Abstract

In this research, temporal trends and change points in heating degree-days (HDD), cooling degree-days (CDD), and their simultaneous combination (HDD + CDD) were analysed for a 60-year period (1960–2019) in Iran. The results show that less than 20% of the study stations had significant trends (either upward or downward) in HDD time series, while more than 80% of the stations had significant increasing trends in CDD and HDD + CDD time series. Abrupt changes in HDD time series mostly occurred in the early 1980s, but those in CDD time series were mostly observed in the 1990s. The cooling energy demand in Iran has dramatically increased as CDD values have raised up from 690 ºC-days to 1010 ºC-days in the last 60 years. HDD, however, almost remained constant in the same period. The results suggest that if global warming continues with the current pace, cooling energy demand in the residential sector will considerably increase in the future, calling for a change in residential energy consumption policies.

Highlights

• Monotonic trends in HDD, CDD and HDD + CDD time series were analysed in Iran.

• The series were also analysed for possible change points using the non-parametric method.

• Energy demand for cooling houses increased, while that for heating houses remained constant.

• Up to three upward abrupt change points were observed in the annual CDD series.

中文翻译：

---

伊朗冷暖度日数时空分析

摘要

本研究分析了伊朗 60 年（1960-2019 年）采暖度日（HDD）、制冷度日（CDD）及其同时组合（HDD + CDD）的时间趋势和变化点. 结果表明，不到20%的研究台站在HDD时间序列上有显着趋势（上升或下降），而80%以上的台站在CDD和HDD+CDD时间序列上有显着上升趋势。HDD 时间序列的突变多发生在 1980 年代初期，而 CDD 时间序列的突变多发生在 1990 年代。在过去的 60 年里，随着 CDD 值从 690 ºC 天上升到 1010 ºC 天，伊朗的冷却能源需求急剧增加。然而，HDD 在同一时期几乎保持不变。结果表明，如果全球变暖以目前的速度继续下去，

强调

• 在伊朗分析了 HDD、CDD 和 HDD + CDD 时间序列的单调趋势。

• 还使用非参数方法分析了该系列的可能变化点。

• 冷却房的能源需求增加，而供暖房的能源需求保持不变。

• 在年度 CDD 系列中观察到多达三个向上的突变点。