Incorporating high-resolution climate, remote sensing and topographic data to map annual forest growth in central and eastern Europe

To enhance our understanding of forest carbon sequestration, climate change mitigation and drought impact on forest ecosystems, the availability of high-resolution annual forest growth maps based on tree-ring width (TRW) would provide a significant advancement to the field. Site-specific characteristics, which can be approximated by high-resolution Earth observation by satellites (EOS), emerge as crucial drivers of forest growth, influencing how climate translates into tree growth. EOS provides information on surface reflectance related to forest characteristics and thus can potentially improve the accuracy of forest growth models based on TRW. Through the modelling of TRW using EOS, climate and topography data, we showed that species-specific models can explain up to 52 % of model variance (Quercus petraea), while combining different species results in relatively poor model performance (R2 = 13 %). The integration of EOS into models based solely on climate and elevation data improved the explained variance by 6 % on average. Leveraging these insights, we successfully generated a map of annual TRW for the year 2021. We employed the area of applicability (AOA) approach to delineate the range in which our models are deemed valid. The calculated AOA for the established forest-type models was 73 % of the study region, indicating robust spatial applicability. Notably, unreliable predictions predominantly occurred in the climate margins of our dataset. In conclusion, our large-scale assessment underscores the efficacy of combining climate, EOS and topographic data to develop robust models for mapping annual TRW. This research not only fills a critical void in the current understanding of forest growth dynamics but also highlights the potential of integrated data sources for comprehensive ecosystem assessments.

Estimation of Aboveground Biomass in Agroforestry Systems over Three Climatic Regions in West Africa Using Sentinel-1, Sentinel-2, ALOS, and GEDI Data

Agroforestry systems (AFS) offer viable solutions for climate change because of the aboveground biomass (AGB) that is maintained by the tree component. Therefore, spatially explicit estimation of their AGB is crucial for reporting emission reduction efforts, which can be enabled using remote sensing (RS) data and methods. However, multiple factors including the spatial distributions within the AFS, their structure, their composition, and their variable extents hinder an accurate RS-assisted estimation of the AGB across AFS. The aim of this study is to (i) evaluate the potential of spaceborne optical, SAR and LiDAR data for AGB estimations in AFS and (ii) estimate the AGB of different AFS in various climatic regions. The study was carried out in three climatic regions covering Côte d'Ivoire and Burkina Faso. Two AGB reference data sources were assessed: (i) AGB estimations derived from field measurements using allometric equations and (ii) AGB predictions from the GEDI level 4A (L4A) product. Vegetation indices and texture parameters were generated from optical (Sentinel-2) and SAR data (Sentinel-1 and ALOS-2) respectively and were used as predictors. Machine learning regression models were trained and evaluated by means of the coefficient of determination (R²) and the RMSE. It was found that the prediction error was reduced by 31.2% after the stratification based on the climatic conditions. For the AGB prediction, the combination of random forest algorithm and Sentinel-1 and -2 data returned the best score. The GEDI L4A product was applicable only in the Guineo-Congolian region, but the prediction error was approx. nine times higher than the ground truth. Moreover, the AGB level varied across AFS including cocoa (7.51 ± 0.6 Mg ha^-1) and rubber (7.33 ± 0.33 Mg ha^-1) in the Guineo-Congolian region, cashew (13.78 ± 0.98 Mg ha^-1) and mango (12.82 ± 0.65 Mg ha^-1) in the Guinean region. The AFS farms in the Sudanian region showed the highest AGB level (6.59 to 82.11 Mg ha^-1). AGB in an AFS was mainly determined by the diameter (R² = 0.45), the height (R² = 0.13) and the tree density (R² = 0.10). Nevertheless, RS-based estimation of AGB remain challenging because of the spectral similarities between AFS. Therefore, spatial assessment of the prediction uncertainties should complement AGB maps in AFS.

The Sacred Waterscape of Ancient Egyptian Temples - The Example of the Temple of Bastet at Bubastis, Nile Delta (Egypt).. [DOI: 10.5194/egusphere-egu22-1436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

<p>The temple areas in ancient Egypt were most sacred and characterized by a multitude of elements that emphasized their importance and enabled daily cultic activities. Very specific and important features of such temples were sacred water canals or lakes, the so-called <em>Isheru</em>, which provided water for all kinds of purification rites and activities. In addition to textual records, preliminary sedimentological analyses of core drillings and geophysical surveys provided geoarchaeological evidence of a sacred water body at the Temple of Bastet in the ancient city of Bubastis. To further explore the location, shape, or course of the already detected canal and to find evidence on the existence of a second waterway described by Herodotus in the 5th century BCE, 34 drillings and five 2D geoelectrical measurements were carried. Drilling and sediment analyses revealed loamy to clayey deposits with a thickness of up to five meters near the northern and southern enclosures of the Temple of Bastet. 2D electrical surveying confirmed the drilling results, indicating trench-formed layers of low resistivity values. The recovered deposits were interpreted as fluvial sediments, most likely deposited in a very low energy system, e.g. a canal or lake. Evidence of these fluvial sediments in numerous boreholes allows the reconstruction of two separate sacred canals both north and south of the Temple of Bastet. In addition to the course, the width of the canals of about 30 m can also be confirmed according to Herodotus' writings. The presence of numerous artefacts in the fluvial deposits, such as ceramic and limestone fragments, proves the anthropogenic use of the ancient canals. Presumably, these waterways were connected to the Nile via a tributary or canal located west or northwest of Bubastis.</p>

Finding karstic caves and rockshelters in the Inner Asian mountain corridor using predictive modelling and field survey

The area of the Inner Asian Mountain Corridor (IAMC) follows the foothills and piedmont zones around the northern limits of Asia's interior mountains, connecting two important areas for human evolution: the Fergana valley and the Siberian Altai. Prior research has suggested the IAMC may have provided an area of connected refugia from harsh climates during the Pleistocene. To date, this region contains very few secure, dateable Pleistocene sites, but its widely available carbonate units present an opportunity for discovering cave sites, which generally preserve longer sequences and organic remains. Here we present two models for predicting karstic cave and rockshelter features in the Kazakh portion of the IAMC. The 2018 model used a combination of lithological data and unsupervised landform classification, while the 2019 model used feature locations from the results of our 2017-2018 field surveys in a supervised classification using a minimum-distance classifier and morphometric features derived from the ASTER digital elevation model (DEM). We present the results of two seasons of survey using two iterations of the karstic cave models (2018 and 2019), and evaluate their performance during survey. In total, we identified 105 cave and rockshelter features from 2017-2019. We conclude that this model-led approach significantly reduces the target area for foot survey.

Experimental observation of resonance manifold shrinking under zonal flow shear

In two-dimensional turbulent systems the redistribution of energy can be described by quadratic nonlinear three-wave interactions, which are limited by resonance conditions. The set of coupling modes can be understood as resonant manifold. It has been predicted by theory that, in the presence of a shear flow, the resonant manifold in wave-number space shrinks in time favoring large-scale structures. The phenomenon of manifold shrinking in the presence of shear flows is studied the first time experimentally in drift wave turbulence at the stellarator TJ-K by bicoherence analysis. By estimating effective mode numbers characterizing the width of the manifold, it is demonstrated that increasing shear leads to a shrinking of the resonance manifold.

Is the EU ready for a generic set of indicators for health system performance? A qualitative study

Background

As part of the EU funded BRIDGE Health project, 23 headline indicators for assessing and comparing the performance of public health systems were proposed. They were shortlisted out of the currently existing and often overlapping pool of over 2000 health system performance assessment (HSPA) indicators. In this qualitative study, we explored their validity and perceived national-level utility for policy making and factors affecting the potential uptake of an indicator hierarchy (headline, operational & explanatory levels) at Member States' and EU levels.

Methods

Semi-structured interviews with a purposive sample of 24 policy makers and senior policy advisors from 15 EU Member States and one candidate country were performed between July and November 2018. All interviews were transcribed and coded using summative and directed content analysis to generate thematic categories in MAXQDA.

Results

Preliminary results suggest that experts positively perceived the overall balance of the shortlist across performance domains reflecting most of the important policy areas. However, some further amendments to the generic set of indicators were recommended to increase their policy relevance and measurement validity while keeping the size manageable. The concept and usage of headline HSPA indicators is mostly viewed as a communication tool whereas more granular information at explanatory levels is perceived to be more appropriate for data driven policymaking and cross-country learning.

Conclusions

Interviews showed a considerable heterogeneity in the feasibility of applying a generic HSPA framework in an EU-wide health strategy as a compass for improvement through comparisons of health systems. Factors such as flexibility in adaptation to the national context, improvement in building knowledge capacity, potential misinterpretation in the 'European Semester' context, as well as lack of appropriately defined benchmarks were recurrent themes in hindering its uptake.

Key messages

Policy makers assess explanatory level indicators to be more actionable than headline level indicators. To facilitate the use of headline indicators at EU-level as a navigation tool for health systems, the list has to be stable to create trends and sufficiently flexible in adapting to new priorities.

Biomass Assessment of Agricultural Crops Using Multi-temporal Dual-Polarimetric TerraSAR-X Data

The biomass of three agricultural crops, winter wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and canola (Brassica napus L.), was studied using multi-temporal dual-polarimetric TerraSAR-X data. The radar backscattering coefficient sigma nought of the two polarization channels HH and VV was extracted from the satellite images. Subsequently, combinations of HH and VV polarizations were calculated (e.g. HH/VV, HH + VV, HH × VV) to establish relationships between SAR data and the fresh and dry biomass of each crop type using multiple stepwise regression. Additionally, the semi-empirical water cloud model (WCM) was used to account for the effect of crop biomass on radar backscatter data. The potential of the Random Forest (RF) machine learning approach was also explored. The split sampling approach (i.e. 70% training and 30% testing) was carried out to validate the stepwise models, WCM and RF. The multiple stepwise regression method using dual-polarimetric data was capable to retrieve the biomass of the three crops, particularly for dry biomass, with R² > 0.7, without any external input variable, such as information on the (actual) soil moisture. A comparison of the random forest technique with the WCM reveals that the RF technique remarkably outperformed the WCM in biomass estimation, especially for the fresh biomass. For example, the R ² > 0.68 for the fresh biomass estimation of different crop types using RF whereas WCM show R ² < 0.35 only. However, for the dry biomass, the results of both approaches resembled each other.

[Initial experiences with Winkelmann "clavicula pro humero" operation in malignant bone tumors of the proximal humerus in childhood]

Between 1980 and 1995, 11 children with osteosarcoma were treated at the Clinic of Pediatric Surgery of the Martin-Luther-University, Halle-Wittenberg. In the first years of this period we treated six of the children according to the protocols of the study group "Tumors" of the Society for Pediatric Surgery. At that time the preferred concept was radical surgical resection followed by adjuvant chemotherapy. For several years we favored the therapeutic regime of the Society for Pediatric Oncology and Hematology and treated five children according to the principles of the cooperative studies of osteosarcoma. With the introduction of aggressive neo-adjuvant chemotherapy it was possible to perform reconstructive limb surgery. We report on our own first experiences with the "Clavicula pro humero", an operation according to Winkelmann for malignant bone tumors of the proximal humerus. This new operative method is described and possible complications are discussed.