فصلنامه مطالعات جغرافیایی مناطق خشک
پیاپی 49 (پاییز 1401)

Severe climate change, declining rainfall, rising temperatures, and subsequent increased evapotranspiration have led to significant reductions in water levels in recent decades. In the meantime, the study of fluctuations in the water level of lakes, in order to protect them in terms of importance, has gained a special place in recent years among countries at the national and regional levels. The purpose of this study is to investigate the physical changes of Arjan wetland and the trend of climatic parameters as well as the relationship between the mentioned cases. To achieve this goal, the area of ​​the lakes from 1986 to 2018 was calculated using Landsat satellite images and the NDWI index. The results indicate a reduction in area over the period under study. It has been dried so that Arjan wetland has been completely since 2013. It is the lowest amount of precipitation recorded in this period in 2008 and 2010 with the amount of 127.82 and 107.7 mm, respectively. The average temperature in the study period 2018-1986 was 19.44 degrees Celsius and the temperature in this period has increased by 0.6 degrees Celsius. Among the studied climatic parameters, the precipitation parameter with a correlation coefficient of about 0.53 and the potential evapotranspiration with a correlation coefficient of about -0.43 were more correlated with changes in the area of ​​lakes. The HadCM2 model of Cordex-WAS project under two scenarios of RCP4.5 and RCP8.5 was used to predict the climatic parameters of temperature and precipitation of the study area in the coming decades (2020-2050). The results show a decreasing trend of precipitation. And rising temperatures. Among the factors studied in this study, two main factors, the average annual rainfall of the study area and annual evaporation in recent years were considered as the factors that had the greatest impact and correlation with the physical changes of the wetland.

Today، the reduction of land resources due to soil erosion causes many human and financial losses every year. Therefore, in this research in order to estimate soil erosion and sediment production, using the modified PSIAC experimental method (MPSIAC) and the use of geographic information system (GIS) in the Kozetopraghi watershed of Ardabil province. For this purpose, the required information layers were prepared using basic maps and GIS. After collecting, preparing and entering the information layers into the GIS environment and combining these layers, the amount of specific sediment of the basin was calculated between 7.69 and 0.76 tons per hectare per year. The total and average amount of annual soil erosion of the basin was also equal to 0 to 57.62 and 11.66 tons per hectare per year, respectively. Also, the highest and lowest amount of erosion in the sub-basins is based on the prioritization of sub-basins 15 and 36, whose values are respectively It was calculated as 28.50 and 2.83 tons per hectare per year. The average production sediment for the studied basin was estimated to be 3.16 tons per hectare per year. The prioritization of sub-basins based on the amount of soil erosion showed that sub-basins 15 and 34 have the highest and lowest amount of erosion (28.48 and 2.8 tons per hectare per year), respectively. Based on the amount of sediment, sub-basins 16 and 34 produce the highest and lowest amount of sediment respectively (7.16 and 0.76 tons per hectare per year). Based on the results obtained from the analysis of parameters related to erosion in the MPSIAC model, it can be concluded that the prioritization can be considered as the basis for decision-making and management in controlling erosion and sediment production.

The purpose of this research is to evaluate and explain the role and position of local activists in the process of sustainable regeneration of inefficient and worn-out tissues of Mashhad.In this research, an attempt has been made to answer these questions, what is the role and position of different actors with special emphasis on local actors in the process of sustainable urban regeneration? And how do they play a role in this process? This research is conducted with a qualitative approach in order to determine the position and realization of cooperation between the actors of this process.The strategy of this research is a combination of case study and theorizing. Observation, interview and questionnaire (targeted sampling) techniques have been used to collect the required information.The results of this research show that according to the identification of 57 active actors and the division of actors into primary and secondary actors (16 homogeneous categories), different interests and interests as well as the power to influence other actors, it is necessary to change the attitude in their role based on Collaborative governance should be realized.. In this regard, it is necessary to emphasize the need for a joint plan and program to manage the actors of this process, and there should be a strong leadership to support the presence of all actors in this process.The investigations carried out in this research show that collaborative governance in the process of sustainable urban regeneration in Mashhad city occurs when both at the macro and strategic level and at the operational level, there is integrated interaction and coordination between actors based on a joint action plan to be considered and acted upon.

Residential satisfaction can be defined as residents' perception of the extent to which their expectations of the residential environment are met. Failure to meet these expectations will lead to dissatisfaction with the residential environment. Residential dissatisfaction, while reducing the quality of individual life, can also have negative social effects. Therefore, measuring residential satisfaction and the factors affecting it is very important. The purpose of this study is to measure residential satisfaction and analyze the impact of residential environment dimensions on this variable in Bâlâ neighborhood as an old neighborhood in Qaen city. This research is a field study and a questionnaire was used to collect data and sample size is 370 people. One-sample t-test, Pearson correlation, multiple regression analysis and Chow test were also used to analyze the data. The results show that people's satisfaction with their residential environment is above average. Also, all 4 studied residential dimensions (housing/dwelling, environmental quality, access to facilities and social environment of neighborhood) have a significant effect on residential satisfaction. According to the results of multiple regression, the independent variables explain and predict 58% of the variance of the residential satisfaction variable. The beta coefficient, the environmental-visual quality of the neighborhood with a coefficient of 0.383 has greatest impact on residential satisfaction and in the next rank is the social environment of the neighborhood with a coefficient of 0.326, and the variable of access to facilities and housing quality has been assigned the third and fourth ranks.Therefore, it can be said that the role of the neighborhood in residential satisfaction is more than the role of the housing. Also, the results of Chow test showed that demographic characteristics of residents have a moderating role in some relationships between independent and dependent variables.

Potholes are one of the spectacular landforms of rocks, especially sandstones. In this paper, 48 samples of Agha-Jari Sandstones were prepared and thin sections were obtained from them to investigate the sandstone minerals and porosity by Polarizing microscope and also by Bernard calcium meter. For estimating of rock hardness we use Schmidt Hammer Model N and ISRM (1978) standard. Maps were prepared with 1:25000 topographic map, Arc/GIS software and Jmicrovision software was used to obtain the amount and percentage of thin section minerals. The results showed that Potholes are a function of physical conditions of rocks and mineralogy compounds of rocks with the erosion role of water flow in calcium carbonate of stone. Based on the data and results, it was found that the characteristics of Agha-Jari sandstone compounds play an important role in the generation of Potholes in this formation. It was determined that the abundant presence of Feldspar minerals and high percentage of porosity in the oldest layer (A) of Agha-Jari Formation plays a great role in the looseness and creation of Potholes in that layer. Other layers with Potholes such as (B, D, C, and F Layers) show a significant relationship between increasing quartz percentage and decreasing the percentage of feldspar and calcium carbonate. The results also showed that the mean calcium carbonate of Agha-Jari sandstone is about 50% which is one of the reasons for the existence of Potholes in layers despite the hardness of Schmidt Hammer is high.

Among the various forms of water erosion, badland erosion is one of the most important emerging factors in water resources and its sustainability. The purpose of this study is to zoning of e badland erosion in the kelerz Basin in Garmsar. For this purpose environmental factors including geological formations, elevation classes, slope, slope direction and vegetation were compared using pairwise comparisons. Also, pairwise comparisons between sub-basins were performed in each of the five criteria mentioned above, and by calculating the multiplication of the total weight of the criteria and sub-basins relative to each other, the priority of each sub-basin was determined. In parallel with the above steps, the area distribution map was mapped using Landsat 8 OLI satellite imagery and Google Earth imagery and was monitored and modified with the help of field surveys and operations to eventually overlap sub-basin priority maps with the existing erosion status map. The accuracy of the proposed model was evaluated. The results of the overlap of the badland Distribution layer with the Erosion Intensity Layer show that sub-basins 2, 3, 4 and 12 have a 100% correlation between the rank calculated in the study with the rank obtained from the frequency ratio. Also sub-basins 1, 5, 9, 10 and 11 with amplitude difference of maximum 2 rank imply high accuracy of calculations. The results also show that sub-basins 12 and 9 have the highest intensity of badland erosion. The sub-basins 11, 4, 6 and 7 are characterized by high erosion and sub-basin 10 with moderate erosion and the rest of the sub-basins are evaluated with low erosion.