Bertram Ostendorf - Academia.edu (original) (raw)

Papers by Bertram Ostendorf

…, 2010

A simple approach to predict spatial pattern of SOC using a surrogate variable, soil Munsell valu... more A simple approach to predict spatial pattern of SOC using a surrogate variable, soil Munsell value, with the aid of digital terrain analysis is presented. Digital elevation models (DEMs) were prepared using readily available digital topographic maps and then enhanced for a small sloping catchment in the Adelaide hills using plausibility algorithms. Seven terrain parameters were calculated from the DEMs. One hundred random points were identified across the 5.6 ha site and soil Munsell value was obtained. Correlation analysis showed elevation, specific catchment area, profile curvature, and wetness index influence soil Munsell value. It was also found that the application of plausibility algorithms to DEMs derived from topographic maps produced better correlation coefficients compared to unsmooth DEMs.

Agricultural and Forest Meteorology

Austral Ecology, 2022

Our understanding of the habitat needs of grassland fauna is often incomplete because of their cr... more Our understanding of the habitat needs of grassland fauna is often incomplete because of their cryptic behaviour. This presents a barrier to identifying important habitat attributes, whether these change at different spatial scales, and how this informs management decisions. Here, we use a critically endangered bird, the Plains‐wanderer (Pedionomus torquatus, Pedionomidae), as an exemplar of the challenge of managing grasslands for cryptic species. Until now, almost all ecological knowledge of Plains‐wanderers has come from the detection of nocturnally roosting individuals and habitat assessments at fine‐scales that indicate open swards are preferred habitat. We GPS‐tracked 13 adult Plains‐wanderers to better understand diurnal habitat utilization in native grasslands of south‐eastern Australia. Using these data, we assessed whether Plains‐wanderers select for different habitat attributes during the day and night, and whether this varied according to spatial scale. At the fine‐scale...

Scientific Reports, 2021

Modern satellite imaging offers radical new insights of the challenges and opportunities confront... more Modern satellite imaging offers radical new insights of the challenges and opportunities confronting traditional Aboriginal ecology and land use in Australia’s Western Desert. We model the likely dynamics of historic and precontact desert land use using Earth observation data to identify the distribution of suitable foraging habitats. Suitability was modelled for an ideal environmental scenario, based on satellite observations of maximal water abundance, vegetation greenness, and terrain ruggedness. Our model shows that the highest-ranked foraging habitats do not align with land systems or bioregions that have been used in previous reconstructions of Australian prehistory. We identify impoverished desert areas where unsuitable foraging conditions have likely persisted since early in the last glacial cycle, and in which occupation would always have been rare. These findings lead us to reconsider past patterns of land use and the predicted archaeological signature of earlier desert pe...

Environmental Modelling and Software, Apr 1, 2007

A number of spatial decision support systems (SDSSs) are already available for the systematic pla... more A number of spatial decision support systems (SDSSs) are already available for the systematic planning of conservation reserves. These existing systems offer varying levels of integration and interactivity. However, these systems generate solutions that are sub-optimal. Integer programming (IP) optimisation techniques guarantee optimal solutions but have been criticised for excessively long or intractable solution times. Modern IP software has addressed this criticism by finding solutions in quick time. The aim in using IP techniques in this paper is to design conservation reserves that are of the minimum possible area to satisfy defined conservation targets, thereby producing reserve systems of greatest efficiency. The Conservation Reserve Evaluation and Design Optimisation System (CREDOS) is a fully integrated SDSS that calls on a thirdparty optimiser to generate solutions. We attempt to provide a foundation for a viable alternative to existing systems by tightly coupling CREDOS with a proprietary geographic information system (GIS) and IP analytical software by means of an interactive interface. It provides conservation planners with a fully featured planning system for both terrestrial and marine conservation reserves that is easy to use, offers high levels of interactivity and flexibility, and produces practical and efficient solutions that can be used to support their experience and judgement. This paper describes the methodology used in the design and construction of CREDOS, and discusses the effectiveness of the system in facilitating the planning of conservation reserves. The functionality of CREDOS is assessed in the context of designing Marine Protected Areas (MPAs). The results are maximally efficient, practical, and manageable arrangements of potential MPA sites that satisfy conservation targets.

Remote Sensing of Environment, Jun 1, 2018

Monitoring of the southern hairy-nosed wombat (Lasiorhinus latifrons) population via satellite im... more Monitoring of the southern hairy-nosed wombat (Lasiorhinus latifrons) population via satellite imagery was first proposed in 1980. However, the imagery that was available at that time was inadequate for the task as it did not permit the direct observation and counting of warrens. Since then, advances in the availability and resolution of satellite imagery mean that it is now possible to map the entire distribution of southern hairy-nosed wombats and to estimate their population abundance using very high-resolution imagery (≤1.0 m). However, other landscape features such as rabbit warrens can make the identification of wombat warrens problematic, and not all wombat warrens are visible, even in the best resolution imagery. By comparing data that we collected from field surveys conducted between May 2015-May 2017 with satellite imagery we could identify that many wombat warrens have visible trails linking warrens with each other. Whilst this allowed us to differentiate between wombat and rabbit warrens in most circumstances, the lack of visible trails in some instances highlighted the need for ground truthing surveys to be conducted as part of any broad scale wombat population survey. Based on the difference between the number of warrens that we marked during our ground surveys with the number which were visible in the satellite imagery, we calculated a range of indices which can be used to correct future broad-scale population estimates based on satellite imagery, to account for warrens which may be obscured by vegetation and other confounding factors.

http://www.publish.csiro.au/pid/5201.ht

Journal of Arid Environments, Jul 1, 2008

One of the major indirect effects of artificial watering points in a grazed landscape is the deve... more One of the major indirect effects of artificial watering points in a grazed landscape is the development around them of a zone of extreme degradation called a piosphere. We investigated the use of the moving standard deviation index (MSDI) applied to Landsat TM band 3 data for detection and assessment of these zones in the arid grazing lands of South Australia. We found that watering points had significantly higher MSDI values (po0.001) than non-degraded reference areas in four different land systems. Comparison of two vegetation indices, the normalised difference vegetation index (NDVI) and perpendicular distance vegetation index (PD54), used as reference indices, showed that the PD54 was more appropriate than NDVI in this perennial-dominated arid environment. Piospheres were found to be more heterogeneous in vegetation cover, with higher MSDI values, compared with non-degraded areas, and spatial heterogeneity in cover decreased with increasing distance from water points. This study indicates that MSDI can be used as an appropriate method for land degradation assessment in naturally heterogeneous arid lands of South Australia.

International Journal of Environmental Research and Public Health, Sep 13, 2019

Traffic accidents impart both economic and social costs upon communities around the world, hence ... more Traffic accidents impart both economic and social costs upon communities around the world, hence the desire for accident rates to be reduced. For this reduction to occur, the factors influencing the occurrence of accidents must be understood. The role of congestion in modifying accident risk has been widely studied, but consensus has not been reached, with conflicting results leaving open questions. An inverse relationship between accidents and congestion would imply a benefit of congested conditions for road safety, posing a difficult situation for traffic management. This paper assesses articles that reveal the shape of the relationship between traffic accidents and congestion. We find a positive linear response to dominate the literature. However, studies with higher numbers of statistical units tend to show a U-shaped relationship. This suggests an important role of high spatio-temporal traffic data in understanding factors causing accidents and identifying the combination of real-time conditions which may lead to increased accident risk. Modern advancements in traffic measurement systems provide the ability for real-time alleviation of accident-prone conditions before they can fully develop.

International Journal of Remote Sensing, Oct 3, 2011

Australian Forestry, Oct 2, 2017

ABSTRACT Fuelwood derived from community forests of Nepal is critical for rural livelihoods. Supp... more ABSTRACT Fuelwood derived from community forests of Nepal is critical for rural livelihoods. Supply of fuelwood is regulated through 5-year operational plans. The aim of this study was to evaluate the adequacy of operational plans in addressing the demand and supply of fuelwood in community forests of Nepal. Data was gathered from operational plans, household interviews and fuelwood supply assessment in 13 community forests of Nalma (inaccessible by road) and Taksar (accessible by road) villages in the Lamjung district. Our study revealed that per capita annual fuelwood consumption in Nalma (486 kg) was significantly higher than in Taksar (398 kg), and also significantly different combinations of fuelwood, biogas and electricity were utilised between the villages. These differences were associated with their respective distances from the main road. Community forests contributed 57 and 63% of the total fuelwood consumption in Nalma and Taksar, respectively. Of 13 community forests, nine have planned annual demand and supply of fuelwood well below our estimates of actual supply and consumption, indicating that most of the operational plans inadequately represented the prevailing demand and supply of fuelwood. In addition, the planned quantities of fuelwood demand and supply in current operational plans were markedly different and poorly linked to the previous projections, which suggest inconsistent and inadequate application of standard planning guidelines. We recommend a revision of the methods used in the preparation of these plans to determine fuelwood demand and supply in community forestry implementation.

Congress on Modelling and Simulation, 2005

We have developed the Optimisation Support System (OSS), a spatial decision support system, to de... more We have developed the Optimisation Support System (OSS), a spatial decision support system, to deliver optimal solutions to the problem of identifying comprehensive, adequate and representative locations for conservation planning.

Journal of Southern Hemisphere earth systems science, Sep 20, 2021

Reanalyses are important tools for understanding past weather and climate variability, but detail... more Reanalyses are important tools for understanding past weather and climate variability, but detailed verification of near surface humidity variables have not been published. This is particularly concerning in tropical regions where humid conditions impact meteorology and human activities. In this study, we used screen level temperature and humidity data from a high-resolution atmospheric regional reanalysis, the Bureau of Meteorology Atmospheric high-resolution Regional Reanalysis for Australia (BARRA), validated against automatic weather stations (AWS) data for 32 sites across northern Australia. Overall, the BARRA data was reliable, with the time series from the AWS and BARRA being very highly correlated, but there were some seasonal and diurnally varying biases. The variability of the differences also changed from location to location and as a function of time of day and season, but much less than the biases. This variability was less than the 'weather signal' as evidenced by the high correlations. In particular, the amplitude of the diurnal cycle was overestimated, particularly in the dry (winter) season. In general, the differences in temperature were larger than those of the dew point temperature, and the wet bulb temperature had the least uncertainty. Overall, this study contributes to a better understanding of the effectiveness of reanalyses for examining the impact of moist variables on tropical climate variability.

Proceedings of SPIE, Nov 8, 2014

Earth systems and environment, Nov 8, 2017

Background Food security globally depends primarily on three components: food availability, food ... more Background Food security globally depends primarily on three components: food availability, food access, and food utilization. Regional variations of these components may affect food security via spatial differences in natural, social or economic conditions and the interaction of these in a complex environmental system. Purpose It is important to understand the regional variation of food security, particularly where and under what natural and socioeconomic circumstances people become vulnerable to low food security in a country. Methods This article provides an overview of food security in Bangladesh in terms of the three main components, identifies knowledge gaps in present food security research, reviews possible impacts of climate change on food security, and sourced a wide range of spatio-temporal data relevant for food security. Results The study highlights potentials and indicates different processes to develop spatially informed food policies in a country, particularly focuses on Bangladesh. This will contribute to improved food security by considering regional food security conditions, region-specific deficits, climate change, other future risks, and devises actions related to the respective components. Conclusion The study concludes that different processes can provide a foundation for policy development and these will advance research-policy linkage to improved food security.

Agricultural Systems, Jul 1, 2019

Long-term, continuous, accurate, daily weather records for precipitation, temperature and solar r... more Long-term, continuous, accurate, daily weather records for precipitation, temperature and solar radiation are critical inputs for modelling long-term climate risk in cropping systems. However, comprehensive weather data often exhibit short record length and missing or inaccurate records, which can lead to inconsistencies. Using risk profiles (cumulative probability curves of crop yield) as a tool for quantifying the performance of cropping systems under climate variability, this study examines how sensitive risk profiles of a worldwide staple food crop are to temporal coverage of climate data, and additionally to the presence of extreme weather events. Here, we focused on the risk profile of modelled wheat grain yield across the Australian grain-belt using high-quality weather records. To test the effect of the discontinuity and limited record length often found in weather records, long-term risk profiles (i.e. obtained for a baseline period of 100 years, from 1917 to 2016) were compared with long-term risk profiles constructed using variable temporal coverages (record lengths 10, 20, …, 90 years, and three sampling periods: random, continuous and non-continuous). Long-term risk profiles based on > 40 years showed reasonable small bias and root mean square errors when compared to those built for the baseline period, implying that even relatively short climate records can produce reliable long-term performance indicators. Longterm risk profiles able to account for severe frost and heat events required longer climate records (60 years). For most locations in Australia, long-term risk profiles built using data from the last 10-40 years also revealed negative yield trends which may be partially attributed to climate change. Results were consistent across soils and different simulated sowing dates. Findings highlight rainfall as the main climate driver of wheat productivity and the importance of the record length and period considered for extreme weather event analysis in agricultural studies.

Hydrology and Earth System Sciences, Mar 31, 1998

International Journal of Environmental Research and Public Health, Nov 8, 2018

The establishment of an effective policy response to rising heatwave impacts is most effective wh... more The establishment of an effective policy response to rising heatwave impacts is most effective when the history of heatwaves, their current impacts and future risks, are mapped by a common metric. In response meteorological agencies aim to develop seamless climate, forecast, and warning heat impact services, spanning all temporal and spatial scales. The ability to diagnose heatwave severity using the Excess Heat Factor (EHF) has allowed the Australian Bureau of Meteorology (the Bureau) to publicly release 7-day heatwave severity maps since 2014. National meteorological agencies in the UK and the United States are evaluating global 7-day and multi-week EHF heatwave severity probability forecasts, whilst the Bureau contributes to a Copernicus project to supply the health sector with global EHF severity heatwave projection scenarios. In an evaluation of impact skill within global forecast systems, EHF intensity and severity is reviewed as a predictor of human health impact, and extended using climate observations and human health data for sites around the globe. Heatwave intensity, determined by short and long-term temperature anomalies at each locality, is normalized to permit spatial analysis and inter-site comparison. Dimensionless heatwave event moments of peak severity and accumulated severity are shown to correlate with noteworthy events around the globe, offering new insights into current and future heatwave variability and vulnerability. The EHF severity metric permits the comparison of international heatwave events and their impacts, and is readily implemented within international heatwave early warning systems.