فصلنامه فضای جغرافیایی
پیاپی 76 (زمستان 1400)

Gully erosion is considered to be one of the most destructive and complex types of water erosion. The gully is a stream with steep slopes and active erosional forehead which has been routinely created by erosion due to the alternating surface flow during intensive rain or after it. Gullies are deep canals that are not destroyed by normal plowing, but temporary gullies in agricultural fields, such as ravines, are so small that their repairing is possible by usual plowing. Formation and expansion of gully erosion are influenced by various factors such as physical properties and distribution of its forming particles and amount of salts in the soil and geological formations. Incorrect using of land and changing land use, excessive grazing, lack of correct management of agricultural lands, plowing in the direction of slope, road construction and mining in basins also lead to dredging. The purpose of this study is to investigate the physical and chemical properties of soil and morphometry of gullies in order to identify and control this type of erosion to proper regional planning and actions of water management to control and reduce the damages caused by soil erosion in line with sustainable development goals in the study area.

 It was used from the library documents, topographic maps with the scales of 1: 25000, 1:50000 and the geological maps of 1:100000 of the area for primary identifying of the natural features of the basin. Then 10 samples were selected from identified gullies with surveys and measured the morphometric characteristics of the gullies including the length, width and depth of them. 10 soil samples were collected, transferred to the soil laboratory for analyzing and measured for the specimens. The Pearson coefficient of correlation and regression analysis were used to investigate the correlation between dependent and independent variables. Regression analysis is a statistical process to estimate the relationship between variables, how the amount of the dependent variable changes with the turn of each independent variables and fixing other independent variables.

The morphometric features include the average depth, width, length and volume of the gully. According to the table data (2), the average length is 67/3 meters, width is 3/43 meters and depth is 2 meters which is from small and little depth of the gullies. The volume of the gully is correlated with other variables, which has the highest correlation with EC with the amount of (./796). The correlation between sodium and electrical conductivity with the growth of the gullies is positive. The reason of this, is the release of sodium in the replacement of calcium or potassium, and the increase of soil propagation and the spread of its particles, and provides the field of the development of gully erosion. Accoding to the obtaied results of creating of regression relations between the volume of gullies with soil features, it is seemed that there is a significant correlation in the surface of 95% with high correlation coefficient, which indicates the high soil propagation property in the location of gullies and the formation of gully erosion .Different factors influence in creating and expanding the gullies that physical and chemical characteristics of the soil are very important among them.

 The obtained results of gullies’ morphometry by regression methods show that the volume of the gully is correlated highly and directly with its depth as among the morphometric parameters, (the width, depth, length and volume of the gully) the depth and length of the gully have more relation with its volume and the amount of wasted soil. The obtained results of the correlation between gully volume and soil properties (PH, electrical conductivity, organic matters, sodium, calcium, magnesium and lime) showed that the volume of gullies is increased by decreasing PH, organic matters, lime and potassium.  This means, these parameters have a significant correlation with the volume of the gullies in the opposite direction. The correlation between the volume of the gully with the sodium parameters and the electrical conductivity is positive, and being high of these parameters causes the soil spreading and expanding of the volume of the gullies. The correlation between the expansion of the gullies is also positive relation with electrical conductivity, as by increasing solutes in the soil, the volume of the gullies is also increased.

One of the most important and essential steps in using rain water harvesting systems is to locate and identify suitable places for implementing this technology.Considering that the utilization of the agent based spatial systems is rapidly expanding and the technology of operating agent based systems has become a growing field of research and research,the purpose of the present study is to develop a framework for the identification of areas with potential for rain water harvesting within the campus of Hakim Sabzevari University to provide appropriate tools for supporting decision making by managers and managers of the operation and management of local water resources.As a result, in this study, the simulation environment with NetLogo software as a tool for creating agent based spatial models was investigated and after mapping for each index in the ArcGIS environment, analyzes related to decision making of agent based were performed in the form of existing functions, and finally an assessment of the spatial collection rain water harvesting was studied in the studied area. The results showed that by using agent based spatial models modeling, it is possible to identify areas site selection of collecting rain water harvesting by simulating rain conditions and assessing the location of rain water harvesting collection. Also the results showed bayer lands without construction, appropriate empty space, placing on the course of runoff and a significant drop in water flow in the southwest of the university due to slope reduction, the main factors have been suitable places for collecting rain water harvesting.

Studies show that landing area crops and crop growth curves for countries have provided them with several million new jobs and billions of dollars in gross income, with more than 50% of them being farmers. Due to the growth curve of crops in 8 plots of land applied to Landsat 8 images, alfalfa (105) had the best, most lively and least stressful vegetation, and alfalfa (303) had the least vegetation at peak vegetation growth and also The highest coefficient of variation was in its growth curve. According to the results obtained from the crop area of NDVI image, we found that wheat (304) had the highest difference and wheat (108) had the least difference. In the year 98, the total area of these 8 plots is 82.775 hectares and according to the results of the company was 89 hectares. In other words, the area calculated from the NDVI image in 1398 was only about 7% lower.

Over recent years, the extreme temperature events (cold and heat waves) have been a burning issue driving the scientific society to carry out extensive researches to investigate and discover the trend, frequency, intensity, and scope of their occurrence. The goal of this study is also the recognition of the trend and spatial analysis of the frequency and maximum of extreme cold days in northwest Iran. For this purpose, the data of minimum daily temperature from 21 synoptic stations of the country for the months of January, February, March, April, November, and December from 1986 to 2017 were used. By using the standard index coefficient, the cold days with an intensity of less than -1/2 were extracted as the extreme cold days for each station monthly. The Mann-Kendall test and spatial analysis with the Anselin Local Moran's I and  hotspot index were used to identify the behavior of extreme cold days. The results demonstrated that the presence of a decreasing trend of extreme cold days in most months (except for a few stations) had no statistical significance, and a significant decreasing trend occurred only in March in almost 50% of the stations. The spatial analysis of the trend of March indicated that the significant decreasing trend had created a cluster and a cold spot. Moreover, the results obtained from spatial analysis indexes in the northwest of the country demonstrated that the frequency and the maximum number of events of extreme cold days in the area in the studied months had formed a high cluster pattern (positive autocorrelation) and a low cluster pattern (negative autocorrelation), while more than 50% of the area of the studied zone had no spatial pattern. The cluster patterns in different months of the year formed in various places and the spatial arrangement of autocorrelation patterns and hotspots were not similar in the studied months. Furthermore, the obtained results based on the  index confirm the formation location of clusters in the Anselin Local Moran's I.

Development-driven projects are the context in which urban regeneration can revitalize the fabric. The implementation of these projects, while creating functional-social vitality and revitalizing urban identity and heritage, strengthens economic structures and attracts large investments in the area of ​​worn-out urban structures. For this purpose, in this research, the stimulus project for the development of Imam Ali (AS) Square in Isfahan has been studied and evaluated. The research method is descriptive-analytical and applied in the framework of positivism and with inductive approach. The method of data collection is library and field. The statistical population of the study includes urban management experts in the study area and residents, businesses and other people passing through the area of ​​Imam Ali (AS) and the sample size is 266 people for citizens and 30 people for experts. Data analysis methods include confirmatory factor analysis, central mean parameter and T-test. The results showed that the evaluation model of development stimulus projects consists of five dimensions. These dimensions include social, economic, physical, environmental and spatial sustainability indicators. Also, the results of the analysis of experts showed that the model has validity and each of the factor loads indicates the high validity of the five components. Also, the analysis of residents' opinions showed that the project stimulating the development of Imam Ali Square (AS) in terms of social and physical factors with averages of 3.65 and 3.37, respectively, has had a somewhat positive effect; But its impact on other aspects of regeneration, especially economic and environmental variables has been less.

The purpose of this study is to analyze the winter temperature status of Iran during the Siberian High Rule in Iran. For this purpose, daily winter temperature data of 283 ynoptic stations of the country were extracted from the Meteorological Organization during the period of 1341 to 2011. Then, to extract the Siberian high-pressure model, ground-level pressure data were extracted from the US National Oceanic and Oceanographic Database. Then, by performing cluster analysis, the Siberian high pressure pattern is identified and extracted. In order to evaluate and validate the identification of Siberian High Pressure Pattern, Davis-Bouldin Validity Index (DBI), Silhouette Index (SI), Diagnostic Function Analysis (DFA), Cummins Analysis (k-M) have been used. The results of this study indicate that the spatial distribution of mean daily temperature is strongly influenced by the Siberian high pressure system, so that during the dominance of this system over the Iranian climate, the temperature in most parts of Iran has declined sharply, which is a higher share of December. This system enters Iran in the east-west direction more than northeast and west of the Caspian Sea and causes cold air to fall on the Iranian climate, so that in addition to the thickness of the atmosphere, cold air circulation almost dominates all over Iran. Along the Zagros Mountains and the northwestern highlands, these spatial variations in temperature are more pronounced.

Geographical places and spaces have different values that are not stable and change over time. An example of this example in the surrounding environment of the Islamic Republic of Iran is the geopolitical basin of the Caspian Sea, which in the past was considered one of the low geopolitical regions, but today has a high geopolitical value. Therefore, accurate and continuous knowledge of the geopolitical environment of this area is a crucial issue. One of the most important geopolitical aspects of the Caspian Basin is the domestic policy dimension of these countries, which due to its high effects on other geopolitical components of this environment and consequently on the national interests of our country, has been the basis for compiling this article. In fact, the main purpose of this article is to identify the geopolitical variables related to the domestic policy of the countries around the Islamic Republic of Iran in the Caspian Sea basin. In this work, the descriptive-analytical method is used and the author tries to extract the research findings by conducting library and theoretical studies, recognizing the components of domestic politics of the Caspian countries, presenting a questionnaire and conducting tests on the questionnaire data. Present research results. Finally, the five variables "divergence, autonomy and separatism", "type and political structure of government", "national consensus and social participation", "status of political independence", "constitution and quality of legislation" have been counted, which are very effective. Above it, on other geopolitical dimensions and variables, can be the basis of the study of geopolitical environment in the domestic policy of the Caspian Sea countries to obtain a more accurate and complete understanding of the geopolitical environment around the Islamic Republic of Iran in this area.

Today, with the help of new agricultural technologies, efforts are being made to increase the productivity of the crop. To achieve this goal, while using the latest technologies in the world, agricultural lands are being expanded geographically. However, the mere use of new technology, and the uncontrolled development of arable land, does not in itself increase productivity, but rather the manpower employed in those industries, to embrace and use existing technologies. Therefore, this study was conducted with the main purpose of assessing the acceptance factors of the use of new technologies in the agricultural industry, and seeks to answer the fundamental question of "why most farmers continue to cultivate traditionally, and do not welcome modern production methods?». For this purpose, with the help of Daniel Lernerchr('39')s modernization theories and Smelserchr('39')s theories of development, we collected data and conducted two semi-standard interviews and a questionnaire. Qualitative data analysis was performed by structuring technique (slt) and quantitative data was performed by SPSS software. During the research process, interviews were conducted with 60 farmers who were operating in the downstream route of Sattar Khan Ahar Dam. Theoretical sampling continued until the theoretical saturation point was reached. After extracting 4 factors(individual-economic-social and cultural-psychological and motivational)and 13 concepts, the most important factors for accepting the use of new agricultural technologies, in order of priority include: farmerschr('39') ignorance, mental norms, expectations from government officials, cost Expect training classes from experts in extension, monetary and financial capital, industry innovation, individual farmer talent and ability, self-confidence, marketing, education and experience, psychological renewal and a sense of pleasure.

Geomythology is the scientific study of the oral traditions of ancient cultures to explain some mysterious phenomena and to understand geological events such as volcanoes, earthquakes, megafloods, and climate change. Geology is also trying to identify some of the past catastrophic events through the interpretation of myths. The purpose of this research is to analyze the legend of the submerged city of Marivan in ancient times. The legend is similar to Noah's storm in the Bible, but on a local scale. Noah's storm in the Sami mythology, "Ut-Napishtim" in the Babylonian mythology, Ducalion’s Storm in the Greek mythology, and the Var-Jamkard in Iranian mythology. The universality of this narrative shows a major geological event around the world at the same time. Storms are likely to occur in most parts of the world due to heavy rainfall in the Middle Holocene, causing seas and lakes to rise, especially in the Middle East, with crowded settlements. Zaribar Lake, located in Located inside the structural depression (Graben) of Marivan, has created by the traction of the two main faults in the region includes the Zagros and the Chenareh faults, and also their second and third degree Riddle faults. With increasing rainfall in the Middle Holocene, the lake is likely to reach more than 60 square kilometers and submerged settlements in the Marivan Plain. Numerous studies of the region's Paleoclimate have also shown an increase in precipitation at this time and justify the myth.

Today, due to water stress Caused by reduced rainfall and drought in the country on the one hand and the growth of uncontrolled consumption of limited water resources on the other hand, formulating and developing strategies to improve planning, management, sustainability of water resources and consumption patterns in The country is a necessity. One of the most practical methods in this regard is to determine and estimate the effectiveness of effective factors in the resilience of water resources in the country. After reviewing related researches, it was concluded that most of the researches done in this regard have been in order to identify the effective criteria in the evaluation, planning and sustainability of water resources systems and So far, no separate research has been conducted to identify the effective criteria and sub-criteria in the resilience of Iran's water resources; However, relying on the results of articles and authoritative references, it was found that achieving the most effective factors in determining the resilience of water resources, using the Delphi method (due to scientific validity and usability at different levels) is possible. Accordingly, the present study has been written with the aim of identifying, screening and prioritizing resilience criteria and sub-criteria using the Delphi method. According to the first step of the Delphi method, first a list of criteria and sub-criteria was selected by reviewing the research background and then evaluated by a group of 24 environmental and water resources experts (called experts) in two stages. The result of this evaluation is to determine 3 ecological, socio-cultural and economic criteria as the main criteria and to extract 9 criteria and 18 sub-criteria. The result was that after prioritizing the sub-criteria based on two factors of degree and percentage of importance, surface water sub-criteria (spring and river) and precipitation with a coefficient of importance of 2.62 and 2.28 as the most important and permeability sub-criteria (drainage) and temperature, respectively. Significance coefficients of 1.23 and 1.31 were identified as the least important sub-criteria, respectively. Also, by normalizing the obtained coefficients for each of the sub-criteria, a linear formula was proposed to estimate the resilience of water resources.