Loading...
Search for: lakes
0.01 seconds

    Analysis of Water Governance’s Effects in Urmia Lake’s Basin on Water Resources According to Adaptive Management Framework

    , M.Sc. Thesis Sharif University of Technology Saravani, Soroush (Author) ; Tajrishy, Masoud (Supervisor)
    Abstract
    Lake Urmia is the largest inner lake in Iran that has been dessicated continuously over the past two decades, and most of it has dried up. Urmia Lake basin is one of the country's agricultural and industrial pillars and has more than 5 million inhabitants. The conflict between people’s interests and the environmental ones besides increased demand for water harvesting has led to a reduction in water inflow to the lake. As the water resources management issues became more complex in last two decades with the entrance of political and socio-economical, the concept of water resources management has been promoted in the broader sense of water governance. The solution to the problem of Lake Urmia... 

    Development of a Model for Monitoring and Prediction of Drought under Climate Change at Watershed Scale

    , Ph.D. Dissertation Sharif University of Technology Abbasian, Mohammad Sadegh (Author) ; Abrishamchi, Ahmad (Supervisor) ; Moghim, Sanaz (Supervisor)
    Abstract
    The objective of this dissertation is to develop a model to monitor and project the long-term changes in meteorological drought under climate change at watershed scale. In this model, drought is defined based on joint precipitation-temperature values since negative correlation between precipitation and temperature implies that drier periods are often warmer, and therefore, the consequences of drought are more severe compared to low-precipitation periods with mild temperature. This is of particular importance considering global warming. To quantify drought, an indicator called precipitation-temperature deciles index, which is an extension of precipitation deciles index, is introduced. Copula... 

    Estimation of Chitgar Lake Evaporation and the Impact of Chemical Coverings on its Reduction

    , M.Sc. Thesis Sharif University of Technology Nejatian, Amir (Author) ; Tajrishy, Masoud (Supervisor) ; Irajizad, Azam (Supervisor)
    Abstract
    Reducing water evaporation is one of the ways to overcome the low precipitation and drought conditions in water reservoirs. For this purpose, extensive studies have been investigated on physical and chemical coatings on lakes and reservoirs. Physical methods often involve the use of floating covers on the water surface to block evaporation by shading, most of which are only suitable for reservoirs with surface areas smaller than 5 hectares. In chemical methods, the evaporation can be decreased by nanomaterial coating, usually, containing long-chain molecules, which by spraying them on the surface, molecular monolayers are formed. In this study, the effect of nanometer coatings on the surface... 

    Determination and Quantification of Social, Economic, and Climatic Factors in the Uncertainty of Urmia Lake Restoration Program (ULRP)

    , M.Sc. Thesis Sharif University of Technology Jahesh, Farhad (Author) ; Tajrishi, Massoud (Supervisor)
    Abstract
    Lake Urmia in northwest Iran is an important water body at the national and international level and plays a significant role in the natural, social, and economic aspects of life in the region. Unfortunately, as a result of natural and anthropologic factors, the lake has suffered a severe water decline in recent decades and was even on the verge of complete drying. Being aware of the catastrophic consequences of lake Urmia's desiccation, a megaproject called Urmia Lake Restoration Program (ULRP) aiming to revive the lake was launched in 2013. Failure in megaprojects is common and frequent in which a high level of uncertainty is one of the main contributing factors. The purpose of this study... 

    The Investigation and Tracking of Dust Particles and Their Properties over Hamoun Lake and the Aral Sea

    , M.Sc. Thesis Sharif University of Technology Goftari, Ehsan (Author) ; Moghim, Sanaz (Supervisor)
    Abstract
    Dry bed of lakes and surrounding areas play an important role in dust production. This work tries to develop an Aerosol Type Detection Index for the two regions of Lake Hamon in Sistan, Iran, and the Aral Sea in Central Asia. Using the parameters of Extinction Coefficient and Depolarization Ration of CALIPSO satellite, the proposed index differentiates and categorizes fine dust particles and clouds according to the physical behavior of each in absorbing and backscattering satellite rays. This index shows values between zero and 0.15 for desert dust and -0.3 to zero for polluted desert dust particles. In order to verify the accuracy of determining the type of particles by the proposed index,... 

    Modelling Evaporation & Salinity Variation in Saline Lakes Using Spatial System Dynamics: The Case of Urmia Lake

    , Ph.D. Dissertation Sharif University of Technology Sima, Somayeh (Author) ; Tajrishy, Masoud (Supervisor)
    Abstract
    Evaporation is the most important water loss from terminal lakes which can influence the chemistry of lakes. In large lakes, the spatial distributions of meteorological and water quality variables affect the evaporation rates. Therefore, it is crucial to consider such variations in estimating evaporation rates from large lakes. This study aims at developing an evaporation estimation model for saline lakes considering salinity and spatial distribution of variables in/over the lakes and investigating the interaction between meteorological, hydrological and water quality variables in natural saline systems. To accomplish these objectives, first a distributed model was developed for estimating... 

    Estimating the Amount of Evaporation, Salinity, Precipitation and Dissolution of Salt on Lake Urmia

    , M.Sc. Thesis Sharif University of Technology Hosseinzadeh, Ahmad (Author) ; Tajrishy, Masoud (Supervisor)
    Abstract
    Lake Urmia is the largest hypersaline lake in Iran, as well as a significant aquatic habitat. In recent decades, extreme increasing of extent plans and exploitation of water resources in this basin, cause decreasing inflow, water level and creating several environmental and economic issues. In recent decades, the excessive expansion in the development and exploitation of this basin's water resources has resulted in a drop in the flows into the lake, a decline in the lake's water level, and the creation of several environmental and economic issues. In recent years, these stressors have caused the lake's salinity to exceed 400 g/L, and salt deposits have emerged on the lake bottom and... 

    Determining the Ecological Balance of Lake Urmia According to Climatic Fluctuations and New Water Conditions in the Region

    , M.Sc. Thesis Sharif University of Technology Roshni, Fatemeh (Author) ; Agha Mohammad Hossein Tajrishi, Masoud (Supervisor)
    Abstract
    Lake Urmia is the largest inland lake of Iran and one of the most important water ecosystems in Iran and the world. The ecosystem of this lake is a typical example of a closed drainage basin into which all the runoff flows in the rivers of the basin are discharged. Because of its unique natural and ecological features, Urmia Lake has been declared as a national park since 1346, along with Kabudan and Qion Daghi islands, among the protected areas. Among the most important invertebrates in the lake, we can mention Artemia, which is a species of saltwater shrimp and one of the native species of Lake Urmia. This species is the most important source of food for many water birds such as flamingos.... 

    GROTESQUE: Noisy group testing (Quick and Efficient)

    , Article 2013 51st Annual Allerton Conference on Communication, Control, and Computing, Allerton 2013, Monticello, IL ; 2013 , Pages 1234-1241 ; 9781479934096 (ISBN) Cai, S ; Jahangoshahi, M ; Bakshi, M ; Jaggi, S ; Sharif University of Technology
    Abstract
    Group-testing refers to the problem of identifying (with high probability) a (small) subset of D defectives from a (large) set of N items via a 'small' number of 'pooled' tests (i.e., tests have a positive outcome if even one of the items being tested in the pool is defective, else they have a negative outcome). For ease of presentation in this work we focus the regime when the number of defectives is sublinear, i.e., D = O (N1-δ) for some δ > 0. The tests may be noiseless or noisy, and the testing procedure may be adaptive (the pool defining a test may depend on the outcome of a previous test), or non-Adaptive (each test is performed independent of the outcome of other tests). A rich body... 

    Simultaneous variation-aware architecture exploration and task scheduling for MPSoC energy minimization

    , Article Proceedings of the ACM Great Lakes Symposium on VLSI, GLSVLSI ; 2011 , Pages 271-276 ; 9781450306676 (ISBN) Momtazpour, M ; Ghorbani, M ; Goudarzi, M ; Sanaei, E
    Abstract
    In nanometer-scale process technologies, the effects of process variations are observed in Multiprocessor System-on-Chips (MPSoC) in terms of variations in frequencies and leakage powers among the processors on the same chip as well as across different chips of the same design. Traditionally, worst-case values are assumed for these parameters and then a deterministic optimization technique is applied to the MPSoC application under design. We show that such worst-case-based approaches are not optimal with the increasing variation observed at system-level, and instead, statistical approaches should be employed. We consider the problem of simultaneously choosing MPSoC architecture and task... 

    Rescheduling of power systems constrained with transient stability limits in restructured power systems

    , Article Electric Power Systems Research ; Volume 81, Issue 1 , 2011 , Pages 1-9 ; 03787796 (ISSN) Kheradmandi, M ; Ehsan, M ; Feuillet, R ; Hadj-Saied, N ; Sharif University of Technology
    2011
    Abstract
    This paper investigates various approaches to relieve the transient stability constraint in restructured power systems. The approaches adopted fall into two broad categories: those based on eliminating the constraint in the least-cost way and those based on eliminating with the least possible rescheduling. The latter group can, on the other hand, emerge in the form of a pool-protected policy in which the bilateral contracts are rescheduled to maintain the stability or in the form of a contract-protected policy in which the realizable bilateral contracts are maximized while minimizing the rescheduling in pool market. Transient energy function (TEF) method is used as a tool to calculate the... 

    Transmission loss allocation via loss function decomposition and current projection concept

    , Article World Academy of Science, Engineering and Technology ; Volume 62 , 2010 , Pages 675-678 ; 2010376X (ISSN) Ebrahimi, M. R ; Ghofrani, Z ; Ehsan, M ; Sharif University of Technology
    2010
    Abstract
    One of the major problems in liberalized power markets is loss allocation. In this paper, a different method for allocating transmission losses to pool market participants is proposed. The proposed method is fundamentally based on decomposition of loss function and current projection concept. The method has been implemented and tested on several networks and one sample summarized in the paper. The results show that the method is comprehensive and fair to allocating the energy losses of a power market to its participants  

    The lake urmia environmental disaster in Iran: a look at aerosol pollution

    , Article Science of the Total Environment ; Volume 633 , 2018 , Pages 42-49 ; 00489697 (ISSN) Hossein Mardi, A ; Khaghani, A ; MacDonald, A. B ; Nguyen, P ; Karimi, N ; Heidary, P ; Karimi, N ; Saemian, P ; Sehatkashani, S ; Tajrishy, M ; Sorooshian, A ; Sharif University of Technology
    Abstract
    Lake Urmia (LU) once was the second largest hypersaline lake in the world, covering up to 6000 km2, but has undergone catastrophic desiccation in recent years resulting in loss of 90% of its area and extensive coverage by playas and marshlands that represent a source of salt and dust. This study examines daily Aerosol Optical Depth (AOD) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) between 2001 and 2015 over northwestern Iran, which encompasses LU. Intriguingly, salt emissions from the LU surface associated with ongoing desiccation do not drive the study region's AOD profile, whereas pollution transported from other regions and emissions around LU are more important.... 

    Customer choice of reliability in spinning reserve procurement and cost allocation

    , Article 2008 IEEE Electrical Power and Energy Conference - Energy Innovation, Vancouver, BC, 6 October 2008 through 7 October 2008 ; January , 2008 ; 9781424428953 (ISBN) Ahmadi Khatir, A ; Fotuhi Firuzabad, M ; Sharif University of Technology
    2008
    Abstract
    Reliability is one of the main factors influencing customer loyalty in a competitive power industry. The system operator must ensure that there is sufficient spinning reserve to maintain system security. Contractually such commodity requires a willing buyer and a willing seller. A novel pool-based market clearing algorithm for spinning reserve procurement and the cost allocation associated with provision of spinning reserve among DisCos is developed in this paper. Rational buyer model is used for energy and reserve market model. In the proposed algorithm, generating units bid simultaneously to energy and spinning reserve markets and these markets are sequentially cleared. In such a market,... 

    Spatial-temporal Variation of Urmia Lake Basin Using Artificial Intelligence Algorithms

    , M.Sc. Thesis Sharif University of Technology Novin, Soroush (Author) ; Torkian, Ayoub (Supervisor)
    Abstract
    Water shortages resulting from macro-environmental climate changes as well as local inefficient agricultural practices and dam constructions activities have resulted in the gradual reduction of water level in Urmia Lake, located in the northwest of Iran. As such, restoration efforts were initiated to prevent further adverse impacts exacerbating the conditions and creating secondary problems such as regional salt dust generation and dispersion, resulting in health issues for the greater area population in the neighboring vicinities. The utilization of advanced forecast modeling based on deep learning algorithms can assist the authorities to manage better multi-dimensional issues affecting the... 

    METRIC and WaPOR estimates of evapotranspiration over the Lake Urmia basin: Comparative analysis and composite assessment

    , Article Water (Switzerland) ; Volume 11, Issue 8 , 2019 ; 20734441 (ISSN) Javadian, M ; Behrangi, A ; Gholizadeh, M ; Tajrishy, M ; Sharif University of Technology
    MDPI AG  2019
    Abstract
    Evapotranspiration is one of the main components of water and energy balance. In this study, we compare two ET products, suitable for regional analysis at high spatial resolution: The recent WaPOR product developed by FAO and METRIC algorithm. WaPOR is based on ETLook, which is a two-source model and relies on microwave images. WaPOR is unique as it has no limitation under cloudy days, but METRIC is limited by clouds. METRIC and WaPOR are more sensitive to land surface temperature and soil moisture, respectively. Using two years (2010 and 2014) of data over Lake Urmia basin, we show that in most areas, ET from METRIC is higher than WaPOR and the difference has an ascending trend with the... 

    Multi-site statistical downscaling of precipitation using generalized hierarchical linear models: a case study of the imperilled Lake Urmia basin

    , Article Hydrological Sciences Journal ; Volume 65, Issue 14 , 2020 , Pages 2466-2481 Abbasian, M. S ; Abrishamchi, A ; Najafi, M. R ; Moghim, S ; Sharif University of Technology
    Taylor and Francis Ltd  2020
    Abstract
    A downscaling model capable of explaining the temporal and spatial variability of regional hydroclimatic variables is essential for reliable climate change studies and impact assessments. This study proposes a novel statistical approach based on generalized hierarchical linear model (GHLM) to downscale precipitation from the outputs of general circulation models (GCMs) at multiple sites. GHLM partitions the total variance of precipitation into within- and between-site variability allowing for transferring information between sites to develop a regional downscaling model. The methodology is demonstrated by downscaling precipitation using the outputs of eight GCMs in Lake Urmia basin in... 

    Increasing risk of meteorological drought in the Lake Urmia basin under climate change: Introducing the precipitation–temperature deciles index

    , Article Journal of Hydrology ; 2020 Abbasian, M. S ; Najafi, M. R ; Abrishamchi, A ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    Meteorological droughts due to the concurrent occurrence of low-precipitation and high-temperature events can lead to severe negative impacts on agriculture, economy, ecosystem, and society. This study proposes a novel framework to characterize such drought conditions based on the joint variability of precipitation–temperature, particularly under climate change. Generalized hierarchical linear model is used to downscale precipitation and temperature at multiple stations from the outputs of nine General Circulation Models (GCMs) under Representative Concentration Pathways (RCPs) 4.5 and 8.5. A bivariate drought index called Precipitation–Temperature Deciles Index (PTDI) is developed using... 

    System dynamics to assess the effectiveness of restoration scenarios for the Urmia Lake: A prey-predator approach for the human-environment uncertain interactions

    , Article Journal of Hydrology ; Volume 593 , 2021 ; 00221694 (ISSN) Barhagh, S. E ; Zarghami, M ; Alizade Govarchin Ghale, Y ; Shahbazbegian, M. R ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    In recent decades, population growth, agricultural development and climate change have caused environmental problems in the world, especially in the arid and semi-arid regions such as Iran. Urmia Lake, one of the unique biosphere reserves of the world, has suffered from these problems in the last 20 years. Although many studies conducted to the negative impacts of human-induced activities, especially agricultural expansion on the lake, few studies focused on providing restoration plans for that. This study uses a system dynamics method for modelling the restorations scenarios of Urmia Lake based on the prey-predator approach. This method is helpful to simplify the complicated feedbacks and... 

    An uncertain agent-based model for socio-ecological simulation of groundwater use in irrigation: a case study of Lake Urmia Basin, Iran

    , Article Agricultural Water Management ; Volume 249 , 2021 ; 03783774 (ISSN) Anbari, M. J ; Zarghami, M ; Nadiri, A. A ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    Socio-ecological systems include diverse resources of complexity involving complicated interactions, feedback, dynamic behavior patterns, heterogeneity in agents’ characteristics and behaviors, as well as system uncertainties. Agent-based modeling is introduced as a tool to simulate different levels of stakeholders and interactions, including individual, group, and institutional agents in complex socio-ecological systems. In the present study, an agent-based model was developed to explore sustainable solutions in uncertain conditions for groundwater restoration of a critical aquifer in the Lake Urmia Basin, Iran. Different projects for aquifer restoration such as wells monitoring, license...