Spatio-temporal analysis of cooling degree day requirement in North East of Iran

Abstract

Global warming is one of the current and future challenges for humankind which can have an impact on agriculture, transportation, water resources, energy production, architecture, heating and cooling needs of the building, plant phenology, etc. In this research, for the spatio-temporal analysis, the need for cooling day was used from daily data of minimum temperature and maximum temperature of 16 stations in the north east of the Iran during the period of 20 years (1996-2015). First, data matrices were created in the MATLAB software with an S-dimensional array (7035*16), where are the rows, representing time (day) and columns, representing the locations (stations). Finally, it was calculated of cooling degree day per month and plotted spatial mapping in ArcGIS. The results showed that significant and reverse correlation between altitude and latitude with cooling day requirements in all warm months of the year, also according to the need for cooling degree day, the Khorasan area can be divided into six climatic groups. The most need for cooling with more than 500 degrees of day is in the southern and lowlands of the area and the least need for cooling are located in the northern and highlands part. So that the highest percentage of need for cooling day degrees in April and May white %27.5, related to the semi-cold climate group; In June with %24.5; in July %23.7; in august %22.4 and in September whit %22.5, Belongs to the cold climate group. Also, the study of the process of cooling needs suggests that in April most of the stations lack a significant trend, and only stations in the north and south of the region have a declining trajectory. In September, there is also a drop in cooling needs at most stations.

Keywords

• mann-kendall trend
• cooling degree days
• north east
• iran