jumps, and has lost its long-term normal state.

Climate change is considered as one of the environmental challenges in recent decades. Climatologists have evaluated the behavior and change of climatic elements to identify weather change and its importance to the structure of the Earth's weather in recent years. Trend is one of the most critical components of a series, which is very practical in climate to investigate the long-term orientation of time series. Outgoing long Wave Radiation (OLR) is one of the basic variables of weather, as well as the core component of the earth radiation budget (Whitburn et al., 2021: 1. Scherrick et al., 2018: 1), which is known as an essential parameter in applications for cloud identification and precipitation estimation. Therefore, it is necessary to study Outgoing long Wave Radiation trends at different temporal and spatial scales. Mann-Kendall test is one of the widely used non-parametric tests, which has been applied in climate studies, especially in examining the trend significance (Gauss and Trajkovic, 2013: 172. Nelson, 2001: 57). Kefayat Motlagh et al. (2018: 128) indicated that the trend of earthlight radiation is increasing by 0.4 watts per square meter in each decade, while the trend of Iran's earthlight radiation is more than three times (1.4 watts per square meter) the global trend in the same period. Sari Sarraf et al. (2015: 33) investigated the effects of global warming on the cities’ climate in the Urmia Lake basin using the Kendall method and the least-squares error. They concluded that the average rainfall in the whole region decreased by about 4 mm per year. Chu and Wang (1997: 636) examined the trend through Mann-Kendall statistics to find climate change in convective precipitation in the western Pacific and Indian Oceans from Outgoing long Wave Radiation. They found a significant decrease in OLR in the tropical central and western Pacific and a large part of the Indian Ocean, while the largest increase in OLR over time was in North Australia. In this study, the trend and changes were investigated using the non-parametric Man Kendall method, the amount of changes was determined by Sen's Slope method, and hot spots analysis was performed by Jay statistical method given. In addition, spatial and cluster analysis was performed on the average data and seasonal variation coefficient due to the importance of Outgoing long Wave Radiation at different temporal and spatial scales.

Iran, with an area of 1648195 square kilometers, is located between 25 to 40 degrees north latitude and 44 to 63 degrees east longitude. The data of the Atmospheric Infrared Sounder (AIRS), Aqua satellite, were used to measure Outgoing long Wave Radiation for a statistical period of 17 years (01/07/2002 to 01/07/2019). MATLAB, ArcGIS, and SPSS software were used for calculations and maps. First, the average monthly data maps of Outgoing long Wave Radiation were prepared, and then, the standard deviation parameter was used to show the data dispersion. Moreover, the Mann-Kendall test was used to determine the trend of outgoing long wave radiation on each cell in Iran, and the slope of the data series trend line was calculated by Sen's Slope estimator method. Spatial variations of outgoing long wave radiation were calculated over time as spatial behavior using hot spot map analysis.

According to Stefan–Boltzmann law, the Earth's surface and atmosphere emit energy in waves in proportion to their temperature. These waves propagate in the range of long wavelengths, i.e., between 4 and 100 microns given the normal surface temperature and atmosphere (Kaviani and Alijani, 2000: 94). According to the maps, the average long-wave radiation fluctuates between wet and dry seasons as well as geographical offerings, and its amount is higher in the dry season and the southern regions of the country. One of the reasons for the maximum outgoing long wave radiation of southern Iran in early spring is the angle of vertical radiation of the sun and the clear sky, which receives more energy than the latitudes, and the amount of energy output is more in the south of Iran than in the north. The outgoing long wave radiation increases gradually due to the decrease in cloudiness, and more energy is received in longer geographical areas gradually, in May and June, with the onset of summer as the day length increases. The ingoing and outgoing radiation becomes more uniform throughout the regions of Iran, except for the mountainous areas and the coasts. According to the results of cluster diagrams in the three seasons of spring, autumn, and winter, the radiation patterns of the basins are similar to the latitude and mountainous areas in Iran. The largest cluster in spring belongs to the south of the Alborz Mountains and the west of the Middle Zagros Mountains depending on latitude and sunny slopes. The highest uniformity in all seasons is located in the southwestern quarter of Iran, and Haraz heights in southern Iran are distinguished as a cold spot among the surrounding basins. Examination of the trend by the Mann-Kendall method showed no significant trend on an annual scale, but monthly and seasonal anomalies are quite evident. The descending trend of long wave radiation can be confirmed only in May and September in some parts of the country, and the dominant trend in most months of summer, autumn, and winter is increasing in most parts of the country, including northern offerings. The results of the G-statistic study also show the changes of hot spots towards northern offerings.

The trend of 17 years of outgoing long wave radiation of the earth (2003-2019) was investigated in monthly, seasonal, and annual time scales using non-parametric Men-Kendall test and hot spot statistics (G). Changes and abnormalities of long wave radiation were observed on a monthly and seasonal time scale in most parts of the country. These changes can be due to changes in the amount of energy input, cloud cover, and the type of clouds, aerosols, atmospheric compounds, such as moisture from global warming and other greenhouse gases. In addition, changes in land cover such as vegetation, forests, water resources, salinities, and sand dunes can influence the sensible heat and change of ground wave radiation due to the amount of moisture, which needs further investigation in this regard.