Die flächenhafte Ausweisung von Bodenfeuchteregimes: Eine Methode im Rahmen des pre-processing für die Modellierung des Landschaftswasserhaushaltes

In dem Einzugsgebiet „Obere Brachtpe“ (2,6 km², Sauerland, Deutschland) wurden mit einer konventionellen Bohrstock-Kartierung (319 Bodenprofile) die verschiedenen Böden mit ihren spezifischen pedohydrologischen Eigenschaften erfasst und darauf aufbauend das Klassifikationskonzept zur Ableitung von Bodenfeuchteregime-Typen nach Zepp (1995) angewendet. Anhand dieser Informationen konnte die vorherrschende Wasserbewegungsrichtung und folglich verschiedene Abflussprozessflächen ausgewiesen werden. Um dieses Raumgliederungskonzept hinsichtlich der Frage, ob es zum pre-processing für die Modellierung des Landschaftswasserhaushalts beitragen kann, zu verfizieren, wurden zwei Niederschlags-Abfluss-Ereignisse tracerhydrologisch untersucht. Die Resultate zeigen, dass sich das Klassifikationskonzept nach Zepp (1995) zur hydrologischen Raumgliederung eines Einzugsgebietes gut eignet, es wird aber auch deutlich, dass neben den Bodeneigenschaften insbesondere die Lage der schnell reagierenden Flächen (Sättigungsflächen) innerhalb des Einzugsgebietes und deren Konnektivität mit dem Vorfluter entscheidend für den Beitrag schneller Abflusskomponenten sind. Besteht eine direkte Verbindung zwischen Sättigungsflächen und Vorfluter, so ist eine schnelle Abflussreaktion und ein hoher Anteil an Ereigniswasser zu erwarten.In the catchment “Obere Brachtpe” (2,6 km², Sauerland, Germany) the soils and their specific pedohydrological characteristics were investigated using a conventional drilling rig (319 drills). Based on the results the classification concept for deducing the soil moisture types by Zepp (1995) was applied so that the dominant flow directions and dominant runoff process areas could be detected. The question if this classification concept could be used as tool for the pre-processing within the runoff modelling was verified by the tracer hydrological investigation of two rainfall runoff-events. The results confirm that the classification concept by Zepp (1995) is an applicable tool for the spatial delineation of a catchment in hydrological response units. On the other hand it became apparent that in addition to the soil properties, the location of saturated areas within the catchment and their connectivity to the channel are especially important for the contribution of accelerated runoff components. If there exists a direct connection between the saturated areas and the channel a fast runoff reaction and a high portion of event water can be estimated

NfL and pNfH are increased in Friedreich's ataxia

Objective To assess neurofilaments as neurodegenerative biomarkers in serum of patients with Friedreich's ataxia. Methods Single molecule array measurements of neurofilament light (NfL) and heavy chain (pNfH) in 99 patients with genetically confirmed Friedreich's ataxia. Correlation of NfL/pNfH serum levels with disease severity, disease duration, age, age at onset, and GAA repeat length. Results Median serum levels of NfL were 21.2 pg/ml (range 3.6-49.3) in controls and 26.1 pg/ml (0-78.1) in Friedreich's ataxia (p = 0.002). pNfH levels were 23.5 pg/ml (13.3-43.3) in controls and 92 pg/ml (3.1-303) in Friedreich's ataxia (p = 0.0004). NfL levels were significantly increased in younger patients (age 16-31 years, p < 0.001) and patients aged 32-47 years (p = 0.008), but not in patients of age 48 years and older (p = 0.41). In a longitudinal assessment, there was no difference in NfL levels in 14 patients with repeated sampling 2 years after baseline measurement. Levels of NfL correlated inversely with GAA1 repeat length (r = - 0.24, p = 0.02) but not with disease severity (r = - 0.13, p = 0.22), disease duration (r = - 0.06, p = 0.53), or age at onset (r = 0.05, p = 0.62). Conclusion Serum levels of NfL and pNfH are elevated in Friedreich's ataxia, but differences to healthy controls decrease with increasing age. Long-term longitudinal data are required to explore whether this reflects a selection bias from early death of more severely affected individuals or a slowing down of the neurodegenerative process with age. In a pilot study over 2 years of follow-up-a period relevant for biomarkers indicating treatment effects-we found NfL levels to be stable