GAF AG

Forest change detection and monitoring is a key part of the Copernicus Land Monitoring Service (CLMS) (https://land.copernicus.eu/). Various methodologies already implement near real-time (NRT) forest monitoring in tropical regions (e.g. Reiche et al., 2021) with the focus on timely detection of deforestation activities. However, there is not yet an operational pan-European product tracking forest dynamics at such temporal frequency, which has moreover the capability to separate also subtle disturbances of the tree canopy from signal noise. This kind of product is under demand by the user community, hence a new CLMS prototype on “Continuous Forest Monitoring”, with the goal to capture natural and human-induced forest disturbances by detecting tree cover vitality loss on a monthly basis is tested and implemented within the Horizon Europe project Evolution of the Copernicus Land Service portfolio (EvoLand). In a second instance, the feasibility to detect disturbance agents, i.e., (i) windthrow/storm damage, (ii) wildfire, (iii) insect infestations, as well as (iv) human-induced disturbances (e.g., forest clearing, clear-cutting, and thinning activities) is tested.Dense time series from Sentinel-2 serve as main input for both prototypes, supported by forest masks from the CLMS High Resolution Vegetated Land Cover Characteristics (HRL VLCC) and ancillary data on forest disturbance locations and agents. From a benchmarking of various tools, the Exponentially Weighted Moving Average (EWMA) – proposed by Brooks et al. (2014) for Landsat time series data and implemented as part of the JRC-NRT tool (https://github.com/ec-jrc/nrt) – yielded the most promising results, especially considering the balance between accuracy, NRT capability, and computational effort. It is an unsupervised data-driven approach using univariate input indices to detect location and timing of disturbances. A supervised classification to derive the disturbance agents is added on top.This study describes the implementation and results of this prototype and compares the detected forest disturbance locations and dates to the radar-based Tree Cover Disturbance Monitoring (TCDM) product and the 3-yearly VLCC forest change product. Two large EvoLand European sites were chosen for a first phase implementation: one in Germany (analysis years 2019-2021) and another in Spain (analysis years 2020-2022). The evaluation is carried by disturbance agent, concluding to different effects on either the physical structure of the trees and/or the spectral signal of the canopy, and hence also on the suitability of a method of detection. Products are delivered at pixel level (10m spatial resolution), improving the 20m resolution of the currently available CLMS forest change products, while increasing the change frequency from 3-yearly or yearly to monthly.The resulting information can be utilized to enhance forest management and planning, aid forest-related decision-making or contribute to reporting on forest-related EU policies. These two prototypes are proposed within EvoLand to enhance the CLMS forest portfolio and to meet or go beyond users' requirements and demands. 

In this study data products of the European Ground Motion Service (EGMS) are evaluated regarding their applicability for monitoring alpine terrain and human infrastructure with special focus on our changing climate. Potentially this results in changing surface stability and increased landslide dynamics with a potential risk for human infrastructure and inhabitants of alpine regions.Therefore, the use of continuous and accurate ground deformation information for the existing infrastructure and its vicinity becomes evident. EGMS, as a Pan-European service, provides validated and accurate data since 2021, therefore key information for ground deformation monitoring on a wide scale.Our analysis provides an assessment of wide area information in its temporal, mainly deformation time series, and spatial context and its applicability to changing permafrost and ground stability conditions. Based on EGMS measurements the distribution of deformation features is evaluated in correspondence to permafrost index maps, e.g. the Alpine Permafrost Index Map (APIM). An indication of respective active areas and their relation to infrastructure elements and settlements is proposed. This includes the integration of auxiliary and reference data - in the alpine permafrost zone and along human infrastructure in low-lying areas.

Ouarzazate igneous rocks from Sidi Ifni, SW Morocco, define a >3 km thick pile of mostly pyroclastic falls and flows of rhyolitic and dacitic ignimbrite and tuff, underlain by co-magmatic granitoid plutons. These rocks formed during two closely spaced periods of magmatism dated to c. 595–585 and 575–560 Ma, with the majority of rocks comprised of ferroan alkali feldspar rhyolite, syenorhyolite or monzorhyolite. They can be divided into high and low heavy rare earth element types that discriminate as both volcanic arc and within-plate magma types. Coeval, but less common, mafic rocks consist of olivine-normative trachybasalt and basaltic trachyandesite. Temporal and compositional equivalents of the Ouarzazate volcanic and intrusive rocks crop out widely across North Africa and extend into the previously contiguous regions of NE North America. Collectively, these erupted/shallowly emplaced Ouarzazate-like rocks represent asthenospheric partial melts that are variably hybridized by additions from the lithospheric mantle and crust. The root cause of asthenospheric upwelling remains unknown, although the foundering of pre-collison subducted oceanic lithosphere may provide a plausible explanation. The vast geographical extent over which Ouarzazate-like igneous rocks are found, together with their composition and intra-plate setting, support the conclusion that these rocks represent the remnants of a late Ediacaran silicic large igneous province. Supplementary material: A tabulation of the geochronologic and geochemical datasets from Sidi Ifni is available at https://doi.org/10.6084/m9.figshare.c.5945756

We report on first results of the European Ground Motion Service from the perspective of GAF AG and DLR who are responsible for specific tasks and areas of the overall project. The EGMS products and processing chain are shortly described and first results on point density and data quality are presented.

Abstract. Against the backdrop of global change, in terms of both climate and demography, there is a pressing need for monitoring of the global water cycle. The publicly available global database is very limited in its spatial and temporal coverage worldwide. Moreover, the acquisition of in situ data and their delivery to the database have been in decline since the late 1970s, be it for economical or political reasons. Given the insufficient monitoring from in situ gauge networks, and with no outlook for improvement, spaceborne approaches have been under investigation for some years now. Satellite-based Earth observation with its global coverage and homogeneous accuracy has been demonstrated to be a potential alternative to in situ measurements. This paper presents HydroSat as a database containing geometric quantities of the global water cycle from geodetic satellites. HydroSat provides time series and their uncertainty in water level from satellite altimetry, surface water extent from satellite imagery, terrestrial water storage anomaly represented in equivalent water height from satellite gravimetry, lake and reservoir water volume anomaly from a combination of satellite altimetry and imagery, and river discharge from either satellite altimetry or imagery. The spatial and temporal coverage of these datasets varies and depends on the availability of geodetic satellites. These products, which are complementary to existing products, can contribute to our understanding of the global water cycle within the Earth system in several ways. They can be incorporated for hydrological modeling, they can be complementary to current and future spaceborne observations, and they can define indicators of the past and future state of the global freshwater system. HydroSat is publicly available through http://hydrosat.gis.uni-stuttgart.de (last access: 18 May 2022​​​​​​​). Moreover, a snapshot of all the data (taken in April 2021) is available in GFZ Data Services at https://doi.org/10.5880/fidgeo.2021.017 (Tourian et al., 2021).

Eucalyptus spp. and Acacia mearnsii are common exotic tree species in eastern Africa that have shown (strong) invasive behavior in some regions. Acacia mearnsii is considered a highly invasive species that is replacing native species and Eucalyptus spp. are known to consume high amounts of groundwater with suspected effects on native flora. Mapping the occurrence of these species in the Taita Hills, Kenya (part of the Eastern Arc Mountains Biodiversity Hotspot) is important as there is lack of knowledge on their occurrence and ecological impact in the area. Mapping methods that require a lot of fieldwork are impractical in areas like the Taita Hills, where the terrain is rugged and the infrastructure is poor. Our aim was hence to map the occurrence of these tree species in a 100 km2 area using airborne imaging spectroscopy and laser scanning. We used a one class biased support vector machine (BSVM) classifier as it needs labeled training data only for the positive classes (A. mearnsii and Eucalyptus spp.), which potentially reduces the amount of required fieldwork. We also introduce a new approach for parameterizing and setting the threshold level simultaneously for the BSVM classifier. The second aim was to link the occurrence of these species to selected environmental variables. The results showed that the BSVM classifier is suitable for mapping Acacia mearnsii and Eucalyptus spp., holding the potential to improve the efficiency of field data collection. The introduced parametrization/threshold selection method performed better than other commonly used approaches. The crown level F1-score was 0.76 for Eucalyptus spp. and 0.78 for A. mearnsii. We show that Eucalyptus spp. and A. mearnsii trees cover 0.8% and 1.6% of the study area, respectively. Both species are particularly located on steeper slopes and higher altitudes. Both species have significant occurrences in areas close to the biggest remaining native forest patch (Ngangao) in the study area. Nonetheless, follow-up studies are needed to evaluate their impact on the native flora and fauna, as well as their impact on the water resources. The maps created in this study in combination with such follow-up studies could serve as base data to generate guidelines that authorities can use to take action in handling the problems these species are causing.

We have optimized asymmetric InGaAsP QWs with respect to the quantum confined Stark effect (QCSE). We have found structures with a red shift of 40 meV at a field of 70 kV/cm. Moreover, it was our aim to find structures with a strong blue shift. A new principle for the integration of a laser and a modulator is presented, which is based on the application of blue shift asymmetric QW's in the active layer for laser and modulator simultaneously. A calculation of the laser and modulation properties for a QW-structure with 27 meV blue shift at a field variation of 70 kV/cm is presented.

Abstract LANDSAT-5 TM images of the nuclear power plant of Chernobyl are analysed with the emphasis on estimating the reactor surface temperature. The investigation was done for TM channels 5 and 7 using the simulation model SENSAT developed at DFVLR. It accounts for the sensor characteristics (spectral response, IFOV) and target/background properties (size, temperature, emissivity). For the atmospheric part the LOWTRAN-6 model is used. The estimated surface temperature is 1000-1300 K for 29 April 1986, 3 days after the nuclear accident.