فصلنامه جغرافیا و پایداری محیط
پیاپی 39 (تابستان 1400)

Snow reservoirs are one of the most important sources of water supply in Iran. This study aims to investigate the changes in snow cover in Sefidrood basin and its sub-basins. To achieve this goal, snow cover images of MODIS's MOD10cm product were used over a period of 19 years (2000 to 2019). After analyzing the images in ENVI software, the snow area of each image was calculated and, consequently, monthly values for all years of the study period were extracted and transferred to ArcGIS software. The modified Mann-Kendall test was applied to examine the annual and seasonal trends of snow cover. Then, the Sen’s slope estimator test was used to determine the rate of change. Based on the findings, it can be seen that the time of beginning and end of snow in Sefidrood basin and its sub-basins has undergone very little change. The snow cover of the basin starts in October and reaches its minimum in April after increasing towards the cold period of the year. January is the month with maximum snow cover in all sub-basins. During the period under review, the range of snow cover was maximum in the water year 2006-2007 and minimum in 2009-2010. Findings from the fit of the modified non-parametric Mann-Kendall test on the annual time series of the snow cover of the basin indicate a decrease and of course insignificant trend in most of the basin area, although sometimes slight increasing trends are also seen. In terms of spatial distribution, in the central and eastern regions of the basin, there is a significant decreasing trend of snow cover; its annual decreasing rate in some areas is 17.77% per decade. Seasonal trends are also decreasing. The highest rate of decrease is related to winter, which in some areas reaches about 33% per decade.

In addition to domestic dust sources, Ahvaz city is affected by most of the foreign sources of dust which is mainly due to locating in the passage of southeast-northwest winds and vice versa. In this study, internal and external dusts were separated to determine the role of climatic factors in the occurrence of dust in Ahvaz. Therefore, the data related to parameters and climatic phenomena affecting the occurrence of dust have been used. Besides, the analysis and comparison of different neural networks have been applied to figure out the importance of each climatic factor in the occurrence of dust. In this study, 70% of the data are entered the network as educational data and 30% as test data. The square sum of educational data error and test data, the relative error of educational data test data and also the correlation coefficient between the measured and estimated values have been compared to evaluate the accuracy of different functions. Finally, the model showing the lowest error rate and the highest correlation coefficient has been selected as the optimal model to investigate the contribution of climatic factors affecting the occurrence of internal and external dust. The results show that wind factor with a speed of more than 6 meters per second and then the wind less than 6 meters per second have played the most important role in the occurrence of internal dust. Moreover, rainfall-changes factor is the third effective one. In the case of foreign dust, since Ahvaz is influenced by the conditions of more remote areas that are almost outside the political borders of Iran, drought factors, SPEI and DTR indices, are considered as the important factors in the occurrence of regional widespread dusts that reach Ahvaz.

Today, the ecotourism industry has become one of the important sources of income for the villagers. IT, as an empowerment and integrator of the value network in the ecotourism industry, can play a significant role in the development of this industry by increasing local employment, increasing the income of local people and capabilities of rural areas. This study aims to provide a model to develop ecotourism industry in Iran with an emphasis on IT. This research is a qualitative research that has been carried out by content analysis and Delphi methods. In the content analysis method, the indicators of the initial model have been extracted. Then, this model has been completed and tested by the Delphi method. The statistical population in the content analysis method included all texts related to the research topic and in the Delphi method were experts and university professors specializing in e-tourism and e-tourism industry which 30 experts cooperated until the end of the third round. Sampling method was done in content analysis method using counting and in Delphi method using snowball. Based on the findings of the first part of the research, 38 indicators have been identified, and in the second part, 24 indicators have been added to model, of which six of the identified indicators have not been agreed by experts. The research model includes 56 indicators, 34 components and 9 dimensions (including legal infrastructure, financial infrastructure, mobile commerce infrastructure, e-advertising management, content marketing, customer relationship management, e-HRM, local partnership and software infrastructure). Paying attention to the model extracted from this research can pave the way for the further development of the ecotourism industry in Iran by using the capabilities of IT.

Landslides are one of the most important environmental processes, especially in mountainous landscapes. Identifying sensitive areas and preparing a landslide risk zoning map is an important step in preventing and reducing the damage caused by this phenomenon. Hashtjin basin, with its mountainous face and considering the geological, lithological, climatic and human conditions, has the necessary conditions for the formation of landslides; therefore, the current study aims at landslide risk zoning in the given area. Therefore, landslide sensitivity analysis for Hashtjin watershed is evaluated according to the efficiency of the results obtained from two models of logistic regression and Anfis to achieve the research goal. Using the interpretation of aerial photographs and field visits, control areas, as a dependent variable, were recorded by GPS. Then, the factors affecting landslides in the area including slope, direction, elevation lines, distance from waterway, distance from fault, distance from road, geology, land use and rainfall were identified according to various sources, field studies and consultation with experts; Then, layers were prepared as independent variables in GIS Arc environment. Moreover, logistic and ANFIS regression models were implemented by entering the aforesaid layers into TERRSET and MATLAB software environment, respectively. The final landslide hazard map of the area was prepared in 5 hazard classes. In this study, 25% of the control samples were used as test data to measure the accuracy of the studied models. The results of validation of the performance of the mentioned models by performing the ROC curve showed that the accuracy of Anfis model and logistic regression were equal to 88.23 and 86.45%, respectively. The findings from Enfis model reveal that approximately 4854 hectares, equivalent to 20.6% of the Hashtjin area are in high and very high class in terms of landslide risk.

Rivers have a lot of complexity and diversity in different environmental conditions, and various natural and human factors affect rivers and change their hydromorphological conditions. In fact, hydromorphological degradation is one of the most important types and causes of river changes which happens due to human interventions and consequently the adjustment of the river channel. Several methods have been developed to study the hydrogeomorphology of rivers. One of these methods is the morphological quality index, which has been proposed as a new protocol to assess the morphological quality of river flow. The present study aims to classify hydromorphological quality of the Haji-Arab River (which is located in the west of Bouin-Zahra city) by Morphological Quality Index (MQI). In this study, two main phases and three sub-phases are used for each phase and applied to eight spans. Various indicators such as: functionality index, artificiality index and adjustment index have been applied on this river. The results show that the amount of MQI in the studied intervals was between 0.82 to 0.74%. Among these, the maximum value was in the spans of 1,2,3,6 with a score of 0.82, while the minimum value was in the span of 8 with a score of 0.74.  In terms of quality, Haji-Arab River is on a good class and has good conditions. The functionality index in this river was zero, which was the result of non-intervention of human in the river. Therefore, it is suggested to protect Haji-Arab River appropriately by proper management.

The danger of amplitude movements is considered as one of the hazards that has occurred in many areas in recent years. Identifying the areas exposed to amplitude movements and estimating its rate plays an important role in managing and controlling this phenomenon. Radar interference technique is an efficient method in measuring ground surface displacement which makes it possible to monitor small movements of the earth surface continuously, with high accuracy and in a wide range. This technology has become very common in the study of natural disasters of the earth, including slope displacement, subsidence, earthquakes and volcanic activity. This technique compares the phase taken from two radar datasets at two different times and. Besides, creating an interrogram, it is able to measure changes on the earth surface over time. In the current study, the radar images of 2015 and 2020 have been applied in order to identify and measure landslides. SARSCAPE software has been used to process information. The land-use map of the study area was extracted using Landsat 8 image and object-oriented classification method. The findings reveal that radar images have a good potential to detect the instability of slopes and to calculate their displacement. During the study period, the maximum amount of material movement has been recorded as 21 cm, indicating the area is active in terms of amplitude movements. The overlap of the landslide map with the land use layer also confirms the maximum occurrence of landslides in the use of vegetation and rainfed agriculture.

Ecotourism was defined as the responsible travel to natural areas that conserves the environment, sustains the well-being of the local people, and involves interpretation and education. To achieve sustainable development in the watersheds with a comprehensive management approach, it is important to identify the important key elements and parameters. The main purpose of this study is to present and prioritize the best management strategies to achieve sustainable ecotourism in the Vennaei region. The strengths, weaknesses, opportunities, and threats of the region were identified via descriptive-analytical-developmental method. The SWOT analysis matrix was used to codify the best strategies for the region. Quantitative programming matrix were applied to arrange strategies. Therefore, first internal factors (strengths and weaknesses) and external factors (opportunities and threats) of the region have been identified and evaluated based on the field visits and expert judgments. The results of this study showed that the final score for internal factors and external factors are 2.43 and 2.51, respectively. Accordingly, the strategic position of the study area is conservative type (WO). Based on the results, four strategies were proposed for the study area including using the active and young force of the village to provide tourism services, increasing the information of the tourist attractions of the region through the cooperation and participation of local people, developing case infrastructure of ecotourism with the help of the government and the attraction of public participation, and increasing capital and income by providing accommodation centers for travelers and tourists. The results of prioritizing strategies using quantitative planning matrix revealed that the development of infrastructure required for the development of sustainable ecotourism with government assistance and attracting public participation is the top management priority for the Vennaei Basin with a final attractiveness score of 4.92.