List of Articles Extreme precipitation

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  1 - Projection of extreme precipitation in climate change condition and sensitivity analysis of results to downscaling method
  Mohammad Reza Khazaei Reza Kazemi
  The frequency and intensity of extreme rainfalls will increase over many areas of the globe due to climate change. So, it is required to revise result of such studies based on the climate change scenarios. One of the most effective tools in such studies is Weather Gener More

  The frequency and intensity of extreme rainfalls will increase over many areas of the globe due to climate change. So, it is required to revise result of such studies based on the climate change scenarios. One of the most effective tools in such studies is Weather Generators, including LARS-WG. While GCMs predict future changes in the various characteristics of precipitation, usually in downscaling using LARS-WG, just changes of monthly averages are considered. In this paper, the future climate change impact on extreme precipitation in Gorgan and Khoramabad stations are assessed; while, the results of two methods of applying just change in averages (simple method) or applying changes in various characteristics of precipitation (complete method) in downscaling are compared. For future, CanESM2 outputs under RCP2.6, RCP4.5, and RCP8.5 scenarios for 2036-2065 period were used. The results showed that for climate change impact assessment on extreme rainfalls, additional to change in averages, change in other precipitation characteristics should be considered. Because the results of the two methods are different. In Gorgan, for example, the annual maximum daily rainfall with a return period of 15 years in the future will increase by 16 to 21 percent according to the more complete method, but between 37 and 49 percent according to the simpler method. Based on the complete, Intensity of the extreme rainfalls at both stations will increase in the future. This increase will be between 23% and 30% for the 2-year return period and between 25% and 29% for the 30-year return period. Manuscript profile
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  2 - بررسی تاثیر تغییراقلیم بر بارش‌های حداکثر و حداکثر سیلاب محتمل رودخانه کارون
  زهرا رامک جهانگیر پرهمت ابراهیم فتاحی مهران زند حسین صدقی
  تغییر اقلیم یکی از مهم ترین چالش هایی است که بخش های مختلف زندگی انسان را در روی زمین تحت تاثیر قرار داده است و یکی از آثار آن، تاثیر بر وقایع حدی (سیلاب و خشکسالی) می باشد. امروزه یکی از مهم ترین موضوعات مورد بحث این است که در آینده شدت بارش های سنگین و سیلاب ها نسبت ب More

  تغییر اقلیم یکی از مهم ترین چالش هایی است که بخش های مختلف زندگی انسان را در روی زمین تحت تاثیر قرار داده است و یکی از آثار آن، تاثیر بر وقایع حدی (سیلاب و خشکسالی) می باشد. امروزه یکی از مهم ترین موضوعات مورد بحث این است که در آینده شدت بارش های سنگین و سیلاب ها نسبت به دوره کنونی چگونه تغییر خواهد کرد. در این تحقیق تلاش شده است تا تاثیر این پدیده بر بارش های حدی و حداکثر سیلاب محتمل (PMF) رودخانه کارون در محل پل شالو مورد بررسی قرار گیرد. برای اینکار، دما و بارش دوره آتی (2039-2011) با استفاده از مدل HadCM3 و بر اساس سناریوهای انتشار A1B، A2 و B1 و مدل ریزمقیاس نمایی آماری LARS-WG شبیه سازی شده است. در گام بعدی حداکثر بارش محتمل حوضه به روش سینوپتیکی برآورد و پس از آن، با استفاده از مدل بارش- رواناب HEC-HMS و مدل ذوب برف SRM، حداکثر سیلاب محتمل این حوضه برآورد و در نهایت تاثیر تغییر اقلیم بر بارش های حداکثر و نیز حداکثر سیلاب محتمل این حوضه بررسی شده است. نتایج حاصل از این تحقیق نشان می دهد که حداکثر بارش محتمل حوضه در دوره 2039-2011 نسبت به دوره کنونی تحت سناریوی A1B، با 5 درصد کاهش و تحت سناریوهای A2 و B1 به ترتیب با 5 درصد و 10 درصد افزایش روبه رو خواهند شد. همچنین پیش بینی می شود سهم سیلاب ناشی از ذوب برف در مطالعات PMF، تحت سه سناریوی ذکر شده به ترتیب 24/1 ، 58/1 و 23/1 برابر افزایش داشته باشد. به همین ترتیب حداکثر سیلاب محتمل (PMF) این حوضه در تداوم های مختلف تحت سناریوی A1B کاهش و تحت سناریوی A2 و B1 افزایش خواهد داشت و شدت تغییرات تحت سناریوی B1 شدیدتر خواهد بود. Manuscript profile
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  3 - Synoptic-thermodynamic analysis and modeling of heavy spring rains in Lorestan province
  Farzad Nourizadeh Amir Gandomkar Morteza Khodagholi
  Heavy rains are one of the most important climatic hazards of Lorestan province, which has increased during recent decades in the context of climate change.In this research, the main goal is to reveal the synoptic-thermodynamic patterns that generate heavy spring rains More

  Heavy rains are one of the most important climatic hazards of Lorestan province, which has increased during recent decades in the context of climate change.In this research, the main goal is to reveal the synoptic-thermodynamic patterns that generate heavy spring rains in Lorestan province.In this regard, three categories of daily precipitation data from Lorestan stations, synoptic factors from NCEP/NCAR climate database, and upper atmosphere data from University of Wyoming database were used.First, using the 95th percentile method, the heavy rainfalls of the studied stations during the statistical period of 1995 to 2020 were determined in Lorestan province. Two cases of heavy spring rain (April 14, 2016, April 1, 2019) were extracted by applying the percentile method on the daily rainfall of Hamdid stations in Lorestan province. The results of synoptic analysis in the middle and upper level of the atmosphere, in the selected samples of the spring season, showed a deep trough over the eastern Mediterranean Sea and the western part of Iran, which has prepared the conditions for the ascent and entry of low pressure systems for the west of the country.At the surface of the earth, low pressure has prevailed in the west of Iran. The center of Wachrokhandi is formed over the Oman Sea and the Persian Gulf, which directs moisture from the Oman and Arabian Seas to the south and southwest of Iran. But the thermodynamic indicators did not reveal a significant difference in the atmospheric conditions of high spring rains. Manuscript profile