干旱区生态环境知识资源中心(Arid): Comparison of two remote sensing models for estimating evapotranspiration: algorithm evaluation and application in seasonally arid ecosystems in South Africa

Arid

	Comparison of two remote sensing models for estimating evapotranspiration: algorithm evaluation and application in seasonally arid ecosystems in South Africa
	Dzikiti Sebinasi; Jovanovic Nebo Z; Dh Bugan Richard; Ramoelo Abel; Majozi Nobuhle P; Nickless Alecia; Cho Moses A; Le Maitre David C; Ntshidi Zanele; Pienaar Harrison H
来源期刊	Journal of Arid Land
ISSN	1674-6767
出版年	2019
卷号	11 期号:4 页码:495-512
英文摘要	Remote sensing tools are becoming increasingly important for providing spatial information on water use by different ecosystems. Despite significant advances in remote sensing based evapotranspiration (ET) models in recent years, important information gaps still exist on the accuracy of the models particularly in arid and semi-arid environments. In this study, we evaluated the Penman-Monteith based MOD16 and the modified Priestley-Taylor (PT-JPL) models at the daily time step against three measured ET datasets. We used data from two summer and one winter rainfall sites in South Africa. One site was dominated by native broad leaf and the other by fine leafed deciduous savanna tree species and C_4 grasses. The third site was in the winter rainfall Cape region and had shrubby fynbos vegetation. Actual ET was measured using open-path eddy covariance systems at the summer rainfall sites while a surface energy balance system utilizing the large aperture boundary layer scintillometer was used in the Cape. Model performance varied between sites and between years with the worst estimates (R~2<0.50 and RMSE>0.80 mm/d) observed during years with prolonged mid-summer dry spells in the summer rainfall areas. Sensitivity tests on MOD16 showed that the leaf area index, surface conductance and radiation budget parameters had the largest effect on simulated ET. MOD16 ET predictions were improved by: (1) reformulating the emissivity expressions in the net radiation equation; (2) incorporating representative surface conductance values; and (3) including a soil moisture stress function in the transpiration sub-model. Implementing these changes increased the accuracy of MOD16 daily ET predictions at all sites. However, similar adjustments to the PT-JPL model yielded minimal improvements. We conclude that the MOD16 ET model has the potential to accurately predict water use in arid environments provided soil water stress and accurate biome-specific parameters are incorporated.
英文关键词	MOD16 ET drought stress model validation Penman-Monteith Priestley-Taylor sensitivity analysis
类型	Article
语种	英语
开放获取类型	Bronze
收录类别	CSCD
WOS研究方向	Meteorology & Atmospheric Sciences
CSCD记录号	CSCD:6569766
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/336170
作者单位	Dzikiti Sebinasi, Council for Scientific and Industrial Research, Natural Resources and Environment, Stellenbosch, 7599, South Africa.; Jovanovic Nebo Z, Council for Scientific and Industrial Research, Natural Resources and Environment, Stellenbosch, 7599, South Africa.; Dh Bugan Richard, Council for Scientific and Industrial Research, Natural Resources and Environment, Stellenbosch, 7599, South Africa.; Le Maitre David C, Council for Scientific and Industrial Research, Natural Resources and Environment, Stellenbosch, 7599, South Africa.; Ntshidi Zanele, Council for Scientific and Industrial Research, Natural Resources and Environment, Stellenbosch, 7599, South Africa.; Pienaar Harrison H, Council for Scientific and Industrial Research, Natural Resources and Environment, Stellenbosch, 7599, South Africa.; Ramoelo Abel, Council for Scientific and Industrial Research, Natural Resources and Environment, Pretoria, 0001, South Africa.; Majozi Nobuhle P, Council for Scientific and Industrial Research, Natural R...
推荐引用方式 GB/T 7714	Dzikiti Sebinasi,Jovanovic Nebo Z,Dh Bugan Richard,et al. Comparison of two remote sensing models for estimating evapotranspiration: algorithm evaluation and application in seasonally arid ecosystems in South Africa[J],2019,11(4):495-512.
APA	Dzikiti Sebinasi.,Jovanovic Nebo Z.,Dh Bugan Richard.,Ramoelo Abel.,Majozi Nobuhle P.,...&Pienaar Harrison H.(2019).Comparison of two remote sensing models for estimating evapotranspiration: algorithm evaluation and application in seasonally arid ecosystems in South Africa.Journal of Arid Land,11(4),495-512.
MLA	Dzikiti Sebinasi,et al."Comparison of two remote sensing models for estimating evapotranspiration: algorithm evaluation and application in seasonally arid ecosystems in South Africa".Journal of Arid Land 11.4(2019):495-512.