Accurate estimates of land surface energy fluxes and irrigation requirements from UAV-based thermal and multispectral sensors

• DOI: 10.1016/j.isprsjprs.2023.03.009
• Publication Date: 2023-03-28T03:29:20Z
• Authors: Junxiang Peng; Hector Nieto; Mathias Neumann A...; Kirsten Kørup; Rene Larsen; Julien Morel; David Parsons; Zhenjiang Zhou; Kiril Manevski
• Keywords: 2. Zero hunger; Drought stress; 550; Evapotranspiration; Oceanography, Hydrology, Water Resources; Unmanned aerial vehicle; 15. Life on land; Oceanography; 6. Clean water; 631; 13. Climate action; Sap flow; Water Resources; Two system energy balance; Hydrology; Potato

The two-source energy balance model estimates canopy transpiration (Tr) and soil evaporation (E) traditionally from satellite partitions of remotely sensed land surface temperature (LST) the Priestley-Taylor equation (TSEB-PT) at seasonal time with limited accuracy. high spatial–temporal resolution spectral data collected by unmanned aerial vehicles (UAVs) provide valuable opportunity to estimate Tr E precisely, improve understanding diurnal cycle evapotranspiration (ET), timely detect agricultural drought. UAV vary in spatial uncertainty imposed on TSEB-PT outcome has thus far not being considered. To address these challenges prospects, a new flux modelling framework based for thermal multispectral is proposed this paper. Diurnal variations LST fields were recorded infrared camera installed an during drought 2018 2019. Observing potato as test crop, LST, plant biophysical parameters derived corresponding data, meteorological forcing variables employed input TSEB-PT. All analyses conducted different pixelation quantify effect performance. 1 m produced highest correlation between modelled measured sap flow sensors (R2 = 0.80), which was comparable 0.06, 0.1, 0.5 2 pixel sizes 0.76–0.78) markedly higher than lower resolutions 24 0.30–0.72). Modelled highly significantly correlated leaf water potential 0.81) stomatal conductance 0.74). computed irrigation requirements (IRs) reflected field treatments, ET conventional practices area It also found that using net primary production explicit representation influences made it possible distinguish effects vis-a-vis heat stress crop productivity use efficiency. results showed excellent performance retrieving dynamics under proved remote sensing scale promising tool investigation demand; particularly relevant local regional irrigations scheduling.