Decomposing Dual Scale Soil Surface Roughness for Microwave Remote Sensing Applications

Soil surface roughness, as investigated in this study, is decomposed in a dual scale process. Therefore, we investigated photogrammetrically acquired roughness information over different agricultural fields in the size of 6-22 m(2) and decomposed them into a dual scale process by using geostatistical techniques. For the characterization of soil surface roughness, we calculated two different roughness indices (the RMS height s and the autocorrelation length l) differing significantly for each scale. While we could relate the small scale roughness pattern clearly to the seedbed rows, the larger second scale pattern could be related to the appearance of wheel tracks of the tillage machine used. As a result, major progress was made in the understanding of the different scales in soil surface roughness characterization and its quantification possibilities

Possible environmental effects on the evolution of the Alps-Molasse Basin system

We propose three partly unrelated stages in the geodynamic evolution of the Alps and the sedimentary response of the Molasse Basin. The first stage comprises the time interval between ca. 35 and 20 Ma and is characterized by a high ratio between rates of crustal accretion and surface erosion. The response of the Molasse Basin was a change from the stage of basin underfill (UMM) to overfill (USM). Because the response time of erosional processes to crustal accretion and surface uplift lasts several millions of years, the orogen first experienced a net growth until the end of the Oligocene. As a result, the Molasse basin subsided at high rates causing the topographic axis to shift to the proximal basin border and alluvial fans to establish at the thrust front. During the Aquitanian, however, ongoing erosion and downcutting in the hinterland caused sediment discharge to the basin to increase and the ratio between the rates of crustal accretion and surface erosion to decrease. The result was a progradation of the dispersal systems, and a shift of the topographic axis towards the distal basin border. The second stage started at ca. 20 Ma at a time when palaeoclimate became more continental, and when the crystalline core became exposed in the orogen. The effect was a decrease in the erosional efficiency of the Swiss Alps and hence a reduction of sediment discharge to the Molasse Basin. We propose that this decrease in sediment flux caused the Burdigalian transgression of the OMM. We also speculate that this reduction of surface erosion initiated the modification of Alpine deformation from vertically- to mainly horizontally directed extrusion (deformation of the Southern Alps, and the Jura Mountains some Ma later). The third stage in the geodynamic development was initiated at the Miocene/Pliocene boundary. At that time, palaeoclimate possibly became wetter, which, in turn, caused surface erosion to increase relative to crustal accretion. This change caused the Alps to enter a destructive stage and the locus of active deformation to shift towards to the orogenic core. It also resulted in a net unloading of the orogen and thus in a flexural rebound of the foreland plate. We conclude that the present chronological resolution is sufficient to propose possible feedback mechanisms between environmental effects and lithospheric processes. Further progress will result from a down-scaling in research. Specifically, we anticipate that climate-driven changes in sediment flux altered the channel geometries of USM and OSM deposits, the pattern of sediment transport and thus the stacking arrangement of architectural elements. This issue has not been sufficiently explored and awaits further detailed quantitative studie

Slip rates variability and sediment mobilization on a shallow landslide in the northern Swiss Alps

Geomorphic and morphometric data imply that process rates of the Schimbrig landslide, located in the Entle watershed (Central Switzerland), are still limited by the elevation of the LGM base level. At present, the Entle watershed is in a stage of adjusting to the lowered post-glacial base level as indicated by knick zones in the trunk stream. Some thousands of years later when these knick zones will reach the Schimbrig site, we anticipate a substantial increase in process rates and sediment flux for the landslide. The pattern of slip rates was measured on the Schimbrig landslide over a 14-months period. We propose that a Bingham plastic model explains much of how measured slip rates are linked to the observed topography, climatic variations and thickness variability of the landslide mass. This model explains why slip rates have been highest where the thickness of the material is substantially higher. It also explains why slip rates are highest in late summer/autumn and early spring. It appears then that snow melt in spring and decreasing temperatures in late summer/autumn potentially result in a high retention of the pore water and thus in a low viscosity of the material, which, in turns, promotes slip rates. Interestingly, an extreme rainstorm like the one of August 2005 only had a local impact on the landslide mass by triggering small scale earth flows and debris flows. This implies that the earth slide material does not directly respond to an episodic pattern of rainfall. Such precipitation events, however, superimpose a smaller-scale imprint on the landslide relie

Morphological measurement using close range digital photogrammetry-guidance from ISPRS V6

The revolution in digital camera technology has provided Earth Scientists with new opportunities for spatial measurement. High-resolution sensors at ever reducing costs, combined with software increasingly marketed as "easy-to-use", has tempted a new generation of physical geographers and geomorphologist to consider using digital photogrammetry. This trend, combined with the parallel revolution in terrestrial laser scanning technology, has allowed Earth Scientists to carry out their own spatial data acquisition, with some notable successes. The International Society of Photogrammetry and Remote Sensing (ISPRS) recognises this trend and has established Working Group V6 to provide an international focus for close range measurement for the earth sciences (http://isprsv6.lboro.ac.uk/). The fear is that many new users may be disappointed with initial results, often the result of inexperience and not limitations of the science of photogrammetry. This paper therefore provides basic guidance to allow new users to carry out photogrammetric surveys with a higher degree of confidence and hopefully increased success. It covers aspects relating to camera and lens selection, camera calibration, photo acquisition, photo control requirements and issues relating to data processing. The material represents the combined expertise of 85 members from across the world, particularly the detailed and combined contributions from the named authors

Contrasting sediment flux in Val Lumnezia (Graubünden, Eastern Swiss Alps), and implications for landscape development

This paper presents qualitative estimates of sediment discharge from opposite valley flanks in the S-N-oriented Val Lumnezia, eastern Swiss Alps, and relates inferred differences in sediment flux to the litho-tectonic architecture of bedrock. The valley flank on the western side hosts the deep-seated Lumnezia landslide where an area of ca. 30km2 has experienced slip rates of several centimetres per year, potentially resulting in high sediment discharge to the trunk stream (i.e. the Glogn River). High slip rates have resulted in topographic changes that are detectable on aerial photographs and measurable with geodetic tools. In contrast, a network of tributary channels dissects the valley flank on the eastern side. There, an area of approximately 18km2 corresponding to < 30% of the surface has experienced a change in the landscape mainly by rock avalanche and rock fall, and the magnitudes of changes are below the calibration limit of digital photogrammetry. We thus infer lower magnitudes of sediment discharge on the eastern tributaries than on the western valley side, where landsliding has been the predominant erosional process. These differences are interpreted to be controlled by the dip-slope situation of bedrock on the western side that favours down-slope slip of material. Morphometric investigations reveal that the western valley side is characterized by a low topographic roughness because this valley flank has not been dissected by a channel network. It appears that high sediment discharge of the Lumnezia landslide has inhibited the establishment of a stable channel network and has largely controlled the overall evolution of the landscape. This contrasts to the general notion that channelized processes exert the first-order control on landscape evolution and formation of relief and needs to be considered in future studies about landscape architecture, drainage network and sediment discharg

Face to face - close range inspection of head vases

Several hundred attic head vases are known worldwide and stored in museums and collections. In 1929, Beazley has categorized twenty groups (A-W) based on stylistic properties and historic methodology. Head vases are assembled in several steps, most important for our comparison is the moulding of the head area. While the other parts of head vases like the size of the handle and the painting can differ significantly from each other, one can notice similarities in the head shapes of the same group. Since molds were used to shape the heads, our initial hypothesis was to perform a quantitative comparison of head shapes based on digital scan data. Comparison of scan data is straight forward and is very similar to quality control and inspection processes in industrial applications. Nonetheless, quality control of approximately 2,500-year-old artefacts that are distributed among several different places is not straight forward. Initial analysis was performed on older scan data. In addition, a high-resolution fringe projection scanner was employed to scan further head vases in additional museums in Germany and Italy. Scan resolution and accuracy of approximately 0.1 mm in all dimensions were required to reveal differences below 1 mm. All new scans were performed with an AICON SmartScan-HE C8. This scanner captures not only shape, but at the same time records color textures which can be employed for presentation or future analyses. Shape analysis results of the head areas do not only confirm that it is likely that the same mold was used for shaping some of the head vases. According to these results, it is also not unlikely that a first generation of larger head vases was used to prepare molds for consecutive generations of head vases that are slightly smaller by 10-15%. This volume loss resembles closely the volume loss observed after oven-burning of pottery. Scanning will continue to increase the data set for further analyses

Relationships between landscape morphology, climate and surface erosion in northern Peru at 5°S latitude

The northern segment of the Peruvian Andes is affected by a twofold climate with measurable implications on landscapes and landscape dynamics. During ‘normal' or ‘neutral' years easterly winds bring rain from the Atlantic and the Amazon Basin to the Sierras, which results in a seasonal climate with rather low-intensity precipitations. In contrast, during the large-scale warm phase of the ENSO cycle, El Niños transfer moisture from the Pacific to the Peruvian coast by westerly winds and result in high-intensity precipitation. We investigate the effects of this twofold climate for the case of the Piura drainage basin at ca. 5°S latitude (northern Peru). In the headwaters that have been under the influence of the easterlies, the landscape is mantled by a thick regolith cover and dissected by a network of debris flow channels that are mostly covered by a thick layer of unconsolidated sediment. This implies that in the headwaters of the Piura River sediment discharge has been limited by the transport capacity of the sediment transfer system. In the lower segment that has been affected by high-intensity rainfall in relation to the westerlies (El Niños), the hillslopes are dissected by debris flow channels that expose the bedrock on the channel floor, implying a supply-limited sediment discharge. Interestingly, measurements at the Piura gauging station near the coast reveal that, during the last decades, sediment was transferred to the lower reaches only in response to the 1982-1983 and 1997-1998 El Niño periods. For the latter period, synthetic aperture radar (SAR) intensity images show that the locations of substantial erosion are mainly located in areas that were affected by higher-than-average precipitation rates. Most important, these locations are coupled with the network of debris flow channels. This implies that the seasonal easterlies are responsible for the production of sediment through weathering in the headwaters, and the highly episodic El Niños result in export of sediment through channelized sediment transport down to the coastal segment. Both systems overlap showing a partially coupled sediment production-delivery syste

Geometric Stability and Lens Decentering in Compact Digital Cameras

A study on the geometric stability and decentering present in sensor-lens systems of six identical compact digital cameras has been conducted. With regard to geometrical stability, the variation of internal geometry parameters (principal distance, principal point position and distortion parameters) was considered. With regard to lens decentering, the amount of radial and tangential displacement resulting from decentering distortion was related with the precision of the camera and with the offset of the principal point from the geometric center of the sensor. The study was conducted with data obtained after 372 calibration processes (62 per camera). The tests were performed for each camera in three situations: during continuous use of the cameras, after camera power off/on and after the full extension and retraction of the zoom-lens. Additionally, 360 new calibrations were performed in order to study the variation of the internal geometry when the camera is rotated. The aim of this study was to relate the level of stability and decentering in a camera with the precision and quality that can be obtained. An additional goal was to provide practical recommendations about photogrammetric use of such cameras

Methanol Mitigation during Manufacturing of Fruit Spirits with Special Consideration of Novel Coffee Cherry Spirits

Methanol is a natural ingredient with major occurrence in fruit spirits, such as apple, pear, plum or cherry spirits, but also in spirits made from coffee pulp. The compound is formed during fermentation and the following mash storage by enzymatic hydrolysis of naturally present pectins. Methanol is toxic above certain threshold levels and legal limits have been set in most jurisdictions. Therefore, the methanol content needs to be mitigated and its level must be controlled. This article will review the several factors that influence the methanol content including the pH value of the mash, the addition of various yeast and enzyme preparations, fermentation temperature, mash storage, and most importantly the raw material quality and hygiene. From all these mitigation possibilities, lowering the pH value and the use of cultured yeasts when mashing fruit substances is already common as best practice today. Also a controlled yeast fermentation at acidic pH facilitates not only reduced methanol formation, but ultimately also leads to quality benefits of the distillate. Special care has to be observed in the case of spirits made from coffee by-products which are prone to spoilage with very high methanol contents reported in past studies