hamed nozari

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Papers by hamed nozari

Effect of different detrending approaches on the accuracy of time series forecasting models

Sustainable Water Resources Management

Management of agricultural saline drainage using system dynamics approach

Water and Environment Journal, 2022

Drought Forecasting Using Artificial Wavelet Neural Network Integrated Model (WA-ANN) and Time Series Model (ARIMA)

Ì'UlÅ«m va muhandisÄ«-i Ä?byÄ?rÄ«, 2018

Drought prediction in water resources systems plays an important role in reducing drought damage.... more Drought prediction in water resources systems plays an important role in reducing drought damage. In recent decades, Traditional methods including: fitting and mathematical models have been widely used to predict droughts. The combination of wavelet theory and neural networks has led to the expansion of the wavelet-neural networks. The application of the wavelet as training function in the neural network has recently been identified as a substitute method in neural networks. In these models, the position and scale coefficients of the wavelets are optimized in addition to the weights (Thuillard, 2000). Considering the importance of short-term drought prediction in water resources engineering and the nonlinear characteristics of the SPI series of three months, the purpose of this study is to present an Artificial Wavelet Neural Networks integrated model for predicting short-term drought at Bidestan station in Qazvin plain. <br />In this research, Multi-Layer Perceptron (MLP), Ra...

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Investigating The Effectiveness Of Seasonalization Based On Statistical Parameters In Normalizing, Modeling And Forecasting Inflow Time Series

To solve many problems such as estimation of average monthly river inflow, it is necessary to con... more To solve many problems such as estimation of average monthly river inflow, it is necessary to consider a time-dependent phenomenon which is involved in several factors. So, a stochastic model has to be obtained to calculate the probability of a future amount of inflow. Studying of river behavior and the ability to forecast the future events is a prerequisite for the preparation of optimization models. In the present study, methods for creating, diagnosis and assessing the rate of compatibility with seasonal ARIMA time series models have been<br> provided. It is also supposed that the seasonal classification based on their statistical parameter similarities, could lead to a better normalized series in comparison to the other transformation methods. The discussed methods are suitable for continuous systems. The ARIMA method was used to predict the future amounts of the inflow into the Karaj<br> reservoir by using its previous and present values. For implementing models, fi...

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Evaluation of different allocation scenarios for Choghakhor dam reservoir using system dynamic

Iranian Journal of Watershed Management Science and Engineering, 2017

Determining the Minimum Price of Drinking Water and Optimal Scheduling of Water Pipe Replacement in Urban Distribution Network

In urban water distribution networks, as the age of the pipes increased, the rates of pipe breaka... more In urban water distribution networks, as the age of the pipes increased, the rates of pipe breakage and water losses increased which causes financial losses to the water and sewerage company. Therefore, to reduce the number of breaks and leaks in pipes, worn pipes should be replaced. Replacing old pipes is an expensive and costly procedure. Thus, it may be more economical to replace the pipe at the appropriate time. In this research, the urban water supply network of Hamedan was simulated by using system dynamics approach. Then the optimal time for pipe replacement was estimated by using analytical solution of the net present value equation and the combined method of system dynamics-net present value. Also, in order to improve the financial balance of Hamadan Water and Sewerage Company, the optimal price of drinking water was determined by using the Powell optimization algorithm method. Dynamic simulation was performed in VENSIM. To test the model, the simulated data were compared w...

Effect of Dam Construction on Lake Urmia: Time Series Analysis of Water Level via ARIMA

Journal of Agricultural Science and Technology, 2018

Lake Urmia is one of the water bodies that face severe drought conditions nowadays. Therefore, th... more Lake Urmia is one of the water bodies that face severe drought conditions nowadays. Therefore, the present study aimed to study monthly time series of the lake water level. Modeling the series was accomplished in two ways. First, all data were used to analyze the water level time series of the lake. Although the results of generating were quite well, the results of validity test were not satisfying. Second, only water level data after the year 1995 were used, which showed a continuously decreasing trend. These data start from the year when dam constructions and operations in Urmia Watershed were increased one by one. The values of R and RMSE were 0.99, 0.001 m, respectively, for generating the data at this stage. These values were 0.93 and 0.03 m for the validity test of the model (from 2005 to 2009). The results of our study show that the lake water level behavior changed after 1995 due to constructing many dams in Urmia Lake Watershed.

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Simulation of the Effect of Salinity and Water Stress on Sugar beet Using the System Dynamics Approach

Journal of Water and Soil Science, 2019

Due to the growing population, crop production is one of the essential needs of the society. Sinc... more Due to the growing population, crop production is one of the essential needs of the society. Since soil and water salinity can have a great impact on the crop yield loss; so, the appropriate irrigation method can be applied to reduce these effects. In this study, the system dynamics model was developed using VENSIM. The model simulated the effect of salinity and water stress on the crop yield, moisture and salinity of the root zone. In order to calibrate and validate the model results, 9 treatments data were collected from the Right Abshar Irrigation Network, on the Zayandehrud basin. After statistical analysis and calculation of RMSE index and the standard error, the fit between the measured and simulated crop yield, the moisture and salinity of root zone was calculated. The average of these indexes for all treatments was 2776.98 kg/ha and 0.07 for crop yield, 0.026 and 0.09 for soil moisture and final, 0.54 dS/m and 0.08 for the salinity of root zone, respectively. The results showed that the model could be calibrated accurately and completely in estimating the crop yield with the reasonable accuracy.

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Simulation of a Right Abshar Irrigation Network and Its Cropping Pattern Using a System Dynamics Approach

Journal of Irrigation and Drainage Engineering, 2014

ABSTRACT

Experimental Study of Drainage Pipes' Openings Arrangement Effect on Drainage Water Salt Load

In this study, effect of three different openings arrangements of drainage pipes on the drainage ... more In this study, effect of three different openings arrangements of drainage pipes on the drainage water salt load was investigated using a physical model. The first arrangement of openings for drainage of the subsurface flow had four parallel rows on the upper and lower sides of the pipe (M4). In the second arrangement the pipes had three parallel rows of openings with 120 degrees apart between the rows (M3) and the third one had one row of holes on top of the pipe (M1). Drainage pipes were installed at 20 and 60 cm depths with spacing of 60 and 180 cm. The results showed that the M1 and M3 cases experienced a decline in the contribution of the groundwater in the drained water. The M4 case had the highest contribution of the groundwater, while the M1 had the lowest one of that. So, there was a significant difference between the drainage salt loads at M4 and M1cases. In all cases, deep drain installation led to increase the drainage water salt load.

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System dynamics simulation of crop yield under different irrigation water quality and quantity

Water Practice & Technology, 2020

Agricultural products are one of the major sources of food for people in many countries. So, incr... more Agricultural products are one of the major sources of food for people in many countries. So, increasing crop yield is a major challenge for governments as increasing the population. On the other hand, agricultural improvement needs to take into consideration the type of land and water available. The decrease of water availability and soil salinity are two major limiting factors in sustainable agriculture in the arid and semiarid regions. In this study, the combined effect of salinity and water stress on crop yield was simulated by developing a computer model based on a system dynamics approach. Model calibration and validation were performed using data collected from the Abshar Irrigation Network located on the hydrological Zayandehrud River. For each individual run of the model, two statistics were calculated: Root Mean Square Error and Standard Error. The averages of these indices were estimated as 2,777 kg·ha 1 and 0.07 for sugar beet yield, 0.026 and 0.09 for soil moisture and f...

Evaluation of the Efficiency of Linear and Nonlinear Models in Predicting Monthly Rainfall (Case Study: Hamedan Province)

Uncertainty Analysis of Reservoir Operation Based on Stochastic Optimization Approach Using the Generalized Likelihood Uncertainty Estimation Method

Water Resources Management, 2021

This study evaluated the reservoir operation for effective water allocation under uncertainty usi... more This study evaluated the reservoir operation for effective water allocation under uncertainty using linear programming (the water evaluation and planning model: WEAP) and evolutionary optimization (the particle swarm optimization algorithm: PSOA). The stochastic autoregressive integrated moving average (ARIMA) and seasonal autoregressive integrated moving average (SARIMA) models were used to forecast monthly inflow into the AmirKabir dam reservoir (Iran) as well as its net evaporation (2018-2025), respectively. For this purpose, the best-fitted model was selected based on the minimum Akaike criterion and the autocorrelation function (ACF) test. The resulting uncertainty of monthly release for the WEAP and PSOA were analyzed using the generalized likelihood uncertainty estimation method (GLUE). The results showed that the WEAP model proved to be better in meeting water demands during low inflows, whereas the PSOA had a higher certainty in meeting demands during high inflows periods. ...

Investigating Groundwater Extraction from the Hamedan-Bahar Plain , s Aquifer

Hamedan-Bahar plain is one of the groundwater restricted areas. The excessive groundwater extract... more Hamedan-Bahar plain is one of the groundwater restricted areas. The excessive groundwater extraction has led to significant drop in water table in the past three decades. Therefore, in this study water extraction from groundwater resources was calculated. Then, the amount of groundwater recharge was estimated based on the type of crop and irrigation system. Data from 2132 groundwater wells of Hamedan - Bahar plain during the years 2008 to 2009 was collected. The ArcGIS 9.3 software was also used to find the spatial distribution of rainfall, the amount of runoff and the relevant groundwater recharge rate. The results showed that the groundwater recharge volumes were 96.08, 41.02, 76.01, and 55.8 million cubic meters and also the groundwater extraction volumes of the aquifer were 112.6, 143.7, 31.5, and 7.04 million cubic meters for spring, summer, autumn, and winter, respectively. In summer, the groundwater extraction rates at 15.27 and 21.69 percent of the plain , s area were five t...

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Evaluation of the Efficiency of Conventional and Computerized Methods for Reconstruction of Monthly Flow Time Series in Hydrometric Stations

The lack of complete data should not hinder the study of the hydrological condition and the long-... more The lack of complete data should not hinder the study of the hydrological condition and the long-term forecasts for performing hydro-projects in one region. Various researchers have used different methods such as Ratio Analysis, Fragment, and Thomas-fiering for the reconstruction of incomplete flow data in hydrometric stations. So, in this study, the accuracy of these methods and computerized methods such as, artificial neural network, hybrid wavelet-neural network, and support vector machine have been investigated and compared. The results showed that the computerized methods have the higher accuracy than the other three methods. Comparison amongst the computerized methods showed that the artificial neural network method (R2 = 0.98, RMSE = 6.18, SE = 0.476), the support vector machine method (R2 = 0.902, RMSE = 6.074, SE = 0.486), and the hybrid wavelet-neural method (R2 = 0.889, RMSE = 6.96, SE = 0.54) ranked first to third, respectively. Although, these three methods have not sig...

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Simulation of real-time variations of saline drainage water: comparing system dynamics with DRAINMOD-S

Water Practice and Technology

Accurate simulations of wastewater quality and quantity, particularly in saline and semi-arid are... more Accurate simulations of wastewater quality and quantity, particularly in saline and semi-arid areas, are important in agricultural water management. In this study, a system dynamics (SD) approach was proposed to simulate drainage water and groundwater salinities, water table fluctuation, and drainage discharge at field scale. The results of the SD approach were compared with results from DRAINMOD-S, a computer simulation model. For model validation, earlier experimental data from two field units were used. The field units each contained three rows of piezometers. During irrigation, daily water table fluctuation, drainage discharge, irrigation and drainage water salinity, and the salinity in each piezometer, were measured. The SD approach simulated these parameters more accurately than DRAINMOD-S for both units.

Simulation and optimization of control system operation and surface water allocation based on system dynamics modeling

Journal of Hydroinformatics

In the present study, the performance of Dez Reservoir, its regulatory and downstream diversion d... more In the present study, the performance of Dez Reservoir, its regulatory and downstream diversion dams are studied using the system dynamics method (SD) in the Vensim software. In the first step, all the effective parameters with their relationship were identified and then the simulation was carried out considering the minimum and maximum reservoir volume and downstream demand over an eight-year period (2006–2013). After model validation, the statistical indices of correlation coefficient (R2), root mean square error (RMSE), and standard error (SE) for the reservoir volume were calculated as 0.99, 3.1690, and 0.18, respectively. The statistical indices for the regulatory dam were 0.98, 7.51, and 0.13, respectively. These statistical indices were 0.92, 4.71, and 0.37 for the diversion dam. The achieved results showed that the SD-simulated releases met downstream demands and the SD method has high accuracy in simulating the performance of the surface tank system. Moreover, for a better ...

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System Dynamics Approach for Water Resources Systems Analysis

Springer Water

Evaluation of Field Performance of Steady State Drainage Equations for Sugarcane Agro-Industrial Company in Khuzestan

Journal of Water and Soil Science

Predicting Sediment Load Using Stochastic Model and Rating Curves in a Hydrological Station

Journal of Hydrologic Engineering

AbstractThe linking of onsite rates of sedimentation and river water quality represent a major re... more

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