Characterizing spatiotemporal rainfall changes in 1960–2019 for continental Australia. (14th October 2020)

• Record Type: Journal Article
• Authors: Liu, De Li; Teng, Jin; Ji, Fei; Anwar, Muhuddin R.; Feng, Puyu; Wang, Bin; Li, Linchao; Waters, Cathy
• Is Part Of: International journal of climatology. Volume 41(2021)Supplement 1
• Page Start: E2420
• Page End: E2444
• Publication Date: 2020-10-14
• Subjects: Australian rainfall zones -- rainfall -- rainfall change -- rainfall intensity -- rainfall probability -- rainfall trends -- SILO -- wavelet analysis; Climatology -- Periodicals; Climat -- Périodiques; Climatologie -- Périodiques; 551.605
• DOI: 10.1002/joc.6855
• Languages: English
• ISSNs: 0899-8418

Abstract

Abstract: Understanding changes in rainfall at a continental scale can inform adaptation and resilience in all sectors that are sensitive to rainfall. This study examined spatiotemporal changes in annual and seasonal rainfall, extreme and non‐extreme rainfall, and their probability and intensity over the period from 1960 to 2019 across Australia for six rainfall zones (RZs) using high‐quality daily rainfall from 7, 593 climate stations. The results revealed statistically significant changes in long‐term rainfall, with an increasing trend in Northern and Central Australia, and a decreasing trend across Southern Australia where the main agricultural areas are located. The cross‐wavelet power spectrum analysis denoted strong coherent resonance cycles in spring–summer or autumn–winter seasons with varying phase differences across six RZs. More specifically, summer rainfall occurred more regularly in the summer‐dominant and arid RZs, whereas winter rainfall became more unreliable in the winter‐ and winter‐dominant RZs. The changes in regional rainfall were characterized by changes in probability and/or intensity of extreme and non‐extreme rainfall revealed through the Spearman Rank correlation. The upward trend in summer‐dominant and arid RZs appears to be a result of increased extreme rainfall intensity and probability, and non‐extreme rainfall probability, especially in summer. The decreased rainfall in the rest of the RZs can be attributed to decreased extreme rainfall probability and non‐extreme rainfall intensity. These results can help decision makers in the agricultural and water resources management sectors identify risks and opportunities, and to devise strategic plans to mitigate droughts through land use planning and construction of infrastructure. Abstract : We examined spatiotemporal changes in annual and seasonal rainfall, extreme and non‐extreme rainfall and their probability and intensity over the period from 1960 to 2019 across Australia. The results revealed statistically significant changes in long‐term rainfall, with an increasing trend observed in Northern and Central Australia, and a decreasing trend detected across Southern Australia where the main agricultural areas are located. The changes in regional rainfall were characterized by increased extreme rainfall intensity and probability, and non‐extreme rainfall probability in the north, and decreased extreme rainfall probability and non‐extreme rainfall intensity in the south.