Showing posts with label Analysis. Show all posts
Showing posts with label Analysis. Show all posts

Thursday, February 18, 2016

Article: Structural characteristics of annual precipitation in Lake Urmia basin

Hi

At last I got my paper published on the web. It is about patterns of annual precipitation in the basin. You can download it from Springer link.

Structural characteristics of annual precipitation in Lake Urmia basin


The proper citation would be.
Vaheddoost B, Aksoy H (2016) Structural characteristics of annual precipitation in Lake Urmia basin. Theoretical and Applied Climatology (): 1-14, DOI 10.1007/s00704-016-1748-3

Thankfully 
Babak

Monday, February 1, 2016

Annual precipitatition in Lake Urmia Basin

Hi

My last article has now accepted to be published at Theoretical and Applied Climatology. It is about structural characteristics of annual rainfall in Lake Urmia basin. I removed some stuff that I want to share it in here.
My study concludes that, North West and South West of the basin have the highest maximum rainfall amount, while the lowest amounts (i.e. Lowest amount related to max. observed annual rainfall) are related to the East coasts of the LU. To some extent it is confident to recognize that, maximum rainfall in the LUB is related to the altitudes and maximum annual rainfall decreases from West to East. Consequently the main input air fronts of basin are feeding form West and North. Figure 1 shows that the most amount of the vapor and moisture that coming from Turkey toward the LUB is descended inside the Turkish territory (Landsat 4, 5 and 8. USGS, 2015). Minimum amount of rainfall have same pattern while crossing West to East and North West of LUB has the highest min. annual rainfall while the least amounts belongs to Eastern side.

Fig.1. Landsat (4, 5 and 8) views of the West of the basin in the boarder of Turkey and Iran indicating the impact of border’s altitudes on the amount snow available on the land surface. (a) Landsat 4-5. Dec 9, 1987. (b) Landsat 4&5. Feb 4, 2000. (c) Landsat 4&5. May 14, 2007. (d) Landsat 8. Jan 12, 2015. (USGS, 2015)
P.S: please cite the weblog if you want to use this figure in another document

This is first evidence in its own category. Native people believe that Turkish side of the border got more precipitation and this Landsat pictures shows the evidence of such phenomena. Some of my friends believe that the tectonic movements which caused disastrous earthquake at Van (Turky)  in October 2011 is caused in the changes in the terrain which triggered the amount of water vapor crossing the border. 
As a proof they mention that, there were more snow or rain descend in the region but we got a little now a days. This satellite imagery obviously shows the effect of the border's mountains but those not necessarily support the idea of boycotting the air fronts from reaching the inner plains of the basin.

Please share your idea with me
Thankfully
Babak 

Thursday, January 14, 2016

Interaction of coastal aquifer and lake water level

Hi,
Tomorrow is my 3rd thesis report day. I am now finished with the presentation and I just started to do analysis on groundwater.
In the first place, I started with Pearson correlation coefficient. Result are very interesting, as I mentioned before, there is a strong evidence that groundwater and lake have strong relations. Accounting for a probable cross-correlation lag between lake and ground water, it sounds like interaction between these two are inevitable. AS you can see in Fig.1 Pearson correlation coefficient in West bank of the Lake is negative while positive correlations are observed in the East bank of the lake.


Fig.1. Iso-correlation map of the Lake Urmia, defining the negative correlation coefficient for the West (Left) and positive correlation for the East (Right) bank

This values some how make sense while, the incline of the terrain in the West bank is more rapid and sharp. Fig. 2 shows a schematic representation of geological features in the Lake Urmia. In the West bank of the lake, groundwater elevation changes in reverse order with the lake and decreases when the lake water level increase. On the other hand, in East bank, lake water level and ground water elevation changes in the same way. This could be an evidence to recognize that, salinity intrusion is more severe in the East bank of the lake (East Azerbaijan) while the West bank plays more active role in interaction.

Fig. 2. Schematic of lake Urmia and the possible interaction between lake and coastal aquifer

Please share your comments with me
Thankfully
Babak

Saturday, January 2, 2016

Interaction of Coastal aquifer and Lake Urmia

Hey guys.

As I discussed previously, I am a true believer of  existence of interaction between coastal aquifer and Lake Urmia water level. Many authorities and politicians refuse to accept the theory and there are some research articles based on rejection of existence of such an interaction.
Recently I used to publish a conference paper (ASCE, EWRI 2015) about the interaction of water level in some random coastal aquifers in West coast of the Lake Urmia basin and water level in the Lake itself. I used a soft computational method named "Decision Tree" to manipulate my model. It is based on Entropy and probability. Evidence and results of this model are in agreement with a theory of existence of such interaction in Coastal aquifer.
Fig. 1 shows the schematic relation between lake and coastal aquifer which I believe that exist in the hydrological process. In general in closed basin lakes, such interaction is one of the main hydrological variables that should be considered and studied carefully.

Fig. 1. Schematic of interaction of coastal aquifer and Lake Urmia in balance

So I used to select some random wells just near to the west coast of the lake. You can find the position of this wells in Fig. 2. Data in east coast is not ready for use for now and I will try to manipulate them a.s.a.p. Followingly, a Pearson correlation coefficient test between Lake water level and water level in wells is done and interesting results are shown in Fig. 3 with a radar chart including the direction of such relations.
Fig. 3. Correlaogram radar chart

Fig. 2. Position of wells in west coast of the Lake


It is obvious that, there is strong linear relationship specially in North and South of the basin all with negative values. Same analysis on probability distribution function of lake water and water level in wells showed strong similarities in shape and moments of distribution. I have done some investigations on the structure of cross-correlations in time and space between lake and coastal aquifer. Two samples of such investigation are shown in Fig. 4. You can see seasonality and strong interaction between lake and coastal aquifer. As shown in Fig. 3 and 4,  these two stations (Station 1 and 6) have the most impact on the interaction.
Fig. 4. Cross-correlation between lake water level and water level in wells of station 1 and 6

I though a model may reveal more detailed structure of the relation, so I used to select a probabilistic one. As entropy concept is very popular now a days I used DT for manipulation of data and calibrated my tree. Here is the scatter plot of my model in Fig. 5. As you can see these are strong estimation result and I personally satisfied with the results.

Fig. 5. Scatter lot of DT model
That is all I was eager to share for now!
So I think I proved my theory at least to some extent. You may find out my paper's abstract in Related page in my weblog and/or download the whole article from ASCE library.

Please share your points of view with me.
Thank you

Saturday, December 26, 2015

Modified Diagram for Depth-Area-Volume of the Lake Urmia

Hi
I was trying to calculate lake Area and Volume time series for further studies, that I found out there are some gaps. It was about some higher values that were not included in the recorded data. So I decided to extrapolate diagrams and make a modified version of the diagram. You can see extrapolation curves and modified diagram for depth-area-volume of the lake bellow.
Fig. 1. Extrapolation curves for Area and Volume

Fig. 2. Modified diagram for depth-area-volume of the Lake Urmia
Thankfully
Babak

Data generation

Hi
Recently, I used to reconstruct some missing data in my runoff and lake water depth time series to fulfill the gaps in the records. For this, I used Frequency Domain Analysis (FDA) combined with Auto Regressive models to catch the remaining information (persistence) in the FDA residual.

  • Firstly a primary set of data is considered with at least 100 month length in order to reproduce the main properties of the generated time series, moments of the distribution and time dependency.
  • In the second stage, time series of data is transformed to Normal distribution and controlled for stationary. The transformation procedure for runoff time series is done with log-transformation, while lake water level time series is manipulated by means of Box-Cox transformation.
  • Then, analysis of spikes in line spectrum (LS) of the model is calculated for catching the main periodicity in the sets. For instance LS of runoff in Simine River is shown in Fig.1.
Fig.1. LLS of Simine River
  • Due to statistical inconsistency of spikes in line spectrum function, a Tukey window is used to transform it to power spectrum (PS) and use the statistically significant spikes in the PS (Fig. 2).
Fig. 2. PS of Simine River
    • Then residual series of the selected Fourier series is calculated and controlled for being a white noise. If there was a remaining information in the procedure an AR model is used for manipulation. Later a normally distributed random series by mean zero and the same standard deviation with residual series is generated.
    • Fig. 3. shows some Fourier series used in Analysis.
    Fig. 3. Fourier series used in Analysis of Simine River
    •  Then after, estimation time series is calculated using selected Fourier series plus random series and controlled for degree of accuracy in comparison with selected transformed time series.
    • Flowingly, selected Fourier series with the most adequate properties is used in manipulations and filling up gaps between data but original data was not disturbed at all.
    • At last, generated time series was tested for statistical properties compared to primary time series. Fig. 3 shows some Fourier series of Simine river.
    • A competitive results of primary and generated tiem series is shown in Table 1 and Fig. 4. The goal is to catch more information and transfer it to the final time series.
    Add caption
    Table. 1. Statistics related to primary and generated time series (Fourier and combined Fourier and AR)
    • Thus, for this case a combined Fourier and AR model is used for generating data. This issue is also used for other time series of runoff and lake water depth.
    Thankfully yours
    Babak





    Wednesday, July 8, 2015

    Can Water Diplomacy Enable a New Future for the Urmia Lake?

    A two-day workshop on a case study using the Water Diplomacy Framework. July 02-03, 2015 at Tufts University and MIT.

    There was an ongoing workshop and webinar in TUFTS and MIT about the Lake and several investigators and research makers were evolved. I completely forgot to put the link here for those whom are interested to follow the debate.
    Anyway, I am putting some links and picture here about the webinar.

    Participants:


    He received a PhD in hydrogeology from University College London, 1991. He has over two decades of consulting, training and research experiences in groundwater modeling and management, hydrogeochemistry, groundwater contamination and groundwater in fractured rocks. Now, he is Dean of Natural Sciences Faculty in University of Tabriz (Iran).

    Shafiqul (“Shafik”) Islam is Professor of Civil and Environmental Engineering and Professor of Water Diplomacy at the Fletcher School of Law and Diplomacy at Tufts. He was the first Bernard M. Gordon Senior Faculty Fellow in Engineering at Tufts University. Professor Islam’s teaching and research interests are to understand characterize, measure, and model water issues ranging from climate to cholera to water diplomacy with a focus on scale issues and remote sensing. His research group WE REASoN integrates “theory and practice” and “think and do” to create actionable water knowledge. Read more.

    Dr. Razyeh Lak
    She is assistant professor of Research Institute for Earth Sciences, Geological Survey of Iran. Her work experience includes manager of Urmia Lake Restoration Program in the field of geology, president of geoscience and vice president of oceanography committees of the Iranian National Commission for UNESCO.

    Prof. Saeed Morid
    Saeed Morid has over two decades of consulting, training and research experiences in different aspects of water resources management. Presently, he is a faculty member in Tarbiat Modares University (Iran). The main fields of his work are drought, climate change and integrated modeling of water resources systems.
    Prof. James Wescoat
    His research has concentrated on water systems in South Asia and the US from the site to river basin scales. For the greater part of his career, Professor Wescoat has focused on small-scale historical waterworks of Mughal gardens and cities in India and Pakistan. He led the Smithsonian Institution’s project titled, “Garden, City, and Empire: The Historical Geography of Mughal Lahore,” which resulted in a co-edited volume on Mughal Gardens: Sources, Places, Representations, Prospects, and The Mughal Garden: Interpretation, Conservation, and Implications with colleagues from the University of Engineering and Technology-Lahore. These and related books have won awards from the Government of Pakistan and Punjab Government.

    Dr. Kamran Zeynalzadeh

    As director of Urmia Lake Research Institute (Urmia University, Iran) my research focuses on study and evaluation of irrigation and drainage systems, environmental studies, On-farm water management and catchment area, percolation and leakage in soils.

    Speakers (Online)

    Dr. Hamed Ghoddusi
    Hamed Ghoddusi is an Assistant Professor at the School of Business, Stevens Institute of Technology. Before joining Stevens he was a postdoctoral associate at MIT’s Engineering Systems Division (ESD). He has received his Ph.D. from the Vienna Graduate School of Finance (VGSF) and degrees in Economics, Management Science, and Industrial Engineering from the Institute for Advanced Studies (Vienna) and Sharif University of Technology (Tehran). His research interests include Resource and Energy Economics, Society-Centered Financial Innovation, and Risk Management. Hamed has been a visiting scholar/consultant at the International Institute for Applied Systems Analysis (IIASA), Oxford Institute for Energy Studies (OIES), UT Austin, UC Berkeley, UNDP, and UNIDO.

    Dr. Kaveh Madani
    Kaveh Madani is an Environmental Management Lecturer at the Centre for Environmental Policy of the Imperial College London. Prior to this he was an assistant professor of Civil, Environmental, and Construction Engineering and an Alex Alexander Fellow at the University of Central Florida (UCF), where he founded and directed the Hydro-Environmental & Energy Systems Analysis (HEESA) Research Group. His core research interests and experiences include integrated water, environmental, and energy resources engineering and management. His work includes applications of systems engineering, conflict resolution, system dynamics, economics, optimization as well as simulation and modeling methods to water, environmental, and energy resource problems at different scales to derive policy and management insights.

    Prof. Soroosh Sorooshian
    Sorooshian is a Distinguished Professor of Civil and Environmental Engineering and Earth System Science Departments and Director of the Center for Hydrometeorology & Remote Sensing (CHRS) at University of California Irvine. His area of expertise includes the interface of global hydrologic cycle, and climate system. He is a member of the U.S. National Academy of Engineering (NAE); the International Academy of Stronautics (IAA); and the World Academy of Sciences (TWAS). Among his other honors: recently named the 2014 Einstein Professorship by the Chinese Academy of Sciences (CAS); the 2013 recipient of the American Geophysical Union’s (AGU) Robert E. Horton Medal,; Recipient of the 2010 4th Prince Sultan Bin Abdulaziz International Prize for Water Resources Management & Protection; recipient of the 2005 NASA Distinguished Public Service Medal; the 2012 Eagleson lectureship, Consortium of Universities for the Advancement of Hydrologic Science (CUAHSI); honorary Professor at Beijing Normal University, China 2010; named the Walter Orr Roberts Lecturer, American Meteorological Society (AMS), 2009; recipient of AMS Robert E. Horton Memorial Lectureship, 2006; and the William Nordberg Memorial Lecture at the NASA Goddard Space Flight Center in 2004. He has served on numerous advisory committees, including those of NASA, NOAA, DOE, USDA, NSF, EPA, and UNESCO and has testified to both U.S. House of Representatives and U.S. Senate Committees on issues related to water, climate and satellite programs.

    Invited Panelists

    Dr. Seyed Hamed Alemohammad
    Seyed Hamed Alemohammad is a postdoctoral associate in the department of Civil and Environmental Engineering at Massachusetts Institute of Technology (MIT), where he also received his PhD in 2014. His research interests lies on the boundaries of Earth system science, remote sensing and statistics. In particular, characterizing heterogeneous and spatio-temporal processes to better understand the water and carbon cycles at global and local scales. He has worked at the Regional Center on Urban Water Management – Tehran (under the auspices of UNESCO) from 2006 – 2009.

    Dr. Hamed Ashouri
    Hamed Ashouri received his PhD at the University of California, Irvine. His research interests include remote sensing of global precipitation, hydrological and climatic extremes (esp. floods and droughts), hydrological modeling, and climate change and variability. He is currently a research scientist at the research department of the catastrophe risk modeling company, called AIR Worldwide, headquartered in Boston, MA

    Dr. Antje Danielson
    Antje Danielson is the Administrative Director at Tufts Institute of the Environment as well as the graduate interdisciplinary Water: Systems, Science and Society (WSSS) program. She came to Tufts from Durham University (UK), where she served as the Deputy Director for Sustainability, in May 2008. Previously, she worked with the Harvard Green Campus Initiative. A long-time resident of Cambridge, Massachusetts, Antje co-founded the innovative carsharing company Zipcar. She holds a Ph.D. in Geology from Free University, Berlin.
    Dr. Amin Dezfuli
    Amin Dezfuli is a research scientist at the Earth and Planetary Sciences Department, Johns Hopkins University. His research uses a suite of observational and numerical modeling techniques to address questions of regional climate variability and change, and their implications to water resources development plans and environmental sustainability.
    Mr. David Fairman
    David Fairman is a facilitator of natural resource conflict resolution and collaboration, primarily international, with several water engagements over the past twenty years. He recently did strategic planning for TNC’s Great Rivers Partnership, dialogue on India-Pakistan co-management of the Indus basin, and work with Steering Committee for America’s Watershed Initiative. Currently planning additional work on water-food-energy-nexus in the Middle East.
    Prof. Michael Fischer
    Michael Fischer teaches in the MIT Science, Technology and Society Program, the Anthropology Program, and the Health Science and Technology Program. He has lived in Yazd and Qum and traveled around Iran, and is generally interested in the water problems of Iran and similar environments, and so hopes to learn from the workshop. He currently (this spring term) has been living in Singapore and become interested in the very different water problems of Southeast Asia and the technologies features in the annual Water Week trade show and convention held in Singapore. As an anthropologist rather than an engineer, he is interested in the ways in which communities of expertise are fostered and sustained, both within countries and through their diasporas, as well as through collaborations.

    Mrs. Jaleh Jalili
    Jaleh Jalili is a PhD candidate in sociology at Brandeis University. Her research interests include urban sociology and use of public spaces. She has a master degree in urban design form University of Tehran and has worked as an urban designer on revitalization and renovation of old urban fabrics in Tehran and other cities.
    Mr. Babak Manouchehrifar
    Babak Manouchehrifar is a PhD candidate in Urban and Regional Planning, specialization in International Development Planning, at MIT. Interested in comparative studies of planning cultures, his research interests lie in the interface of religion and development planning in the global South with a focus on Iran. He has backgrounds in Civil Engineering and City Planning.
    Mr. Jeff Meller
    CEO of renewable energy start-up, fund manager, lawyer, teacher in water and other infrastructure sectors globally. Former CEO of renewable energy start-up. Former fund manager making private equity and listed company investments in emerging markets. Former lawyer specializing in emerging/frontier market infrastructure (privatization, power, water, highways) representing investors and governments in more than a dozen countries of Asia, Africa, the Middle East, and Latin America. Lived in India for two years while working on independent power projects. Former instructor of international project finance at Boston University School of Law.
    Mr. Hojjat Mianabadi
    Hojjat Mianabadi is a research scholar in Water Diplomacy IGERT project at Tufts University and PhD candidate at TU Delft, the Netherlands. His research interests include hydropolitics and water policy, negotiation and conflict management, water governance, and environmental policy analysis.
    Mr. Leonard A. Miller
    Leonard A. Miller is a 2015 Advanced Leadership Fellow at the Harvard Advanced Leadership Initiative. He is also Senior Counsel to the international law firm Sullivan & Worcester and Senior Advisor to Dawson & Associates, a consulting firm providing assistance on U.S. water issues. Mr. Miller was one of the founding members of the United States Environmental Protection Agency (US EPA) , where, among other things, he developed the U.S. national water discharge elimination permit system and headed the U.S. water enforcement program. Mr. Miller was a charter member of the U.S. Senior Executive Service, and received a Commendation Medal from the U.S. Public Health Service as well as a Distinguished Career Award from the U.S. EPA. Mr. Miller has written two books on the Clean Water Act. Mr. Miller has a law degree from the Harvard Law School and he has been consistently ranked as one of the leading environmental lawyers in the U.S.


    Dr. Balasubramaniam Murali — UNDP Deputy Resident Representative

    Prof. Bish Sanyal
    Professor Bish Sanyal is Ford International Professor of Urban Development and Planning in the Department of Urban Studies and Planning at MIT. He also heads the Hubert H. Humphrey Fellowship Program at MIT and is Director of the MIT Comprehensive Initiative on Technology Evaluation (CITE) as part of USAID’s Higher Education Solutions Network (HESN) to evaluate technologies for the poor. Professor Sanyal has published extensively on cities and city planning in developing countries, particularly, how to integrate the majority of urban population who are poor into the physical and economic fabric of the city. He has also written on internationalization of planning education.
    Dr. Afreen Siddiqi
    Dr. Afreen Siddiqi has joint positions as a Research Scientist at the Massachusetts Institute of Technology (MIT), and a Visiting Scholar with the Science, Technology, and Public Policy Program at Harvard Kennedy School. Her research expertise is at the intersection of engineering and policy, and some of her current research is on quantitative systems analysis of emerging critical linkages between water, energy, and food security at urban, provincial, and national scales in the Middle East and the Indus Basin of Pakistan.

    Prof. Ashok Swain
    Ashok Swain is a Professor of Peace and Conflict Research at Uppsala University Sweden and is a Visiting Professor at Tufts University’s Water Diplomacy Program. He received his PhD from the Jawaharlal Nehru University, New Delhi in 1991, and since then he has been teaching at the Uppsala University. He has been a Mac Arthur Fellow at the University of Chicago, visiting fellow at UN Research Institute for Social Development, Geneva; and visiting professor at University Witwatersrand, University of Science, Malaysia, University of British Columbia, University of Maryland, Stanford University and McGill University. Read More.


    The direct link to the website (Tufts):
     http://environment.tufts.edu/blog/2015/05/11/urmialake/


    Some pictures taken from webinar:
    Fig 1. Wells and Qanats distribution through basin

    Fig 2. Conceptual model of the interaction between Lake and Groundwater in East coast near Azarshar city

    Fig 3. From left to right in the first row Dr. Zeynalzadeh, Dr. Asghari Moghadam and Dr. Morid participating from Iran

    Fig .4 Some information about the Qanats, springs and wells in the basin

    Fig 5. Presentation of Dr. Ghoddusi 
    Fig 6. A general overview through the session in MIT 

    Friday, June 26, 2015

    Parametric vs. Nonprametric estimation in favor of Chaos!!!

    Hi everyone.

    As I promised I am uploading the results of EWRA 2015 conference (i.e. Scatter plot of models) which I used to model the water elevation in Lake Urmia that have GEV distribution as I mentioned before. The full paper of the conference will be soon uploaded in Research gate and inrested people can refer to it. In  this paper I used 11 month lagged data due to high persistence of the procedure (i.e. almost infinite). Then I used to model the water elevation by 9 different method categorized generally in parametric and non-parametric approaches. For the case of parametric approach I used multi linear regression (MLR), nonlinear regression (NLR) and decision tree (DT) while, ANN models namely radial basis function (RBF), feed forward back propagation (FFBP) and generalized regression neural network (GRN) with Gaussian transfer function were used in favor of non-parametric approach. Figure 1, shows the early results of the models indicating that parametric approaches are more favorable but FFBP still is a good competitor to the parametric results.
    Fig 1. Scatter plot of all parametric and non-parametric models

    The most fitted model was NLR with multiplicative nature  and this means that the procedure is extremely nonlinear. This results are in favor of some related research like Khatami Mashhadi (2013) whom tracked Chaos in the procedure.
    GRN, DT and RBF shares the poorest results and generally speaking could not tracked down the real trend of the procedure.

    Sincerely
    Babak


    Refferences:

    Monday, June 15, 2015

    Lake's water elevation distribution

    Hi everyone.
    I want to share the  monthly and yearly distribution function of Lake's water elevation with you. Although most of assumption in null hypothesis is based on normally distributed data it is shown that in reality it LU's water elevation is changing with GEV distribution.


    Distribution of  monthly water elevation in LU

    Distribution of  yearly water elevation in LU

    Sunday, June 7, 2015

    ANN, Decision Tree and Regression Methods for Forecasting Monthly Lagged Lake Water Level

    Hi guys,
    Here I am sharing the abstract of my presentation (Paper) in EWRA 2015 which be held June 10-13, 2015 in Istanbul. I will share more details as soon as it is published in the abstract book.

    ANN, Decision Tree and Regression Methods for Forecasting Monthly Lagged Lake Water Level 
    Babak Vaheddoost(1), Hafzullah Aksoy(2), Hirad Abghari(3), Saieed Zare Naghadeh(4)

    (1) Department of Civil Engineering, Istanbul Technical University, Turkey, e-mail: vaheddoostb@itu.edu.tr
    (2) Department of Civil Engineering, Istanbul Technical University, Turkey, e-mail: haksoy@itu.edu.tr
    (3) Faculty of Natural Resources, Urmia University, Iran, e-mail: h.abghari@urmia.ac.ir
    (4) Department of Civil Engineering, Dokuz Eylul University, Turkey, e-mail: saieed_zare@yahoo.com

    Abstract:

    The forecasting of lake fluctuations with previously observed data is a necessary task in closed basin lake hydrologic analysis. Known as a hyper-saline lake, Lake Urmia is dealing with atrophy and mismanagement through recent years. In this investigation, nine methods in the category of parametric and nonparametric approaches were applied for modelling Lake water level. Eleven months in the form of monthly lagged data were used as independent variables and used arbitrarily for each tested model. The present situation of the lake was considered as the dependent variable. The parametric approaches, used in modelling were multi linear regression (MLR), nonlinear regression (NLR) and decision tree (DT). Nonparametric approaches applied in the modelling were artificial neural networks (ANN) with different functions. Generalized regression neural network (GRNN), radial base function (RBF) and feed forward back propagation (FFBP) were used as ANN models. Three criteria of coefficient of determination, Lin’s concordance correlation coefficient and root mean square percentage error were used in comparison of the results. Each model was given a grade through each criteria of the measurement in the magnitude of zero to ten for comparison. The summation of the grades for each method was accepted as the prosperity of each method. Results show that the NLR is the superior method of all, while GRNN shows the worst results.

    Key words: Decision tree, ANN, lake water elevation, hyper-saline lake, Lake Urmia

    Bbak VDST

    Wednesday, April 16, 2014

    A point of view

    Hi
    I have recently heard about a potential project of government (I.R.IRAN) on trans-boundary transfer of water directly to the lake (Lake Urmia). As you know, in coastal aquifers we have a natural balance of salt and fresh water (Figure 1). This aquifer is highly sensitive throw mass balance in each side of the boundary line and phenomena of salinity intrusion, usually happens when the balance in the coast side (Land) is lost.

    Figure 1. Boundary of fresh and salt water near coastline. [Pic-Reference]
    Therefore, due to reported high decrease in water level of wells near the lake (because of over usage of water table) the balance is impaired. Due to some unverified news, some villages near the lake are experiencing salinity intrusion in wells (Figure 2).

    Figure 2. Salinity intrusion in wells. [Pic-Reference]
     What is more, the elevation of the water table is decreased, probably caused to salt water entered the the coastal lands. Therefore, in my point of view directly injection of water into the lake, while the coastal aquifer remains in the same situation will cause more salinity intrusion to the aquifer. 
    What is more, due to higher specific density of salt water it will go down and salinity intrusion will be accelerated. please do not hesitate to write and share your points of view with me.

    sincerely yours.
    Babak VAHEDDOOST.

    Tuesday, March 11, 2014

    Some Analytics

    Good night.
    I decided to put some of my conference paper's results in the weblog. therefore you can see them underneath. First of all, I had separated the time history of water level in lake every 107 years. you can see the results in Fig.1.
    Fig.1. Trend Analysis.

    you can see the changes in trends here every 107 years. It is obvius that the great changes was occurred in late 90's. Then I decided to fit the best polynomial curve for it. So here is the results (Fig.2).
    Fig.2. Polynomial Curve Fitting Results.
    Then, I simulated the water level in lake by ANN and MLR techniques (time-lag) and you can see the the results of GRN, MLR and RBF in Fig 3~5.
    Fig.3. GRN results
    Fig.4. RBF results
    Fig.5. MLR results
    As you can see here the best fitted model is MLR, so I think the reaction is totally linear (I didn't put the results of FFBP but I tested it, the best result was still in MLR).

    Sincerely yours.
    Babak Vaheddoost.