Extended Abstract Background: Rivers are complex systems in which all kinds of chemical, biological, and physical processes take place and change under the influence of various factors and variables in terms of dimensions, shape, direction, and pattern. The changes that occur in the conditions of rivers have many effects on the river ecosystem. Carrying out any activity in rivers requires knowing the rules governing the river and predicting the river's reaction to it to avoid the related harmful consequences. It is usually difficult to understand the processes of rivers by measuring hydraulic parameters on a real scale. On the other hand, sediment transport modeling is also a very complex and difficult matter because the information that is used to predict bed changes is basically uncertain and the theories used are experimental and highly sensitive to a wide range of physical variables. The high costs of laboratory equipment and the limitation of using measuring devices are among the other reasons that limit the use of physical methods and lead experts to mathematical and numerical modeling to simulate the flow inside water channels. Continuous change is one of the governing principles of every river, and a change in flow conditions also causes changes and displacement in other geometric characteristics of the river. Because rivers are often moving in their alluvial beds, different types of bed forms have been formed in the river bed due to the shear stress in the bed. The formed shapes cause a part of the surface water flow in the river to enter the porous environment below it and return to the surface water flow after oxygenating and feeding benthic organisms. This type of currents that arise from the mixing of surface current and subsurface current in the porous environment under and around the river is called hyperic current. The surface, subsurface, and underground water systems and exchanges between them are in three levels: point, interval, and watershed. Fallen tree trunks are common structures in rivers. One of the factors in creating hyperic exchange is the presence of a pressure gradient at the border of surface flow and the porous medium. The pressure gradient is caused by various factors such as obstacles in the flow path or bed forms. Depending on the magnitude of these factors, they will affect the amount of exchange and the depth of the hyperic expansion. The first step in understanding the hyperic phenomenon and its application is to examine changes in the characteristics of this area, including the amount of current exchange, depth, and retention time. Therefore, the objectives of this research are to investigate the effect of natural obstacles created by tree trunks on hyperic characteristics and the effect of the arrangement of natural obstacles created by tree trunks on hyperic characteristics. Methods: The current field research was carried out in the Garambadesht River of Gorgan in the summer and winter of 2021 to investigate the effect of fallen tree trunks on the river path as a natural flow barrier in different tree trunk thicknesses (30, 60, and 90 cm). As one of the most important sources of drinking water for the city of Gorgan, the Garmabadesht River, originates from the slopes of Yazdaki Mountain at a point 27 km southeast of Gorgan and continues to flow northward. Then, it passes through the high and complex heights and enters the eastern plains of Gorgan. To carry out the present research, piezometers were installed in the upstream and downstream of the tree trunks and then evaluated using a numerical model in the Comsol software environment, compared to the simulation of the hyperic flow to estimate the amount of exchange flow. Results: This study obtained convincing findings regarding the correlation between piezometer observational data and numerical simulation results. A 91% correlation was obtained between piezometer observation data and simulation results, which was used as a basis to investigate the computational exchange flows from the numerical model. The findings showed that the amount of exchanged flow in blocked conditions was higher than in non-blocked conditions. This issue shows that tree trunks can have a significant impact on the dynamics of hyperic flow, an important consequence of which is the direct impact on river ecosystems, especially in relation to the preservation of coastal vegetation and aquatic habitats. The investigation of the retention time of the flow lines in three obstacle states shows that the increase of the obstacle in the flow path has increased the retention time because the flow lines have become deeper and their length has increased with the increase in the height of the obstacle, thereby increasing the retention time. Conclusion: The results indicate that the maximum amount of equilibrium discharge occurs in the case where the thickness of the tree trunk is 30 cm in winter. The amount of exchange flow with obstruction is higher than that without obstruction. The equilibrium flow rate in winter is higher than the exchange flow rate in summer. The investigation of the penetration of flow lines shows that the penetration rate of flow lines has increased with the increase in the thickness of the barrier. Considering the vastness of the research field, it is appropriate to conduct more research to discover more understanding of its mechanism.

In rivers, the combination of surface flow and subsurface flow generates Hyporheic flow in the porous environment beneath and surrounding the river. To quantify exchange rate between surface and subsurface water, it is crucial to estimate hydraulic conductivity between the two sources of water. In this study, hydraulic slope and hydraulic conductivity of river bottom sediments were estimated using a mini-piezometer and manometer. Physical experiments were conducted to investigate the impact of natural obstacles on the river path, specifically tree trunks at varying heights (30-60-90 cm), in the year 2022 and Tuskestan River in Gorgan. Piezometers were placed upstream and downstream of the tree trunks, and the resulting hydraulic head difference was assessed through numerical modeling using COMSOL software to simulate hyporheic flow. The study found a 91% correlation between piezometer observation data and numerical solution results, which facilitated further investigation into computational exchange flows. Based on this, the computational exchange flows from the numerical model were also investigated. The results indicated that the highest amount of equilibrium flow occurs in the case where the height of the tree trunk is 30 cm (the exchange flow is 3.96 times without the tree trunk).

The acquisition of knowledge and the continued development of cosmic ray detection technology has led to new connections between academic disciplines such as physics, geology, agriculture, mining and archaeology. Because of the interaction of these beams with the Earth's atmosphere, a massive flux of secondary particles is produced and collided with the Earth. As one of these energetic charged particles, the muons are capable of penetrating large surface and deep earth structures, which provides a new tool in surface/subsuface mapping. Due to the density dependent interaction of these charged particles with matter, it is possible to image various surface structures such as volcanoes, antiquities and civil structures or reservoirs, cavities, radioactive wastes and subsurface valuable mineral veins. The aim of this paper is to review the recent years of research on this new technique called muography and it was tried here in a new structure to use this technique in all three fields of mapping, surveying and remote sensing to extract information about large surface/subsurface volumes.

The paper concerns with the identification of the surface and subsurface defects based on Lamb wave generation and propagation in a structure with piezoelectric wafer active sensor. The piezoelectric wafer acts as an actuator at the initial instant for Lamb wave generation and then as sensor to monitor Lamb waves reflected from different surfaces of the structure. A finite element model is developed to analyze the response of the structure and piezoelectric wafer subjected to initial activation signal. The model simulates the generation of Lamb waves which are divided into symmetric and anti-symmetric waves propagating with different velocities. The reflection of Lamb waves from exterior surfaces of the structure or the surfaces of the defects are identified using the present model. The performance of the damage identification procedure is evaluated for a plate structure with single or multiple transverse grooves whose dimensions are very small compared to structural dimensions in order to simulate the transverse cracks in the structure. The results have shown that Lamb waves are very sensitive to transverse grooves and determine the location of transverse damages with a reasonable accuracy.

BACKGROUND AND OBJECTIVES: The southeast Indian Ocean is one of the areas where tropical cyclones formed. A comprehensive understanding of the cyclone impact in the Southeastern Indian Ocean is needed to anticipate future changes due to the warming trend. The present study investigates the influence of Cyclone Marcus on oceanographic processes in the subsurface and surface layers and its impact on temperature and Chlorophyll-a in the Southeastern Indian Ocean. The present study applies the Argo Float data located near the peak of the Cyclone Markus path and could capture the subsurface layer vertically that has never been reported previously. METHODS: This study performs Copernicus data set and Argo Float data to analyze the oceanographic feature of the region before, during, and after Cyclone Marcus. FINDINGS: The average surface current velocity increased almost two times during Cyclone Marcus, and the eddy was formed in the clockwise direction following the surface wind pattern. The Argo Float data presents that Cyclone Marcus could induce surface divergence (clockwise eddy) where the cold water and high salinity waters pumped up to the surface layer, starting 1 day after the peak of Cyclone Marcus, resulting in cooling surface temperature by 1. 7 °, C and deepening mixed layer depth up to 60 m. It implies that the lifted nutrient-rich water stays in the mixed layer depth for 11 days, and sea surface Chlorophyll-a concentration increase with time lags of 2. 5 days and 5. 6 days, respectively. The Chlorophyll-a concentration increases 2. 5 times, and since then starts to decrease its ‘, normal concentration’,within two weeks. CONCLUSION: Cyclone Marcus triggers the entrainment between the subsurface layer and the sea surface, forcing a phytoplankton growth, particularly in the path area. The future cyclone could increase in the category in the study area, as the warming trend in the Indian Ocean.

Due to limitation of water resources, the use of wastewater for agriculture and landscape is unavoidable. The wastewater is a new water source and its application requires special management. If wastewater is applied with suitable irrigation methods, it helps to solve the environmental contaminations, sanitary and water scarcity problems. The effects of wastewater on some visual and chemical properties of bermudagrass were investigated in 2005 at Mahmoudabad Research Centre located at Isfahan. The experiment was a factorial completely randomized design with two main treatments (surface and subsurface irrigation methods) and two sub-treatments (groundwater and wastewater) using three replications for each treatment. The results showed that wastewater application had no significant effect on the colour, density and nitrogen uptake of bermudagrass. The height and dry matter yield of bermudagrass irrigated with wastewater were significantly greater than those irrigated with groundwater. Phosphorous uptake of bermudagrass irrigated with wastewater (1268.85 mg/kg) was greater than that of groundwater (809.97 mg/kg). Phosphorous uptake of bermudagrass irrigated with wastewater (12448 mg/kg) was also greater than that of groundwater (11820 mg/kg). The irrigation method had no significant effect on colour, density, height and dry matter yield of bermudagrass and nitrogen, phosphorous and potassium uptake of bermudagrass.

Water restriction is one of the most important factors inhibiting the crop production. Accordingly, application of pressurized irrigation systems to optimize utilization of water resources is inevitable. This study was conducted in Behbahan Agricultural Research Station during three cropping seasons (2013-2016) and based on a randomized complete block design with a split plot and three replications. The main plots were consisted of Subsurface Drip Irrigation (SDI) system that applied irrigation water at three levels of 75, 100 and 125% of water requirement and a surface Drip Irrigation (DI) system with application of 100% water requirement. The sub-plots were consisted of two varieties of date palm; Khasi and Zahedi. The crop water requirement was estimated based on Penman-Montheith method and using a daily weather information data collected from Behbahan weather station. Analysis of variance showed a significant difference (5%) between water use efficiency of different levels of irrigation water. As, the SDI system with 75% irrigation level showed the highest water use efficiency to be 0. 698 kg/m3. The comparison of interaction effects showed that the water use efficiency of Zahedi dates in 75% SDI system with 0. 744 kg/m3 is higher than that of Khasi dates. In the other hand, the 75% SDI system saved 2509. 6, 5019. 2 and 2630. 3 m3/ha irrigation water as compared with 100% and 125% SDI and 100% DI systems, respectively. According to the results, the interaction impact of irrigation levels and varieties on water use efficiency was significant but the interaction of irrigation systems and varieties were not significant. The stiffness of fruits was measured to be 11. 3 lb per square meter in 75% SDI system which was the highest as compared to those for other treatments. The results of this study showed that the SDI system could be used for palms trees without restriction while use less water without significant impact on yield.