Utility of Landsat 7 satellite data for continued monitoring of forest cover change in protected areas in Southeast Asia

Satellite instruments, particularly the Landsat TM (Thematic Mapper) and ETM+ (Enhanced Thematic Mapper Plus) series of sensors, are important tools in the interdisciplinary study of tropical forests that are increasingly integrated into studies that monitor changes in vegetation cover within tropical forests and tropical protected areas, and also applied with other types of data to investigate the drivers of land cover change. However, further advances in the use of Landsat to study and monitor tropical forests and protected areas are threatened by the scan line corrector failure on the ETM+ sensor, as well as uncertainty about the continuity of the Landsat mission. Given these problems, this paper illustrates how ETM+ data were used in an interdisciplinary study that effectively monitored forest cover change in Gunung Palung National Park in West Kalimantan, Indonesian Borneo. Following 31 May 2003, when the ETM+ sensor's scan line corrector failed, we analysed how this failure impedes our ability to perform a similar study from this date onwards. This analysis uses six simulated post-scan line corrector failure (SLC-off) images and reveals that data gaps caused by SLC-off introduce maximum errors of 1.47 per cent and 4.04 per cent in estimates of forest cover and rates of forest loss, respectively. The analysis also demonstrates how SLC-off has transformed ETM+ data from a complete inventory dataset to a statistical sample with variable sample fraction, and notes how this data loss will confound the use of Landsat data to model land cover change in a spatially explicit manner. We discuss potential limited uses of SLC-off data and suggest alternative sensors that may provide essential remotely sensed data for monitoring tropical forests in Southeast Asia.     

A reconstruction of extratropical Indo-Pacific sea-level pressure patterns during the Medieval Climate Anomaly

Subtropical and extratropical proxy records of wind field, sea level pressure (SLP), temperature and hydrological anomalies from South Africa, Australia/New Zealand, Patagonian South America and Antarctica were used to reconstruct the Indo-Pacific extratropical southern hemisphere sea-level pressure anomaly (SLPa) fields for the Medieval Climate Anomaly (MCA ~700–1350 CE) and transition to the Little Ice Age (LIA 1350–1450 CE). The multivariate array of proxy data were simultaneously evaluated against global climate model output in order to identify climate state analogues that are most consistent with the majority of proxy data. The mean SLP and SLP anomaly patterns derived from these analogues illustrate the evolution of low frequency changes in the extratropics. The Indo-Pacific extratropical mean climate state was dominated by a strong tropical interaction with Antarctica emanating from: (1) the eastern Indian and south-west Pacific regions prior to 1100 CE, then, (2) the eastern Pacific evolving to the central Pacific La Niña-like pattern interacting with a +ve SAM to 1300 CE. A relatively abrupt shift to –ve SAM and the central Pacific El Niño-like pattern occurred at ~1300. A poleward (equatorward) shift in the subtropical ridge occurred during the MCA (MCA–LIA transition). The Hadley Cell expansion in the Australian and Southwest Pacific, region together with the poleward shift of the zonal westerlies is contemporaneous with previously reported Hadley Cell expansion in the North Pacific and Atlantic regions, and suggests that bipolar climate symmetry was a feature of the MCA.     

Contested energy futures: Shaping renewable energy narratives in Australia

Narratives and discourses are central to how we interpret and understand the world. The capacity to construct and disseminate compelling stories about particular issues is hence critical to an agent's capacity to advance their interests. This paper examines some of the main narratives through which the conversation about renewable energy in Australia takes place. We label these narratives feasibility (‘Pie in the Sky’); security (‘Keeping the Lights on’); cost (‘Costing the Earth’); and employment (‘Jobs Carnage’). Some of the most effective narratives are those that are constructed around some of the ‘legitimate’ concerns that pertain to an issue. The renewable energy narratives identified in this paper build on ‘reasonableness’ and ‘common sense’ concerns, and their effectiveness is determined as much by contextualising information absent from the energy conversation as present. While our focus is Australia, some of the narrative dynamics revealed have application to energy politics more broadly.     

Magnetic Environments of Young Stellar Objects

We report on early results of magnetic field measurements towards a sample of young stellar objects. The results show a variety of field configurations, some of which can be explained by conventional models, while others cannot. We find that the field in some cases is curved over large scales and influenced by the gas kinematics in the local environment. This implies that, at these scales at least, the magnetic field plays a passive rôle in the star formation process.     

The Magnetic Environments of Young Stellar Objects

We report on early results of submillimetre polarimetric measurements towards a sample of young stellar objects. The results allow us to infer the magnetic field structure and show a variety of configurations, providing evidence for axial, helical and pinched (i.e. ‘hourglass’) magnetic field configurations. We find that in some cases the field is curved over large scales, implying that it is influenced by the gas kinematics in the local environment, and that at these scales at least, the magnetic field plays a passive rôle in the star formation process.     

Hydrology of stockpiled industrial coal exposed to rainfall

The movement of water and particulate matter through a simulated coal pile using a rainfall–coal‐pile simulator is investigated. In conjunction with coal‐pile management practices, this study indicates that coal‐pile systems change their internal and surficial structure with successive rainstorm events. This change in coal‐pile structure alters the proportions, rates and suspended solid concentrations within surface runoff and infiltration during subsequent storm events. Results demonstrate the need to determine the optimal coal‐pile slope that minimizes water contact time, but at the same time minimizes the potential for mass wasting and rill erosion. Promotion of a compacted surface is beneficial for the minimization of solids removal, and a stormwater detention pond with potential flocculant additive is suggested as a viable remedial measure for the containment and treatment of coal‐pile runoff. Copyright © 2002 John Wiley & Sons, Ltd.     

Aerial photography for the assessment of crop condition: a review

Of all the remote sensing techniques available for the study of crop condition, aerial photography has proved to be the most useful. Many of the environmental stresses that affect crops modify the morphology and physiology of individual plants so profoundly that the resultant changes in crop canopy reflectance can be recorded on an aerial photograph. The ability of aerial photography to record the adverse biological conditions of disease, pests, weeds and mismanagement, and the adverse physical and chemical conditions of drought, flood and problem soils are reviewed and illustrated using examples from the United Kingdom.     

Buckling analysis of 3D layered structures using a Cosserat continuum approach

This paper concerns the buckling analysis of three-dimensional (3D) layered continua using the Cosserat approach. The finite element method (FEM) is used to implement the adopted Cosserat formulation. As a result, the interfaces between the layers need not be explicitly modelled. Instead, the internal characteristic length, i.e., the layer thickness and also the interaction conditions between the layers are incorporated into the governing equations of the solution. This paper introduces a new 3D geometric stiffness matrix based on the principle of virtual work. The proposed geometric stiffness matrix is applied to the linear buckling analysis of a number of benchmark problems with various geometries, boundary conditions, and interaction conditions between the layers. In all cases, the FEM Cosserat solution exhibits a high level of consistency with the analytical solution.