scholarly journals Waldentwicklung und flachgründige Rutschungen: eine grossflächige GIS-Analyse

2019 ◽  
Vol 170 (6) ◽  
pp. 318-325
Author(s):  
Peter Bebi ◽  
Alexander Bast ◽  
Christian Ginzler ◽  
Christian Rickli ◽  
Kevin Schöngrundner ◽  
...  
Keyword(s):  
Spatial Data ◽  
Forest Dynamics ◽  
Large Scale ◽  
Shallow Landslides ◽  
Natural Disturbances ◽  
Natural Event ◽  
Root Area ◽  
Spatial Data Sets ◽  
Young Forests

Forest dynamics and shallow landslides: a large-scale GIS-analysis Through continuous and abrupt changes in the forest and particularly in its root area, the disposition for shallow landslides also changes. The aim of this article is to learn more about the relationships between long-term forest dynamics and the risk of landslides with the help of large spatial data sets. A total of 6670 shallow landslides were selected from the natural event register StorMe, the event register of the Canton of Obwalden and the WSL database for shallow landslides and slope debris flows and overlaid with GIS data on the current and former forest situation (Siegfried maps of approx. 1880) and with windthrow areas (Vivian and Lothar). Shallow landslides occurred less frequently in the forest than outside of it at inclinations of less than 35 degrees. Higher landslide densities occurred in coniferous and mixed forests (compared to deciduous forests) and in relatively young forests (ingrown after 1880). Landslides in younger forests occurred on slopes less steep than in older forests. More shallow landslides occurred on former windthrow areas during the first 3 to 17 years after the event, however these landslides occurred on comparatively steep slopes. The analyses show that the disposition towards shallow landslides defined by slope inclination and subsoil can change strongly due to reforestation processes and natural disturbances. Silvicultural interventions may contribute to an improvement of the protective effect in the long term if they are carried out carefully and if they contribute to an increased adaptability to natural disturbances.

scholarly journals Extensive recent wildfires demand more stringent protection of critical old growth forest

2020 ◽  
Vol 26 (4) ◽  
pp. 384
Author(s):  
David Lindenmayer ◽  
Chris Taylor
Keyword(s):  
Spatial Data ◽  
Natural Disturbances ◽  
Old Growth ◽  
Growth State ◽  
The Past ◽  
Old Growth Forest ◽  
Primary Driver ◽  
Vegetation Class ◽  
Young Forests ◽  
Data Layers

Old growth forests have many key values, but temporal changes across their spatial extent are poorly understood. This includes large parts of Australia and is a major knowledge gap given the extent of human and natural disturbances in the Australian forest estate over past decades. We integrated spatial data on the timing and extent of fire and logging across mapped forest and woodland cover in different Ecological Vegetation Class (EVC) groups to quantify disturbance of the old growth forest and woodland estate in Victoria since 1995, including after the 2019–20 wildfires. We found ~77% of old growth forest and woodlands have been disturbed by fire and logging over the past 25 years. Disturbance was particularly marked in some EVCs, such as the Wet and Damp Forest and the Subalpine Woodlands. In contrast, relatively little of the Modelled Old Growth Forest and Woodland has been disturbed between 1995 and 2020 in other EVCs such as in Plains Woodlands and Heathy Woodlands. Wildfire was the primary driver of disturbance in Modelled Old Growth Forest and Woodland. We argue that a range of strategies is critical to increase protection of undisturbed old growth forest. These include re-assessing disturbance data layers to ensure that areas of old growth that have been burned at low severity are protected, and reducing the size of old growth patches to be conserved. There is also a need to increase levels of protection of young forests to enable them to grow through to an old growth state.

Consistency in Spatial Databases

2005 ◽  
pp. 93-98 ◽  
Author(s):  
M. Andrea Rodríguez-Tastets
Keyword(s):  
Spatial Data ◽  
Computer Aided Design ◽  
Large Scale ◽  
Spatial Databases ◽  
Data Sets ◽  
Navigation Systems ◽  
Large Scale Integration ◽  
Spatial Data Sets ◽  
Scale Integration ◽  
Aided Design

During the past several years, traditional databases have been enhanced to include spatially referenced data. Spatial database management (SDBM) systems aim at providing models for the efficient manipulation of data related to space. Such type of manipulation is useful for any type of applications based on large spatial data sets, such as computer-aided design (CAD), very large scale integration (VLSI), robotics, navigation systems, and image processing.

Development of a Visualized Data Management System for Life-Cycle Health Monitoring of Civil Structures

2012 ◽  
Vol 83 ◽  
pp. 188-197
Author(s):  
Ke Chang Lin ◽  
Yi Qing Ni ◽  
Xiao Wei Ye ◽  
Kai Yuan Wong
Keyword(s):  
Life Cycle ◽  
Data Management ◽  
Health Monitoring ◽  
Spatial Data ◽  
Management System ◽  
Large Scale ◽  
Monitoring Data ◽  
Data Management System ◽  
Civil Structures

The data management system (DMS) is an essential part for long-term structural health monitoring (SHM) systems, which stores a pool of monitoring data for various applications. A robust database within a DMS is generally used to archive, manage and update life-cycle information of civil structures. However, many applications especially those to large-scale structures provide little support for visualizing the long-term monitoring data. This paper presents the development of an efficient visualized DMS by integrating 4-dimension (4D) model technology, nested relational database, and virtual reality (VR) technology. Spatial data of the 4D model are organized in nested tables, while real-time (temporal) monitoring data are linked to the 4D model. The model is then reconstructed by use of an OpenSceneGraph 3D engine. A user interface is developed to query the database and display the data via the 4D model. To demonstrate its efficiency, the proposed method has been applied to the Canton Tower, a supertall tower-like structure instrumented with a long-term SHM system

Size and spacing of grouse leks: comparing capercaillie (Tetrao urogallus) and black grouse (Tetrao tetrix) in two contrasting Eurasian boreal forest landscapes

2009 ◽  
Vol 87 (11) ◽  
pp. 1032-1043 ◽  
Author(s):  
Jørund Rolstad ◽  
Per Wegge ◽  
Andrey V. Sivkov ◽  
Olav Hjeljord ◽  
Ken Olaf Storaunet
Keyword(s):  
Forest Dynamics ◽  
Large Scale ◽  
Landscape Scale ◽  
Tetrao Urogallus ◽  
Black Grouse ◽  
Surrounding Area ◽  
Social Attraction ◽  
Tetrao Tetrix ◽  
Habitat Affinities

Capercaillie ( Tetrao urogallus L., 1758) and black grouse ( Tetrao tetrix L., 1758 (= Lyrurus tetrix (L., 1758))) are two sympatric Eurasian lekking grouse species that differ markedly in habitat affinities and social organization. We examined how size and spacing of leks in pristine (Russia) and managed (Norway) forests were related to habitat and social behavior. Leks of both species were larger and spaced farther apart in the pristine landscape. Capercaillie leks were regularly spaced at 2–3 km distance, increasing with lek size, which in turn was positively related to the amount of middle-aged and older forests in the surrounding area. Black grouse leks were irregularly distributed at shorter distances of 1–2 km, with lek size explained by the size of the open bog arena and the amount of open habitat in the surroundings. At the landscape scale, spatial distribution of open bogs and social attraction among male black grouse caused leks to be more aggregated, whereas mutual avoidance in male capercaillie caused leks to be spaced out. In the pristine landscape, large-scale and long-term changes in forest dynamics owing to wildfires, combined with an aggregated pattern of huge bog complexes, presumably provide both grouse species with enough time and space to build up bigger lek populations than in the managed landscape.

Mapping forest natural disturbances dynamics in the Aosta Valley (Italy) through long-term trends derived from Landsat time series and innovative statistical approaches

2020 ◽  
Author(s):  
Raffaella Marzano ◽  
Donato Morresi ◽  
Emanuele Lingua ◽  
Renzo Motta ◽  
Matteo Garbarino
Keyword(s):  
Time Series ◽  
Forest Dynamics ◽  
Vegetation Indices ◽  
Airborne Lidar ◽  
Natural Disturbances ◽  
Spectral Indices ◽  
Long Term Trends ◽  
One Year ◽  
Normalized Burn Ratio

<p>Forest dynamics triggered by natural disturbances occurred in the Aosta Valley region were spatially mapped over time using long-term trends derived from Landsat time series spanning over 35 years, from 1985 to 2019. Among biotic and abiotic disturbance agents, the following were selected: wildfires, windthrows, snow avalanches, landslides and insect outbreaks. Landsat TM, ETM+ and OLI images acquired during the vegetative season (from June to September) with less than 80% cloud cover were employed to create synthetic images at one-year interval using the geometric median approach at the pixel-level. Forest dynamics due to disturbance occurrence and the following vegetation recovery were explored through inter-annual time series of different spectral indices such as normalized vegetation indices (Normalized Burn Ratio, Normalized Moisture Index) and the tasseled cap band transformations (wetness, angle). Changes in the linear trends of the spectral indices time series caused by disturbance occurrence were detected using a novel bottom-up approach in which a wavelet basis is adaptively constructed by merging neighbouring segments of the data. This method doesn’t require a priori knowledge of the time series parameters making it fully automated. Prior to perform the trend analysis, vegetation indices time series were filtered to remove residual invalid pixels and fill gaps of one-year length. Considering abrupt disturbances, this method highlighted sensitivity toward both high and low magnitude events and was able to accurately detect different severity degrees within the perimeter of the affected forest area. Historical wildfire perimeters and crown fires patches provided by the forest fire fighting corps of the Aosta Valley were used to perform preliminary severity maps validation. Considering two severity classes, ‘low to moderate’ and ‘moderate to high’, maps produced using the Normalized Burn Ratio achieved an overall accuracy of 83%. Future work is aimed to validate all the selected natural disturbance agents using historical field data available at the regional scale. Moreover, a rigorous and wide scale-based assessment of the capabilities of the algorithm in tracking post-fire forest recovery will be performed by integrating forest structure data from filed surveys and airborne LiDAR measurements.</p>

Effects of long-term and large-scale ecology projects on forest dynamics in Yangtze River Basin, China

2021 ◽  
Vol 496 ◽  
pp. 119463
Author(s):  
Shanshan Chen ◽  
Zhaofei Wen ◽  
Songlin Zhang ◽  
Ping Huang ◽  
Maohua Ma ◽  
...  
Keyword(s):  
River Basin ◽  
Forest Dynamics ◽  
Yangtze River ◽  
Large Scale ◽  
Yangtze River Basin

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Computer Analyses in Preventive Health Research

1967 ◽  
Vol 06 (01) ◽  
pp. 8-14 ◽  
Author(s):  
M. F. Collen
Keyword(s):  
Medical Research ◽  
Preventive Medicine ◽  
Health Research ◽  
Large Scale ◽  
Preventive Health ◽  
New Era ◽  
Large Numbers ◽  
Normal Test ◽  
Computer Analyses

The utilization of an automated multitest laboratory as a data acquisition center and of a computer for trie data processing and analysis permits large scale preventive medical research previously not feasible. Normal test values are easily generated for the particular population studied. Long-term epidemiological research on large numbers of persons becomes practical. It is our belief that the advent of automation and computers has introduced a new era of preventive medicine.

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