Search published articles


Showing 3 results for Time Series

Somayeh Soltani Gerdfaramarzi, Aref Saberi, Morteza Gheisouri ,
Volume 17, Issue 44 (6-2017)
Abstract

Rainfall is one of the most important components of the water cycle and plays a very important role in the measurement of climate characteristic in any area. Limitations such as lack of sufficient information about the amount of rainfall in time and space scale and complexity of the relationship between meteorological elements related to rainfall, causes the calculation of these parameters using the conventional method not to be implemented. One method of evaluating and forecasting of rainfall in each region is time series models. In this research, to predict the average annual rainfall synoptic station at Mahabad, Uromiya and Mako in West Azarbayejan provience during 1984-2013, linear time series ARIMA was used. To investigate model static, Auto Correlation Function (ACF) and Partial Auto Correlation Function (PACF) was applied and with differencing method, the non-static data transformed to static data. In next step, stochastic models to estimate the annual rainfall average were used. With regard to the evaluation criterion such as T, P-VALUE < 0.05 and Bayesian Information Creterion (BIC), ARIMA (1,0,0), ARIMA (0,1,1) and ARIMA (0,1,1) models was determined as a suitable model for predicting annual rainfall in the three selected stations at Uromiya, Makoo and Mahabad. In the following, the annual rainfall for 3 (2013-2016) years is forecasted which based on rainfall data in that time, the adjusted model was acceptable.


Engineer Amenh Khosravi, Doctor Mahmood Azari,
Volume 22, Issue 66 (10-2022)
Abstract

 The study of meteorological characteristics and its variability is important in assessing the climate change impacts for water resources management. Trend analysis of hydrological and meteorological time series is a method for determining the change in climate variables that is performed with different parametric and non-parametric methods. In this research, the annual, seasonal and monthly trends were analyzed regarding rainfall and temperature time series for 1986-2017 in 28 stations of Kashafroud basin in the Northeast of Iran. For this purpose, the annual, seasonal and monthly trends were evaluated using non-parametric Mann Kendall and Pettitt test at 95% level significance. The results showed the trend for the monthly maximum temperature in spring and winter and also the annual trend for all stations was increasing, whereas the summer and autumn pattern differed. The trend of minimum temperature in all seasons and stations do not have a uniform pattern. The results of precipitation trend indicated that the annual precipitation of the basin had not changed and did not have a significant trend in 5% level of significance. Precipitation of the basin in the winter decreased. There was an increasing trend in the Southern half of the basin in autumn. The noticeable decrease of precipitation in winter season especially during January and February with an increase in November can be a serious challenge for water resource management of basin during the dry season.

 
Saeed Jahanbakhshasl, Ali Mohammadkhorshiddoust, Fatemeh Abbsighasrik, Zahra Abbasighasrik,
Volume 24, Issue 75 (2-2025)
Abstract

 Assessing and predicting future climate change is of particular importance due to its adverse effects on water resources and the natural environment, as well as its environmental, economic and social effects. Meanwhile, rainfall is also an important climatic element that causes a lot of damage in excess conditions. West Azerbaijan Province is no exception. The aim of this study is to model and predict 30 years of rainfall in West Azerbaijan province. The statistical period studied is 32 years (2019-1987). Selected stations in the province include Urmia, Piranshahr, Takab, Khoy, Sardasht, Mahabad and Mako stations. Average slider time series models, Sarima (seasonal Arima), Health Winters were used for analysis and prediction and also linear regression and Mann-Kendall test were used to determine the data trend. The results show an increasing trend of precipitation in Urmia, Piranshahr, Khoy, Sardasht and Mako stations and a decreasing trend in Takab and Mahabad stations. According to the results of comparing the models used, the Health Winters model with the least error in the absolute mean of deviations, mean squared deviations and the percentage of absolute mean errors was introduced as the best precipitation forecasting model for West Azerbaijan province. province.                                     [A1] 



Page 1 from 1     

© 2024 CC BY-NC 4.0 | Journal of Applied researches in Geographical Sciences

Designed & Developed by : Yektaweb