WP2. Retrieval of Soil Hydraulic and Thermal Properties

Lead: Brigitta Szabó (CAR-HAS)

Participate: TAU, Uni. Naples, Uni. Twente

WP2 will retrieve soil hydraulic and thermal parameters (SHP/STP) from spectral signatures and knowledge of near-surface soil moisture dynamics. This WP will initially employ commonly used pedotransfer functions (PTFs) for regional applications and then locally calibrate them using readily measurable surface soil spectral features. The world Soil Spectral Library (SSL, Rossel et al. 2016, ERS), European Spectral Soil Library (LUCAS, Toth et al., 2013, EMA) and some local SSL (e.g. the GEO-CRADLE Mediterranean Balkan SSL) will be used to generate global to local spectral based models to assess soil properties. A harmonized protocol will be developed from the selected sites.

Task 2.1 Collection of field scale data

This task aims to collect and complete relevant data for selected sites (e.g. as those for the Alento River Hydrological Observatory (ARHO, Romano et al., 2018 VZJ) for Tasks 2.2, 2.3 and 2.4). Information on soil physical and hydraulic properties, terrain and environmental attributes (topographical, geological, pedological, and land-use/land-cover information together with hydro-meteorological datasets and soil physical and hydraulic properties), and topsoil spectral data will be collected. Whereas needed, similar activities will be carried out also at other sites (e.g. at the Twente site such field data are collected routinely as the site is used as a SMAP cal/val site (Colliander et al., 2017 RSE)).

Task 2.2 Soil spectroscopy and hyperspectral remote sensing

This task aims at harmonizing standards and protocols for hyperspectral remote sensing in the laboratory, field, air and space domains for soil mapping (Ben Dor, 2012 CPR Press). Existing world SSL with local ones will be utilized for developing spectral based models for soil hydrophobicity, soil hydraulic properties, soil texture, carbonate and organic matter content (Ben Dor et al., 2009 RSE). Attempts will be made to extend the knowledge in hyperspectral remote sensing to the thermal region.

Task 2.3 Basic pedotransfer functions

Application and evaluation of already established PTFs (Toth et al., 2015, EJSS) will be carried out at selected field sites using the 3D Soil Hydraulic Database of Europe at 250 m resolution (Toth et al., 2017, HP) as a baseline dataset. This task will explore if and to what extent the prediction capability of these basic PTFs can be suitably improved through in-situ remote measurements, via both UAS and satellite, of spatial patterns of land cover for mapping soil hydraulic and thermal properties (Zhao et al., 2018 ESSD).

Task 2.4 Advanced pedotransfer functions

Hyperspectral data will be used to derive spectrotrasfer functions (STF) and spectral pedotransfer functions (SPTFs) (Babaeian et al., 2016, RSE) using soil and environmental data as well. Such function will be used for the description and mapping of topsoil hydraulic properties with high level of details. Further to the site specific STFs the relationship between SSLs and hydraulic properties will be analysed on European datasets (LUCAS, EU-HYDI, Weynants et al., 2013 EUR-STR). Hyper- and multi-spectral sensors on ground and UAS will be employed for in-situ prediction of soil organic carbon (SOC), soil sealing and soil particle size distribution by vis–NIR spectroscopy. Soil hydraulic properties will be mapped for the study sites with SPTFs, STFs based on the available data, similarly to Task 2.3. Validation will be performed using measured values obtained in Task 2.1. Such task will support the downscaling procedures described in WP1 – Task 1.1.

Deliverables:

D2.1. Soil spectral libraries of distinct soil groups in both laboratory and field and their relationship (month 10-12);

D2.2. Maps of soil hydraulic properties for the 5 experimental sites based on traditional and vis-NIR spectral analysis (month 22-24).