Forecasting Average Monthly Temperature Using Improved Gray Model
(Case Study: Climatology Station of Qazvin Airport)
Maryam Karimi Khajehghiasi
Karimi Khajehghiasi
Msc. Student, Department of Industrial Engineering, Faculty of Industrial and Mechanical Engineering, Qazvin branch, Islamic Azad University, Qazvin, Iran
author
alireza
alinezhad
Associate Professor, Department of Industrial Engineering, Faculty of Industrial and Mechanical Engineering, Qazvin branch, Islamic Azad University, Qazvin, Iran.
author
text
article
2018
per
Forecasting Average Monthly Temperature Using Improved Gray Model (Case Study: Climatology Station of Qazvin Airport) Abstract The theory of grey system is used when sufficient information of the community under study is not in hand. The grey forecast model is proper when the information variety is fix and certain. Grey model can apply some additional computations to improve forecasting activities when data is insufficient. Through using improved grey model, the assessment error decreases significantly. This study made use of the mean maximum monthly temperature data for April to September collected by Qazvin climatology station in airport, from 2001 to 2012. The aim was to forecast of the mean maximum monthly temperature for April to September in 2013. The findings revealed that the improved grey model (changeabl estarting point model and metabolism method) can increase the precision of forecasting the mean variable of maximum monthly temperature. Forecasts for April (20.9 versus 21.3 cellcious degree) and June (30.6 vs. 30.9 cellcious degree) had a good accuracy, while August and September's predictions were less trusted. Key words: Forecast, gray model, metabolism, meteorology.
Nivar
IRIMO
1735-0565
42
v.
102-103
no.
2018
1
8
https://nivar.irimo.ir/article_79191_81146e921962879db38544a4a8363cb8.pdf
dx.doi.org/10.30467/nivar.2018.120806.1081
Spatiotemporal Variations of Rainfall Erosivity Factor in Gorganroud Watershed
Raoof
Mostafazadeh
Dept of Natural Resources, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili
author
Mohsen
Zabihi
Ph.D Student, Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran
author
Khadijeh
Haji
M.Sc Graduate of Watershed Management Engineering, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
author
Mohammad Hossein
Ghavimipanah
Ph.D Student, Department of Watershed Management Engineering, Faculty of Natural Resources, Sari Agriculture and Natural Resources University, Sari, Iran
author
text
article
2018
per
Dramatic increase of soil erosion due to the lack of proper management and inappropriate use of land is considered as one of main concerns of experts, researchers and decision makers in recent decades. the most important factor affecting soil erosion is rainfall erosivity. rainfall erosivity factor is used to describe the ability of rain to erode soil. Therefore, understanding of its spatiotemporal changes lead to planning, policy making and correct decision making of soil erosion control. Due to the effects of climate change on the extreme precipitation events, the timing of heavy rainfall occurrence has also changed. Determining the seasonality and the occurrence of erosive rainfall can be used in predicting natural hazards such as floods and erosion and reducing their destructive effects. Accordingly, the present study aims to analyze the spatiotemporal variations of the rainfall erosivity factor hazard in North-eastern of Iran, Golestan province. Toward this attempt and according to the purpose of the study, the amount of rainfall erosivity factor were calculated for 41 rain gauge stations with 42 years’ time span based on modified Fournier erosivity index in the Gorganroud watershed. Spatial investigation of rainfall erosivity index was provided by mapping mean, maximum, minimum and standard deviation of rainfall erosivity factor. Inverse Distance Weighting (IDW) and natural break algorithm were used for developing of maps and classification of mentioned maps, respectively. The spatial interpolations of the results were done in the ArcGIS environment.
Nivar
IRIMO
1735-0565
42
v.
102-103
no.
2018
9
18
https://nivar.irimo.ir/article_79222_77ad936cbf39459a6dc34f5ff0d7b17a.pdf
dx.doi.org/10.30467/nivar.2018.122605.1083
Drought monitoring based on satellite index (SDI) and TRMM data.
(Case Study: Khorasan Razavi province)
Mozhdeh
Salimi fard
Ph-D student of agrometeorology / Ferdowsi university
author
Seyed Hossein
Sanaei-nejad
Associate Professor of water engineering department , Ferdowsi university of mashhad.
author
adel
sepehr
Assistant Professor, Faculty of Natural Resources and the Environment, Ferdowsi university of Mashhad
author
leila
sabet dizavandi
meteorology
author
text
article
2018
per
Iran located in arid and semi-arid area has many parts with high susceptibility to drought. The average rainfall of Iran is less than a third of the average annual rainfall in the world which has an inappropriate spatial -temporal distribution. Meteorological indices can be used for drought monitoring calculated by situations data. One of the main problems for applying these indices in Iran is inappropriate distribution of station and lack of data. In other hand, remote sensing technology is able to extract data from remote area. In this study in order to analyze drought risk in Khorasan Razavi province Synthesis Drought Index (SDI),”between 2001 to 2010” was applied. Vegetation Condition Index (VCI), Temperature Condition Index (TCI) and Precipitation Condition Index (PCI) through Principal Component Analysis (PCA) were measured for estimating SDI. For assessing the accuracy of SDI, correlation between these indicators and SPI (3, 6, 9-month) have been studied during the growing season, comparison was also done between total annual rainfall and long-term average rainfall in 10 synoptic stations in the studied area, as well as correlation between two indices VCI and SDI with the yield of rainfed wheat and barley. The results indicated that drought has been occurred in years 2001, 2002, 2006 and 2008 in the Khorasn Razavi province. The result of validation showed high correlation between SDI and SPI. Also the results showed that the Synthesis Drought Index in addition to monitor meteorological drought with ability of enhanced spatial resolution could be applied for identifying agricultural drought.
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IRIMO
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42
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102-103
no.
2018
19
30
https://nivar.irimo.ir/article_79224_097716042ad36dcd8cbb6b108323b2b4.pdf
dx.doi.org/10.30467/nivar.2018.125918.1085
Study of mixing layer height in Mehrabad airport,Case Study: Period 2017-1998
saman
mortezapoor
gilan meteorology organization
author
Mohammad
Moradi
Assistant Prof. of Atmospheric Science and Meteorological Research (ASMERC)
author
text
article
2018
per
In this study we obtained the maximum height of the mixed layer for each day in the time period 1998 to 2017 by using the radiosonde zero Greenwich data of Mehrabad airport station in Tehran and also using the maximum temperature measured at 12 GMT at the same station. The mean value of the depth of the mixed layer whit monthly time separation during the studied time period as well as the maximum, minimum and average height of the mixed layer for January, December, July and August were calculated as the representative of the two cold and two warm months. In the following the selected samples were analyzed by the SKEW-T chart. The results showed that the average maximum height of the mixed layer in warm seasons was between 3 to 4 km and in cold seasons between 1 and 2.5 km. The purpose of this research is to provide a method that predicts the depth of the mixed layer by using the upper air data of the zero GTM and also using the predicted maximum temperature. The predicted results can be used in suitable time range for practical, scientific and prognosis purposes.
Nivar
IRIMO
1735-0565
42
v.
102-103
no.
2018
31
40
https://nivar.irimo.ir/article_79154_12600384f145865c6df7dd2419ebdc37.pdf
dx.doi.org/10.30467/nivar.2018.130815.1087
Risk Assessment of Global Warming in Asia in the period of 1949 to 2014
مسعود
مسعودی
دانشیار دانشگاه شیراز
author
یاسین
همتی
گروه مهندسی منابع طبیعی و محیط زیست، دانشکده کشاورزی، دانشگاه شیراز، شیراز
author
زهرا
بهرامی
گروه مهندسی منابع طبیعی و محیط زیست، دانشکده کشاورزی، دانشگاه شیراز، شیراز
author
S. Razieh
Hendizadeh
Former Student, Department of Natural Resources and Environmental Engineering, Shiraz University
author
text
article
2018
per
Global warming is considered as one of the important environmental problem for the earth. The aim of this study is to investigate the changes of temperature in Asia. For this purpose, the monthly temperature data of 66 points were studied in all over Asia from 1949 to 2014. In this study, the changes of temperature were investigated in terms of increase, decrease and the level of significance. According to nearest points to considered urban points from NOAA site, annual average of temperature during 1949 to 2014 was calculated for each point. Also temperature change graph for each point in the period was prepared and trend of it based on regression linear equation was investigated. Different interpolation methods in GIS were used to determine the changes of temperature. According to the results obtained, 99% of Asia shows increasing and in 1% of the area doesn’t show any significant changes in 5% level. In total, amount of temperature in Asia has been increased by 0.94◦C during the study period. In a developed hazard classification for global warming, 34.7% shows slight hazard, 29.1% in moderate hazard, 33.8% in severe hazard and 2.4% in very severe hazard. According to prepared maps northern parts of the continent showed more increasing in temperature and more severe hazard.
Nivar
IRIMO
1735-0565
42
v.
102-103
no.
2018
41
48
https://nivar.irimo.ir/article_79221_a8260eda5b2da06917e34e316621338e.pdf
dx.doi.org/10.30467/nivar.2018.82231.1057
Evaluation and Comparison of Drought Indices and Determination the Suitable Index in Zayandehroud Basin
Morteza
Khodagholi
Associate Prof.,Research Division of Natural Resources, Isfahan Agriculture and Natural Resources Research and Education Center, AREEO, Isfahan, I.R.Iran
author
Razieh
Saboohi
expert, Soil conservation and Watershed Management Research Department, Isfahan Agriculture and Natural Resources Research and Education Center, AREEO, Isfahan, I.R.Iran
author
text
article
2018
per
Determination of indices is one of the basic and important steps in the study of wet and drought in each area. Indices can be evaluating the severity and duration of drought, and then the effect of them is determined on the water resources of the area. In this study, meteorological indices (Root Mean Square Error, Percent of Normal Precipitation Index, Rainfall Anomaly Index, Standardized Precipitation Index, DI, PNPI, and SIAP) was calculated using data of eight synoptic stations. The names of the stations are Meime, Varzane, Esfahan, Daran, Koohrang, Shahrekord and Shahreza in Zayandehroud watershed. Then for determine of the most suitable index in Zayandehroud watershed, meteorological drought indices using the minimum of precipitation and correlation methods were evaluated. The results of meteorological drought indices showed that the percentage of drought is different using different indices, as the RAI, DI, BMDI, SPI, SIAP showed that 35 to 45, 30, 20 to 40, 15 to 25, 25 to 35 percent of studied years are drought, respectively. RAI, BMDI, SPI and SIAP showed the highest percentage of occurrence of drought in Shahreza, Varzane, Abadeh and Varzane, respectively. DI index had equal percent of drought in all station except for Daran and Kuhrang stations. Finally, by the attitude of the two methods at the same time, was determined that meteorological drought of RAI and SIAP are better Indices than other drought indices.
Nivar
IRIMO
1735-0565
42
v.
102-103
no.
2018
49
60
https://nivar.irimo.ir/article_79306_006decfa8c663d8da0ef2eb2b5b76eaa.pdf
dx.doi.org/10.30467/nivar.2018.117878.1078
Evaluation of solar radiation estimation methods for reference evapotranspiration estimation (Case study: Khorram Abad)
Zeynab
Mikhak Beiranvand
PhD student in Irrigation and Drainage, Faculty of Water Sciences Engineering,
Shahid Chamran University of Ahvaz, Iran
author
Amir
Soltani Mohammadi
Associate Professor of Irrigation and Drainage Department, Faculty of Water Sciences Engineering,
author
Maryam
Saremi
MSc Graduate of Irrigation and Drainage, Agricultural and Natural Resources,
Campus of Razi University of Kermanshah, Iran
author
text
article
2018
per
Abstract: Solar radiation is a very important factor in the estimation equations for evapotranspiration and its proper estimation in the development of simulation models of plant growth is very important. In this study 10 solar radiation estimation models and their impact on the seven models of estimation of reference evapotranspiration were evaluated in the city of Khorramabad. The required solar radiation is calculated from the equations of Penman-Monteith, Hargreaves Samani, Irmak, Allen, Annandale, Self-Calibrating, Bahel, Glover and Mc Culloch, Bristow and Campbell , Angstrom-Prescott and used in reference evapotranspiration equations, FAO Penman-Monteith, Priestley–Taylor, Irmak, Turc, Doorenbos and Pruitt, McGuinness - Bordne and Abtew. The calculated evapotranspiration was compared with the measured values from four lysimeter in the growth period (March, April, May and June), and for the evaluation of the results were used the statistical criteria MBE, RMSE, R2, t and R2/ t. The results showed that the reference evapotranspiration calculated with all models of solar radiation and use of Irmac and McGuinness - Bordne equations were lower than the measured values and the Penman Montieth radiation model used in the FAO Penman Montieth, Priestley–Taylor and Doorenbos - Pruitt equations showed that the calculated evapotranspiration values would be closer to the lysimetric. Also, the self-calibrating radiation model in the Turc evapotranspiration equation with R2 /t = 0.38 had the best results and the Penman Montieth radiation model in the Doorenbos and Pruitt equation with R2 /t = 0.27 was in the second order compared to other models.
Nivar
IRIMO
1735-0565
42
v.
102-103
no.
2018
61
72
https://nivar.irimo.ir/article_79448_1fe6f8d714458981bbecddbc8d07d28e.pdf
dx.doi.org/10.30467/nivar.2018.89724.1064
Literature Review on the Connection Between Iran’s Climate and Teleconnection in the Period of 1999 to 2014
مهدی
غلامی رستم
دانشجوی دانشگاه تهران
author
سید جواد
ساداتی نژاد
عضو هیئت علمی دانشگاه تهران - دانشکده علوم و فنون نوین
author
آرش
ملکیان
عضو هیئت علمی دانشگاه تهران - دانشکده منابع طبیعی
author
text
article
2018
per
Considering the obvious effects of the large-scale climatic signals on the global climate, numerous studies have been carried out to clarify the types of these effects in many countries. Most of these studies have concluded to a meaningful connection between large-scale signals and the climatic parameters. The main objectives of many studies in Iran are about this topic too. The focus of present study is to investigate the researches in the period of 1999 to 2014 conducted in Iran. The results will lead us to recognize not only the procedure of all studies in mentioned period, but also the type of the connection between these signals and the climatic features in Iran. To achieve this goal, 58 studies were investigated and categorized in 102 classes regarding to the types of the signals. These results represented that the main focus of these studies are on SOI by 29% and NAO by 21%. The most of them showed that Iran’s climate is influenced by NAO and southern oscillation. For instance, most of the studies proved that El-Nino causes wetness and La-Nina leads to drought. Nevertheless, it is impossible to claim that one specific signal plays the significant role in Iran’s climate by itself.
Nivar
IRIMO
1735-0565
42
v.
102-103
no.
2018
73
88
https://nivar.irimo.ir/article_81045_7a9ec5d1d0fc43f9b64493cd15779ad5.pdf
dx.doi.org/10.30467/nivar.2018.81045