نشریه اقلیم و بوم سازگان مناطق خشک و نیمه خشک
پیاپی 1 (پاییز و زمستان 1402)

Different phenomena in different regions of natural geography acquire their characteristics through the dynamics of the environment and by receiving energy from various external and internal sources of the earth. Therefore, if for some reasons, changes are made in the quality of the environmental dynamics, different characteristics will be obtained in the environment (Pirestani & Shafaghati, 2009). Dams have acted as geomorphic factors since their construction (Bayati Khatibi, 2007), reducing water flow and food concentration. They leave adverse effects on the plant and animal communities downstream (Naderi & Tadari, 2004). Among other factors that cause changes in the coastal environment are tectonic movements (Aghanabati, 2013). Such phenomena as the uplift of coast of Oman Sea, from Jask to Gwatar and the continuation of subduction under the Makran zone are the reason that these movements are still active in this zone (Aghanabati, 2013). It seems that at least a part of the Sahara Sindhi forest habitat of Hormozgan Province, in the western plains of Makran, has been established on the abandoned riverbeds. This research examines the effects of river processes and uplifting of Oman Sea coasts on creating a geomorphological environment suitable for establishment of Sahara Sindhi forests as an ecosystem in arid and semi-arid regions.

The coasts of Oman Sea start as a belt from east of the Persian Gulf (Minab fault) and extend to the north of coast of Indian Ocean in Pakistan. These lowlands are mainly based on the eroded structure of Makran lithology, which was deposited by large flood rivers such as Jegin, Gabrik, Sedich, and Kehir, originating from inner Makran. Wherever Makran folded structure has shown relatively more resistance against erosion factors, the width of the plains has been minimized and the remnants of the Makran folds have divided the Oman plain into six parts in the form of a mountain tongue. Based on the location of the first and third capes, which are respectively located in Bunji (west of Koh Mubarak), Bahal (east of Jask), and Guhert (100 km east of the latter), the study area is divided into three main sites. Considering the differences in the stretch of the plain, characteristics of the rivers, and extent of the Sahara Sindhi forests, the first site in the east of Jask and the third site on the edge of the Strait of Hormuz are the scopes of this research. The research data includes spatial distribution of geomorphological forms, river dynamics, and extent of Sahara Sindhi forests in the coastal plain. Topographic maps, fieldwork tools, and computer software such as ArcGIS and Google Earth were used as research tools. Initially, morphodynamics of the rivers was studied. Geomorphological forms were analyzed by interpretation of satellite images, Google Earth software, and repeated fieldwork, and the morphodynamic changes of rivers affected by coastal uplift were investigated by referring to the study records. The map of Sahara Sindhi forests was also prepared by visual interpretation of satellite images and field works. Then, by combining and analyzing the results, the role of tectonic and river hydrodynamics on the establishment and expansion of Persian Sahara Sindhi forests on deltas of Jegin, Gabrik, and Sedich was studied.

Sahara Sindhi forests have a significant extent on the deltas of Sedich, Gabrik, and Jegin rivers in the eastern part of Jask county. In the west, along the coast of the Strait of Hormuz, apart from scattered trees, there is no dense coverage of Sahara Sindhi forests on the deltas of Guz, Torkend, Zarani, and Hivi rivers. The extensive old riverbeds resulting from the various changes in the courses of Sedich, Gabrik, and Jegin rivers occupy a wide area around these rivers. These basins have similar erosion conditions, and river discharge can be used as an indicator of their sediment yield. The Jegin River has the highest discharge, followed by the Sedich and Gabrik rivers. The Gaz and Zarani rivers (both on Site 3) have less discharge compared to the rivers on Site 1.

Results showed that the extent of Sahara Sindhi forests is consistent with the abandoned riverbeds. Since the sinuosity coefficients of the rivers in the western parts are higher than those in the eastern part of the plain, the extent of the abandoned riverbeds is not solely related to the sinuosity of the rivers. It seems that factors other than sedimentological characteristics and slope of the plain have been involved in changing the river courses, leading to the extensive abandoned riverbeds on the eastern deltas (Sedich, Jegin, and Gabrik). Among these factors, tectonics and differences in coastal uplift due to the movement of Oman plate beneath the Makran plate can be mentioned. Due to the difference in coastal uplift, the eastern rivers change their course and create extensive abandoned riverbeds upstream of the plain when they reach a certain sinuosity threshold, which is lower than that of the western rivers. These abandoned riverbeds have gradually provided the conditions for the establishment and expansion of the Sahara Sindhi forests over time.

Land degradation, as one of the serious and common environmental problems in the world, has affected two billion hectares (22.5%) of agricultural lands, rangelands and forests in the world (Dregne et al., 1991; Oldeman et al., 1991; Reynolds and Stafford,2002). Land degradation indicators should be determined, selected and evaluated for the purpose of land management and used by researchers. Considering that in any region at risk of desertification, according to the specific environmental and management conditions governing it, it is necessary to identify the factors of desertification and the intensity of the effect of each factor in order to choose the appropriate measures to control and prevent degradation. In this research, the indicators of land degradation were determined using the RALDE model for the Pardisan watershed, which has sensitive and fragile environmental conditions against desertification factors and the risk of land degradation was determined.

Pardisan watershed with an area of 222.87 km2 is located in the northwest of Qom province. Its climate is arid and hyper-cold. Based on the RALDE model, eight main parameters of soil and land, climate, vegetation, underground water, population, grazing pressure, development and socio-economic were examined to prepare the land degradation potential map. After collecting data, existing maps and information on hydrology, soil, geology, vegetation, population, meteorology, etc. and their interpretation, field studies were conducted. Then scoring indicators and criteria of degradation and its evaluation was done based on natural factors, human factors and trend factor according to the quantitative tables of the RALDE model. Finally, by combining the information of the layers of human factors, environmental factors, the process of land degradation and the current state, a map of land degradation capability was prepared.

The results showed that the risk of natural factors is moderate in more than half of the area, and severe and very severe in 31% of the area. Also, in 38% of the area, the risk of human factors is medium, which especially this area should be considered for control measures and prevention of further degradation. Investigating the process of degradation using changes in the NDVI index in the period from 2002 to 2016 and field studies investigating the state of vegetation showed that in 55% of the area, the risk of degradation is moderate and in 12%, the risk is severe and very severe. The current state of land degradation in the region is mostly in the range of low risk with a probability of 80-100% and severe risk with a probability of 0-20%. Finally, in about three-fourths of the area, the risk of degradation is low and in one-fourth of the area, the degradation is moderate. Severe and very severe risk of destruction was observed only at less than one percent of the area.

Natural degradation risk factors have a greater impact on the destruction of the region compared to human factors. Among these, climate and soil are the most important limiting natural factors. Although only about 1% of the area is in severe danger of degradation due to various protection and restoration measures in a large area of the region, the investigation of the degradation process using the evaluation of vegetation changes showed that in 55% of the area, An average of 4% of the vegetation was destroyed during the years 2002 to 2016. These results show that in most of Pardisan watershed, land resources have not been properly managed and exploited, and if the current trend continues, we will see widespread degradation and loss of resources soon.

Water shortage has become a global crisis since the past few decades. Therefore, using water for domestic purposes judiciously and fairly has become an essential part of a sensible water policy worldwide. Iran is squandering thrice the global average in water loss. This challenge is particularly serious in Kohgilouyeh and Boyer-Ahmad province. From a theoretical perspective, the proposal that people's domestic water use is associated with their conservative attitude is supported by literature that states that the magnitude of people's behavior patterns can influence the degree to which they act on those habits. Research has also established that many factors, such as religious values, concern for the environment, knowledge of environmental issues, as well as educational level, size of household, income, and gender of householders, and where they live, can critically influence their attitude towards the environment. Several studies from a range of areas, such as economics, have examined the probable influence of preserving actions targeted toward water utilization. Considering the vital role of water users in water wastage management, this survey study has investigated factors affecting attitude of beneficiaries toward saving domestic water among the rural households in Kohgilouyeh and BoyerAhmad province.

Survey study was the main approach and the methodology used in this study to identify basic information about the pattern of domestic water use in rural households includes: household composition, educational level, sources of income/livelihood, level of income, monthly water use, including indoor and outdoor water use, and sanitation in two different regions of high- and low- level of water in Kohgilouyeh and Boyer Ahmad province. The study population was consisted of rural household heads in this province. Stratified multi-stage random sampling was used to collect data from 282 households of areas with low- and- high level of water. Structural questionnaires were used to collect data. The questionnaires' validity was confirmed by panel of experts and a pilot study was done to assess the reliability. Cronbach's alpha coefficients were equal to 0.62-0.92 for different measures. The final set of explanatory variables controls for the influence of climatic conditions on water conservation attitudes. Climate-related data were obtained from Meteorological and Regional Water Organizations of Kohgilouyeh and Boyer Ahmad province. The Statistical Package for the Social Sciences (SPSS 21) was used to treat and analyze the obtained data.

Analytical results revealed that rural residents of water-rich and waterpoor areas were significantly different with respect to their religious beliefs, perception of saving equipment and social norms. In spite of the fact that intergenerational justice, social norms, awareness towards water crisis, institutional trust and responsibility were the most important predictors of households’ conservative attitude in water-poor areas, religious beliefs, social trust and responsibility could explain 44% of variation in householders’ conservative attitude in water-rich rural areas. Hierarchical regression results also indicated that domestic water use in water-rich regions was positively related to users’ religious beliefs and their accountability. This is while the relation between social trust and water use was negative. Similar results were obtained for the water-poor areas regarding the positive relation between intergenerational justice, social norms, awareness towards water crisis, and accountability. This is while the relation between institutional trust and conservative attitude was negative.

This study sought to analyze the social, psychological, attitudes and behaviors related to household water preservation. Three aspects were targeted in the study: a) complexity of behavior, meaning better understanding of environmental awareness, targeting behavior for improvement, b) behavior patterns: Examining people’s water consumption and saving behaviors, and c) social norms: A close look at people's social backgrounds and their attitudes towards the subject. Results of the research supported that to a significant extent, an individual's behavior is determined by the surrounding social environment as well as social norms. It is possible to promote preservation of water by instilling values into society.

Difficulties in seed germination for many medicinal plants have led to significant limitations in cultivating these plants in managed ecosystems, such as agricultural lands, where they are grown in large areas with a uniform green surface. Given the necessity for medicine production, the raw materials used should possess superior quality and minimum pollution. It seems that investigating the effectiveness of Sesbania rostrata seed priming techniques with biological fertilizers, such as plant growth promoting rhizobacteria, and organic fertilizers, such as humic acid and fulvic acid, is essential, because these fertilizers are compatible with natural ecosystems and align with sustainable agricultural policies. Hence, this research was conducted to investigate the effect of Sesbania rostrata seeds priming with plant growth promoting rhizobacteria as well as fulvic and humic acid (extracted from Oriental plane tree biochar) on the indices of seed germination and seedling growth.

In-vitro cultivation was carried out in a factorial and completely randomized design (CRD) with four replications in a total of 36 experimental units. The first factor, which was implemented at three levels, included seed priming with distilled water (control), humic acid, and fulvic acid; and the second factor, which was implemented at three levels, included seed priming with physiological serum (control), as well as Staphylococcus sp. R38N2 and Pseudomonas sp. R27N7 bacteria strains. Ten surface-sterilized seeds were placed on a filter paper inside each petri dish. Then, the treatments were added to the experimental units and placed in the germinator at a temperature of 25±2 degrees Celsius. Germinated seeds were counted daily from 13 to 30 days after the start of the experiment.

Results showed that fulvic acid- physiological serum was the best treatment compared to the control in terms of improvement of all measured traits. This treatment increased the seed germination indices, including seed germination percentage, germination rate, mean daily germination, peak value, germination value and seedling vigor I and II by 2, 4.5, 2, 3.19, 7.13, 5.66, and 18.96 times, respectively. In addition, it reduced mean germination time by 24.46%. Additionally, seedling growth indices including seedling height, shoot height, root length, and seedling dry weight were increased by 7.44, 20.32, 4.74, and 9.5 times, respectively.

Fulvic acid-physiological serum treatment was found to be the most effective in enhancing all indicators of seed germination and seedling growth in Sesbania rostrata, when compared to the control. Furthermore, the following treatments were ranked right after each other for their ability to enhance seed germination and seedling growth in Sesbania rostrata: fulvic acid-Pseudomonas sp. R27N7, distilled water-Staphylococcus sp. R38N2, humic acidStaphylococcus sp. R38N2, and fulvic acid-Staphylococcus sp. R38N2.

Cold waves are natural phenomena normally occurring in winter and autumn seasons. They likely cause significant damage to agricultural crops and garden yields. Accordingly, both monitoring and prediction of cold waves occurrence are essential for planning and managing the associated risks beneficially.

This study aims at analyzing cold waves data in Semnan province, enhancing a better understanding of this phenomenon, and suggesting practical solutions for effective management. To meet this target, the minimum daily temperature data were analyzed from 1980 to 2020. To identify the cold waves, the standardized minimum temperature (Z-index) was calculated during the same period in Semnan province.

Our findings revealed that the highest occurrences of cold waves occurred in Semnan city with a fairly long-term duration (In 2007, there were two cold waves lasting 3 and 7 days, and in 2016 there was a cold wave lasting 6 days). Moreover, Shahmirzad, Shahrood and Miamey stations recorded the lowest minimum temperature (-16.4 ◦C, -14.2 ◦C, -14.2 ◦C) in November 2016, respectively.

Results demonstrate that the cold waves occur with 10-year return period. Subsequently, developing applicable management plans are essential to reduce cold waves exposures and damages.

Teleconnection patterns can affect climate parameters in different regions of the world. Investigating their effects, especially on the climatic extreme values, can provide appropriate information for optimal management of weather processes as well as terrestrial ecosystems, including vegetation. Temperature is one of the important elements of the atmosphere and is involved in climate changes on a regional and global scale, which quantitatively leads to tremendous events affecting the environment, including increased evaporation and transpiration and plant water needs, increased frequency of droughts, and lack of water resources. The effects of extreme events are often large at the local scale and can severely affect certain sectors and regions. The everincreasing emission of greenhouse gases will cause global warming and cause damages and losses to the water, agriculture, environment, and economy sectors and will have a significant impact on the lives of humans and animals. One of the most important effects of this phenomenon will be the influence on extreme events of atmospheric and climatic elements such as drought, flood, and storm. On the other hand, atmospheric circulations are very variable. These changes lead to the emergence of air patterns and forms of atmospheric currents that occur in different time scales. The teleconnection patterns indicate large-scale changes that occur in the pattern of atmospheric waves and winds and affect the temperature pattern, precipitation, direction of clouds, and position and intensity of the winds in many regions. The effectiveness of these indicators has attracted the attention of researchers in various parts of the world, indicating the importance of these interactions on the atmosphere and surrounding environment. The purpose of present research was to investigate the effect of teleconnection patterns on temperature extreme values (minimum and maximum) in Chaharmahal and Bakhtiari province.

Chaharmahal and Bakhtiari province is one of the mountainous parts of the central plateau of Iran, which has an area of 16421 km2 and is one of the mountainous and rainy provinces of the country, which are the source of two important rivers of the country, Zayandehroud and Karun. This province has one percent of the total area of Iran, which is located in the Zagrosmountain range and in the path of the humid winds of the Mediterranean systems and causes the rise and discharge of these systems. This province has relatively good rainfall. In this research, 8 synoptic meteorological stations of the province in the statistical period of 30 years (1368-1398) were considered. Ten teleconnection indexes were used during this period to investigate their effect on climatic extreme values using Pearson's correlation coefficient.

The changes in average minimum temperature shows that Kohrang station has the coldest minimum temperature in the studied area and annual average fluctuation of this variable has changed from -4.71 to -15.61 degrees Celsius during the studied period. On the other hand, Lordegan station has a higher average minimum temperature than other stations and the range of changes of this variable is from -0.16 to -5.8 degrees Celsius. Lordegan station has the highest values of extreme maximum temperature. The range of changes of this variable fluctuated from 32 to 38.5 degrees Celsius, while the range of these changes for Kohrang station was recorded from 28.7 to 32.2 degrees Celsius during the same period. Based on the results in EGheis and Avergan stations, the average maximum temperature correlation with TNH, NINO3, NINO12, NINO4 and PNA indices was significant at 1% level and with EA/WA, NP and NAO indices at 5% level and had no special relationship with AAO and SOI indices. Among these indices, the highest correlation of this variable with TNH index was 0.728 for EGheis station and 0.71 for Avergan station. At PoleZamankhan and Shahrekord stations, the average minimum temperature correlation was significant at 1% level with TNH, NINO12, and NINO4 indices and with NP, PNA, NAO, and SOI (only for PoleZamankhan station) at 5% significance level. There was no significant correlation with NINO3, AAO and SOI (only for Shahrekord station) and EA/WA indices (only for Kohrang station). The average minimum temperature was significant with TNH, NINO3, NINO12 and NINO4 indices at 1% level and with the EA/WA, PNA, NP and NAO indices at 5% level, and there was no significant correlation with the AAO and SOI indices. The highest correlation coefficient was related to TNH index (0.724) in this station. In Shahrekord and Brojen stations, the average maximum temperature correlation was significant with TNH, NINO3, NINO12, NINO4 and NP indices at 1% level and with EA/WA, PNA and NAO indices at 5% level and there was no significant correlation with the AAO and SOI indices. In PoleZamankhan station, the average maximum temperature correlation was significant with EA/WA, TNH, NINO3, NINO12, NINO4, NAO and PNA indices at 1% level and with NP index at 5% level, and there was no special relationship with the AAO and SOI indices. Results showed that correlation of TNH index with the average maximum temperature of the stations had the highest positive value compared to other indices. The NINO12 index was in the next rank, but its correlation was negative, and it is understood that the occurrence of this index has caused maximum temperature in these stations to decrease. Also, AAO and SOI indices have no significant correlation with this variable in the stations. Also, results reveal that correlation of TNH index with average minimum temperature of the stations had the highest positive value compared to other indices, and the lowest correlation was with Lordegan station and the highest was with Kohrang station. The NINO12 index was in the next rank; but its correlation was negative, and it is understood that the occurrence of this index caused the temperature to decrease at least in these stations. The NINO4 index is also in the third place, with the difference that, like the TNH index, it has a positive correlation in the minimum temperature. The AAO and SOI indices have mainly no significant correlation with this variable in the stations. In Lordegan and Avergan stations, the average minimum temperature correlation was significant with TNH, NINO3, NINO12, NINO4, NAO and PNA indices at 1% level and with EA/WA and NP, NINO3 and NAO indices at 5% level and did not have a significant correlation with AAO and SOI. The highest correlation coefficient related to TNH index was 0.726 and 0.702 for Avergan and Lordegan stations.

In this research, Pearson's correlation was used in 8 meteorological stations in Chaharmahal and Bakhtiari province to investigate the effect of teleconnection indices on extreme maximum and minimum temperature values. In general, it can be said that the teleconnection indices have an effect on the extreme temperature values of the studied area (some have an increasing effect and some have a decreasing effect on these variables). These findings can be used in predicting these extreme values and preventing possible damages to agriculture sector and vegetation. Also, considering the role of temperature values on evaporation and water needs of plants, the results can be used in drought crisis management.