TY - JOUR

T1 - Tempo-differentially selected growth rate model development and improved extraction of remotely sensed phenology in the Qinghai-Tibet Plateau

AU - He, Dong

AU - Zhou, Xiaobing

AU - Huang, Xianglin

AU - Zhang, Wenmin

AU - Tian, Qingjiu

AU - Xu, Nianxu

AU - Xi, Yanbiao

AU - Tian, Jia

AU - Mumtaz, Faisal

N1 - Funding Information: We acknowledge the Project funded by the China Postdoctoral Science Foundation (No. 2021M701653), and Major Special Project—the China High-Resolution Earth Observation System (No. 30-Y30F06-9003-20/22), and the National Natural Science Foundation of China (Nos. 42101321 and 41771370) for funding us. In addition, the authors would like to thank the anonymous reviewers for providing their constructive comments. Publisher Copyright: © 2022 Society of Photo-Optical Instrumentation Engineers (SPIE).

PY - 2022

Y1 - 2022

N2 - We show an improvement in extraction of remotely sensed phenology in the Qinghai-Tibet Plateau (QTP). The improvement includes multiple preprocessing, newly proposed absolute growth rate and relative growth rate models based on botany and phenology, and selection of the appropriate growth rate model at different growing stages. We refer to this model as the tempo-differentially selected growth rate model (TDSGM). The newly developed TDSGM is a comprehensive and accurate remote sensing phenological extraction model without manual intervention, which is better than the current mainstream methods. Results show that: (1) influence of elevation and longitude on the QTP phenology has been more effective than that of latitude and vegetation types; (2) length of the growing season (LOS) was in a shortening trend in the long term, even it showed a slight extension in recent years in the short term; (3) the shortest LOS was identified in the area with an altitude of 3000 to 5500 m, which accounts for 90% of the total area of QTP. High instability of LOS was concentrated in meadows at 4000 to 5000 m; and (4) most previous studies on remotely sensed phenology showed that LOS was more related to the start of the growing season. However, we show that the LOSs of four out of seven QTP vegetation types were closely related to the end of the growth season, consistent with 1455 ground observations.

AB - We show an improvement in extraction of remotely sensed phenology in the Qinghai-Tibet Plateau (QTP). The improvement includes multiple preprocessing, newly proposed absolute growth rate and relative growth rate models based on botany and phenology, and selection of the appropriate growth rate model at different growing stages. We refer to this model as the tempo-differentially selected growth rate model (TDSGM). The newly developed TDSGM is a comprehensive and accurate remote sensing phenological extraction model without manual intervention, which is better than the current mainstream methods. Results show that: (1) influence of elevation and longitude on the QTP phenology has been more effective than that of latitude and vegetation types; (2) length of the growing season (LOS) was in a shortening trend in the long term, even it showed a slight extension in recent years in the short term; (3) the shortest LOS was identified in the area with an altitude of 3000 to 5500 m, which accounts for 90% of the total area of QTP. High instability of LOS was concentrated in meadows at 4000 to 5000 m; and (4) most previous studies on remotely sensed phenology showed that LOS was more related to the start of the growing season. However, we show that the LOSs of four out of seven QTP vegetation types were closely related to the end of the growth season, consistent with 1455 ground observations.

KW - growth rate

KW - phytophysiology

KW - Qinghai-Tibet Plateau

KW - vegetation phenology

U2 - 10.1117/1.JRS.16.018501

DO - 10.1117/1.JRS.16.018501

M3 - Journal article

AN - SCOPUS:85128167196

VL - 16

JO - Journal of Applied Remote Sensing

JF - Journal of Applied Remote Sensing

SN - 1931-3195

IS - 1

M1 - 018501

ER -