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    Modeling spatial variability of daily rainfall in southwest Iran

    , Article Scientia Iranica ; Volume 10, Issue 2 , 2003 , Pages 164-174 ; 10263098 (ISSN) Saghafian, B ; Tajrishy, M ; Shahraini, H. T ; Jalali, N ; Sharif University of Technology
    Sharif University of Technology  2003
    Abstract
    Rainfall characteristics, which include spatial variability, exert a major influence on runoff properties. Many techniques have been proposed for determining the spatial distribution of daily rainfall. One of these techniques is spatial modeling, based on rainfall data measured by rain-gauge networks. In this study, application of different interpolation methods in the GIS environment, for estimating the spatial distribution of daily rainfall in the southwest of Iran with low rain-gauge density, have been compared on a regional scale. The cross validation technique was selected as an accuracy index and statistical parameters, such as MAE (Mean Absolute Error) and MBE (Mean Bias Error), were... 

    Using Hydraulogical Model and Energy Balance in Estimating Groundwater Table, Case Study: Varamin Plain

    , M.Sc. Thesis Sharif University of Technology Khakbazan Fard, Faezeh (Author) ; Tajrishi, Masoud (Supervisor)
    Abstract
    Each country needs water for growing and developing. Water is necessary not only for expansion of cities and industries but also for agricultural development. Agriculture alone uses more than 90 percent of available water in our country. Water limitation and improper and noneconomic use of water are the main factors that limit agricultural development and food production in Iran. So taking appropriate decisions on this issue is necessary to optimize water use. Continuous assessment of water use at different levels in the basin, field and irrigation network is necessary for determining the current status and knowing its strengths and weaknesses and finding practical solutions to improve all... 

    Review of assimilating GRACE terrestrial water storage data into hydrological models: Advances, challenges and opportunities

    , Article Earth-Science Reviews ; Volume 213 , 2021 ; 00128252 (ISSN) Soltani, S. S ; Ataie Ashtiani, B ; Simmons, C. T ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    Global climate change and anthropogenic impacts lead to alterations in the water cycle, water resource availability and the frequency and intensity of floods and droughts. As a result, developing effective techniques such as hydrological modeling is essential to monitor and predict water storage changes. However, inaccuracies and uncertainties in different aspects of modeling, due to simplification of meteorological physical processes, data limitations and inaccurate climate forcing data limit the reliability of hydrological models. Satellite remote sensing datasets, especially Terrestrial Water Storage (TWS) data which can be obtained from Gravity Recovery and Climate Experiment (GRACE),... 

    Evaluating the uncertainty of urban flood model using glue approach

    , Article Urban Water Journal ; Volume 19, Issue 6 , 2022 , Pages 600-615 ; 1573062X (ISSN) Kobarfard, M ; Fazloula, R ; Zarghami, M ; Akbarpour, A ; Sharif University of Technology
    Taylor and Francis Ltd  2022
    Abstract
    This study is an attempt to investigate and analyze uncertainty through the Glue method in parts of Tabriz, Iran, using the SWMM urban flood model. In order to quantify the uncertainty, the initial range of input parameters including curve number, impenetrability percentage, penetrability level’s coarseness coefficient, and impenetrability level’s coarseness coefficient are defined and the GLUE algorithm is used to conduct primary sampling operation from parametric space using Latin hypercube sampling method. Considering the simulation results and the observed values of synchronized events, about %20 of the total outputs and generated parameters series have been excluded as acceptable... 

    Stability Analysis of Slopes with Inclusion of Hydrological and Vegetation Effects

    , Ph.D. Dissertation Sharif University of Technology Emadi Tafti, Mohsen (Author) ; Ataie Ashtiani, Behzad (Supervisor)
    Abstract
    Landslide is a natural hazard associated with economic losses and fatalities. The geometric of the slope, the soil properties, hydrological factors, and groundwater are important factors that affect the stability of a slope. The landslide investigation is important due to the identification and prevention of damages. Thus, more researchers studies on this subject. The new questions in this field are “how can simulate the vegetation effects in slope stability analysis?” and “what effects do precipitation and infiltration have on landslide triggering?”. Although the classic methods of slope stability analysis provide the initial information for the design, they have limitations in answering... 

    Modeling and Calibrating the Soil Moisture and Discharge with VIC Model and SMAP Satellite Data, Saghez Station, Zarinehrood River Basin

    , M.Sc. Thesis Sharif University of Technology Karimi Yalmeh, Mohammad Reza (Author) ; Tajrishi, Masoud (Supervisor) ; Jalilvand, Ehsan (Co-Supervisor)
    Abstract
    In this thesis we evaluate VIC hydrological model’s simulated soil moisture and discharge at Saghez synoptic station, located at ZarinehRood sub basin, Urmia Lake basin in three time periods to overcome observational and satellite data scarcity in the basin. All the input files for this macro scale semi-distributed model chose from satellite data. With a multi-objective calibration algorithm called NSGA-II and utilizing Nash-Sutcliffe (NSE) and R2 as objective functions for discharge calibration and correlation coefficient and RMSE for soil calibration, the model results evaluated. As where as we didn’t have access to observational soil moisture data, we utilized SMAP satellite soil moisture... 

    Improvement of soil moisture and groundwater level estimations using a scale-consistent river parameterization for the coupled ParFlow-CLM hydrological model: A case study of the Upper Rhine Basin

    , Article Journal of Hydrology ; Volume 610 , 2022 ; 00221694 (ISSN) Soltani, S. S ; Fahs, M ; Bitar, A. A ; Ataie Ashtiani, B ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Accurate implementation of river interactions with subsurface water is critical in large-scale hydrologic models with a constant horizontal grid resolution when models apply kinematic wave approximation for both hillslope and river channel flow. The size of rivers can vary greatly in the model domain, and the implemented grid resolution is too coarse to accurately account for river interactions. Consequently, the flow velocity is underestimated when the width of the rivers is much narrower than the selected grid size. This leads to inaccuracy and uncertainties in calculations of water quantities. In addition, the rate of exfiltration and infiltration between the river and the subsurface may... 

    Study of Climate Change Impacts on Temporal and Spatially Varying Groundwater Recharge

    , M.Sc. Thesis Sharif University of Technology Beigi, Ehsan (Author) ; Abrishamchi, Ahmad (Supervisor)
    Abstract
    Increase of concentration of CO2 and other greenhouse gases will have significant effect on global climate. Climate change affects precipitation and hydrology, which in turn influences recharge to groundwater. Recharge to groundwater is an important source, which has the main role in groundwater resources availability. To trace these changes to recharges and its consequent effect on groundwater state, a combined modeling of climate change and groundwater is necessary. In This study impact of climate change on groundwater recharge in two different climatic plains of Karkheh river basin in Khuzestan, Iran, has been investigated using a physically-based methodology that can be used for... 

    Modeling of Water-energy Cycle and Water Particle Pathways in the Gadarchay Subbasin of the Lake Urmia Basin

    , M.Sc. Thesis Sharif University of Technology Rahmani, Javad (Author) ; Danesh Yazdi, Mohammad (Supervisor)
    Abstract
    The water level of Lake Urmia has experienced a drop of 7.83 meters, from 1995 to 2017. According to previous studies, the uncontrolled development of agriculture, high consumption cultivation pattern, overuse of water resources for agricultural use and high water loss due to low irrigation efficiency, are the most important factors in the drying of Lake Urmia. Since agricultural sector is the largest water consumer (approximately 90%), the Lake Urmia Restoration Program has decided to study and implement the 40% reduction of water consumption in agricultural sector plans.Due to the inherent complexity of the Urmia Lake basin, accurate and realistic evaluation of the effectiveness of the... 

    Integration Frameworks for Assimilating Satellite Remote Sensing Observations with Hydrological Model Outputs

    , Ph.D. Dissertation Sharif University of Technology Sadat Soltani, Samira (Author) ; Ataie Ashtiani, Behzad (Supervisor)
    Abstract
    Global climate change and anthropogenic impacts lead to alterations in the water cycle, water resource availability and the frequency and intensity of floods and droughts. As a result, developing effective techniques such as hydrological modeling is essential to monitor and predict water storage changes. However, inaccuracies and uncertainties in different aspects of modeling, due to simplification of meteorological physical processes, data limitations and inaccurate climate forcing data limit the reliability of hydrological models. Assimilation of new observations constrains the dynamics of the model based on uncertainties associated with model and data, which can introduce missing water... 

    Exploring source water mixing and transient residence time distributions of outflow and evapotranspiration with an integrated hydrologic model and Lagrangian particle tracking approach

    , Article Ecohydrology ; 2018 ; 19360584 (ISSN) Maxwell, R. M ; Condon, L. E ; Danesh Yazdi, M ; Bearup, L. A ; Sharif University of Technology
    John Wiley and Sons Ltd  2018
    Abstract
    Understanding the time water takes as it moves from rain or snowmelt through the terrestrial system to arrive as stream discharge, or evapotranspiration (ET) is an important hydrologic quantity. We develop a Lagrangian particle tracking method to capture transient residence times from source to either ET or outflow in an integrated hydrologic model. This method is parallel and efficiently captures time evolution of parcels of water in the model and tracks the source of water for hydrograph or ET separation. We demonstrate this model using hypothetical hillslope simulations driven by snow or rain dominated forcing and two different land cover types. We show that land cover and forcing both... 

    Density-based global sensitivity analysis of sheet-flow travel time: kinematic wave-based formulations

    , Article Journal of Hydrology ; Volume 559 , April , 2018 , Pages 556-568 ; 00221694 (ISSN) Hosseini, S. M ; Ataie Ashtiani, B ; Simmons, C. T ; Sharif University of Technology
    Elsevier B.V  2018
    Abstract
    Despite advancements in developing physics-based formulations to estimate the sheet-flow travel time (tSHF), the quantification of the relative impacts of influential parameters on tSHF has not previously been considered. In this study, a brief review of the physics-based formulations to estimate tSHF including kinematic wave (K-W) theory in combination with Manning's roughness (K-M) and with Darcy-Weisbach friction formula (K-D) over single and multiple planes is provided. Then, the relative significance of input parameters to the developed approaches is quantified by a density-based global sensitivity analysis (GSA). The performance of K-M considering zero-upstream and uniform flow depth... 

    Two-dimensional model for lateral intake flows

    , Article Proceedings of the Institution of Civil Engineers: Water Management ; Volume 158, Issue 4 , 2005 , Pages 141-150 ; 17417589 (ISSN) Kolahdoozan, M ; Taher Shamsi, A ; Sadeghi Bagheney, M ; Mohamadian, A ; Sharif University of Technology
    ICE Publishing  2005
    Abstract
    This paper gives details of the refinement and application of a two-dimensional horizontal model for rivers. An explicit finite-difference algorithm was used for solving the governing differential equations, which includes the conservation of mass and momentum to predict hydrodynamic parameters. The model includes different turbulence closure models - that is, constant eddy viscosity, Prandtl simple mixing length and Smagorinsky methods. An experimental programme was designed and carried out in a laboratory flume to measure the length of eddy produced at the entrance of the intake. Model predictions have been compared with experimental results for a lateral intake. The effect of different... 

    The delusive accuracy of global irrigation water withdrawal estimates

    , Article Nature Communications ; Volume 13, Issue 1 , 2022 ; 20411723 (ISSN) Puy, A ; Sheikholeslami, R ; Gupta, H. V ; Hall, J. W ; Lankford, B ; Lo Piano, S ; Meier, J ; Pappenberger, F ; Porporato, A ; Vico, G ; Saltelli, A ; Sharif University of Technology
    Nature Research  2022

    Study of Climate Change Impacts on Water Resources (Case Study: Karkheh River Basin)

    , M.Sc. Thesis Sharif University of Technology Hosseini, Farzad (Author) ; Abrishamchi, Ahmad (Supervisor)
    Abstract
    Future of the Karkheh River Basin and its people’s livelihoods clearly depends on natural resources like water, soil, vegetation and livestock. As water is the most limiting natural resource in this basin, any increase in water productivity will almost certainly benefit rural livelihoods. To ensure the sustainability of the improvements in water productivity, assessment of the possible impacts of climate change on hydrology and water resources in the basin is necessary. In this study the potential impacts of climate change on hydrology in the Karkheh River Basin were assessed using a macroscale hydrology model driven by 21st century simulations of temperature and precipitation downscaled... 

    Exploring the Efficiency of Machine Learning Algorithms in Estimating Time-Variant Travel Time Distributions in River Basins

    , M.Sc. Thesis Sharif University of Technology Alizadeh Attar, Mehdi (Author) ; Danesh Yazdi, Mohammad (Supervisor)
    Abstract
    This study aimed to investigate the efficiency of machine learning algorithms in capturing the dynamics of water particles' age distribution and in estimating the time series of median travel time (MTT) in river basins. The mechanism of solute transport in a catchment does not follow the hydrograph shape of the catchment and depends on the spatial and temporal distribution of solute resident time. The equations governing the age dynamics of water particles discharged from a catchment have been presented analytically in recent research. These equations showed that the transfer of solutes depends on various factors, including climatic conditions, basin topography, and basin vegetation. Also,... 

    Conceptualization of a fresh groundwater lens influenced by climate change: A modeling study of an arid-region island in the Persian Gulf, Iran

    , Article Journal of Hydrology ; Vol. 519, issue. PA , 2014 , pp. 399-413 ; ISSN: 00221694 Mahmoodzadeh, D ; Ketabchi, H ; Ataie-Ashtiani, B ; Simmons, C. T ; Sharif University of Technology
    Abstract
    Understanding the fresh groundwater lens (FGL) behavior and potential threat of climatic-induced seawater intrusion (SWI) are significant for the future water resources management of many small islands. In this paper, the FGL of Kish Island, an arid-region case in the Persian Gulf, Iran, is modeled using two-dimensional (2D) and three-dimensional (3D) simulations. These simulations are based on the application of SUTRA, a density-dependent groundwater numerical model. Also, the numerical model parameters are calibrated using PEST, an automated parameter estimation code. Firstly a detailed conceptualization of the FGL model is completed to understand the sensitivity of the FGL to some... 

    Vulnerability assessment of urban groundwater resources to nitrate: the case study of Mashhad, Iran

    , Article Environmental Earth Sciences ; Volume 76, Issue 1 , 2017 ; 18666280 (ISSN) Asadi, P ; Ataie Ashtiani, B ; Beheshti, A ; Sharif University of Technology
    Springer Verlag  2017
    Abstract
    Groundwater vulnerability assessment of urban areas is a challenging task in the fast trend of urbanization around the globe. This study introduces a new approach for modifying well-known parameters of common vulnerability indexes to adjust them for urban areas. The approach is independent of a specific weighting system. The aquifer of Mashhad city, contaminated by domestic wastewater, is selected as a case in this study. In order to evaluate the aquifer vulnerability due to anthropogenic activities, at first, parameters of depth to groundwater, recharge, land use, and soil are modified based on their basic concepts and their influences on contamination attenuation. Then, the modified... 

    A generalized semi-analytical solution for the dispersive henry problem: effect of stratification and anisotropy on seawater intrusion

    , Article Water (Switzerland) ; Volume 10, Issue 2 , 2018 ; 20734441 (ISSN) Fahs, M ; Koohbor, B ; Belfort, B ; Ataie Ashtiani, B ; Simmons, C. T ; Younes, A ; Ackerer, P ; Sharif University of Technology
    MDPI AG  2018
    Abstract
    The Henry problem (HP) continues to play a useful role in theoretical and practical studies related to seawater intrusion (SWI) into coastal aquifers. The popularity of this problem is attributed to its simplicity and precision to the existence of semi-analytical (SA) solutions. The first SA solution has been developed for a high uniform diffusion coefficient. Several further studies have contributed more realistic solutions with lower diffusion coefficients or velocity-dependent dispersion. All the existing SA solutions are limited to homogenous and isotropic domains. This work attempts to improve the realism of the SA solution of the dispersive HP by extending it to heterogeneous and... 

    Influence of river cross-section data resolution on flood inundation modeling: Case study of Kashkan river basin in western Iran

    , Article Journal of Hydrology ; Volume 584 , 2020 Geravand, F ; Hosseini, S. M ; Ataie Ashtiani, B ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    In this study, a coupling of a hydrologic and hydraulic model was utilized to assess the impacts of river geometry data resolution on the flood inundation characteristics in a data-scarce environment. Hydrological modeling incorporates soil conservation service curve-number (SCS-CN) and the geomorphologic based instantaneous unit hydrograph model (GIUH) to compute the direct runoff hydrograph in Kashkan river basin located in western Iran. 1D HEC-Geo-RAS model was used and performed to simulate inundation extent of 100-yr floods (~1800 m3/s) along 40 km reach of Kashkan river with a ground survey of river cross-section (2000 cross-sections, each including 500 data-points). The effect of...