干旱区生态环境知识资源中心(Arid): Impact of sum-of-hourly and daily timesteps in the computations of reference evapotranspiration across the Brazilian territory

Arid

DOI	10.1016/j.agwat.2019.105785
	Impact of sum-of-hourly and daily timesteps in the computations of reference evapotranspiration across the Brazilian territory
	Althoff, Daniel; Filgueiras, Roberto; Brant Dias, Santos Henrique; Rodrigues, Lineu Neiva
通讯作者	Althoff, D (corresponding author), Fed Univ Vicosa UFV, Dept Agr Engn, Av Peter Henry Rolfs Sn, BR-36570900 Vicosa, MG, Brazil.
来源期刊	AGRICULTURAL WATER MANAGEMENT
ISSN	0378-3774
EISSN	1873-2283
出版年	2019
卷号	226
英文摘要	Estimating reference evapotranspiration (ETo) in 24 h timesteps has been considered sufficiently accurate for a long time. However, recent advances in weather data acquisition has made it feasible to apply the hourly procedures in ETo computation. Hourly timesteps can improve ETo estimates accuracy, for data averaged daily may misrepresent evaporative power during parts of the day. Only a few studies have assessed vast databases, yet, studies considering tropical regions are basically inexistent. The objective of the present study was to assess the differences between daily ETo computations performed on 24 h (ETo(d)) and hourly (ETo(h)) timesteps for the Brazilian territory. Daily and hourly ETo computations were performed according to the standardized ASCE (American Society of Civil Engineers) Penman-Monteith equation. Large daily weather variations of meteorological parameters resulted in ETo(d) generally underestimating ETo(h), while lower variations resulted in ETo(d )overestimating. Overall, ETo(d) overestimated ETo(h) in 0.7%, with monthly percentage bias ranging from -3.9% to 2.9%. This study considered one year of data from 567 automatic weather stations and, despite acknowledging the existence of interannual climate variability, findings strongly agreed with relevant literature. ETo(d) predominantly overestimated ETo h during wet periods in warm regions. Thus, this behavior is observed almost yearround for the tropical monsoon and rainforest climate, in the Amazon and Pantanal biome. For the tropical savannah and semi-arid climate, ETo(d) overestimated ETo(h )during wetter periods (main crop harvest) but underestimated along the dry season (second harvest). On the other hand, ETo(d) predominately underestimated ETo(h) for colder regions, such as the Pampa (humid sub-tropical climate), regardless of rainfall. The Cerrado and Caatinga are likely to be affected most, for ETo(h )is underestimated in periods of lower water availability, making adequate irrigation techniques fundamental.
英文关键词	ASCE standardized Irrigation management Penman-Monteith Water resources
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000525274200011
WOS关键词	PENMAN-MONTEITH REFERENCE ; CLIMATE-CHANGE ; IRRIGATION ; EQUATIONS ; BASIN ; YIELD
WOS类目	Agronomy ; Water Resources
WOS研究方向	Agriculture ; Water Resources
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/369737
作者单位	[Althoff, Daniel; Filgueiras, Roberto] Fed Univ Vicosa UFV, Dept Agr Engn, Av Peter Henry Rolfs Sn, BR-36570900 Vicosa, MG, Brazil; [Brant Dias, Santos Henrique] State Univ Ponta Grossa UEPG, Dept Soil Sci & Agr Engn, Av Gen Carlos Cavalcanti 4748, BR-84030900 Ponta Grossa, Parana, Brazil; [Rodrigues, Lineu Neiva] Brazilian Agr Res Corp EMBRAPA Cerrados, BR 020,Km 18, BR-73310970 Planaltina, DF, Brazil
推荐引用方式 GB/T 7714	Althoff, Daniel,Filgueiras, Roberto,Brant Dias, Santos Henrique,et al. Impact of sum-of-hourly and daily timesteps in the computations of reference evapotranspiration across the Brazilian territory[J],2019,226.
APA	Althoff, Daniel,Filgueiras, Roberto,Brant Dias, Santos Henrique,&Rodrigues, Lineu Neiva.(2019).Impact of sum-of-hourly and daily timesteps in the computations of reference evapotranspiration across the Brazilian territory.AGRICULTURAL WATER MANAGEMENT,226.
MLA	Althoff, Daniel,et al."Impact of sum-of-hourly and daily timesteps in the computations of reference evapotranspiration across the Brazilian territory".AGRICULTURAL WATER MANAGEMENT 226(2019).