مجله سامانه های سطوح آبگیر باران
سال دوازدهم شماره 2 (پیاپی 41، تابستان 1403)

The existence of quantitative and qualitative limitations of water resources on the one hand and the occurrence of damages and losses caused by surface runoff and seasonal floods on the other hand have necessitated the use of water resources extracted from appropriate seasonal rains. The present study was conducted to choose the best methods of collecting and rainwater harvesting in the cities of Markazi Province. For this purpose, at first, a questionnaire was prepared to identify the main evaluation criteria of the existing methods and it was provided to managers, experts, and specialists familiar with the field of management and rainwater collection methods. Then the weather information was identified in each region of the province. Finally, all available methods were reviewed and classified into three main groups. Finally, based on the method of the meta-invention algorithm of the ants, optimization of suitable places and applicable methods was carried out at the province level. Based on the findings of this study, there are 4 main groups of appropriate criteria for evaluating rainwater collection methods. Also, the most important factors in choosing the right place and method of rainwater collection include the amount of rainfall, maximum rainfall in 24 hours, and rainy days with 10 mm of rainfall. According to the 4 criteria, some regions of the province including Ashtian, Shazand, Tafarsh, and Arak cities have more priority for the implementation of this project than other cities. Finally, the meta-heuristic evaluation of rainwater collection methods shows that the best method in terms of the 4 criteria and on the other hand the weather conditions of Markazi Province, the methods of using the roof surface of residential, commercial, greenhouse, and other sites as well as It is the use of methods to improve water catchment surfaces that can have the highest water efficiency with the lowest cost.

Climate change has had a significant impact on the global production of agricultural products. Studying the impact of climate change on the production of agricultural products is very important for making preventive decisions to improve agriculture. The aim of the current research is to simulate the cultivation pattern of Jiroft plain agricultural products under the influence of different climate scenarios. For this purpose, at the beginning, the effect of temperature and precipitation climatic variables on the yield of onion and potato crops in the period 1991-2022 was investigated using regression analysis. The reason for choosing these two crops is that they occupy a high area under cultivation and are cultivated in spring and autumn. Then, using HasGEM3 general circulation model, the climate variables of Jiroft plain under RCP 8/5, 4/5, 6/2 series scenarios available in the latest report of the International Panel on Climate Change (5th report) for the periods (2011-2045) , (2046-2065), (2066-2079) and (2080-2099) were predicted. In the end, by applying the positive mathematical programming approach, the cultivation pattern of the region was simulated and the effects of climate change on the cultivation pattern in the mentioned periods were investigated. The results showed that the climatic parameters of temperature and precipitation have a significant effect on the performance of selected products. Also, by applying the forecast of climate variability in the cultivation pattern model of all selected crops in the periods (2011-2045), (2046-2065), (2066-2079) and (2080-2099) based on The noses of the HasGEM3 model are affected by different climate scenarios. Considering the effects of climate change and improving the productivity of agricultural products, it is one of the bad effects of this phenomenon. The results of this research can be useful in agricultural planning and economic development of Jiroft city.

Changes in extreme climatic phenomena, such as long periods of hot days or heavy rains, have a much greater impact on human societies and the environment than changes in climatic averages. This study aims to investigate and analyze the risks of temperature threshold data and its relationship with changes in the vegetation index in Iran's six watersheds. In this research, the monthly rainfall data of 80 synoptic stations with at least 30 years of the statistical period from 1988 to 2017 were used, and the value of the standardized precipitation index (SPI) was calculated in eight months until the end of May. It was estimated in three-time intervals of ten years. The findings show that there is a significant spatial correlation between the vegetation cover index and the ground surface temperature values in Iran, which indicates the increasing trend of the vegetation cover index. The reports of Iran's Natural Resources and Watershed Management Organization indicate that in the last 30 years, we have increased the level of agriculture (rainfed and irrigated) in the country, along with the reduction and destruction of natural areas. This increase has neutralized the effect of the decreasing trend of pastures and forests in the spatial average of the vegetation cover index. The achievement of the upcoming research is worthy of consideration in the sense that it shows that the increase in the greenness of the country is a false result and can diminish the trend of natural areas (forests and pastures) in the analysis. Finally, if the land use change continues in the country, and droughts intensify with the decrease in rainfall and the increase in temperature extremes; The country will move towards increasing desert areas and land destruction. To prevent the wastage of water in the country's watersheds, the effect of drought should be reduced by implementing watershed measures and comprehensive management of watersheds.

Vegetation cover is one of the basic and key ecological factors in arid regions, which will be severely affected by the drought process. As a result of these impacts, there will be increased intensity of soil erosion and soil degradation. Therefore, the present research was conducted to evaluate the process of drought and its impact on changes in vegetation in Sarakhs county in Khorasan Razavi province. In this research, the climate data of precipitation and monthly temperature of synoptic and evapotranspiration stations in a period of 21 years (2000 to 2021) were used to estimate the standardized precipitation-evaporation-transpiration index (SPEI). To investigate the vegetation changes, the images of ETM+ and OLI satellite sensors and the difference vegetation index (NDVI) were used. The index SPEI was calculated in the software environment R. Prediction of future vegetation cover changes is done using the Markov model and in the IDRISI-TerrSet software environment. Finally, the correlation between two indicators of drought and vegetation was compared with a linear regression test. The results of this research showed that the highest level of drought in the years 2000, 2010, and 2020 occurred in Sarkhas city at moderate and severe levels. The investigation of changes in vegetation cover in 2030 showed that the soil without cover increased compared to the year 2020, and the area of land with other classes, including vegetation with medium, high, and thin density, has decreased. Correlation analysis between vegetation cover and drought indicators showed that the highest correlation value of 0.59 at the significance level of 0.01 has been observed, and in the years 2000 and 2020, the correlation coefficient was higher at 0.52 and 0.51, respectively. The results of examining the relationship between the NDVI vegetation cover index and SPEI climatic index indicated the existence of a positive relationship between these indices.

Groundwater resources are facing unprecedented pressures due to overexploitation and contamination. Effective management necessitates robust tools for understanding and predicting groundwater behavior. Numerical simulation models have emerged as indispensable instruments in this regard. This study employs a bibliometric analysis to explore research trends, influential authors, and journals within the field of numerical simulation and groundwater from 1997 to 2023. The analysis, based on the Web of Science Core Collection, reveals a substantial increase in research output over the past two decades. Journal of Hydrology, Water Resources Research, and Water emerged as the most prolific journals in the field. Wang Y was identified as the most productive author. While early research predominantly focused on spatial distribution and finite element methods, recent studies have shifted towards addressing complex hydrological processes such as inrush flow, drainage, and watershed management. The analysis also highlights the growing importance of computational advancements, including the integration of distributed parameters and isotopic analysis, in enhancing the accuracy and applicability of groundwater models. The findings underscore the need for continued research to address emerging challenges in groundwater management, with a particular emphasis on inrush currents and evolutionary algorithms as promising areas for future exploration.

Rainwater storage is very important as a sustainable and practical solution for managing water resources, especially in places with dry and semi-arid conditions such as Iran. This method has been considered as a strategic solution in response to environmental challenges and agricultural and drinking needs. There are various structures for collecting and storing rainwater, the most important of which is the reservoir in Hormozgan. The possibility of using the rainwater stored in this pond to irrigate urban greenery has been the focus and goal of this research. For this purpose, Bibi Pond in Qeshm Island was chosen. For this purpose, the volume of water stored in this pond was calculated. Next, other parks and green spaces around the pond were investigated and their area and details were estimated. The results showed that there are 73 trees and shrubs and about 3400 m2 of green space (grass) in this park and its surrounding area. Estimates showed that the main reservoir of the covered pond and the open side pond are able to store about 400 and 1000 m3 of water, respectively, and this volume of water can supply the water needed for irrigating the green space of the park and the adjacent area in the major part of the year or at least in the stressful time (warm season). This issue will show the unique capacity of such structures for non-drinking purposes in urban environments and therefore should be considered in the planning and management of urban runoff.

The increase in the world's population has increased the amount of water consumption. Understanding the impact of climate change on various aspects of water resources can create methods to reduce or adapt to these effects. Therefore, the present study aims to investigate the impact of climate change on the vulnerability of the groundwater aquifers of Taibad Plain through Nistor's inference matrix method and using the GFDL-ESM2M fifth report model under the two release scenarios RCP4.5 and RCP8.5 in the period from 1991 to 2100 was done. For this purpose, De-Martonne's aridity index and available water were used. The results of the available water index showed that the lowest amount of available water is located in the eastern part of the region, and in the future, the trend of decreasing available water will spread to the west of the region. De-Martonne's aridity index results also showed that most of the dry areas under both scenarios are located in the eastern part of the basin. The results of Nestor's inference matrix showed that the areas with a very high effect on the recharge of groundwater aquifers are located in the north and southwest parts, and the regions with a very low effect are visible in the eastern part of the area. Also, the areas with a very low effect are without any special trend, which indicates the poor recharge of these parts, and climate change in the future has not impacted this issue. Parts with low impact also have an increasing trend. Also, sections with medium and high effects show a decreasing trend. These conditions exist in both RCP4.5 and RCP8.5 scenarios. In general, the change in climate parameters until the year 2100 will reduce the recharge potential of underground aquifers in about 55-60% of the studied area by at least one class.

Flood spreading is one of the most important soil protection and improvement measures, which both prevent flood waste and help fight desertification. This research aimed to investigate the effect of flood spreading and plant type on the activity of some physicochemical and biological properties of the soil in pasture fields with and without flood spreading in the Garbayegan, Fasa in 2019-2020. Soil sampling was carried out in spring and autumn to a depth of 20 cm in three repetitions around the rhizosphere of plants and modified according to the materials and methods section. The averages were compared with Duncan's test at the level of 1.5% and using R software. The results showed that the amount of usable phosphorus and potassium in the flood spreading conditions and the control area was without significant difference, but the amount of carbon and nitrogen in all the studied species in the flood spreading area was significantly different. It was more significant than the witness was. However, the amount of respiration in the flood spreading area was the highest, while the respiration and microbial biomass in the control area showed the highest amount. However, the amount of basal heat and microbial biomass in flood spreading areas showed a lower amount, which can be the result of the low amount of organic matter in the soil as a result of excessive livestock grazing in these areas. Finally, it is recommended to implement flood-spreading projects in arid and semi-arid areas to increase the productivity of soil characteristics.