Frequency Analysis of River Basins Associated With Storm Floods in the Armand Basin

Document Type : Research Article

Authors

• Alireza Dehghanpour
• zeynab Ashoory

Payame Noor University, Yazd Center

10.22067/geo.v0i0.50623

Abstract

Introduction

In all air maps, without exception, belts or wind straps are seen at high speeds that extend over very long distances. According to the World Meteorological Organization, if the velocities of these velocities are more than 30 meters per second, the flow of the Jet stream is created (Alijani & Kaviani, 2000). However, jet stream is referred to the extreme horizontal winds at speeds exceeding 50 knots or about 26 m/s above the planet's winds. Since the geographical distribution of rainfall intensity on a planetary scale, in addition to system pressure patterns, seating tropical convergence belt, ocean currents affect the make-up jet stream, position and expand them as well. In this paper, an attempt has been made to identify a process of effective factors in the occurrence of storms in order to optimize the use of these rainfall in the study area. In other words, the purpose of this article is to determine the position and frequency of the storms and their average velocity during the storm events of Armand basin.

Materials and Methods

Essentially, in every ongoing study, there is a need for two databases; one for the environmental event database (surface), and another for the atmospheric database that identifies how atmospheric flows are. First, the daily precipitation data of the synoptic stations of Chaharmahal and Bakhtiari province from 1973 to 2004 were selected and prepared as environmental event database. The second group of variables consisted of wind and orbital component data that was used to plot the basins at 250 and 300 hpa. The first and second groups of variables were obtained from the Iranian Meteorological Organization and website www.cdc.noaa.gov.

Results and Discussion

3.1. The Role of Jet Stream Instability
The core of the jet stream in the context of long and short wave move.  the entrance area on the left and the exit area on the right. In fact, based on the circle model, the core of the velocity is drawn into four sections: the right and left inputs of the divergence and the left and right inputs are convergent.

Frequency and average velocity analysis of the Jet Stream at 300 hectares

The large Jet Stream drawings at 300 hectares indicate that in the hours of 00:00 the highest frequency of inflows is observed on Saudi Arabia. There are two abundant small rivers, one on Uzbekistan and another on the north of the Caspian Sea and on Kazakhstan.

Frequency analysis and average velocity flow of 250 hPa

Frequency analysis of jet stream at the level of 250 hpa shows that in the hours of 00:00, the highest frequency of river flows extends from the Red Sea to the Persian Gulf, and south and west of the country. The analysis of average speed of the storms in the synoptic hours in this alignment shows that the average speeds of the storms are more than 40 m/s. The maximum velocity in the territory under question is at 6:00 pm, with its central core at 55 m/s on the Persian Gulf, Saudi Arabia and the southwest of the country, which also includes the study area. The mean velocity map for the above hour, which corresponds to the maximum occurrence of coincidences and coincidence with their maximum velocity occurrences in the study area, indicates that the fourth quarter (which is associated with positive precipitation increase as well as upper surface divergence and convergence of low atmospheric levels) is located on the study area. This can lead to high-level air mass expansion or upward movement. This seems to provide the necessary basis for the occurrence of instability at the time of flood and basin storms in the area under discussion.

Conclusion

The abundance analysis of the riverbeds at the 250-hp level revealed that over the hours of 00:00, 06:00, 12:00 and 18:00, the abundance of the riverbeds has spread over Saudi Arabia to the Persian Gulf, the center and west of the country In other words, in this area more than 50% of the formation and establishment of the jet stream.. During the four hours of the occurrence of synoptic atmospheric jet streams this level only based on the maximum frequency of the jet stream jet stream At 06:00, the range expanded under the influence of jet streams and jet streams while a wide range of western and southern half of Iran are obvious especially in the southwestern and southern parts of Iran. The most frequent occurrence of the river is the same hour, with the western zone of the country which is more than 60% consistent. The study of riverbed frequencies at 300 hPa level also indicated that the inflow of the Jet Stream in the four-hour significantly reduced compared to the higher levels.

Keywords

• frequency analysis
• Instability
• River Basin
• Extreme Rainfall
• Convergence
• Divergence
• Armand Basin

---

References

بابائیان، ایمان و همکاران؛1380)، بررسی الگوی سینوپتیکی سیل تابستان 1380 استان‌های گلستان و شمال خراسان، بولتن علمی مرکز ملی اقلیم‌شناسی، سال اول، شماره پنجم، تهران.

حلبیان، امیرحسین؛ حسینعلی پور جزی، فرشته؛ 1393. تحلیل فراوانی رودبادهای مرتبط با بارش‌های حدی و فراگیر در کرانه‌های غربی خزر، فصلنامه تحقیقات جغرافیایی، سال 29، شماره اول، بهار 1393، صص 220- 205.

خسروی، محمود؛ 1380. ((تأثیر پدیده انسو بر ناهنجاریهای بارش تابستانی و پاییزی منطقه جنوب شرق ایران))، فصلنامه تحقیقات جغرافیایی، سال شانزدهم، شماره پیاپی 62، پاییز، صص 174-141.

خوشحال دستجردی، جواد؛ 1376. تحلیل و ارائه مدل‌های سینوپتیک کلیماتولوژی برای بارش‌های بیش از صد میلی‌متر در سواحل جنوبی دریای خزر، پایان نامه دکتری جغرافیای طبیعی گرایش اقلیم شناسی، دانشگاه تربیت مدرس، بهار.

علیجانی، بهلول؛ 1381. اقلیم شناسی سینوپتیک، تهران: سمت، 257.

فرج زاده اصل، منوچهر، لشکری، حسن و خورانی، اسدالله؛ 1384. ((تحلیل موقعیت رودباد در رابطه با سامانه‌های بارشی غرب کشور))، فصلنامه مدرس علوم انسانی ویژه جغرافیا، بهار 1386، صص 256- 239.

کاویانی، محمدرضا؛ علیجانی، بهلول؛ 1379. مبانی آب وهواشناسی، تهران: انتشارات سمت، 576.

مارتین، جاناتان ای. ترجمه سید ابوالفضل مسعودیان؛ 1388. دینامیک جو در عرض میانه، تهران: انتشارات سمت و دانشگاه اصفهان، 426.

مسعودیان، سیدابوالفضل و محمدی، بختیار؛ 1390. ((تحلیل فراوانی رودبادهای مرتبط با رخداد بارش‌های ابر سنگین ایران))، مجله تحقیقات منابع آب ایران، سال هفتم، ش 2، صص 91- 80.

مسعودیان، سیدابوالفضل؛ 1390. آب و هوای ایران، مشهد: انتشارات شریعه توس، 277.

مسعودیان، سیدابوالفضل؛ کاویانی؛ محمدرضا؛ 1387. اقلیم شناسی ایران، اصفهان: انتشارات دانشگاه اصفهان، 168.

مفیدی، عباس؛ زرین، آذر و جانباز قبادی، غلامرضا؛ 1386. ((تعیین الگوی همدیدی بارش‌های شدید وحدی پاییزه در سواحل جنوبی دریای خزر))، مجله فیزیک زمین فضا، دوره 33، ش 3، صص 154- 131.

مفیدی، عباس، زرین، آذر، جانباز قبادی، غلامرضا؛ 1390. شناسایی الگوهای همدید بارش‌های شدید زمستانه در سواحل جنوبی دریای خزر، مجله جغرافیا و برنامه‌ریزی محیطی، سال 22، شماره 24، تابستان 90، ص 40-23.

Alexandar; L.V., and 23Co- authors., 2006. Global Observed Changes in daily Climats extremes of temperature and precipitation, J.Geophys.Res., 111, D05109, doi: 10.1029/ 2005JD006290.

Andrew Hoell, Mathew Barlow, and Roop Saini., 2012. The Leading Pattern of Intraseasonal and Interannual Indian Ocean Precipitation Variability and its Relationship With Asian Circulation During the Boreal Cold Season AMS journals online, doi: 10.1175/JCLI- D- 11- 00572.1

Dayan. U, Abramski. R., 1983. Heavy Rain in the middle East related to Unusual Jet Stream Properties, Bulletin American Meteorological Society, Vo1. 64, No.10, October 1983, pp.1138-1140.

Degrimrndzic.J. and Wibig.J., 2007. Jet Stream Patterns Over Europe in The Period 1950- 2001 Classification and basic Statistical Properties, Theoretical and Applied Climatology, Volume 88, Numbers 3-4/March, 2007, pp.149- 167.

Eltantawy.A.I., 1960. Jet Stream Clouds in the Middle East, pure and Applied Geophysics, Volume 46, Number 11May, 1960,pp.352-359.

Farajzadeh. M; et al., 2008. the Relation Between Jet Stream Location and Cyclones Over the Western Iran, American Journal of Applied Sciences, 5(10):pp. 1308 -1312.

Geer, I.W; et al., 1996. Glossary of Weather and Climate, American Meteorological Society, Boston..272p.

Herron. T. j. and Tolstoy. I., 1968. Tracking Jet Stream Winds From ground Level Pressure Signals, Journal of the atmospheric Sciences. Vol 26, pp. 266-269.

Jhonson. D. H, Danials. S.M., 2006. Rainfall in Relation to the Jet Stream, Journal of the Royal Meteorological, Vo1 80, Issue 344, pp. 212-217.

Kalnay, E., et al., 1996. the NCEP/NCAR 40 year Reanalysis Project, Bulletin of American Metrological Society, vol. 77, No.3, pp.437-471.

Nicholls, No, Trewin, B. and Haylock, M., 2000. climate Extremes: Indicators for state of the Environment Monitoring, Australia: State of the Environment, Second Technical Paper Series (the Atmosphere), Department of the Environment and Heritage, Canberra, 20p.

Peterson, T. C. Folland, C., Gruza, G., Hogg, W., Mokssit, A., and plummer, N., 2001. Report on the activities of the working Group on climate Change Detection and Related Rapporteurs 1998-2001, word Meteorological organization Rep. WCDMP- 47, WMO- TD 1071, Geneva, Switzerland, 143p.

Prezerakos,N.G.& et al (2006. the Role of the Interaction Between Polar and Subtropical Jet in a Case of Depression Rejuvenation Over the Eastern Mediterranean, Meteorol. Atmos. Phys, 92:139-151.

Strong. C., and Davis. R.E., 2007. Variability in the Position and Strenght of Winter Jet Stream Cores Related to Northern Hemisphere Teleconnections, Journal of climate, Vol 21, pp 584-592.

Weinert. R. A., 1968. Statistics if the Subtropical jet Stream Over the Australian, Central office, Bureau of Meteorology, Melbourne, Manuscript Received November 1998.

WoolingsT, et al., 2009. Variability of the North Atlantic eddy-driven Jet Stream, Quarterly Journal of the royal Meterologycal Society, Published online in Wiley Interscience.

Yuan, Jiacan, Steven B. Feldstein, Sukyoung Lee, Benkui Tan., 2011. the Relationship between the North Atlantic Jet and Tropical convection Over the Indian and Western Pacific Oceans. J. Climate, 24, 6100-6113.

Zhang, X, and 23Co- authors., 2005. Trends in Middle East Climate extreme indices from 1950 to 2003, J, Geophys. Res, 110, D22104, doi:10.1029/2005JD006181.