نشریه خشک بوم
سال دوازدهم شماره 1 (بهار و تابستان 1401)

This study was conducted to investigate the expansion of Farmland in the protected area of Kavir. In order to achieve this approach, an area of ​​33933 ha was selected in the northern part of the region, where Farmlands are only expanded in this part. Land use maps were prepared for 1986, 1994, 2002, 2013 and 2020 using the images of Landsat's TM and OLI sensors and SVM algorithm by coding in Google Earth Engine. LUCC were calculated by the LCM model. The land use map for 2054 was predicted by CA Markov. Finally, the habitat changes were evaluated by landscape metrics. The results showed that the validation coefficient of SVM was more than 0.98. The land uses were divided into three classes: Farmlands, desert scrublands, and shrub pastures. The area of ​​Farmland increased from 434.5 ha in 1986 to 4,243 ha in 2020, which has increased by 3,809 ha, of which 3,067 ha were related to the conversion of shrublands to agriculture and 822 ha were related to the conversion of shrub pastures to agriculture. Farmland has been extended towards the center of the district and along the Golu River. The most changes and increase in the cultivated area were related to the period from 2002 to 2013 (2104 ha). The forecast results for the year 2054 also indicate that the Farmlands will expand downstream along the Golu River and compared to 2020, about 2787 hectares of Farmlands will grow, of which about 2010 hectares are related to bush conversion. Shrublands to agriculture and 725 ha of it will be related to the conversion of shrub pastures to agriculture. The number and weighted profile of the shape of patches of shrubland and shrub meadows increases, the average area, contiguity and size of the patches decreases, which indicates destruction and decomposition.

Water resources management, especially in watersheds without statistics all data, requires the recognition of hydrological processes, especially runoff, as one of the most important and most practical phases of the hydrological cycle. The aim of this study was to determine the efficiency and usability of the SWAT model in simulating the water balance of the Fakhrabad watershed. For the initial implementation of the model, the data required for the model implementation include meteorological data (precipitation, minimum and maximum temperature, relative humidity, and wind speed), baseline maps of the region (digital elevation map, land use, slope and soil map) and monthly discharge data of Fakhrabad hydrometric station. Were used. After the initial implementation of the SWAT model, the output was called to SWAT-CUP software for calibration and validation after sensitivity analysis, the model was implemented to determine the sensitive parameters and the results were reviewed. Calibration and validation were performed for the period 1998-2014 and the accuracy of monthly runoff simulation using the coefficient of determination (R2) and Nash Sutcliffe (NSE) for the calibration phase of 0.73 and 0.71 and for the validation phase of 0.54 and 0.53 was obtained. Acceptable values were also obtained for the uncertainty assessment indicators. P-factor and R-factor were 0.56 and 0.65 for the calibration period and 0.54 and 0.68 for the validation period, respectively. The final results showed that on average of 67% of precipitation enters the atmosphere through evapotranspiration, 23% enters the canals as surface run off and subsurface flow. The results show the efficiency of the SWAT model in simulating the water balance of Fakhrabad watershed and helps to more accurately programing water resources in this basin.

Increasing of migration from rural to urban areas threats the village, especially in arid regions. This has caused the depopulation of many villages in different parts of the country and has reduced the role of the village as a production unit. In recent years, various solutions and measures have been proposed to reverse migration from cities to villages and increase their prosperity. The formation and development of rural cooperatives are among these measures. In the present study, the role of cooperatives in reducing the migration in some villages of Nodoshan district of Meybod city in Yazd was investigated. For this purpose, a questionnaire was evaluated using statistical methods and hierarchical analysis. Indices of personal characteristics, economic factors, social factors and managerial factors were selected for research. The results of comparing the main criteria using the hierarchical method showed that among the studied factors, economic factors weighing 0.683 are the most important in the cooperative role in reducing the migration and then the management and social factors with weights of 0.200 and 0.117, respectively. The factors of buying and selling agricultural and livestock products by cooperatives and marketing of produced products with weights of 0.255 and 0.241, respectively, were more important than the criteria of economic factors. The results showed that the variables of age and level of education, as well as the history of agriculture and animal husbandry and membership in cooperatives have a positive effect on the continuation of life in the village.

This study aimed to evaluate and compare the structure and function status of some areas with different desertification classes around Gavkhoni International Wetland using Landscape Function Analysis (LFA), and Cover Directional Leakiness Index (CDLI) extracted from Landsat 8 OLI sensor and NDVI, SAVI-A, PD54, and STVI-1 vegetation indices. In this research, six different areas were selected, and two or three transects with a length of 50 meters were established in each area. The length and width of the patches and inter-patches were continuously measured. Then 11 soil surface indicators were assessed in all ecological patches, and inter-patch areas with three replications. The results showed that although range places did not differ significantly in terms of soil stability and nutrient cycling indices, the infiltration index in the areas covered by Haloxylon ammodendron, Seidlitzia rosmarinus and Halocnemum strobilaceum varied significantly compared with the other areas (p < 0.05). According to the results, there were no significant differences between the structure and function indices in the areas with various desertification classes (p > 0.05). The PD54 index showed the best performance among vegetation indices due to its better differentiation of resource leakage between different areas, and it had a high relationship with CDLI (R2 = 71.9 %). There was a negative correlation between CDLI and vegetation cover percentage (p < 0.05). The present study indicated that integrating the results of LFA method with CDLI can be used to evaluate the structure and function status of desert ecosystems appropriately.

In this study, the efficiency of two fuzzy methods and the integrated desertification index in Torbat-e-Heydariyeh, Khorasan Razavi province, have been compared using enhanced vegetation indices, vegetation condition index, salinity index, synthetized drought index, and temperature index for 2000 and 2020. The indices were normalized using maximum-minimum and fuzzy methods and weighted by analytical hierarchical method (AHP). Next, by weighted overlay combination and IDI method, the intensity of desertification was determined. The results showed that in the fuzzy method, 45% (1676 Km2) of the region suffers from severe and very severe desertification, and a major section (ie 55%, 2048 sq. Km) has mild and moderate intensity. In comparison, in the IDI method, no area fell into the very severe class, but at the same time, 67% (2496 Km2) of the total area fell into the extreme class. Accordingly, although the two methods have classified the area at risk of desertification, but this classification in the fuzzy method has been much stricter than the IDI method. The IDI method tends to overestimate desertification conditions. The comparison between the measured field data and similar values ​​in the obtained maps showed that the IDI method (kappa index of 0.73) was more compatible with the ground truth than the fuzzy method (kappa index of 0.54). Therefore, it can be concluded that the IDI method, although more efficient, has also overestimated the desertification in the region. Finally, this method is proposed to evaluate desertification in the region against the fuzzy method.

Soil erosion is a natural and global threat to water and soil resources. One of the most important effective factors in increasing soil erosion is changes in land use due to human activities. In this study, the impact of land use change on soil erosion in the town of Behbahan was studied using the RUSLE model in the Geographic Information System (GIS). In order to extract the final soil erosion map, the parameters of the RUSLE model consisting of R, K, L, S, C and P were first prepared for the years 2000 and 2021. These parameters were then converted into GRID format and the soil erosion map was obtained at the pixel level in the area by several of the parameters. Results from the erosion map in 2000 and 2021 indicated that the extent of soil erosion has increased over time. In 2021, the highest amount of erosion using the RUSLE model prediction is more exclusive to streams and rivers, although there is erosion across the region in different forms. The largest area in the region is classified as low erosion risk, which should be considered in planning. Among the effective erosion factors, the rain-induced erosion factor was high in the northern parts of the upstream region. Land use maps also show reduced vegetation at the soil surface. It causes a change in the number of efficient parameters in the model and thereby affects the amount of erosion in the region. Vegetation cover decreased from 2000 to 2021. The area of residential and agricultural land has increased, resulting in a reduction in natural land surface cover, and as a consequence, soil erosion conditions due to the impact of raindrops are increasing.

The first step in the implementation of natural resource improvement, restoration or exploitation programs is to know the vegetation of different regions of the country. There is a mutual relationship between soil and vegetation, and soil is the most important factor in plant growth and geographical distribution. Fars province has many pasture and forest habitats and can be used as a research center to select and introduce appropriate plant species that are compatible with harsh ecological conditions and soil characteristics of the country. The aim of this research was to investigate the effect of Zygophyllum euryptrum plant on some chemical characteristics of its habitat soils in Abadeh, Sarvestan and Khonj. This research was carried out using a factorial design in the dimensions of 2 × 2 × 3 (three zones, two depths and two distances) and in the form of a completely randomized design with three replications. Soil samples were taken from two profiles within canopy and outside the canopy, from two depths of 0-20 and 20-40 cm in the three indicated zones. The chemical properties of the soil have been measured. The results showed that there was a significant difference in pH, EC, concentration of soluble anions (chlorine, bicarbonate and sulfate), SAR, OM and CEC between different areas, depths and distances. There was a significant difference in the area and depth of CCE. There was no significant difference in the distance. The growth of Zygophyllum eurypterum plant has turned the soil of its habitat into saline soil by increasing the EC of the surface soil under the canopy. Despite the SAR increase under the canopy, the obtained values didn’t show any threat related to sodium ion hazards. Zygophyllum eurypterum showed high sodium accumulation factor in the shoot (AF). According to this research, the important role of Zygophyllum eurypterum in surface characteristics of soil development is determined.

The main challenge to compromising with climate change from a management approach is dealing with the uncertainty of future climate changes. Analyzing the effect of climate change on tree species used for afforestation in Robat Karim as a city in the central arid regions of Iran was the purpose of this study. Afforestation with two-year seedlings of Mulberry (Morus alba), Tehran pine (Pinus eldarica), Tree of heaven (Ailanthus altissima), Ash (Fraxinus rotundifolia), Blackberry (Acer negundo), and, Acacia (Robinia pseudoacacia) took place after preparing the planting substrate in 2016. The diameter of the trunk, the height of the seedlings, the freshness of the leaves (good, medium, and pale), and the health of the seedlings (healthy, semi-healthy, infested) were measured during the planting. These parameters were measured again in 2022 after five years. Furthermore, to analyze the trend of seven climatic factors such as mean temperature (°C), mean maximum temperature (°C), the mean minimum temperature (°C), mean wind speed (m/s), the mean number of daily sunny hours from 1951 to 2021 and average reference evapotranspiration (mm) from 1991-2021, was carried out. The analysis results of climate elements showed that climate changes are taking place in the form of an increase in the mean annual temperature, an increase in the maximum and minimum temperature, a reduction in the total annual rainfall, a decrease in the wind speed, and an increase in the reference evaporation and transpiration. The number of Boxelder maple reached 80 trees, while the number of Tehran pine and Acacia seedlings did not change much and were equal to 145 individuals in 2022. The highest annual diameter growth rate includes Acacia and Tehran pine with 1.1 and 1.05 cm, respectively, while the lowest annual diameter growth rate involves black maple with 0.78 cm. The ANOVA test results to compare the condition of the trees in terms of the decay degree of the studied species in 2022 indicate a significant difference (p=0.05) between the studied groups. The priority is to determine native species and species such as Tehran pine and Acacia that can adapt to occurring tensions.

The achievement of sustainable development is contingent upon a holistic strategy that takes into account the ecological, economic, social, and cultural factors specific to each locality. The safeguarding of renewable natural resources serves as a crucial foundation for enhancing the standard of living for human beings. The objective of this study was to assess the ecological sustainability of the ecosystems present in the Khosroshirin Abadeh watershed. The present investigation employed two techniques, namely the International Union for Conservation of Nature (IUCN) methods and the guidelines of the Organization of Natural Resources and Watershed Management. The initial approach involved partitioning the domain into five distinct sub-domains, followed by an assessment of its sustainability based on three criteria, 10 indicators, and 26 variables within the ecosystem sustainability category. Additionally, two criteria, six indicators, and 16 variables were utilized to evaluate human welfare within the domain. The mean value of the chosen metrics within the domains of ecosystem and human welfare were determined to be 61.8 and 47.2, correspondingly. The stability barometer analysis indicates that the ecosystems under investigation are currently exhibiting moderate levels of stability. The second approach involved an assessment of the rangeland ecosystem and economic and social issues based on the Natural Resources and Watershed Organization's guidelines. The evaluation of the rangeland ecosystem section involved the consideration of 3 criteria, 9 indicators, and 14 variables. On the other hand, the economic and social issues was evaluated based on 5 criteria and 16 indicators, which served as variables. The present approach involved the computation of a final score of 46 for the rangland ecosystem and a final score of 36 for the human welfare human ecosystem. A value of 2.2 was obtained based on the analysis of the 16 selected variables. The score estimation matrix table was utilized to derive a total score of 5.5 for both rangland ecosystems and human welfare. The sustainability assessment table indicates that the Khosroshirin basin's ecosystem is currently in a state of weak sustainability, according to the assigned score. Enhancing the existing livestock and plant composition indicators, along with promoting sustainability of the ecosystem and ensuring ownership, justice, equality, nutrition, and food security in the human ecosystem, can lead to improved living standards of the watershed inhabitants and foster better health and sustainability of the ecosystems in question.

The phenomenon of dust in recent years has been one of the most important environmental challenges, which has been exacerbated by destructive human activities and has had adverse effects on the environment and human health. Considering that wetlands play an essential role in the balance of water and climate and also prevent the entry of fine dust; The present study was conducted with the aim of analyzing the relationship between the optical depth of aerosol particles (AOD) and the indices of dust-based soil in the area of Horulazim wetland. For this purpose, daily AOD product, MODIS sensor bands and hourly data of dust occurrences related to 3 meteorological stations of Ahvaz, Safi-Abad and Sulaiman masjed were obtained from their supply sources in a period of 18 years (2000-2018). Hourly data recorded in synoptic stations were used to calculate dust storm index (DSI) and MODIS sensor bands were used to extract BTD, BTDI, TIIDI, TDI, Miller and NDDI indices. Linear and non-linear regression methods were used to analyze the relationship between the mentioned indices and AOD. The results of the analysis of the relationship between DSI-AOD showed the very poor performance of this index in the analysis of dust events in all three study stations (R2<0.2). In Ahvaz, Safi Abad and Masjid Sulaiman masjed stations, the maximum value of R2 was observed between AOD-BTDI (0.48), AOD-Miller (0.503) and AOD-BTD (0.50), respectively. These results indicate that, on average, about 50% of the changes in the optical depth of aerosols can be explained using the three indices BTDI, Miller and BTD. Therefore, it is recommended to use these indicators in order to analyze the dust events around Horul Azim lagoon.

The health of the soil, as an ecosystem, influences the health of other ecosystems. The most essential factors associated to soil quality are its physical, chemical, and biological features, as well as its fertility. However, it is influenced by the type of plant that grows in it. Paying attention to the type of species and their effects on the qualitative characteristics of the soil as a management strategy can help maintain the quantity and long-term stability of restored areas in arid and desert areas in many land restoration projects, particularly in arid lands with limited resources. The purpose of this research is to look into the effect of the Ziziphus tree on physicochemical, microbiological, and stoichiometric ratios of soil in the arid region surrounding the Persian Gulf in the province of Khuzestan. For this purpose, 15 mixed soil samples were randomly selected from the surface soil at the foot of the Ziziphus tree, and 15 mixed samples were selected from the control areas in locations where the Ziziphus tree is not present. The characteristics of the soil samples were the same, including texture, acidity, organic carbon, organic matter, nitrogen, phosphorus, and potassium. The independent t-test was carried out to determine whether there was a significant difference between the two sample groups once the prerequisites for the two sample groups, such as the normality test and the homogeneity of variances, were completed. The results showed that in the Ziziphus samples, organic carbon was 41%, organic matter 47%, nitrogen 69%, C:K ratio 24%, and N:K ratio was 42% higher than in the control area with no Ziziphus. In terms of biological indicators, the Ziziphus samples rose 91% in basic respiration and 90% in microbial biomass carbon, indicating an increase in organic matter mineralization and soil health. In terms of the balance of ions in the exchange phase and solution. The results demonstrate that an increase of one unit in SAR raises the ESR level in the control samples by 1.6 times, compared to the side samples. This indicates that as the concentration of divalent ions in the solution phase increases, the exchange sites where the tree is absent, sodium ions will fill those spaces more quickly. According to the above findings, it can be concluded that using Ziziphus in land restoration projects improves microbiological conditions while also restoring the soil and enhancing its fertility and health.

In addition to rich resources of fossil fuels, Iran has a lot of renewable energy potential. On the other hand, considering the climate diversity in the country and the natural conditions and potentials in different regions, instead of national planning, we should move towards regional energy planning and develop a regional renewable energy portfolio. In the present research, firstly, the potential measurement criteria of different types of renewable energy, including solar, wind, geothermal, hydroelectric and biomass, based on geographic information system maps and data received from the Meteorological Organization and SATBA, for 1361 latitudes and longitudes, has been scored. Then, using the Rapidminer software, the geographic points were divided into 5 clusters, each cluster includes areas of equal potential with the greatest similarity. Two of these 5 clusters are considered to be among the dry lands of the country. Then, based on the review of library resources and usage from the opinions of SATBA experts (Renewable Energy Research Group), a fuzzy inference model based on 5 sustainable development criteria including: access to technology, investment costs, capital productivity, employment rate, and environmental consequences along with design potential measurement criteria and based on the fuzzy rules defined on these criteria. The percentage share of each type of energy in the energy portfolio of each cluster was calculated. In the final step, based on demographic criteria including unemployment rate, population growth rate, acceptance culture (literacy rate), investment security, to prioritize clusters for strategic planning of the government and other influential institutions such as governorates, municipalities and chambers of commerce. For example, in cluster 4, includes some cities in the provinces of Isfahan, Khorasan, Yazd, Kermanshah, Fars, and Kohkiloyeh, which are classified as arid and semi-arid regions of the country according to the criteria of potential measurement and development criteria that has an energy portfolio with 25% share of wind energy, 39% share of solar energy, 10% share of hydroelectric energy and 26% share of biomass energy. Population growth and investment security are the first priority.