Geomorphology
Batoul Zeinali; Mahdei Aalijahan; fatemeh dashtbani; Rahim Fazeli
Abstract
Floods are one of the most destructive atmospheric hazards which push different communities all over the world to suffer from life and financial damages. The present research has the aim of detection of synoptic and hydrometeorology features of flood in Herochay. For this goal, the data from daily rainfall ...
Read More
Floods are one of the most destructive atmospheric hazards which push different communities all over the world to suffer from life and financial damages. The present research has the aim of detection of synoptic and hydrometeorology features of flood in Herochay. For this goal, the data from daily rainfall of stations in Khalkhal, Khanghah, Arpachayi and Lamber and the data from Hydrometer station in River Kivichay was used to detect the rainfall and flood happened and for synoptic inspection of this phenomenon, the data from Sea level pressure, upper layers of atmosphere like Geopotential high, Omega, Orbital wind, Meridional wind and Relative humidity in levels of 500 to 1000 HPA was used. The obtained results show that presence of low-pressure system on the surface of ground, occurrence of blocking and located of the study area on the east of the trough on the upper levels, negativity of atmospheric eddies and omega on different levels with humid supply of Black Sea and Mediterranean sea on the levels of 500 to 700 HPA, Red sea and Persian Gulf and Oman Sea on the levels of 850 and Caspian Sea on the levels of 925 and 1000 HPA have prepared the conditions needed for generation of instability over the atmosphere of the studied area. The mentioned conditions have caused intense thunderstorm and increase of Herochay discharge and generation of flood in that region.
Yousef Gavidelrahimi; Manochehr Farajzadehasl; Mehdi Alijahan
Abstract
Today, global warming effects on various aspects of the Earth are no secret to anyone. Because of this, the research ahead is done for the detection of global warming on minimum temperatures, monthly and periodic (hot and cold) as well. For this study, two groups of data, temperature data of 17 synoptic ...
Read More
Today, global warming effects on various aspects of the Earth are no secret to anyone. Because of this, the research ahead is done for the detection of global warming on minimum temperatures, monthly and periodic (hot and cold) as well. For this study, two groups of data, temperature data of 17 synoptic stations and corresponding amounts of data in global temperature anomalies were figured out over 60 years period of time (1951 to 2010). Goals, the Pearson correlation method for detecting relationships between data, linear and polynomial regression for trend analysis time series data , To illustrate the correlation between the spatial distribution of temperature data with global warming stations nationwide Geostatistical model Finally, non-parametric test for detecting significant temperature change Man - Kendall were used. Based on the results, apart from Khorramabad and urmia stations that have negative relation with global warming and Hamadan and Kerman stations that do not show any significant relationship with global warming, global warming is seen as a positive influence on the other stations. Caspian Bank stations than any other stations in the cold months of global warming have much more influence. Checking the changes of minimum temperature trend showed a significant change in several months. In the warm months the maximum temperature variability is seen in the southern stations of Ahwaz, Abadan, Bushehr and Shiraz. Results obtained from the survey period (hot and cold) minimum temperature, indicate a greater influence global temperature anomaly on the minimum temperatures are warm period of year. During the warm period, southern stations have had the highest influence on the station and during the cold period Caspian Bank stations have had the highest relationship with it. The changes were made based on both periods the obtained results are clarity significant.