تحليل فضايي تغييرات زماني مكاني درجه روز سرمايشي ماهانه ايران

Spatial analysis of temporal variations of monthly Cooling Degree Days in Iran

تغيير اقليم وافزايش دما يكي ازمسايل مهم زيست محيطي بشر به حساب مي­آيد كه در سال هاي اخير مطالعات زيادي را به خود اختصاص داده است هدف از اين مطالعه واكاوي روندوشيب روندجمع ماهانه درجه روزسرمايش باآستانه دمايي25 درجه مي باشد. ميانگين دماي روزانه در طي دوره آماري 44 ساله (13831340)برگرفته ازپايگاه داده هاي اسفزاري[1]استخراج گرديد. سپس به كمك آزمون ناپارامتري من كندال روند وشيب روندجمع ماهانه درجه روز سرمايش را در سطح معني داري 05/0براي هر كدام ازياخته‌ها در نرم‌افزار مطلب محاسبه كرديم ابعاد ماتريس به دست آمده 44*7187 مي باشد كه در آن سطرها بيانگر زمان(سال) وستون ها مكان(ياخته) مي‌‌باشند.درنهايت نقشه هاي روند وشيب روند اين فراسنج درنرم افزارسورفر ترسيم ومورد واكاوي قرار گرفت.نتايج به دست آمده نشان‌دهنده روند افزايشميزان نياز به سرمايش در چاله هاي داخلي وسواحل وجلگه‌هاي جنوبي كشور در ماه‌هاي گرم سال مي باشدكه بيانگر روند افزايشي دما درنواحيگرم درماه‌هاي گرم كشور است.روند منفي درنياز به سرمايش نيز درنيمه غربي شهركرد وخرم آباد، شرق بجنورد ونيمه شمالي زنجان وسنندج مشاهده شده است.بيشترين ميزان شيب روند درماه‌هاي مختلف مثبت وبه ميزان 0 تا 2 درجه روز در سال است.   2 اين پايگاه داده در دانشگاه اصفهان توسط دكتر مسعوديان تهيه گرديده است.

Introduction Whereas contemporary ecology mental (thinking) space has been filled by global warmness subject, there are a little literature that has been demonstrated day degree mechanisms trend discussion. Global warmness and its effects on human societies are one of the apprehensive subject that this warmness is the result of the hothouse (greenhouse) effect (Zangou et al ,2008) .Day degree is the existent difference between the average weather temperature and selective temperature threshold ,snow melting , freezing weather, plant growth, blossoming, products harvest , consumption energy for metropolis warmness and coldness and transportation systems that all of them are related to the relative value of these upermeasurments. (Kedia Glouseen 1999, Rahmano et al 2010, Jiango et al 2009) selective temperature thresholds for calculating coldness day degree trend is according to the specific purposes . For an exle selective day degree for human relaxation is 18 degree.   Materials and Methods In this research for investigating ( researching) in monthly trend gradient and trend of day degree ,the coldness day degree with 25 degree temperature threshold, the daily temperature average during 44 years statistical periods (13401383) has been extracted from Sfazar data base . Coldness day degree data with cells 15*15 kilometer were mediated for all of the Iran, that its yield was a matrix by dimension 7187*44 (time * cells). Finally by the help of  MannKendall nonparameter test , test trend and gradient the total trend for coldness day degree were calculated for every cells. The used software included Matlab and Surfer a)First based on statistical the differences between observation calculate, one by one. (raining, temperature, or any other ecological parameter).   b) And n=the total observation that xj and xk respectively are the series j and k amounts. The above output function make every series sign clear as followed.                                                              After determining the sign the Variance of every observation will be calculated by the followed formulation The amount of observation should be higher than 10(n>10) V(s)= c)The followed stage is Z statistical calculation.                                                                       Results Researching (investigating) the coldness trend in Iran territory represent the needs positive trend of coldness in summer and spring season. According to the figure 1 most of regions that have the same trend in the first 6 month of the year their trends are positive. In Farvardin and Ordibehesh months the internal hollowes ,  forests and southern coast(shores) exept for Oman sea shore strip by having 45 percentage of Iran extent have the coldness needs positive trend . In Khordad months some strips of southern Zagros slope , the west of Kermanshah , Moghan plain and the east of Oroumieh lake will add to these regions. By beginning of summer season coldness needs positive trend will represent in half of the country that its maximum location in Shahrivar month will be by 62 percentage of Iran territory. Most of regions that in the spring and summer seasons month have this trend their trend gradient  are positive and their rate is 0 to 2 degree of day degree in the year and it means that for this rate in the year their coldness need will be increased. In Ordibehesht the quantitative maximum of the positive trend gradient belongs to the  postcoast of Oman sea ,Lout block medium, and Khouzestan plain by having 24 percentage of region extent and have the positive trend by 24 day degree in the year.In Khordad month by adding plain desert and Persian Gulf s west shores ,29 percentage of country have the positive trend gradient (24 day degree ). In summer season observe intensive warmness trend in the middle of   Lout  and  Kahnouj block as positive trend gradient of coldness  needs of these regions is  46 day degree in the year.   Conclusion According to the positive trend and increasing the needs of Coldness in internal hollowes and forests and southern shores and as in Shahrivar month more than 60percent of country extent was witness of increasing trend of coldness could point out to being the more warmness of other Iran regions and shortend of autumn season. This is itsef represent the increasing the trend of temperature in ratio to temperature threshold (25 degree).The coldness needs negative trend in summer season in half of the west shahrekord and Khoramabad the west half of Birjand , the north of Sanandaj and Zanjan and east half of the Tehran  give glad tidings the  coolness trend of these regions .The most rate of trend gradient in year months is positive and is as the rate 0 to 2 day degree in the year. The coldness needs positive trend in the half of the year in the southern strip of the country and internal hollowes confirm the country warm regions temperature is increasing. 2 statement and contemporary outlook of study The warm regions of country have the increasing trend that  cause to increasing energy consumption for coldness and energy consumption decreasing for warmness .Coldness needs negative trend in some of the high regions of country the coolness of temperature show to us the coolness of temperature in the mountain  strip of country.