غلامرضا شوبیری

Interactions and conflicts, or in general, the relationships between different stakeholders in a large-scale water resources scheme, are very important factors affecting the status of water systems. In this study, the conflict was studied, mapped, and rooted in a water system using the social network analysis approach, utility analysis, and conflict tree. After finding the major problems in a water system, influential stakeholders were first identified. Then, using the social network analysis method the relationships between these stakeholders were studied to estimate their conflicts. Next, by assessing the desirability of stakeholders, the ground of conflict emerging between them was investigated using desirability mapping. Using the output of the desirability analysis, social network analysis, and important problems recognition, the roots, core, and results of the conflict were presented using the conflict tree approach. The catchment area in the west of Tehran, namely the Kan River basin, has been studied using the mentioned method. The little interest of the municipal institution in utilizing groundwater resources, the problem of subsidence and the quality of water resources, coupled with the interest in expanding green spaces and urban development are among the challenge between the regional municipality and the regional water authority. The minor consideration for the management of illegal water extraction, return water, aquatic ecosystems, and water quality has been the cause of conflict between the agricultural institution and the regional water authority. It is also critical that the interest of the industrial sector is focused on development of industries and other interests are of less importance in this sector. The lack of interest in institutions such as the urban development stakeholder to consider the water cycle's importance in urban development is another challenging issue.

Flow resistance is a key factor in open channels hydraulic analysis. Resistance to bed particles causes energy loss. As the particle size increases, the resistance increases. Experimental evidence shows that large particles in the river bed exert flow resistance. In this study, the factors that cause flow resistance in rivers have been investigated and the effective parameters (depth and width of flow, equivalent roughness height) on the habitat have been discussed. To investigate the effect of flow resistance parameters on aquatic habitat, Jajrood River and rainbow trout species have been selected. During the field visit, the coordinates of the map were matched with the location and samples of surface and subsurface materials were taken. By performing gradation in the laboratory and using Manning’s equation and stage discharge curves, the hydraulic roughness coefficient was calculated. Then grain size roughness was obtained using experimental relationships. Shape roughness coefficient was calculated by subtracting the two roughness coefficients and was used in the hydraulic simulation. Water levels obtained from the hydraulic model were used to simulate the habitat. The effect of flow depth and width and equivalent roughness height parameters on the habitat at the three life stages of the target species, namely fry, juvenile and adult, was analyzed using simulation results. In general, with increasing the width and depth of the stream and the equivalent roughness height, the habitat suitability for the target species increased. The factor that causes the most change in habitat suitability is the width of the stream,

In recent years, the discussion of nonlinear behavior in seismic evaluation of structures has been raised. One of the best and newest methods of evaluating buildings is the use of nonlinear dynamic analysis. This type of analysis shows a comprehensive behavior of structures in the linear to nonlinear domain. In this study, in addition to nonlinear dynamic analysis, in order to match the reality, seismic components with different angles have been applied to the structure to show a more accurate seismic evaluation of the structure. In this research, steel buildings with intermediate moment-resisting frame was modelled in three dimensional state in SAP2000 software with 8 and 12 stories and square and rectangular planes and their seismic performances have been studied and compared according to the angle of 8 pairs of accelograms (16 accelograms) under near and far-fault earthquakes (0, 30, 60 and 90 degree) using nonlinear dynamic time history analysis. The results showed that the performance of the structures at angles of 60 and 90 degree was more critical due to the larger seismic responses. Also, in most accelograms, the height of the structure was more effective than the plan shape on seismic responses. In addition, the studied structures had more critical seismic responses due to near-fault earthquakes compared to far-fault earthquakes.

Seismic isolation is an earthquake resistant design method based on reducing seismic demand instead of increasing structural capacity. With regard to the multiplicity of studies conducted to investigate the seismic behaviour of isolators under the effect of earthquakes, in this study, role of the base isolator in improving the behaviour of steel structures under the influence of earthquakes with different angles was investigated along with considering the effect of structural height and plan shape. In the present study, steel structures with and without Lead Rubber Bearing (LRB) base isolator are modelled in 3D with 8 and 12 stories and square and rectangular plans. The seismic performance of these buildings has been reviewed and compared according to 4 pairs of near-fault earthquake records (8 records) with angles (0°, 30°, 60° and 90°) based on FEMA P695 instruction under the nonlinear dynamic time history analyses in SAP2000 software. The results showed that steel structures at angles of 60 and 90º had larger and more critical seismic responses. Based on results, the effect of seismic isolator on reducing the seismic responses of buildings at angles of 0 and 30º was low, while at the angles of 60 and 90º was more significant. The use of separators had a great impact on improving the performance and seismic responses of structures. The results also presented that in most records, the height of the structure was more effective than the plan shape regarding the seismic responses of the isolated structures.