Modeling and forecasting of evaporation from the pan stations west of Lake Urmia

Number of pages: 106 File Format: word File Code: 32550
Year: 2013 University Degree: Master's degree Category: Agricultural Engineering
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  • Summary of Modeling and forecasting of evaporation from the pan stations west of Lake Urmia

    Dissertation for Master's Degree in Water Resources Engineering

    Abstract

    Today, due to the issue of water crisis and the need for accurate planning, the use of statistical models and methods is increasing. The research conducted in this field has also shown the usefulness of using statistical methods. The use of different forecasting methods has many advantages, including reducing costs, and in addition, in these methods, available and accessible information can be used. Considering the importance of Urmia lake problem, which is a social, political and cultural problem, and in order to provide a scientific tool to prepare the necessary preparations for the protection of the lake, finding a model for the evaporation data from the pan and its prediction was investigated. Evaporation from the pan is one of the most important and influential climatic parameters in the policy and optimal management of water resources, and the use of time series models is one of the practical ways to predict this hydrological component. In this research, the non-parametric tests of Kendall, seasonal Kendall and Spearman correlation coefficient at 95% confidence level have been performed to test the trend of evaporation data from the pans of Abajalu, Saro, Yalquz-Aghaj, Qamishlo, Muzaffar Abad and Urmia synoptic station. The results show the presence of decreasing and increasing trends in some stations. ADF and KPSS tests were used to check the stationarity of the data, and the results showed that after removing the instability factors and standardizing the data, the monthly and annual series became stationary. The BDS test has also been used to check the linearity or non-linearity of the data. Evaporation data from two stations, Abajalu and Saro, located in the west of Lake Urmia, have been used on monthly and annual scales with statistical periods of 34 years (1388-1355) to select and fit appropriate time series models. The aim of the current research is to produce the best time series model on the evaporation values ??and use it to predict the evaporation values ??from the west basin of Lake Urmia. After performing the BDS test, it was found that the evaporation data has a linear property and linear models can be used with acceptable reliability. The fitting results of common linear models showed that the AR(1) model is the selected model for the annual series of two stations. And the selected models for the monthly series of each station were different, ARMA(1,5) model was chosen for Seru station and ARMA(2,5) model was chosen for Abagalo station. rtl;">1-1 Introduction

    Laplace stated in 1776 that if we can identify the initial conditions of any phenomenon, we can accurately predict its future. This thinking was accepted by thinkers in the field of experimental sciences for a long time. But Poincaré stated in 1903 that small errors today lead to big errors in predicting tomorrow, and since accurate knowledge of the current situation is often not possible and is accompanied by error, prediction is also impossible. Anyway, even though today's dominant opinion is very close to Poincaré's opinion, thinkers of various sciences have focused a huge part of their studies on predicting the variables and phenomena investigated by their sciences. Among these, hydrological and climatic sciences can also be mentioned (Salami, 2010).

    Prediction of accidental processes is a key element in decision making. The final efficiency of any decision depends on the law of a set of events, which follows the decision. The basis of many decisions in hydrological and climatic processes is the decision to use water resources based on forecasting and analysis of time series. In fact, another important application of time series processes in hydrology is the prediction of the modeled hydrological variable for one or more time steps ahead (Malmir, 2015). Every year, thousands of billion cubic meters of fresh water evaporates from the reservoirs of the dams, which were collected at a great cost, and the salts and salts left by the evaporated water reduce the water quality.

    Evaporation from the pan is one of the important and influential components in the hydrological cycle and planning and management of water resources, and its estimation in different time scales, as one of the most important atmospheric parameters, is of special importance in irrigation planning in agriculture. On the other hand, Iran is considered a dry and semi-arid country, and the management of the correct use of water resources is essential (Kaherman 2018). Therefore, this hydrological phenomenon has been analyzed and investigated.

    In another definition, it can be said that evaporation is a physical process during which water or ice is transferred from a wet surface or a free surface to the atmosphere in the form of gases, and this transfer takes place in the form of water vapor at a temperature lower than the boiling point of water (Chacherlo, 2013).

    Therefore, the measurement of all these factors and their modeling is considered an important and big task, and the prediction of evaporation from the free surface of Lake Urmia, especially at the current time when it is drying up, is a necessary and necessary thing in order to manage the exploitation of water resources.

    1-2 Statement of the problem

    According to the ever-increasing downward trend of the water level of Lake Urmia and the special importance of this lake as one of the most important water ecosystems of Iran and one of the biophosphorous resources of the Man and Biophosphorus Program of UNESCO, and considering that evaporation is the main factor in the removal of water from existing water resources (Shir Gholami, 2013), therefore, the study of evaporation and the factors affecting them in the management issues of water resources of Lake Urmia, It is necessary.

    Evaporation from the surface of the evaporation pan can be considered as an indicator of the combination of the effects of radiation, temperature, humidity and wind on evaporation. The evaporation pan shows the actual amount of evaporation and with the help of observing the water level drop in it and the use of experimental coefficients, it can be used to estimate evaporation from free water levels. (Fernandes 2007) The pan coefficient changes between 0.65 and 0.75 depending on the humidity and the amount of daily wind. There will be water during periods of low water and eventually lowering the water level of the lake. The greatest effect of this factor is in the early summer and in the conditions when a large volume of water returns to the atmosphere from the surface of water bodies and soil (Malmir, 2015). The first step in the integrated management of water resources is to evaluate the available water resources, determine the flow rate and water level and its changes based on the evaporation rate and predict hydrological variables. The random nature of hydrological phenomena has caused hydrologists to take help from the concepts of random variables and time series in predicting hydrological variables. To model evaporation, stochastic models can be used, especially time series analysis, which is a suitable management tool for predicting the future values ??of hydrological processes. Many different models have been proposed to describe this process, which have different capabilities and complexities. Among these models are stochastic models (Hamidi, 1389).

    These stochastic models include common linear models of time series, which include AR autocorrelated model, ARMA autocorrelated moving average models, with fixed parameters and its derivatives including AR and MA. ARIMA cumulative autocorrelated moving average model, as well as PAR and periodic autocorrelated moving average PARMA models) and its nonlinear models (bilinear or nonlinear BL model, TAR threshold or limit autocorrelation model, and ARCH autocorrelated heterogeneous conditional variance model are rarely used in water resources. The most widely used are MA, AR, and ARMA. Providing a method that can predict gives a suitable and relatively accurate estimate of the amount of evaporation from the pan, it can be important in identifying the need for future developments, including the management and protection of water resources.

  • Contents & References of Modeling and forecasting of evaporation from the pan stations west of Lake Urmia

    List:

    1-1- Introduction. 3

    1-2- Statement of the problem. 4

    1-3-    Objectives. 5

    1-4- Thesis structure. 5

    2- The second chapter of the basics of time series. . 7

    2-1- Introduction. 7

    2-2-    Trend test. 8

    2-2-1- The advantages of non-parametric statistics. 8

    2-2-2- Disadvantages of non-parametric methods. 9

    2-3-    Static test. 9

    2-4- Non-linear BDS test. 10

    2-5-    Time series models. 10

    2-6-    Linear models. 12

    2-6-1-    Autocorrelation (AR) model. 13

    2-6-2-    Moving average process MA(q) 13

    2-6-3-    Cumulative autocorrelated moving average model ARIMA(p,d,q) 14

    2-6-4-    Fractional moving average cumulative autoreversion model (FARIMA) 15

    2-7-    Nonlinear models. 15

    2-7-1- Threshold or threshold autocorrelation model (TAR) 16

    2-7-2- ARCH correlated heterogeneous conditional variance model. 16

    2-7-3- Bilinear model. 17

    3-       The third chapter is a review of previous studies. 19

    3-1- Introduction. 19

    3-2-    Rainfall. 19

    3-3- Temperature. 20

    3-4-    Discharge and flow. 21

    3-5-    Evaporation. 22

    3-6- Reviewing previous studies on important characteristics of evaporation time series such as trends. 26

    4- Chapter 4 Materials and Methods 33

    4-1- The study area. 33

    4-1-1- Used evapotranspiration stations (west of Lake Urmia). 34

    4-1-2- Data used for trend analysis. 35

    4-2- Trend analysis. 38

    4-2-1- Mann-Kendall (MK) test 39

    4-2-2- Spearman correlation coefficient. 40

    4-2-3- Seasonal Kendall method. 41

    4-3-    Static test. 41

    4-3-1- Dickey-Fuller unit root test (ADF). 42

    4-3-2- KPSS test. 43

    4-4- Non-linear BDS test. 44

    4-5- Linear modeling. 45

    4-6-    Normalization and standardization of data 46

    4-6-1-    Normalization of time series variables. 46

    4-7- Model identification. 47

    4-8-    Estimation of parameters 49

    4-8-1-   Calculation of autocorrelation and partial autocorrelation functions. 50

    4-8-2- Determining the rank or order of the model. 50

    4-9- Best fit test. 51

    4-10- Analysis of residuals 51

    4-10-1 Using the sample autocorrelation function. 51

    4-10-2 Portmanteau test 52

    4-11- Model evaluation. 52

    4-12- Prediction. 53 5- Chapter 5 results and discussion 55 5-1 Introduction. 56

    5-2-    The results of the basic characteristics of time series. 56

    5-2-1- The results of data normality using the skewness test. 56

    5-2-2- Trend test results. 57

    5-3- Results of static test. 61

    5-4-    BDS test results. 62

    5-5- Results of linear modeling of time series. 64

    5-5-1- The results of the best fit test. 64

    5-6-    Prediction results. 75

    6- Chapter Six Summary of results and suggestions. 80

    6-1- Summary of results. 80

    6-2 -     Proposals. 82

    Sources   83

    Source:

    Silk, A. Tajrishi, M. Face painter, b. (2014), "Regional stochastic models of annual flow in western Iran watersheds," Water Resources Research, Volume 1, Number 1. Ahmadi, F. Din Pajoh, Y. Fakheri Fard, A. Khalili, K. (2012), "Prediction of river flow using non-linear time series models (case study of Barandoz Chai River in Urmia)", Second International Conference on Plant, Water, Soil and Air, University of Advanced Industrial and Technology Education, Kerman, May 18-19. Ahmadi Joghi, A. (2008), "Modelling and Forecasting of Caspian Sea Water Height Fluctuations", Master's Thesis in Applied Statistics, Department of Statistics, Shahid Beheshti University, Tehran.

    Azghani DA. Iraqinejad, Sh. (1381), "Investigation of the effect of climate change on the water resources of Mazandaran province, basics and issues of climate change", Tehran Mashhad University Press, second edition.

    Asghari Eskoui, M. (1381), "The use of neural networks in forecasting time series", Iranian Economic Research Quarterly / Number 12.

    Bashri, M. faithful,. Wafakhah, M. (2009), "Comparison of different methods of time series analysis in forecasting the monthly discharge of Karkheh watershed", Irrigation and Water Scientific Research Quarterly, first year number 2.

    Bigleri, B. Samani, M. (1382), "Surface runoff precipitation time series and lag time studies in Bazfat catchment", 7th conference of Geological Society of Iran, University of Isfahan.

    Tabesh, M. Dini, M. Khosh Khalq, A. Zahrai, b. (2007), "Estimation of daily water consumption in Tehran using time series". Scientific Research Journal of Ayran Water Resources Research. Fourth year, number 2, page 57-65.

    Turabi, S. (1380), "Survey and Forecast of Temperature and Precipitation Changes in Iran" PhD Thesis, Faculty of Human Sciences, Tabriz University.

    Hajam, S., Khoshkho, Y. Shamsuddin Vandi, r. (2007), "Analysis of seasonal and annual rainfall changes in several selected stations in the central area of ??Iran using non-parametric methods", Geographical Research, Volume 40, Number 64, Pages 168-157. Hamidi, R. Imam Qolizadeh, p. (2008), "Stochastic modeling of the annual discharge of the Karun River using the ARMA model", Proceedings of the first national conference of applied research on water resources in Iran.

    Khalili, K. (2008), "Drought Frequency Analysis and Design of Reservoirs for Agriculture and Drinking (Case Study of Urmia City)". Master thesis, Faculty of Agriculture, University of Tabriz. Khalili, K. Fakheri Fard, A. Din Pajoh, Y. Ghorbani, M. (1389), "Analysis of the trend and stability of river flow in order to model hydrological time series", Journal of Water and Soil Science, Volume 1/20, Number 1. Khalili, K. Din Pajoh, Y. Ahmadi, F. Bahmanesh, J. (2012), "Introduction and application of the combined BL-ARCH model in predicting the daily discharge of the Chai Shahr River of Urmia", Mashhad Water and Soil Journal, Volume 27, Number 2, pp. 342-350.

    Khalili, K. Ahmadi, F. Abakari, H. Basharat, S. (2017), "Static analysis and investigation of the nature of river flow in different time scales (case study of Barandozchai River)" 9th International Conference on River Engineering, Shahid Chamran University, Ahvaz, 3-5 Bahman. Khalili, K. fence b. (1383), "Prediction of meteorological drought trends by time series models (case study of Urmia synoptic station)", the first annual conference on water resources management in Iran, 26-27 November, Faculty of Engineering, University of Tehran. (2016), "Analysis of intensity curves - duration and frequency of drought and design of reservoirs for agriculture and drinking". The third civil engineering congress, May 11-13, Tabriz University, 1386.

    Jahanbakhsh Asl, S. Turabi, S. (1383), "Investigation and forecasting of temperature and precipitation changes in Iran, Journal of Geographical Research", No. 19, pp. 104-125.

    Cakherlo, Mehrdad. (2017), "Analysis of changes in evapotranspiration in Urmia lake basin", master's thesis on drainage irrigation, water department, Urmia University.

    Dehghani, A. Piri, M. Hossam, M. Dehghani, N. (1389), "Estimation of daily evaporation from a pan using three Perceptron neural networks, multilayer, radial basis function and German", Journal of Water and Soil Conservation Research, Volume 17, Number 2, Gorgan Faculty of Agriculture and Natural Resources.

    Rezaei, H. P., Bahnia, A. (2007), "Analysis of annual and seasonal rainfall changes during the past half century in southern Iran". The first international conference on water crisis: March 13-15, Zabul University. Ababai, b. "Using time series models in estimating missing values ??and predicting future values ??of evaporation time series" 3rd National Conference on Management of Irrigation and Drainage Networks, Shahid Chamran University of Ahvaz, Faculty of Water Sciences Engineering, March 10-12, 2019.

    Sharifian, H. Hero, b.  (2006) "Evaluation of rain forecast using SARIMA technique in Golestan province." Journal of Agricultural Sciences and Natural Resources, Volume 4, Number 3, August-September.

    Shahabfar, A. "Evaluation and goodness-of-fit methods of statistical distribution functions and using time series to predict annual rainfall in Mashhad". Proceedings of the first national conference on solutions and dealing with the water crisis, Zabul University, volume three, 395 pages.

    Shir Gholami, b. Hero, A. Alizadeh, J. Jamali, b. "Investigation of the process of transpiration evaporation of Iran's reference plant", Caspian Agricultural Sciences and Natural Resources Research Journal, second year, third issue, autumn 2013.

    Sabuhi, R. Soltani, S. Yaghmai, L. (2007), "Analysis of the trend of climatic parameters and its impact on water resources in the cities of Tabriz and Urmia".

Modeling and forecasting of evaporation from the pan stations west of Lake Urmia