Statistical modelling of district-level residential electricity use in NSW, Australia

Electricity network investment and asset management require accurate estimation of future demand in energy consumption within specified service areas. For this purpose, simple models are typically developed to predict future trends in electricity consumption using various methods and assumptions. This paper presents a statistical model to predict electricity consumption in the residential sector at the Census Collection District (CCD) level over the state of New South Wales, Australia, based on spatial building and household characteristics. Residential household demographic and building data from the Australian Bureau of Statistics (ABS) and actual electricity consumption data from electricity companies are merged for 74 % of the 12,000 CCDs in the state. Eighty percent of the merged dataset is randomly set aside to establish the model using regression analysis, and the remaining 20 % is used to independently test the accuracy of model prediction against actual consumption. In 90 % of the cases, the predicted consumption is shown to be within 5 kWh per dwelling per day from actual values, with an overall state accuracy of ?1.15 %. Given a future scenario with a shift in climate zone and a growth in population, the model is used to identify the geographical or service areas that are most likely to have increased electricity consumption. Such geographical representation can be of great benefit when assessing alternatives to the centralised generation of energy; having such a model gives a quantifiable method to selecting the ‘most’ appropriate system when a review or upgrade of the network infrastructure is required.     

Avoiding Land Disposal of Hazardous Waste

In response to a growing societal mandate, land disposal of hazardous wastes is gradually being replaced by treatment technologies. This shift to "alternative technologies" is the result of the impacts of past land disposal practices on other environmental media (groundwater, surface water, and air). A prime motivation for adopting alternatives to land disposal is to eliminate these cross-media impacts. Alternative technologies, however, can themselves have cross-media environmental impacts which must be recognized and addressed before such technologies are extensively applied. This paper discusses hazardous waste constituents, common disposal practices, alternative technologies currently being applied, possible cross-media environmental impacts of the alternative technologies, and proposed methods of mitigating these environmental impacts. Case studies from uncontrolled hazardous waste sites and industrial operations are used to illustrate the application of alternative technologies. Case studies include the application of waste treatment technologies as well as the adoption of waste minimization techniques.     

Greenhouse gas fluxes from an irrigated sweet corn (Zea mays L.)-potato (Solanum tuberosum L.) rotation

Intensive agriculture and increased N fertilizer use have contributed to elevated emissions of the greenhouse gases carbon dioxide (CO(2)), methane (CH(4)), and nitrous oxide (N(2)O). In this study, the exchange of CO(2), N(2)O, and CH(4) between a Quincy fine sand (mixed, mesic Xeric Torripsamments) soil and atmosphere was measured in a sweet corn (Zea mays L.)-sweet corn-potato (Solanum tuberosum L.) rotation during the 2005 and 2006 growing seasons under irrigation in eastern Washington. Gas samples were collected using static chambers installed in the second-year sweet corn and potato plots under conventional tillage or reduced tillage. Total emissions of CO(2)-C from sweet corn integrated over the season were 2071 and 1684 kg CO(2)-C ha(-1) for the 2005 and 2006 growing seasons, respectively. For the same period, CO(2) emissions from potato plots were 1571 and 1256 kg of CO(2)-C ha(-1). Cumulative CO(2) fluxes from sweet corn and potato fields were 17 and 13 times higher, respectively, than adjacent non-irrigated, native shrub steppe vegetation (NV). Nitrous oxide losses accounted for 0.5% (0.55 kg N ha(-1)) of the applied fertilizer (112 kg N ha(-1)) in corn and 0.3% (0.59 kg N ha(-1)) of the 224 kg N ha(-1) applied fertilizer. Sweet corn and potato plots, on average, absorbed 1.7 g CH(4)-C ha(-1) d(-1) and 2.3 g CH(4)-C ha(-1) d(-1), respectively. The global warming potential contributions from NV, corn, and potato fields were 459, 7843, and 6028 kg CO(2)-equivalents ha(-1), respectively, for the 2005 growing season and were 14% lower in 2006.     

Spending Environmental Expenditure More Effectively: A Case Study from Brisbane, Australia

Growing urbanisation causes pressures on many environmental assets such as groundwater systems, waterways, atmosphere, ecosystems and others. To manage and mitigate the negative effects of these pressures, environmental programs are typically launched, which comprise of eligible projects in different affected locations. The implementation of individual projects has a cost. However, due to budget constraints, most frequently not all suggested projects can be implemented which makes necessary to choose a subset. In this paper, we use a cost utility approach and a subsequent combinatorial optimisation based on metaheuristics to determine a project portfolio which returns a maximum aggregated utility while keeping the budget constraint. To ensure that the mutual exclusiveness of projects at one particular site is guaranteed, we further developed the employed metaheuristics. We apply this approach within a waterway health program in a river catchment in Brisbane, Australia, and compare its results to a commonly used selection process that does not involve combinatorial optimisation. We find that the use of combinatorial optimisation leads to a considerable improvement of the selection process and can help to more effectively allocate environmental expenditure.     

Quantification of gasoline-ethanol blend emissions effects

ABSTRACT

Emissions levels from current gasoline spark-ignited engines are low, and emissions changes associated with the blending of ethanol into gasoline are small and difficult to quantify. Addition of ethanol, with a high blending octane number, allows a reduction in aromatics in market gasoline. Blending behavior of ethanol is nonlinear, altering the distillation curve, including the 50% temperature point, T50. Increase in gasoline direct injection (GDI) engine technology in the fleet challenges ability of older models based on port fuel injection (PFI) results to predict the overall air quality impact of ethanol blending. Five different models derived from data collected through U.S. Environmental Protection Agency Energy Policy Act (EPAct) programs were used to predict LA92 Phase 1 particulate matter (PM) emissions for summer regular (SR) E0 (gasoline with 0% ethanol by volume), E10 (gasoline with 10% ethanol) and E15 (gasoline with 15% ethanol). Substantial reductions of PM for E10 and E15 relative to E0 were predicted when aromatics were displaced by ethanol to maintain octane rating. SR E0 and E10 were also matched to linear combinations of EPAct fuels and results showed a 35% PM reduction for SR E10 relative to SR E0. For GDI vehicles the Coordinating Research Council (CRC) E-94-3 study found that E10 had 23% or 29% PM increase. However, CRC E-129 found an E10 PM reduction of 10% when one E0 fuel and its splash blended (SB) E10 were compared. Both CRC project E-129 SB data and fuel triplets selected from the EPAct study showed variation for E15 emissions, although E-129 suggests that E15 in GDI offers about a 25% reduction of PM with respect to E0. Overall, data suggest that ethanol blending offers a modest to a substantial reduction of cold-start PM mass if aromatic levels of the finished products are reduced in response to ethanol addition.

Implications: Studies of exhaust emissions effects of ethanol blending with gasoline vary in conclusions. Blending properties are nonlinear. Modeling of real-world emissions effects must consider all fuel composition adjustments and property changes associated with ethanol addition. Aromatics are reduced in E10 or E15, compared with E0, and distillation changes. PFI-derived models show reductions in cold-start PM for expected average E10 versus E0 pump fuel, due to reduced aromatic content. Relative emissions effects from older technology (PFI) engines do not predict newer engine (GDI) results reliably, but recent GDI data show reduced cold-start PM when ethanol displaces aromatics.     

The first world conservation lecture

Summary This, The First World Conservation Lecture, was presented at the Royal Institution, London, UK, on 12 March 1981. The Lecture celebrated the 20th anniversary of the World Wildlife Fund, and the first anniversary of the World Conservation Strategy. The Lecture was organized by the World Wildlife Fund, UK.Published with the kind permission of the World Wildlife Fund, UK.Edward Max Nicholson, CB, CVO, Commandeur (Netherlands), Order of the Golden Ark, holds honorary doctorates from the University of Aberdeen, and The Royal College of Art London. He was educated at the University of Oxford, and was a member of the University's expeditions to Greenland (1928) and to British Guiana (1929). He was General Secretary (until 1940), later Chairman of PEP (Political and Economic Planning): now Vice-President of its successor body, the Policy Studies Institute. From 1945 to 1952 he was Secretary of the Office of the Lord President of the Council, then Deputy Prime Minister of the United Kingdom. He was member of the Advisory Council on Scientific Policy from 1948–1964. In 1952 he was leader of the joint UN/FAO Development Team in Baluchistan. Charter Member from 1949, and Director-General (1952–1966) of the Nature Conservancy, London, UK. From 1963 to 1974 he was Convenor of the Conservation Section of the International Council of Scientific Unions' International Biological Programme. President of the IUCN Technical Meeting in Edinburgh in 1956, concerned with rehabilitation of areas biologically devastated by human disturbance, and relation of ecology to landscape planning. Member, Panel on Landscape Action Program, The White House Conference (USA) on Natural Beauty (1965). Secretary, HRH The Duke of Edinburgh's Study Conference on The Countryside in 1970 (1963 and 1965). Council and Board Member of IIED. Godman-Salvin Medallist British Ornithologist Unions. Phillips Medallist and Member of Honour IUCN, Geoffroy St. Hilaire Gold Medal, Société Nationale de Protection de Nature de France, Premio Europeo Cortina-Ulisse (1971), Europa Preis für Landespflege (1972), Hon Member of World Wildlife Fund, Chairman Ecological Parks Trust, President RSPB, 1980. Principal Consultant and Chairman of Land Use Consultants Ltd (London) since 1966. Author of many books,Birds and Men (1951);Britain's Nature Reserves (1958),The System (1967);The Environmental Revolution (1970).     

Monitoring Liverworts to Evaluate the Effectiveness of Hydroriparian Buffers

In the coastal temperate rainforest of British Columbia (BC) in western Canada, government policies stipulate that foresters leave unlogged hydroriparian buffer strips up to 25 m on each side of streams to protect wildlife habitat. At present, studies on the effectiveness of these buffers focus on mammals, birds, and amphibians while there is comparably little information on smaller organisms such as liverworts in these hydroriparian buffers. To address this gap of knowledge, we conducted field surveys of liverworts comparing the percent cover and community composition in hydroriparian forested areas (n = 4 sites, n = 32 plots with nested design) to hydroriparian buffer zones (n = 4 sites, n = 32 plots). We also examined how substrate type affected the cover of liverworts. Liverwort communities in buffers were similar to those in riparian forest areas and most liverworts were found on downed wood. Thus, hydroriparian buffers of 25–35 m on each side in a coastal temperate rainforest effectively provide habitat for liverworts as long as downed wood is left intact in the landscape. Because liverworts are particularly sensitive to changes in humidity, these results may indicate that hydroriparian buffers are an effective management strategy for bryophytes and possibly for a range of other riparian species that are particularly sensitive to forestry-related changes in microclimate.