توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Investigation of climatic extreme events of Northwest of Iran by using daily precipitation and minimum and maximum temperature
نویسنده(ها): ، ،
اطلاعات انتشار: اولین کنفرانس بین المللی مدیریت منابع آب، سال
تعداد صفحات: ۷
It is hard to disguise the fact that climate change turns to a global crisis which is preoccupied most of scientists' mind. Northwest of Iran is one of the prominent area from agricultural point of view, and this area is a mountainous region, where fluctuations of various parameters of climate is ordinary. Therefore, this region is sensitive to climatic indices. Also it is the extreme events of climate which are playing key role in frequency and intensity of climatic events. In this study, Ardebil, Oroomiye, Tabriz, and Zanjan stations were investigated. Daily temperature (maximum and minimum) and precipitation data were used over the period of 1976 to 2007. Data were quality controlled and processing into indices of climate extremes. Although warm spell (WSDI) indicate slight declining trend, other temperature indices are compatible with warming. These indices put emphasis on quick pace of the climate of this region toward warm climate. Frost and cold days (FD and ID) and cold spell (CSDI) dramatically dwindle with regionally averaged showed –5.3, –6.3 and – 1.57days\decade respectively, while hot days and warm night indices (SU & TR) increase 1.7 and 0.07days\decade relatively. In comparison with Temperature indices, precipitation indices include smaller number of statistically significant trends. These indices indicate considerable decline. Annual rainfall, simple daily intensity, very wet day precipitation, maximum 1 and 5– day rainfall (PRCPTOT, SDII, R95p, RX1day and RX5day) decrease –2, –0.17, –0.03, –0.12 and 0.38mm\decade respectively. Although increasing in temperature is desirable because of cold climate in this region, in near future climate of this region will move toward arid climate; moreover intense decreases in precipitation indices will accelerate this movement. It is Tabriz station which indicates the most statistically significant trends, 18 indices have significant trends. This is maybe stems from higher concentration of CO2 in the so–called station.<\div>

۲Investigation of temperature and precipitation indices by using RClimDex and R software in Semnan province
نویسنده(ها): ، ،
اطلاعات انتشار: اولین کنفرانس بین المللی مدیریت منابع آب، سال
تعداد صفحات: ۷
In spite of profound impact of extreme events on frequency and intensity of various climatic events, in many of developing countries, such as Iran, there has been a paucity of information on trends in daily climate and climate extremes. In this study 2 stations (Shahroud and Semnan) situated in Semnan province have been investigated. We use daily temperature (maximum and minimum) and precipitation data over the period of 1966 to 2006. Data were quality controlled, and processing into indices of climate extremes, and the indices were calculated by RClimDex which is based on R software and is developed and maintained by the Climate Research Branch of Meteorological Service of Canada. Temperature extremes show patterns consistent with warming over most of the analyzed indices in both Shahroud and Semnan stations, with 10 and 8 statistically significant trends respectively, which are correspond to the same indices. From 1961 to 2006 cold days and nights has decreased, while over the same period the incident of extreme hot days and nights has increased. Therefore, growing season length (GSL) has increased over the studied period. Except simple daily intensity (SDII) index in Semnan station, other precipitation indices do not illustrate statistically significant trends across the whole region. These indices show increasing trend in annual rainfall (PRCPTOT), simple daily intensity, maximum 1–day and 5–day precipitation (RX1day and RX5day). However, the results of other precipitation indices indicate a declining trend in the intensity of rainfall. In spite of the results of the precipitation indices which may lead to less run off and more effective rainfall, the temperature trends increase sharply and dramatically. Therewith, the climate of the region is approaching arid climate.<\div>
نمایش نتایج ۱ تا ۲ از میان ۲ نتیجه