Emergency service response and costs in british floods

The costs of emergency response to flood disasters has received little attention. This paper presents and discusses a method for estimating the economic costs incurred through the use of the emergency services during flood events in Britain. First, a model of British emergency service response to flood events is presented. Secondly, cost evaluation principles relevant to each emergency service are discussed. Thirdly, a set of "standard" emergency service cost data are presented - these data are derived from research based upon the model of response and the evaluation principles. Finally, the "standard" data are applied to the case of the York and Selby floods of 1982 where data from research on the reported actions and costs of each emergency service are compared with those predicted through the use of the "standard" data.     

USE AND MISUSE OF COMPLEX MODELS: EXAMPLES FROM WATER DEMAND MANAGEMENT1

ABSTRACT: The power of computers has increased in recent decades, and one might expect improved management to result because decisions can be made with understanding available only via models. However, there is potential for quite the opposite: poor decisions due to unrealistic model output generated by users without access to appropriate training in the use of models. We discuss and, by reference to water demand models (IWR-MAIN, MWD-MAIN), illustrate three areas in which unintended errors of judgment by untrained personnel may cause difficulty:

• * Attributes of management models; if output from any type of model has no measure of confidence, then results may be over- or undervalued
• * Input data; with complex models, problems here typically will be difficult to detect.
• * Calibration and history-matching (verification); if these steps or data are combined, then users should be less trustful of model output than otherwise.

Because all models have weaknesses and because there always is uncertainty about output from any model, we end with suggestions for coping with complex models. Monitoring programs play a central role in such efforts because they can identify discrepancies between model predictions and actual events and because they can ensure time is available to develop solutions for problems unanticipated in the modeling effort.     

Ecological Monitoring for Assessing the State of the Nearshore and Open Waters of the Great Lakes

The Great Lakes Water Quality Agreement stipulates that the Governments of Canada and the United States are responsible for restoring and maintaining the chemical, physical and biological integrity of the waters of the Great Lakes Basin Ecosystem. Due to varying mandates and areas of expertise, monitoring to assess progress towards this objective is conducted by a multitude of Canadian and U.S. federal and provincial/state agencies, in cooperation with academia and regional authorities. This paper highlights selected long-term monitoring programs and discusses a number of documented ecological changes that indicate the present state of the open and nearshore waters of the Great Lakes.     

Effect of operational parameters on the removal of particulate chemical oxygen demand in the activated sludge process.

The removal of particulate material in the aeration basin of the activated sludge process is mainly attributed to bioflocculation and hydrolysis of particulate substrate. The bioflocculation process in the aeration tank of the activated sludge process occurs only under favorable conditions in the system, and several common operational parameters affect its performance. The principal objective of this research was to observe the effect of mixed liquor suspended solids, solids retention time (SRT), and extracellular polymer substances on the removal of particulate substrate by bioflocculation. A first-order particulate removal expression, based on flocculation, accurately described the removal rates for supernatant suspended solids and colloidal chemical oxygen demand. Based on the results presented in this investigation, a mixed liquor concentration of approximately 2200 mg/L, an SRT of at least 3 days, and a contact time of 30 minutes are needed for relatively complete removal of the particulate substrate in a plug-flow reactor.     

Effect of source variability and transport processes on carbon isotope ratios of TCE and PCE in two sandy aquifers

Chlorinated ethenes often migrate over extended distances in aquifers and may originate from different sources. The aim of this study was to determine whether stable carbon isotope ratios remain constant during dissolution and transport of chlorinated ethenes and whether the ratios can be used to link plumes to their sources. Detailed depth-discrete delineation of the carbon isotope ratio in a tetrachloroethene (PCE) plume and in a trichloroethene (TCE) plume was done along cross-sections orthogonal to groundwater flow in two sandy aquifers in the Province of Ontario, Canada. At the TCE site, TCE concentrations up to solubility were measured in one high concentration zone close to the bottom of the aquifer from where dense non-aqueous phase liquid (DNAPL) was collected. A laboratory experiment using the DNAPL indicated that only very small carbon isotope fractionation occurs during dissolution of TCE (0.26 per thousand), which is consistent with field observations. At most sampling points, the delta(13)C of dissolved TCE was similar to that of the DNAPL except for a few sampling points at the bottom of the aquifer close to the underlying aquitard. At these points, a (13)C enrichment of up to 2.4 per thousand was observed, which was likely due to biodegradation and possibly preferential diffusion of TCE with (12)C into the aquitard. In contrast to the TCE site, several distinct zones of high concentration were observed at the PCE site and from zones to zone, the delta(13)C values varied substantially from -24.3 per thousand to -33.6 per thousand. Comparison of the delta(13)C values in the high concentration zones made it possible to divide the plume in the three different domains, each probably representing a different episode and location of DNAPL release. The three different zones could still be distinguished 220 m from the DNAPL sources. This demonstrates that carbon isotope ratios can be used to differentiate between different zones in chlorinated ethene plumes and to link plume zones to their sources. In addition, subtle variations in delta(13)C at plume fringes provided insight into mechanisms of plume spreading in transverse vertical direction. These variations were identified because of the high-resolution provided by the monitoring network.     

Strengthening artisanal mining research and policy through baseline census activities

Over the past 10–15 years, several governments have implemented an array of technology, support‐related, sustainable livelihoods (SL) and poverty‐reduction projects for artisanal and small‐scale mining (ASM). In the majority of cases, however, these interventions have failed to facilitate improvements in the industry's productivity and raise the living standards of the sector's subsistence operators. This article argues that a poor understanding of the demographics of target populations has precipitated these outcomes. In order to strengthen policy and assistance in the sector, governments must determine, with greater precision, the number of people operating in ASM regions, their origins and ethnic backgrounds, ages, and educational levels. This can be achieved by carrying out basic and localized census work before promoting ambitious sector‐specific projects aimed at improving working conditions in the industry.     

INFLUENCE OF REMOTE SENSING IMAGERY SOURCE ON QUANTIFICATION OF RIPARIAN LAND COVER/LAND USE1

ABSTRACT: This paper compares approaches to quantifying land cover/land use (LCLU) in riparian corridors of 23 watersheds in Oregon's Willamette Valley using color infrared aerial photography (AP) and Thematic Mapper (TM) imagery. For each imagery source, LCLU adjacent to stream networks were quantified across a range of lateral and longitudinal scales. Single‐date AP data had higher LCLU class accuracies than the multi‐date TM data, except for row crops. Correlations among LCLU classes for the two imagery sources increased with increased spatial extent. In general, LCLU proportions for AP and TM differed, but lateral/longitudinal patterns were similar. An aggregated vegetation class comprised of forest, shrub/scrub, and grass/forb was strongly associated with a fish index of biotic integrity (IBI) for both AP and TM data, although AP correlations were higher. Highest fish IBI correlations for both data sources were with the aggregated vegetation class close to the stream and for the longest longitudinal scales. The row crop class was strongly associated with stream nitrate for both data sources, although correlations for the TM data were higher. Stream nitrate correlations were strongest for the widest lateral and longest longitudinal scales. Overall, both single‐date AP and multi‐date TM imagery appear to have potential for use in estimating indicators of stream ecological condition.     

The Genetic Diversity of Native, Stocked, and Hybrid Populations of Brook Trout in the Southern Appalachians

Using mitochondrial DNA (mtDNA) restriction analysis and starch-gel electrophoresis of the CK-A2 locus product, we examined genetic variation in 311 brook trout (Salvelinus fontinalis) from 11 native, 5 hatchery-derived, and 8 hybrid populations in the southern Appalachian Mountains. Native southern Appalachian fish were genetically distinct from hatchery-derived fish. Southern and hatchery-derived fish were reliably distinguished based on three mtDNA restriction sites. Native southern haplotypes differed from hatchery-derived haplotypes by an average of 0.84%. Northern hatchery-derived haplotypes varied little in mtDNA compared to native southern haplotypes. Introgression of mtDNA haplotypes and the CK-A2 locus varied among populations, and introgression of allozyme and mtDNA markers was positively correlated. Continued introductions of nonnative strains of brook trout in the southern Appalachians could simplify the genetic structure of native brook trout populations and eliminate unique genotypes.     

The illusion of environmental iodine deficiency

The distribution of endemic goitre in England and Wales was compared with the distribution of environmental iodine (atmospheric deposition, soil, surface water). Despite a very clear goitre belt through the west of England and Wales there was no patterning in the environmental iodine distribution. A clear seasonal variation in depositional iodine exists, with an unusually high concentration of iodine in March 1997. The temporal variation in iodine concentration is determined at the monthly and not the annual level. The presence of endemic goitre is no indicator of how iodine is distributed in the environment or vice versa!