The environment and Britain's aid programme

Summary Some of the environmental and developmental activities assisted by Britain's Programme of Overseas Aid are outlined. In particular, the article draws attention to a new booklet published by the Overseas Development Administration to mark the European Year of the Environment which, in the Minister's words, shows how through British aid, programme improvements are possible by a combination of sound scientific research and a sensitivity to people's needs.Mr Christopher Patten, Member of Parliament for Bath, is the UK's current Minister for Overseas Development. He also serves as Minister of State for Foreign and Commonwealth Affairs. The Minister may be contacted through the offices of the Overseas Development Administration, Eland House, Stag Place, London SW1E 5DH, UK.     

FLOW CAPACITY OF CULVERTS ON OREGON COAST RANGE FOREST ROADS1

ABSTRACT: One hundred twenty-eight stream-crossing culverts in the central Oregon Coast Range were evaluated for peak flow capacity and were compared with current design guidelines. Their ability to pass the 25-year peak flow, as mandated by Oregon State Forest Practice Rules, and their maximum flow capacity were determined. Over 40 percent of the culverts were unable to pass the 25-year peak flow at a headwater to diameter ratio of 1. About 17 percent could not pass the 25-year peak flow without headwater overtopping the roadfill. Installing the next larger pipe size at an additional original installation cost of about 14 percent would have allowed nearly all these culverts to pass the 25-year peak flow. Culvert capacity varied with ownership and watershed size.     

Field water balance of landfill final covers

Landfill covers are critical to waste containment, yet field performance of specific cover designs has not been well documented and seldom been compared in side-by-side testing. A study was conducted to assess the ability of landfill final covers to control percolation into underlying waste. Conventional covers employing resistive barriers as well as alternative covers relying on water-storage principles were monitored in large (10 x 20 m), instrumented drainage lysimeters over a range of climates at 11 field sites in the United States. Surface runoff was a small fraction of the water balance (0-10%, 4% on average) and was nearly insensitive to the cover slope, cover design, or climate. Lateral drainage from internal drainage layers was also a small fraction of the water balance (0-5.0%, 2.0% on average). Average percolation rates for the conventional covers with composite barriers (geomembrane over fine soil) typically were less than 12 mm/yr (1.4% of precipitation) at humid locations and 1.5 mm/yr (0.4% of precipitation) at arid, semiarid, and subhumid locations. Average percolation rates for conventional covers with soil barriers in humid climates were between 52 and 195 mm/yr (6-17% of precipitation), probably due to preferential flow through defects in the soil barrier. Average percolation rates for alternative covers ranged between 33 and 160 mm/yr (6 and 18% of precipitation) in humid climates and generally less than 2.2 mm/yr (0.4% of precipitation) in arid, semiarid, and subhumid climates. One-half (five) of the alternative covers in arid, semiarid, and subhumid climates transmitted less than 0.1 mm of percolation, but two transmitted much more percolation (26.8 and 52 mm) than anticipated during design. The data collected support conclusions from other studies that detailed, site-specific design procedures are very important for successful performance of alternative landfill covers.     

Measuring forest ecosystem sustainability: A resource accounting approach

A new environmental paradigm has emerged, reflecting a change in the public's understanding of resource sustainability. Forest policy makers need to be better informed about such changes to achieve economic, social, and environmental objectives in a manner that balances human needs and aspirations with ecosystem constraints. As an aid to this task, a forest resource accounting system based on the key concept of natural capital could help reshape forest policies to provide an even wider spectrum of benefits for both present and future generations by maintaining and enhancing the productive capacity of forest capital. Such a resource accounting system would provide a tool for integrating multidimensional information requirements in measuring the health of both forest ecosystems and economic systems. This paper outlines some of the features of this accounting system and proposes and framework that would integrate economic and ecological characteristics of natural resources. Forest resource accounting is urgently needed to achieve the sustainability goals of ecosystem management.     

Assessment of contamination from arsenical pesticide use on orchards in the Great Valley region, Virginia and West Virginia, USA

Lead arsenate pesticides were widely used in apple orchards from 1925 to 1955. Soils from historic orchards in four counties in Virginia and West Virginia contained elevated concentrations of As and Pb, consistent with an arsenical pesticide source. Arsenic concentrations in approximately 50% of the orchard site soils and approximately 1% of reference site soils exceed the USEPA Preliminary Remediation Goal (PRG) screening guideline of 22 mg kg(-1) for As in residential soil, defined on the basis of combined chronic exposure risk. Approximately 5% of orchard site soils exceed the USEPA PRG for Pb of 400 mg kg(-1) in residential soil; no reference site soils sampled exceed this value. A variety of statistical methods were used to characterize the occurrence, distribution, and dispersion of arsenical pesticide residues in soils, stream sediments, and ground waters relative to landscape features and likely background conditions. Concentrations of Zn, Pb, and Cu were most strongly associated with high developed land density and population density, whereas elevated concentrations of As were weakly correlated with high orchard density, consistent with a pesticide residue source. Arsenic concentrations in ground water wells in the region are generally <0.005 mg L(-1). There was no spatial association between As concentrations in ground water and proximity to orchards. Arsenic had limited mobility into ground water from surface soils contaminated with arsenical pesticide residues at concentrations typically found in orchards.     

Household water use behavior: An integrated model

Water authorities are dealing with the challenge of ensuring that there is enough water to meet demand in the face of drought, population growth and predictions of reduced supply due to climate change. In order to develop effective household demand management programs, water managers need to understand the factors that influence household water use. Following an examination and re-analysis of current water consumption behavioral models we propose a new model for understanding household water consumption. We argue that trust plays a role in household water consumption, since people will not save water if they feel others are not minimizing their water use (inter-personal trust). Furthermore, people are less likely to save water if they do not trust the water authority (institutional trust). This paper proposes that to fully understand the factors involved in determining household water use the impact of trust on water consumption needs investigation.     

Nitrate enhancement of in-situ bioremediation of monoaromatic compounds in groundwater

Removal of benzene, toluene, and the isomers of xylene (BTX) from gasoline-contaminated groundwater under denitrifying conditions was investigated. In laboratory microcosms, benzene removal was found to be significantly stimulated by phosphorus addition. For total xylenes, removal followed a similar response, but toluene disappearance was unaffected by phosphorus enrichment. An in-situ bioremediation project was conducted to extend this laboratory work to an actual field-scale cleanup of gasoline-contaminated groundwater. The flow of groundwater from two extraction wells to an infiltration gallery created a mostly closed loop to recycle the groundwater enriched with added nutrients and the electron acceptor (nitrate). The coincident occurrence of BTX loss (greater than 90 percent) in situ, nitrate (as well as phosphorus and ammonia) appearance, and increased levels of denitrifying bacteria at a downgradient well all suggested that denitrification may play a significant role in BTX remediation at this site.     

Modelling mining: Open pit copper production in British Columbia

Open pit copper mining in British Columbia is modelled to examine how different price levels affect rates of output and stocks of reserves and to consider the existence and distribution of economic rents. The model depicts the influence of different economic circumstances on production plans, for example, with respect to scale of operations and cutoff grade. To achieve this it represents a balance between the high level of abstraction which has characterized the writing of most economists and the degree of detail and complexity required of models used by operating mines. The model provides a basis for the study of the consequences of alternative forms of taxation, a subject to be pursued in subsequent articles.     

Quantifying current and potential contributions of Australian indigenous peoples to threatened species management

Formal engagement of indigenous peoples in conservation is increasing globally and leads to multiple benefits to communities while contributing to national and international biodiversity goals and obligations. This and ongoing declines in biodiversity have led to calls to increase opportunities for indigenous people to engage in managing their estates. However, there is no overarching understanding of indigenous peoples’ involvement in conservation, which limits the identification of new opportunities. We amalgamated information across governments and large nongovernmental organizations in the megadiverse country of Australia to quantify the involvement of indigenous people in management of threatened species. We identified 153 Australian‐based projects undertaken by different indigenous groups around the nation in 2015 and 2016 that included explicit funds for management of threatened species or threatened ecosystems. Most were in remote parts of western and northern Australia. Almost one‐quarter of all threatened animals and 2% of threatened plants were the subject of some formal conservation action by indigenous people. Occurrence records for 1574 threatened species showed that 823 (89.2%) of 923 species recorded on indigenous peoples’ lands were not listed in management projects. This gap may represent new opportunities for conservation initiatives. Because at least 59.5% of Australia's threatened species occur on indigenous peoples’ lands, efforts to build appropriate and effective indigenous conservation alliances are vital. However, it is also important to recognize that threatened species are part of complex social, ecological, economic and cultural systems, and to achieve successful outcomes requires consideration of indigenous peoples’ priorities, rights, and obligations and relationships with their traditionally owned land and sea.