Enhancing SWAT with remotely sensed LAI for improved modelling of ecohydrological process in subtropics

doi:10.1016/j.jhydrol.2019.01.024

	Enhancing SWAT with remotely sensed LAI for improved modelling of ecohydrological process in subtropics
	Ma, Tianxiao 1,2; Duan, Zheng 3,4; Li, Runkui 1,5; Song, Xianfeng 1,2,5
刊名	JOURNAL OF HYDROLOGY
	2019-03-01
卷号	570 页码:802-815
关键词	Vegetation growth Subtropics LAI MODIS Integration Modified SWAT
ISSN号	0022-1694
DOI	10.1016/j.jhydrol.2019.01.024
通讯作者	Song, Xianfeng(xfsong@ucas.ac.cn)
英文摘要	Vegetation growth in Soil and Water Assessment Tool (SWAT) is a crucial process for quantifying ecohydrological modelling, as it influences evapotranspiration, interception, soil erosion and biomass production. The simplified version of Environmental Policy Integrated Climate (EPIC) in SWAT was originally designed for temperate regions and naturally based on temperature to simulate growth cycles of vegetation. However, tropical or subtropical vegetation growth is mainly controlled by rainfall. Due to this limitation, current SWAT simulations in tropics and subtropics have been facing a series of problems on vegetation dormancy, water balance and sediment yield. Therefore, we proposed an approach to enhance the modelling of SWAT vegetation dynamics with remotely sensed leaf area index (LAI), to finally increase the applicability of SWAT in tropical or subtropical areas. Spatially and temporally continuous LAI products (1 day, 500 m) from Moderate Resolution Imaging Spectroradiometer (MODIS) observations were integrated into SWAT to replace the LAI simulated by built-in EPIC module. Two advanced filter algorithms were employed to derive a downscaled LAI (30 m) to keep a consistent spatial scale with the size of Hydrological Response Units (HRU) and open data (i.e. SRTM, 30 m), and the source code of the plant growth module were correspondingly modified to incorporate the downscaled LAI into SWAT. To examine the performance of our proposed approach, a case study was conducted in a representative middle-scale (6384 km(2)) subtropical watershed of Meichuan basin, China, and detailed analysis was performed to investigate its ecohydrological effects, such as streamflow, sediment yield and LAI dynamics from 2001 to 2014. Model performances were compared among three scenarios: (1) original SWAT, (2) SWAT with a corrected plant dormancy function, and (3) modified SWAT after integration of MODIS LAI (our proposed method). Results showed that the modified SWAT took advantage of downscaled MODIS LAI and produced more reasonable seasonal curves of vegetation cover factor (C) of plants than the original model. Correspondingly, the modified SWAT substantially improved streamflow and sediment simulations. The findings demonstrated that SWAT model can be a useful tool for simulating ecohydrological process for subtropical ecosystems when integrated with our proposed method.
资助项目	National Key Research and Development Program of China[2017YFB0503702] ; National Key Research and Development Program of China[2016YFC0503602] ; National Key Research and Development Program of China[2017YFB0503605] ; National Natural Science Foundation of China[41771435] ; National Natural Science Foundation of China[41201038] ; National Natural Science Foundation of China[41601486] ; China Scholarship Council[201704910297] ; Guangxi Science and Technology Major Project[GK-AA17202033] ; CAS Huairou Eco-Environmental Observatory
WOS关键词	LEAF-AREA INDEX ; RIVER-BASIN ; VEGETATION DYNAMICS ; ECOSYSTEM SERVICES ; BLENDING LANDSAT ; WATER-QUALITY ; MODIS DATA ; SOIL ; RESOLUTION ; PRECIPITATION
WOS研究方向	Engineering ; Geology ; Water Resources
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000460709400064
资助机构	National Key Research and Development Program of China ; National Natural Science Foundation of China ; China Scholarship Council ; Guangxi Science and Technology Major Project ; CAS Huairou Eco-Environmental Observatory
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/49163]
专题	中国科学院地理科学与资源研究所
通讯作者	Song, Xianfeng
作者单位	1.Univ Chinese Acad Sci, Coll Resources & Environm, Beijing 100049, Peoples R China 2.Univ Chinese Acad Sci, Sino Danish Coll, Beijing 100049, Peoples R China 3.Univ Lancaster, Lancaster Environm Ctr, Lancaster LA1 4YQ, England 4.Tech Univ Munich, Chair Hydrol & River Basin Management, Arcisstr 21, D-80333 Munich, Germany 5.Chinese Acad Sci, State Key Lab Resources & Environm Informat Syst, Inst Geog Sci & Nat Resources Res, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	Ma, Tianxiao,Duan, Zheng,Li, Runkui,et al. Enhancing SWAT with remotely sensed LAI for improved modelling of ecohydrological process in subtropics[J]. JOURNAL OF HYDROLOGY,2019,570:802-815.
APA	Ma, Tianxiao,Duan, Zheng,Li, Runkui,&Song, Xianfeng.(2019).Enhancing SWAT with remotely sensed LAI for improved modelling of ecohydrological process in subtropics.JOURNAL OF HYDROLOGY,570,802-815.
MLA	Ma, Tianxiao,et al."Enhancing SWAT with remotely sensed LAI for improved modelling of ecohydrological process in subtropics".JOURNAL OF HYDROLOGY 570(2019):802-815.