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soil-moisture
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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 ; 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...
Soil Moisture Monitoring in Precision Agriculture Using Estimation Theories
, Ph.D. Dissertation Sharif University of Technology ; Nobakhti, Amin (Supervisor)
Abstract
Monitoring of soil moisture plays an essential role in correct decision making and implementation of any closed loop control system in precision agriculture. On the one hand, continuous using of a lot of moisture sensors and monitoring of soil moisture via direct measurement is restricted by practical prohibitions. On the grounds that activation of a lot of sensors continuously requires communication of a large amount of information and causes high power consumption for a moisture monitoring system. On the other hand, using remote sensing methods such as satellite methods, for moisture monitoring in arbitrary spatial and time resolution for control purposes, is not practically possible. The...
Determining the Optimal Irrigation Pattern in Agricultural Areas Using a Combination of Remote Sensing Data and the Development of a Lump Soil Moisture Model
, M.Sc. Thesis Sharif University of Technology ; Danesh-Yazdi, Mohammad (Supervisor)
Abstract
The purpose of this study is to introduce a new indicator to estimate the amount of irrigation water in excess of the need and also to determine the optimal irrigation pattern to reduce water loss in agriculture. According to the Food and Agriculture Organization of the United Nations, the major loss of fresh water takes place in agriculture, and the reduction of water resources is more significant in developing countries that do not have advanced agricultural equipment. One of the challenges in the studies related to reducing the amount of water used in agriculture is a lack of knowledge on the spatial distribution and temporal changes in water loss in a region. Although estimation of...
Zoning of Dust Hotspots and Investigation of their Formation Factors
, M.Sc. Thesis Sharif University of Technology ; Tajrishy, Massoud (Supervisor)
Abstract
Identification of dust storm hotspots using high resolution 1 km MODIS Aerosol Optical Depth (AOD) data obtained by MAIAC algorithm for a region including Iran and its neighbors, is one of the objectives of the present study. By implementing three important statistics on AOD and averaging over the last decade time period (2009-2019), dust sources of Iran, Iraq, Syria, Saudi Arabia, Oman, Afghanistan, and Pakistan were specified. These statistics include frequency of occurrence AOD>0.3, mean and coefficient of variation of aerosol optical depth. The membership rank of source zones in the set of hotspot areas has been obtained by applying the fuzzy logic approach on the three mentioned layers....
Management of Dams Release According to Agricultural Water Needs with the Aim of Increasing Water Supply to Environmental Needs (A Case Study of Bukan Dam)
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Mohammad Massoud (Supervisor)
Abstract
The purpose of this research is to first provide an algorithm to reduce the scale of large-scale microwave soil moisture images and then develop an algorithm based on it to manage the release of dams downstream of which are agricultural lands and wetlands. Considering that providing irrigation needs is the purpose of building dams and agriculture is the main consumer of water in dams, optimizing the related releases has a significant effect on reducing water consumption and the possibility of releasing more water for water needs. It has a downstream environment, also agricultural water management has a direct impact on the production of agricultural products and preservation of natural...
Estimation of Rainfall Values by using Soil Moisture as a Natural Measurment with SM2RAIN Algorithm (Case study: Orumia lake Catchment)
, M.Sc. Thesis Sharif University of Technology ; Tajrishy, Masoud (Supervisor)
Abstract
The direct impact of rainfall in human life and its fundamental role in water resources management cause the development of methods and algorithms to estimate the rainfall among the researchers. In the past decades the traditional methods were used to measure the amount of rainfall until the advent of Meteorological Satellites has sparked a revolution in this field. Significant temporal and spatial changes of rainfall and the small number of the synoptic stations caused negative impact on the actual distribution of the amount of rainfall in a vast area. The rainfall satellite data were somewhat overcome by existing deficiencies in Synoptic methods by providing a better rainfall distribution...
Relationship between Dust Outbreaks and Soil Moisture in the Urmia Lake Periphery
, M.Sc. Thesis Sharif University of Technology ; Tajrishi, Masoud (Supervisor)
Abstract
Desiccation of different salty lakes around the world has been considered as one of the most critical environmental events. Gradual desiccation of the Lake Urmia and retreatment of its shoreline with respect to ecological level (1274.1 meters) have resulted in new hotspots for dust outbreaks, especially in east and south-east peripheries, which were previously under water. These areas, part of which are salty, are now exposed to open air and susceptible to wind-erosion. Soil moisture, as one of the most important parameters for dust prevention, determines the threshold friction wind speed over playa because it increases the cohesion between soil particles. Therefore, compared with dry soil,...
Integration Frameworks for Assimilating Satellite Remote Sensing Observations with Hydrological Model Outputs
, Ph.D. Dissertation Sharif University of Technology ; 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...
Soil Moisture Content Estimation Based on Satellite Imagery
, M.Sc. Thesis Sharif University of Technology ; Tajrishy, Masoud (Supervisor) ; Jalilvand, Ehsan (Co-Supervisor)
Abstract
The aim of this study is to provide an algorithm for estimating the Soil Moisture Content (SMC) using Sentinel satellite images for the Varamin and Karaj provinces. Soil moisture varies greatly due to various factors such as land surface changes (roughness, soil type, and vegetation cover), topography and weather conditions. Due to the high cost of traditional methods of measuring soil moisture and also the large spatial changes of soil moisture, the use of these methods to prepare high-precision maps and for long periods of time or in a global scale is not possible. This study examines the relationship between soil spectral reflection diagrams using optical images in the range of 400 to...
Estimation of the Total Water Entering the Soil (Precipitation and Irrigation) Using in Situ and Satellite Soil Moisture Data
, Ph.D. Dissertation Sharif University of Technology ; Tajrishy, Masoud (Supervisor) ; Brocca, Luca (Supervisor)
Abstract
Precipitation is the most important term in the world water balance and irrigation is the major consumer of fresh water resources. However, most of the precipitation products are unable to accurately estimate the amount of water that is reaching the ground. Moreover limited information are available in terms of irrigated area and irrigation water use (IWU) at the global scale. On the other hand the confounding effect of the climate change and the world population growth has accelerated the decline in the world fresh water resources. Thereby, the precise estimates of these two parameters (i.e. Precipitation and irrigation) is essential for food and water security. In this study the soil water...
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) ; 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...
A three-dimensional mesh-free model for analyzing multi-phase flow in deforming porous media
, Article Meccanica ; Volume 51, Issue 3 , 2016 , Pages 517-536 ; 00256455 (ISSN) ; Pak, A ; Sharif University of Technology
Springer Netherlands
Abstract
Fully coupled flow-deformation analysis of deformable multiphase porous media saturated by several immiscible fluids has attracted the attention of researchers in widely different fields of engineering. This paper presents a new numerical tool to simulate the complicated process of two-phase fluid flow through deforming porous materials using a mesh-free technique, called element-free Galerkin (EFG) method. The numerical treatment of the governing partial differential equations involving the equilibrium and continuity equations of pore fluids is based on Galerkin’s weighted residual approach and employing the penalty method to introduce the essential boundary conditions into the weak forms....
Modeling spatial variability of daily rainfall in southwest Iran
, Article Scientia Iranica ; Volume 10, Issue 2 , 2003 , Pages 164-174 ; 10263098 (ISSN) ; 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...
Geotechnical characterization and collapsibility of a natural dispersive loess
, Article Engineering Geology ; Volume 250 , 2019 , Pages 89-100 ; 00137952 (ISSN) ; Kiani, M ; Sadeghi, M ; Jafarzadeh, F ; Sharif University of Technology
Elsevier B.V
2019
Abstract
During preliminary investigation phase of the national Chabahar-Zahedan railway line, serious geotechnical problems including non-uniform settlements, tensile cracks, and local collapse were reported in parts of the path near the coastline. A follow-up field investigation revealed that the in-situ soil at construction site has a metastable structure being sensitive to saturation and loading. Therefore, a comprehensive series of physical, chemical, electro-chemical, and geotechnical tests were conducted to classify and characterize the soil properties and behavior in its natural state. The natural soil was classified as a clayey loess with moderately dispersive to dispersive characteristics....
Hysteresis of soil water retention and shrinkage behaviour for various salt concentrations
, Article Geotechnique Letters ; Volume 11, Issue 1 , 2021 , Pages 21-29 ; 20452543 (ISSN) ; Nasiri, H ; Sharif University of Technology
ICE Publishing
2021
Abstract
Laboratory investigation on the influence of solute concentration on the soil water-retention curve (SWRC) and volumetric behaviour of expansive soils has received much attention in recent years due to increasing environmental pollution. However, most studies only considered applying wetting or drying path with almost no attention to hydraulic hysteresis. Furthermore, these studies have focused on examining expansive soils and only marginal effort has been devoted to collapsible soils. Therefore, the main objective of this study is to systematically explore the SWRC and shrinkage characteristics of an artificially made collapsible soil at various molar concentrations. The tests were...
A vacuum-re lled tensiometer for deep monitoring of in-situ pore water pressure
, Article Scientia Iranica ; Volume 27, Issue 2 , 2021 , Pages 596-606 ; 10263098 (ISSN) ; Chiu, A. C. F ; Ng, C. W. W ; Jafarzadeh, F ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
Real-time measurement of soil water pressure has been recognized as an essential part of investigating water ow in unsaturated soils. Tensiometry, amongst di erent measuring techniques, is a common method for direct evaluation of water pressure. However, the lower limit of measurable water pressure by a conventional tensiometer becomes even more limited by increasing its length in the vertical installation. This paper describes the development of a Vacuum-Re lled Tensiometer (VRT) for monitoring soil water pressure independent of installation depth. This is achieved by xing the distance between pressure sensor and ceramic cup together with incorporating an ancillary vacuum-re lling assembly...
A vacuum-refilled tensiometer for deep monitoring of in-situ pore water pressure
, Article Scientia Iranica ; Volume 27, Issue 2A , 2021 , Pages 596-606 ; 10263098 (ISSN) ; Chiu, A. C. F ; Ng, C. W. W ; Jafarzadeh, F ; Sharif University of Technology
Sharif University of Technology
2021
Abstract
Real-time measurement of soil water pressure has been recognized as an essential part of investigating water ow in unsaturated soils. Tensiometry, amongst different measuring techniques, is a common method for direct evaluation of water pressure. However, the lower limit of measurable water pressure by a conventional tensiometer becomes even more limited by increasing its length in the vertical installation. This paper describes the development of a Vacuum-Refilled Tensiometer (VRT) for monitoring soil water pressure independent of installation depth. This is achieved by fixing the distance between pressure sensor and ceramic cup together with incorporating an ancillary vacuumre filling...
An improved Kalman filtering approach for the estimation of unsaturated flow parameters by assimilating photographic imaging data
, Article Journal of Hydrology ; Volume 590 , 2020 ; Belfort, B ; Lehmann, F ; Weill, S ; Ataie Ashtiani, B ; Fahs, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
As a non-invasive method, photographic imaging techniques offer some interesting potentials for characterization of soil moisture content in unsaturated porous media, enabling mapping at very fine resolutions in both space and time. Although less explored, the wealth of soil moisture data provided by photographic imaging is also appealing for the estimation of unsaturated soil hydraulic parameters through inverse modeling. However, imaging data have some unique characteristics, including high susceptibility to noise, which can negatively affect the parameter estimation process. In this study a sequential data assimilation approach is developed to simultaneously update soil moisture content...
Quantifying the impacts of agricultural alteration and climate change on the water cycle dynamics in a headwater catchment of Lake Urmia Basin
, Article Agricultural Water Management ; Volume 270 , 2022 ; 03783774 (ISSN) ; Danesh Yazdi, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
The rapid shrinkage of Lake Urmia over the past two decades has raised serious environmental concerns. Several restoration plans have been proposed to reduce agricultural water consumption to supply a remarkable fraction of the lake's environmental flow requirement. However, an accurate and realistic evaluation of the effectiveness of these plans in reducing agricultural water consumption across the basin is still poorly understood. This study assessed the water-saving potential of agricultural alteration in a snow-dominated catchment in the Lake Urmia Basin. In particular, we explored the impact of crop pattern alteration via reducing the cultivation area and employing different irrigation...
The effect of seasonal variation in precipitation and evapotranspiration on the transient travel time distributions
, Article Advances in Water Resources ; Volume 142 , 2020 ; Danesh Yazdi, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Precipitation (P), plant water use, and evaporation from the soil surface control the travel time of streamflow (Q) and evapotranspiration (ET) in a complex way. However, the impact of soil moisture and energy availability on the travel time distribution (TTD) of evaporated and transpired waters are yet less understood. In this study, we investigate how the seasonal variability of P and ET in terms of phase shift and rate influences the temporal dynamics of TTDs. To this end, we choose four contrasting climate types described as in-phase P and ET, out-of-phase P and ET, year-round constant P with seasonal ET, and year-round constant ET with seasonal P. We use a physically-based hydrological...