In arid and semi-arid regions, groundwater is the main source of development of sectors (industrial, agricultural, domestic). And with the increase in demand for water due to population growth, irrigation of agricultural lands and industrial development, exploitation of groundwater resources has also increased. This issue, combined with droughts and the consequences of climate change, has reduced the groundwater level in arid and semi-arid regions. In order to supply the lack of surface water, as well as to overcome drought in emergency situations and sustainable MANAGEMENT of groundwater resources, installing a managed aquifer recharge system (MAR) to recharge groundwater using FLOOD and surface water in a long-term is important and necessary. The methods of artificial recharge are diverse and depend on the need, facilities and many factors that affect on artificial recharge. Due to this issue, tools such as geographic information system (GIS) are very useful for finding the best places to recharge groundwater. Identifying the groundwater recharge area is an important factor for achieving success and managing water resources in any region. The purpose of this research is the optimal MANAGEMENT of surface and groundwater resources using a hybrid modeling pattern in order to increase the stability of the groundwater resources system and reduce its quantitative and environmental issues in the study area. Therefore, in this study, the identification and MANAGEMENT of groundwater recharge was carried out in the Shahriar PLAIN located in the western outskirts of Tehran, Iran. Methods: In this research, a simulation pattern was presented, according to which, first, the best artificial recharge place was determined by fuzzy and weight method using GIS model in Shahriar PLAIN. Then, HEC-RAS hydraulic model was used to calculate the parameter (the ratio of infiltration debi to FLOOD debi) in the Karaj river. In the next step, two independent models for FLOOD routng in the river and reservoirs of the artificial recharge system were defined by the HEC-HMS model. In the first model, the parameter of the ratio of infiltration debi to FLOOD debi was used in the Massingham-Kange method to determine the FLOOD routng in the river, and in this way, the amount of FLOOD entering to the artificial recharge plan was estimated. In the second model, FLOOD routng was carried out in the reservoirs of the recharge plan and the amount of infiltration, storage and recharge was calculated by the plan. And finally, the amount of recharge in the artificial recharge plan was simulated using the artificial neural network (ANN) model, and the performance of the artificial recharge system and the groundwater level changes resulting from it were estimated. Results: According to the fuzzy and weight analysis, the best place for artificial recharge in the entire studied time horizon was considered to be alluvial fan in the north of the PLAIN. The area of the suitable (good) region obtained by the fuzzy method was calculated to be 8.62 percent more than the weighted method, and the performance of the fuzzy method in estimating the suitable locations was evaluated better than the weighted method. The maximum volume of FLOOD entering the recharge plan from the HEC-RAS model and the first HEC-HMS model in the studied period is 8.56 and 8 (MCM), respectively, and the minimum value of this variable from the HEC-HMS simulator is 0.87 (MCM) and in the case of the HEC-RAS model, the same amount was estimated. The results indicated that the maximum and minimum FLOOD volumes entering to plan are related to the maximum and minimum FLOODs occurred. The total amount of artificial recharge resulting from the HEC-HMS model, in the entire time period studied, without considering the FLOOD output from the recharge plan, was computed as 37.6 (MCM), and the amount of total recharge for the neural network model was computed as 36.3 (MCM). Also, the total level changes due to recharge of the plan resulting from the estimation of the simulator and the neural network model in the entire study period are equal to 1.59 and 1.53 (m), respectively, which indicates the appropriate accuracy of the neural network model. Also, the level changes caused by recharge in the plan and the river in the entire period of desired time was computed to be 1.88 (m). In total, the reserve performance of the plan in the entire period of desired time was 54 percent and the recharge performance of the plan was 89 percent, and the performance of the entire artificial recharge system including (river section and artificial recharge plan) in recharge applications was computed at 90 percent. Therefore, the results of the simulation pattern and the performance of the artificial recharge plan in recharging were evaluated as suitable and acceptable. Finally, according to the results of the hybrid modeling pattern, at the same time, FLOODs, surface and groundwater resources and artificial recharge system are under control, and based on available water resources, increasing the stability of the groundwater resources system and reducing quantitative and environmental issues related to water resources can be managed and controlled according to the existing conditions.

Meanders, as a interesting water flow patterns in nature, is giving dynamic to courses of rivers. Creation of curvature on courses of rivers is give enough energy for migrate active channel on FLOODPLAIN.This migration is main reason for many geomorphology in events is FLOODPLAINs and at final is changing the FLOODPLAIN pattern. These changing is created many problems for man-made structures that is constructed at bank or on courses of rivers. Aji-Chay River, as a typical meander is migrate on FLOODPLAIN by creation curvature on its course (is situated at 37° 58’ to 38° 07’ N and from 46° 15’ to 47 °45’ W). In this article is analyzed and estimated migration rate, migration potential and time of migration, by use of experimental methods, by satellite and areal images In this study rely on parameters of meanders, as bind and width of river corridor is estimated by use of W methods and  Dt, R/W calculation, in order to investigation on capability of rivers for movement. In this study also is estimated time of active channel migration on FLOODPLAIN by use of valid methods .The results of this study show that active channel of Aji-Chay repeatedly movement on FLOODPLAIN in during time and because these movement and changing and bank erosion, is flatten the FLOODPLAIN. In part of Aji-Chay course time period for completed a cycle of migration is from 1 to over 5 years. This period is vary in many parts of river course. The results of this study also suggested that sinuosity rate at length of Aji-Chay course is changed in during time and old race of water flow is evidence these changes.

Research on FLOOD predicting models is one of the first steps in reducing FLOOD damage and managing future FLOODs in catchments. The aim of this study was to evaluate FLOOD susceptibility in Birjand PLAIN catchment through four machine learning models including support vector machine (SVM), J48 decision tree, random forest (RF) and Adaptive neuro fuzzy inference system (ANFIS). Therefore, in order to implement and validate the mentioned models, a list of FLOOD-prone areas in the study area was prepared (42 FLOOD-prone locations). In addition, 19 hydrogeological, topographical, geological and environmental criteria affecting FLOOD occurrence in the study area were extracted to be used to predict FLOOD susceptibility map. The results showed that the highest accuracy was related to the RF model (0.845) and the lowest accuracy was related to the SVM model (0.791). In addition, the validation of the results using the ROC curve showed that the most accurate values of FLOOD susceptibility belong to the RF model (AUC = 0.958). The results of this study can be used to manage vulnerable areas and reduce FLOOD damage.

An investigation was carried out to assess the subsurface suitability of the River Nzoia FLOODPLAIN in Budalangi Division of western Kenya for supporting shallow foundation structures. An analysis of the conditions in the area during FLOOD seasons was conducted using soil mass characterisation, geotechnical testing, slope stability analyses, terrain evaluation and analysis of ground conditions in buildings in the area. The analyses reveal that significant slope failure occurs when the percentage of water exceeds 50% in slopes cut at angles greater that 24°. The suitability of the ground for supporting shallow foundation structures has been established from the results of fieldwork and from laboratory studies.

FLOOD is one of the complex and destructive natural phenomena led to human and financial losses around the country and world every year. Generally methods of FLOOD controlling are classified in two parts consist of structural and non structural methods. Construction of dam is one of the structural methods plays an important role in FLOOD control. A dam by storing a part of FLOOD volume causes to dropping in FLOOD peak and reduces the FLOOD damage in down lands. In this study, by using of river analysis systems (HEC-Ras) and geographic information system (GIS) and utilizing of Google-Earth software, the FLOODPLAIN with frequency of 50, 100, 500 and 1000 years investigated at Narmaab River of Golestan. Then effect of construction of Narmaab Dam on reducing the FLOOD PLAIN at down lands has been studied. Therefore several scenarios were defined for dam FLOOD storage volume and in any case the FLOOD PLAIN and FLOOD damage at down lands was estimated. The results show that construction of Narmaab Dam with a FLOOD storage volume equal to 6 million cubic meters can reduce damage of FLOOD with frequency of 50 and 1000 years by %75.1 and %40.7 respectively.

Nowadays, around the world, environmental impacts, as one of the most important dimensions of sustainable development, play a significant role in strategic decision makings. Water resources MANAGEMENT is one of the most sensitive measures due to its bi-directional relationship with sustainable development and also as a facilitator of this path, especially in arid and semi-arid regions. One of the main purpose of the LCA approach is to assess the environmental impact of emissions. In this study, environmental compatibility of mechanical watershed MANAGEMENT measures to manage water resources is investigated by using this approach. Therefore, material flow, energy and environmental impacts of all stages of the life cycle of one unit of FLOOD spreading system (located in Daefeh watershed in Rafsanjan PLAIN) were analyzed based on IMPACT 2002+ method available in the Simapro software. The results showed that the earthen structure of the FLOOD spreading system with 8. 37 kPt environmental impact is the hot spot of this system (Mostly due to the earthworks), including 91. 34% of environmental burdens in the construction phase and 55. 2% of the total emission effects. The findings of this research showed that the environmental consequences of emissions during the life cycle of this system were 15. 2 kPt. Construction process stage (with the highest amount of environmental burdens in each impact category except for resource depletion) 39. 2%, use stage 31. 3%, extraction and productivity of materials 23. 3% and transportation stage 0. 93% of Environmental burdens were allocated in this study. The environmental consequences of emissions in the categories of adverse effects on human health, climate change, resource depletion and ecosystem depletion of the FLOOD spreading system are 6. 63, 3. 54, 3. 06 and 1. 94 kPt, respectively. Also the results of this study will be useful for evaluating the environmental effects of different structures. Finally, it is suggested that in the integrated watershed MANAGEMENT, which is responsible for protecting our nation's natural resources, life cycle assessment approach be developed and the green building approach could be implemented, such as selecting the design discharge with environmental considerations, selecting quantities and types of environmentally friendly materials.

Planning and providing appropriate tools to reduce the adverse effects of natural hazards including FLOODs is inevitable. Achieving the above goal depends on having sufficient and accurate knowledge and information about the vulnerability of different ecosystems (watersheds) to various destructive factors. Vulnerability assessment by identifying potential stresses and disturbances (natural and man-made) as well as estimating the sensitivity of watersheds allows for predicting the effects and selecting appropriate solutions for the sustainable MANAGEMENT of these ecosystems. Therefore, this study has been designed to identify and rank vulnerable sub-watersheds to FLOODs in the Ardabil PLAIN, taking into account social, economic, infrastructural, and ecological dimensions. First, the indicators and criteria of each dimension were identified taking into account the conditions prevailing in Ardabil PLAIN. Then, information and data on climatic, hydrological, demographic, economic, infrastructure, and land use were obtained from relevant authorities. Then, the mentioned criteria were standardized and the weight according to their importance was calculated based on the BWM method the data obtained from this stage were performed using the TOPSIS technique to rank FLOOD vulnerability for different sub-watersheds in Ardabil PLAIN for the period 2007-2017. Finally, a map of Ardabil's PLAIN vulnerability to FLOODs was prepared and presented. According to the results, the criteria of building density, rainfall, population density, and the unemployment rate were the most important criteria of vulnerability and among the studied dimensions, the infrastructure dimension is too significant in FLOOD vulnerability in Ardabil PLAIN. Based on the comprehensive vulnerability map, sub-watershed 7 in Ardabil PLAIN was identified as the most vulnerable sub-watershed in the study area.