TY - JOUR

T1 - Estimation of water-infiltration rate in Mediterranean sandy soils using airborne hyperspectral sensors

AU - Francos, Nicolas

AU - Chabrillat, Sabine

AU - Tziolas, Nikolaos

AU - Milewski, Robert

AU - Brell, Maximilian

AU - Samarinas, Nikiforos

AU - Angelopoulou, Theodora

AU - Tsakiridis, Nikolaos

AU - Liakopoulos, Vasillis

AU - Ruhtz, Thomas

AU - Ben-Dor, Eyal

N1 - Funding Information: The Greek HySpex airborne campaign was supported by the EnMAP science preparatory program funded under the DLR Space Administration with resources from the German Federal Ministry of Economic Affairs and Energy (grant number: DLR/BMWi 50 EE 1529). In addition, this project was made possible by funding from the Israel Ministry of National Infrastructure, Energy and Water Resources (grant number: 218-17-007) within the iAqueduct project under the Water Joint Programming Initiative project (JPI2018) of the Ministry of Energy, Israel. The activities of the present research were also supported by the COST Action CA16219 “HARMONIOUS —Harmonization of UAS techniques for agricultural and natural ecosystems monitoring.“ We would like to thank Daniel Berger and Christian Hohmann from GFZ for supporting the field acquisitions.

PY - 2023/12

Y1 - 2023/12

N2 - The efficiency of spectral-based assessments of soil attributes using soil spectral libraries (SSLs) covering the visible–near-infrared–shortwave-infrared (VNIR–SWIR: 400–2500 nm) region has been proven in many studies. Nevertheless, as traditional SSLs are commonly developed under laboratory conditions, their application is limited for the assessment of soil surface-dependent properties such as water-infiltration rate (WIR) into the soil profile due to the sampling procedure. Currently, few studies are based on field SSLs for the prediction of physical soil properties. This study used a field-based protocol to measure soil reflectance data and WIR simultaneously in the field, and generate spectral-based decision tree models to predict WIR solely from field spectral measurements using the SoilPRO® assembly. The obtained models were applied to both airborne hyperspectral (HySpex) and satellite multispectral (Sentinel 2) data on a pixel-by-pixel basis to generate raster maps of WIR. The study areas were located in Macedonia (Greece), and were optimal for mapping WIR because the soil crust was well developed, and sites were characterized by bare soils (no vegetation coverage) with a sandy structure. Whereas the WIR map generated with the satellite data was poor due to the low spatial and spectral resolution of Sentinel 2 (20 m, 9 bands), the results obtained with the airborne hyperspectral HySpex sensor (5 m, 408 bands) were satisfactorily validated in the ground-truth stage with good prediction accuracy due to high spatial and spectral resolution. Validation accuracy of the HySpex observations using all field samples gave R2 = 0.68, whereas the predictions of the ground-truth samples that were not part of the calibration stage (field validation group) of the model gave R2 = 0.59. We concluded that these results are favourable for rapid estimation of soil surface conditions and pave the way for a wider spatial view from orbital hyperspectral remote-sensing sensors.

AB - The efficiency of spectral-based assessments of soil attributes using soil spectral libraries (SSLs) covering the visible–near-infrared–shortwave-infrared (VNIR–SWIR: 400–2500 nm) region has been proven in many studies. Nevertheless, as traditional SSLs are commonly developed under laboratory conditions, their application is limited for the assessment of soil surface-dependent properties such as water-infiltration rate (WIR) into the soil profile due to the sampling procedure. Currently, few studies are based on field SSLs for the prediction of physical soil properties. This study used a field-based protocol to measure soil reflectance data and WIR simultaneously in the field, and generate spectral-based decision tree models to predict WIR solely from field spectral measurements using the SoilPRO® assembly. The obtained models were applied to both airborne hyperspectral (HySpex) and satellite multispectral (Sentinel 2) data on a pixel-by-pixel basis to generate raster maps of WIR. The study areas were located in Macedonia (Greece), and were optimal for mapping WIR because the soil crust was well developed, and sites were characterized by bare soils (no vegetation coverage) with a sandy structure. Whereas the WIR map generated with the satellite data was poor due to the low spatial and spectral resolution of Sentinel 2 (20 m, 9 bands), the results obtained with the airborne hyperspectral HySpex sensor (5 m, 408 bands) were satisfactorily validated in the ground-truth stage with good prediction accuracy due to high spatial and spectral resolution. Validation accuracy of the HySpex observations using all field samples gave R2 = 0.68, whereas the predictions of the ground-truth samples that were not part of the calibration stage (field validation group) of the model gave R2 = 0.59. We concluded that these results are favourable for rapid estimation of soil surface conditions and pave the way for a wider spatial view from orbital hyperspectral remote-sensing sensors.

KW - Decision tree

KW - Hyperspectral remote sensing

KW - HySpex

KW - Mediterranean soil

KW - Sandy soil

KW - Sentinel 2

KW - Soil spectroscopy

KW - Water-infiltration rate

UR - http://www.scopus.com/inward/record.url?scp=85169844450&partnerID=8YFLogxK

U2 - 10.1016/j.catena.2023.107476

DO - 10.1016/j.catena.2023.107476

M3 - Article

AN - SCOPUS:85169844450

VL - 233

JO - CATENA

JF - CATENA

SN - 0341-8162

M1 - 107476

ER -