Olaf Conrad

Olaf Conrad
Hamburg University | UHH · Institut für Geographie (IGeogr)

Dr.

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48
Publications
54,311
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8,657
Citations

Publications

Publications (48)
Article
The Anthropocene presents challenges for preserving and restoring ecosystems in human-altered landscapes. Policy development and landscape planning must consider long-term developments to maintain and restore functional ecosystems, ideally by using wildlife umbrella species as proxies. Forest and Landscape Restoration (FLR) aims to support both env...
Article
Full-text available
The impacts of the Anthropocene on climate and biodiversity pose societal and ecological problems that may only be solved by ecosystem restoration. Local to regional actions are required, which need to consider the prevailing present and future conditions of a certain landscape extent. Modeling approaches can be of help to support management effort...
Article
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Current changes in the world's climate increasingly impact a wide variety of sectors globally, from agriculture and ecosystems to water and energy supply or human health. Many impacts of climate on these sectors happen at high spatio-temporal resolutions that are not covered by current global climate datasets. Here we present CHELSA-W5E5 (10.48364/...
Article
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Zusammenfassung Digitale Informationstechniken gewinnen zunehmend an Bedeutung für Optimierungsstrategien in der landwirtschaftlichen Produktion, wobei einer Gewinnmaximierung die Minimierung kritischer Umweltwirkungen z. B. durch Oberflächenabfluss und Bodenerosion gegenübersteht. Mit dem hier vorgestellten Simulationsmodell lassen sich die an den...
Preprint
Full-text available
Current changes in the world’s climate increasingly impact a wide variety of sectors globally, from agricul-ture, ecosystems, to water and energy supply or human health. Many impacts of climate on these sectors hap-pen at high spatio-temporal resolutions that are not covered by current global climate datasets. Here we pre-sent Climatologies at high...
Article
Full-text available
Im Rahmen des IpsPro-Verbundvorhabens wurde ein webbasiertes Werkzeug für eine räumlich explizite Prognose des Befallsrisikos für fichtendominierte Waldbestände durch Borkenkäfer, insbesondere den Buchdrucker, entwickelt. Das sogenannte Borkenkäfer-Frühwarnsystem IpsRisk stellt das "Front End" einer komplexen Modellkette dar, in der das tagesaktuel...
Presentation
Full-text available
The warm and dry years of the recent past have once again impressively shown that bark beetle outbreaks are among the most dangerous natural hazards that occur in forests of Central Europe and North America. The European spruce bark beetle (Ips typographus L.) in particular is one of the most important pests in Central European forests. Induced by...
Presentation
Rindenbrütende Borkenkäfer – insbesondere der Buchdrucker (Ips typographus) – sind die bedeutendsten biotischen Schädlinge der Fichte (Picea abies). Diese ist trotz allmählichen Waldumbaus nach wie vor die anteilmäßig präsenteste sowie wirtschaftlich bedeutendste Baumart in deutschen Mittelgebirgen und wird diese Stellung noch über Jahrzehnte hinwe...
Article
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Aim To determine the global position of tree line isotherms, compare it with observed local tree limits on islands and mainlands, and disentangle the potential drivers of a difference between tree line and local tree limit. Location Global. Time period 1979–2013. Major taxa studied Trees. Methods We modelled the potential climatic tree line bas...
Poster
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Granitoid target rocks underlying the peak ring of the 66 Ma Chicxulub impact crater, Mexico, were drilled in 2016 during IODP-ICDP Expedition 364. The target rocks are replete with centimeter- to decimeter-thick semi-automatic cataclasite zones of variable maturity. Applying the image segmentation work flow of SAGA GIS (System for Automated Geosci...
Article
Full-text available
We propose the implementation of the Soil and Landscape Evolution Model (SaLEM) for the spatiotemporal investigation of soil parent material evolution following a lithologically differentiated approach. Relevant parts of the established Geomorphic/Orogenic Landscape Evolution Model (GOLEM) have been adapted for an operational Geographical Informati...
Article
Full-text available
We propose the implementation of a soil and landscape evolution model (SaLEM) for the spatiotemporal investigation of soil parent material evolution following a lithologically differentiated approach. Relevant parts of the established model GOLEM have been adapted for an operational GIS tool within the open source software framework SAGA, thus taki...
Article
Full-text available
High-resolution information on climatic conditions is essential to many applications in environmental and ecological sciences. Here we present the CHELSA (Climatologies at high resolution for the earth's land surface areas) data of downscaled model output temperature and precipitation estimates of the ERA-Interim climatic reanalysis to a high resol...
Poster
Full-text available
The semi-automatic segmentation of digital images using SAGA GIS (System for Automated Geoscientific Analyses) developed at Hamburg University is an important tool in microstructural analysis. We applied the work flow to petrographic images of the 50-70 m thick Granite Breccia, which underlies the 1.85 Ga Sudbury Igneous Complex (SIC), Canada, the...
Poster
Full-text available
The target of our project is the development of a realtime digital decision system to optimise farming with regard to an increase of crop yield and minimal damage to the environment. Basis for this decision system is SAGA, which is an open-source geographic information system. During our development we add new SAGA tools, which analyse local circum...
Article
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The World Urban Database and Access Portal Tools (WUDAPT) is a community initiative to collect worldwide data on urban form (i.e., morphology, materials) and function (i.e., use and metabolism). This is achieved through crowdsourcing, which we define here as the collection of data by a bounded crowd, composed of students. In this process, training...
Conference Paper
Full-text available
Despite the great importance of cities, relatively little consistent information about their internal configuration (structure, cover and materials) is available. The World Urban Database and Access Portal Tools (WUDAPT) initiative aims at the acquisition, storage and dissemination of data on the form and function of cities indifferent levels. At t...
Conference Paper
Full-text available
Despite the great importance of cities, relatively little consistent information about their internal configuration (structure, cover and materials) is available. The World Urban Database and Access Portal Tools (WUDAPT) initiative aims at the acquisition, storage and dissemination of data on the form and function of cities indifferent levels. At t...
Poster
Full-text available
The analysis of distribution and diversity patterns depends in most parts on climatic variables, such as precipitation and temperature. Today, commonly used climatic predictors at high resolution result from interpolations between climatic stations which record the local climate. However, climatic stations are especially rare in mountainous regions...
Article
Full-text available
High resolution information of climatic conditions is essential to many application in environmental sciences. Here we present the CHELSA algorithm to downscale temperature and precipitation estimates from the European Centre for Medium-Range Weather Forecast (ECMWF) climatic reanalysis interim (ERA-Interim) to a high resolution of 30 arc sec. The...
Poster
Full-text available
Climate models are an important tool for species distribution analyses and biodiversity research. High resolution data on temperature and precipitation is so far mainly based on an interpolation of recorded data from climate stations. Tragically, climatic stations are especially scarce in areas harboring high biodiversity such as tropical rainfores...
Article
The Okavango catchment in southern Africa is subject to environmental as well as socio-economic transformation processes such as population growth and climate change. The degradation of soil and vegetation by deforestation and overgrazing is one of the downsides of this development, reducing the capacity of the land to provide ecosystem functions a...
Article
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Abstract. The System for Automated Geoscientific Analyses (SAGA) is an open source geographic information system (GIS), mainly licensed under the GNU General Public License. Since its first release in 2004, SAGA has rapidly developed from a specialized tool for digital terrain analysis to a comprehensive and globally established GIS platform for sc...
Article
Accurate imaging of minerals in petrographic thin sections using (semi)-automatic image segmentation techniques remains a challenging task chiefly due to the optical similarity of adjacent grains or grain aggregates rendering definition of grain boundaries difficult. We present a new semi-automatic image segmentation workflow for the quantitative a...
Article
Full-text available
The heterogeneity of precipitation rates in high mountain regions is not sufficiently captured by state of the art climate reanalysis products due to their limited spatial resolution. Thus there exists a large gap between the available data sets and the demands of climate impact studies. The presented approach aims to generate spatially high resolu...
Article
Full-text available
Progress in urban climate science is severely restricted by the lack of useful information that describes aspects of the form and function of cities at a detailed spatial resolution. To overcome this shortcoming we are initiating an international effort to develop the World Urban Database and Access Portal Tools (WUDAPT) to gather and disseminate t...
Article
Full-text available
The System for Automated Geoscientific Analyses (SAGA) is an open-source Geographic Information System (GIS), mainly licensed under the GNU General Public License. Since its first release in 2004, SAGA has rapidly developed from a specialized tool for digital terrain analysis to a comprehensive and globally established GIS platform for scientific a...
Article
Full-text available
Zusammenfassung: Die Aufl ösung aktueller globaler und regionaler Klimamodelle ist für viele Zwecke bereits ausreichend. Dennoch erfordern viele auf diese Modelldaten aufbauenden Anwendungsgebiete eine weitere Verfeinerung, sogenanntes Downscaling, um horizontale Aufl ösungen höher als etwa 25 km zu erreichen. In diesem Paper werden vorläufi ge Erg...
Article
Full-text available
For many ecological processes, near-surface temperature is one of the main controlling parameters. Since meteorological observations in high mountains are sparse, climate model data are frequently used. State of the art climate reanalysis products or general circulation models have a horizontal spatial resolution on the order of 50 × 50 km, i.e. fa...
Article
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Abstract: The BMBF-funded project “The Future Okavango” conducts a survey of current land use practices in the Okavango catchment in Angola, Namibia and Botswana. The aim is to get an assessment of the management of natural resources, i.e. ecosystem services and functions, which are presumably under pressure through overexploitation, population gro...
Article
Full-text available
The resolution of modern Global and Regional Climate Models is sufficient for many purposes. Nevertheless, the downscaling of model output is necessary when a higher spatial resolution is needed for smaller scale applications. This article introduces intermediate results of an approach for climate regionalization using the free and open source GIS...
Article
Full-text available
The landscape of the Okavango Catchment is structured much more diverse than is perceptible at first sight. From the mountainous Angolan highlands with altitudes of more than 1700 meters above sea level to less than 1000 meters at the delta and the surrounding Kalahari sands; accordingly the relief intensity decreases steadily, from high mountainou...
Article
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The study examined the effects of two different instructional interventions as support for scientific discovery learning using computer simulations. In two well-known categories of difficulty, data interpretation and self-regulation, instructional interventions for learning with computer simulations on the topic “ecosystem water” were developed and...
Article
System for Automated Geoscientific Analyses (SAGA) is a full-fledged geographic information system (GIS) and many of its features have some relation with geomorphometry that makes it an ideal tool for operational work. This chapter emphasizes the particular characteristics of SAGA and the relation between some of its features and concepts. SAGA is...
Article
Full-text available
Fragmentation is a contextual measurement of deforestation that receives increasing attentions. The peat swamp forest in the Klias Peninsula is an important ecological entity especially because it contains the largest pieces of peat swamp forest in the northern end of Borneo Island. We modified and implemented the fragmentation model proposed by RI...
Article
Within the European Union (EU)-funded Project ‘Wind Erosion on European Light Soils’ (WEELS), a model was designed and implemented with the aim of predicting the long-term spatial distribution of wind erosion risks in terms of erosion hours and wind-induced soil loss. In order to ensure wide applicability, the model structure consists of a modular...
Article
Full-text available
Specific computational procedures have been developed for the regionalisation of soil properties and related data as support system for soil mapping at different scales. The methodological framework integrates digital terrain analysis, climatic, hydrological and process-oriented modelling and geo-statistical approaches as well as pedological rules...
Article
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For assessing a regional water balance in boreal landscapes the extend to which evapo-transpiration is subject to spatial variations needs to be known. Water cycle parameters such as transpiration rates of vegetation are depending on both the vegetation type and hydro-pedologic stand conditions since poor soil drainage respective seasonal soil drou...
Conference Paper
Full-text available
For the suitability towards the reconstruction of geomorphological sound surfaces using digital elevation models different methods as a weighted neighborhood member procedure, a ordinary kriging procedure, a gradient spline technique and a new modification of heat flow equation were tested. Round-off effects and effects of local noise-signal ratio...
Article
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Cellular automata are simple computational operators, but despite their simplicity, they allow the simulation of highly complex processes. This paper shows how to apply the concept of cellular automata to simulate diffusion and flow processes in shallow water bodies. Similar to real world processes, in the model the diffusion and flow process as we...

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