全球智库信息集成服务系统(G2TT): Global investigation of impacts of PET methods on simulating crop-water relations for maize.

G2TT

来源类型	Article
规范类型	其他
DOI	10.1016/j.agrformet.2016.02.017
	Global investigation of impacts of PET methods on simulating crop-water relations for maize.
	Liu W; Yang H; Folberth C; Wang X; Luo Q; Schulin R
发表日期	2016
出处	Agricultural and Forest Meteorology 221: 164-175
出版年	2016
语种	英语
摘要	Crop models are commonly used to investigate crop-water relations over different spatial scales. Estimating potential evapotranspiration (PET) is a basis for this investigation. Most crop models have built-in PET estimation methods. Using different methods can lead to very different PET estimates; but little is known about the sensitivity of large-scale crop model predictions on the choice of the PET estimation methods. In the work reported here, we used PEPIC, a grid-based EPIC (Environmental Policy Integrated Climate) model with a Python environment, to investigate the impacts of five different PET methods on estimated crop-water relations for maize on a global scale at a resolution of 30 arc min. Results show that the estimated PET varied largely among different PET methods for the same climate zones, leading to uncertainties in estimating crop-water relations. Uncertainties in water-related variables such as growing season evapotranspiration (GSET) and irrigation water requirement were more relevant than uncertainties in crop yields. Water availability played an important role in the uncertainties. All PET methods showed similar performance with respect to simulations of GSET for rainfed maize cultivation in low-rainfall regions, while there were large differences for regions with high rainfal. For irrigated agriculture, the estimated irrigation water requirement varied widely among the five PET methods, with a factor of 2 between the smallest and the largest estimates. Overall, using the Priestley-Taylor method led to lowest yield but highest GSET estimates. The Baier-Robertson and Hargreaves methods produced rather high GSET estimates for tropical and humid regions. The Penman-Moneith method gave the best yield estimates, compared to agricultural statistics. The results highlight the importance of considering te uncertainties resulting from the selection of PET estimation methods in investigating crop-water relations, particularly in predicting impacts of future climate change and in formulating appropriate water management strategies.
主题	Ecosystems Services and Management (ESM)
关键词	PET PEPIC maize crop-watr relations modelling uncertainties global scale
URL	http://pure.iiasa.ac.at/id/eprint/12171/
来源智库	International Institute for Applied Systems Analysis (Austria)
引用统计
资源类型	智库出版物
条目标识符	http://119.78.100.153/handle/2XGU8XDN/130749
推荐引用方式 GB/T 7714	Liu W,Yang H,Folberth C,et al. Global investigation of impacts of PET methods on simulating crop-water relations for maize.. 2016.