مجله سامانه های سطوح آبگیر باران
سال دوازدهم شماره 3 (پیاپی 42، پاییز 1403)

This research aims to investigate the effect of flood spreading on the quantity and quality of groundwater in the Tokahour-Hashtbandi plain. For this purpose, first, SPI was calculated in time scales of 1 to 48 months for the existing rain gauge station in the region. The GRI index was calculated using the groundwater level data in the next step. Then, three wells with conventional names A1 to A3 were selected to evaluate quantitative changes. Five wells B1 to B5 were also selected for qualitative evaluation as they had the closest position to the flood spreading area. Then, using the Petit test, the time of the flood's impact on the quantitative and qualitative resources was determined. Also, by dividing the statistical period into two parts, the time before the impact of flood spreading and after the impact of flood spreading, using linear regression analysis, the slope of changes of GRI, EC, and SAR index for both times was done for the selected wells. In the next step, using correlation analysis and linear analysis, the effect of flood spreading on the sensitivity of groundwater resources to drought was evaluated. The results showed that the time of flood spreading effect on the level of three wells A1, A2, and A3 is 2009, 2009, and 2012, respectively, which is not statistically significant. Also, the time of flood spreading effect on EC values of wells B1, B2, B3, and B5 in 2007, 2009, 2013, and 2009 respectively, and on SAR values of well B1 in 2010 was determined. The results of the evaluation of the effect of flood spreading on the quantity of groundwater show the improvement of all three selected wells and the reduction of the slope of EC changes, but it did not have much effect on SAR. The results of the evaluation of the effect of flood spreading on the sensitivity of the groundwater quantity to drought showed that the flood spread has reduced the sensitivity of the GRI and EC index to drought in the selected wells, but it has not been able to reduce the sensitivity of SAR to drought.

If a country wants to move with a caravan of civilization and scientific development, it will have to use its natural resources. One of the most vital resources that life plays in the lives of humans and countries and the continuity of production is water resources. If the use of this vital material, which God has placed at the service of humans for free and unprofitable, would be desirable, many problems of the countries would be solved. One of the water supply methods due to drought problems, especially in the desert areas of the country, is inter-basin water transmission. Water transfer between different basins can be the source of many changes in the areas of origin and destination. In this research, using the ANP method, the criteria used are water quality, environmental factors, social security, sustainable development, utilization, cost of execution, water productivity, and equilibrium in supply and demand, for use in the OWA weight method It was made. Then, using the maximal entropy method in OWA, the weight of each criterion and the weight of the options were determined in two risky and risky situations. Finally, the use of conventional waters of the district (drinking water and sanitation) with a weight of 0.32 in risky and 0.41 in risky and with a relative deviation of risk of 0.11 was chosen as the best option.

Border watersheds, also known as transboundary watersheds, are areas of land that drain water to a shared water body, such as a river, lake, or sea. These watersheds are particularly important for Iran, providing water resources for agriculture, industry, and human consumption, as well as ecological benefits for biodiversity and climate regulation. One such significant border watershed in Iran is located in the eastern province of Balochistan, bordering Pakistan. It, known as Hamoun Mashekil, is the country's easternmost watershed and annually loses 297 million cubic meters of runoff from Iran to Pakistan. Given the crucial role of border watersheds in Iran, especially in arid regions, there is an urgent need for integrated and participatory water management, along with sustainable and efficient water use within the country. This study investigates the necessity and significance of surface water harvesting systems and their role in preventing water loss in the Esfandak Saravan border watershed. Recognizing the importance of analyzing runoff in border watersheds and the significance of the Esfandak watershed in Saravan City, the study begins by examining the status and trend of discharge at the Esfandak hydrometry station located at the source of the Mashkid River. For this purpose, the non-parametric Mann-Kendall test is employed. Due to the absence of hydrometry stations throughout the watershed, the study utilizes Treaclimate satellite imagery data to assess the runoff status and volume of runoff flowing from Iran to Pakistan. The results indicate a downward (decreasing) trend in discharge at the studied station on both seasonal and annual scales. Notably, this trend is statistically significant at the 95% level for spring and summer seasons on an annual basis. Analysis of a 22-year dataset (2000-2020) reveals that, on average, over 13 million cubic meters of water collected by this watershed flows from Iran to Pakistan via the border river. Without water harvesting structures, watershed management, and aquifer storage, this water is lost through runoff. Therefore, by effectively and efficiently implementing rainwater harvesting systems, the region can achieve its sustainable development goals and enhance its water security.

Land surface temperature is a parameter that affects many natural and human processes. In this study, the spatial distribution of surface temperature in Zanjan province from 2001 to 2023 was investigated. In addition, the effects of elevation, longitude, and latitude on the temperature distribution of the land surface, its spatial pattern, and the temperature zones of the province were evaluated and revealed using partial correlation methods, G* statistic, and clustering analysis, respectively. The results showed that the mean temperature of the land surface is 24.6 C° during the day and 5.3 C° at night. The relationship between elevation, longitude, and latitude with surface temperature is negative. elevation has the greatest effect on temperature, but the effect of latitude and longitude is weak. However, the temperature decreases by moving from south to north, west to east, and from lowlands to high elevations. The land surface temperature in the province follows a cluster pattern with a certainty of 95% or more, in which the lowlands and heights of the province have played the most role in its formation; Also, the province can be divided into four temperature zones, where the direction and boundaries of the zones follow the shape of the land. The mean daytime land surface temperature of the earth in the first group is 23.9 C°, the second group is 27.3 C°, the third group is 28.8 C°, and the fourth group is 18.8 C°. In addition, the mean temperature at night in the first group was 4.4 C°, the second group was 6.9 C°, the third group was 12.1 C°, and the fourth group was 1.9 C°.

Effective management of rainwater through the development of integrated nature-based systems, both biotic and abiotic, is achievable. Utilizing rain gardens and permeable surfaces to capture and purify rainwater can help reduce pollution and enhance water resource efficiency. These systems are crucial in environmental conservation and balancing development with natural resource preservation. Nature-based solutions (NbS) such as rainwater harvesting, reducing surface runoff, enhancing evaporation, and improving stormwater quality contribute to better rainwater management. Diverse approaches and collaboration among stakeholders are fundamental to enhancing the efficiency of these systems. These solutions can effectively mitigate urbanization impacts, improve rainwater harvesting, and enhance urban resilience to climate change. Green roofs, as one of the primary NbS strategies in cities, promote environmental sustainability, enhance urban resilience, and reduce natural disaster risks. They are widely applied globally as a suitable technique for reducing runoff. Nevertheless, implementation challenges and high costs have limited the research and widespread adoption of NbS solutions. Additionally, a lack of information regarding green roofs is a major obstacle in this field. Policymakers can facilitate the adoption of green roofs by supporting and establishing appropriate legal frameworks. Understanding local conditions, lifecycle analysis, and cost considerations in each region is necessary for better comprehension. Technological advancements and efficient water management through NbS systems provide numerous benefits to urban ecosystems. There is a need for further research to understand the short-term and long-term positive impacts of these systems and to make better decisions. Implementing practical recommendations for these systems is of utmost importance.

The storage pool (Abbandan), as a system of rainwater catchment systems, have many positive environmental effects and has been very important for the agricultural life and natural resources of the northern regions of Iran. On the other hand, soil is one of the important elements of natural ecosystems, which plays an important role in the distribution of plants. This research was carried out with the aim of investigating the characteristics of the soil and vegetation in the area of the storage pool in the south of Langarud city and the heights overlooking it. Plant samples were collected from storage pools, lowlands and plains around them and forest areas overlooking it during the growing season of 2022. Soil samples were also taken from the surface horizon of different altitudes from -20 to 325 meters above sea level (m.a.s.l.), and some of their physical and chemical properties were measured. Of 250 plant samples collected, 146 taxa were identified, which belonged to 60 families, 127 genera and 146 plant species. Investigating the characteristics of the soil and habitat of these plants shows the uniformity of the soil texture (medium to light class) and the electrical conductivity (EC) is less than 1 (dS/m). The lack of salinity problem is due to the very humid climate and the occurrence of more than 1400 mm of annual rainfall in the region. In different altitude gradients, soil pH ranged from neutral (6.78) to strongly acidic (4.03). The pH of the soil decreased with the increase in altitude. The range of organic carbon was in the medium to optimal class and the amount of N-P-K fertile elements was in the medium to rich class. In this study, the homogeneity of many physical and chemical characteristics of the soil, except for pH, was observed in different parts of the study area. In general, it can be said that the soils in the study area have no restrictions for the establishment of vegetation and the relatively high species diversity in this area confirms this.

Water governance in Khuzestan Province, particularly in the Karkheh River Basin, is a complex and multifaceted process involving multiple stakeholders. Adopting a network perspective can provide a systematic and analytical approach to studying this complexity. This research aims to analyze the network of institutional relationships and conflicts in Khuzestan's water governance using a mixed-method approach. To this end, 43 water governance-related institutions were identified as the social boundary of the network using snowball sampling method. To examine institutional relationships, a questionnaire about the intensity of interactions between these institutions was distributed and completed by the respective representatives. These institutions were categorized based on their predominant roles, and social network analysis indicators were measured at the micro level of the network. Additionally, semi-structured interviews were conducted to examine inter-institutional conflicts. Results of the centrality indices indicated that the Provincial Government holds the highest out-degree centrality (90.48%), betweenness centrality (5.1%), and closeness centrality (97.67%), indicated the significant political influence, control power, mediation role, independence, and access to resources and information, thus playing a prominent role in the water governance network. Moreover, the Khuzestan Water and Power Authority with the highest in-degree centrality of 92.86%, held the greatest political authority. The distribution of centrality measures revealed that, despite the significant role of intermediate subgroups in facilitating institutional cooperation, they have low out-degree and betweenness centrality, with asymmetric power distribution. In the conflict network, the Khuzestan Water and Power Authority receives the highest number of conflict ties, while the Environmental Protection Organization has the most conflicts with others. The presence of severe conflicts between the Khuzestan Water and Power Authority, Department of Environment and Agricultural Jihad Organization underscore the need to resolve these conflicts and strengthen coordination in water governance decision-making. Understanding these interactions and conflicts among institutions can assist policymakers in achieving effective water governance

Unscientific use of natural and agricultural areas in order to meet food needs, especially in arid and semi-arid areas, causes rapid growth of soil erosion, followed by a decrease in the quantity and quality of underground water, a decline in agricultural and livestock products, and the occurrence of destructive floods that instead of blessings, they bring sorrow for the watershed residences. Therefore, in order to conservation water and soil resources, improve the environment and create a suitable platform for sustainable development in these areas, efficient management is required for the use of water and soil resources. One of the high potentials of dry and desert areas are the rainwater catchment systems, which have a high ability to extract rainfall for the improvement and development of these areas. This study investigated the effectiveness of check dams in controlling sedimentation and increasing the land level in one of the hydrological units in Narun Taftan Khash region. In order to conduct this research, one of the hydrological units from the primary sub-branches of this region was selected, where 15 check dams were constructed with public participation. First, the position of the clauses was determined. Then the dimensions and volume of each of them were estimated. Also, the amount of accumulated sediments in the tank of each of them was estimated. For this purpose, the height of sediment was measured in three locations and by obtaining their average as well as the length and width of the area with sediment, the area covered by these sediments was estimated. Then, the volume of sediments in the reservoir of each section was calculated based on the corresponding equation. The results showed that 67.51 cubic meters of stone were used for the construction of 15 Chinese dry dams in this catchment area, and the average contribution of each dam was 4.5 cubic meters. Also, the findings showed that the accumulated sediments in dam reservoirs and the average of each dam were 42.6 and 2.8 cubic meters, respectively.In generally, these structures have improved 232.9 square meters of rocky land, and the share of each of them was 15.5 square meters on average. In general, with the construction of each cubic meter of China dry embankment in this area, 0.63 cubic meters of sediment can be controlled and also 3.5 square meters of rocky land is also corrected. It can be concluded that check dams are one of the suitable options to control erosion and sedimentation in the primary watercourses of watersheds where there are stone materials.