COPING WITH A SEVERE SUSTAINED DROUGHT ON THE COLORADO RWER: INTRODUCTION AND OVERVIEW1

ABSTRACT: In arid regions of rapid economic and population growth, adverse effects of droughts are likely to be increasingly serious. This article presents an introduction and overview of the papers collected in this special issue of the Water Resources Bulletin. The papers report on the second phase of a study of the impacts of and responses to a potential severe sustained drought in the Colorado River Basin in the southwestern U.S. The analyses were performed by a consortium of researchers from universities and the private sector located throughout the Basin. Tree ring studies suggest that droughts of duration and magnitude much more serious than any found in the modern records probably occurred in the Basin during earlier centuries. Taking the present-day configuration of the storage and diversion structures and the economic conditions in the Basin as the base-point, the general objectives of the study are three: first, to define a representative Severe Sustained Drought (SSD) and assess its hydrologic impacts; second, to forecast the economic, social and environmental impacts on the southwestern U.S.; and finally, to assess alternative institutional arrangements for coping with an SSD. The evaluation of impacts and policies was conducted with two distinct modeling approaches. One involved hydrologic-economic optimization modeling where water allocation institutions are decision variables. The second was a simulation-gaming approach which allowed “players” representing each basin state to interact in a real-time decision making mode in response to the unfolding drought.     

On the economics of desalination of brackish household water supplies

Chemical constituents dissolved in household water supplies can cause economic damages in the form of reduced life of water-using appliances and pipes. Technological advances in reducing desalination costs and improved measures of damages have changed the conditions under which desalination of brackish water supplies can be considered to be economically feasible. The analysis shows that estimated benefits of desalination exceed costs for some communities with high saline native waters, such as are found in the Arkansas River Valley of eastern Colorado and elsewhere in the Southwest.     

The military’s responsibility for environmental protection in war and peace

Environmental Science and Pollution Research -     

Complete reproductive skew within white-browed sparrow weaver groups despite outbreeding opportunities for subordinates of both sexes

The distribution of reproductive success within societies is a key determinant of the outcomes of social evolution. Attempts to explain social diversity, therefore, require that we quantify reproductive skews and identify the mechanisms that generate them. Here, we address this priority using life history and genotypic data from >600 individuals in 40 wild groups of the cooperatively breeding white-browed sparrow weaver, Plocepasser mahali. We show that groups comprise up to six males and seven females, but within-group reproduction is completely monopolised by a single dominant male and female, while extra-group males sire 12–18 % of offspring. Strong within-group kin structure could frequently explain these monopolies, as subordinates had typically delayed dispersal from their natal groups and so frequently (1) lacked within-group outbreeding partners, and/or (2) stood to gain little from contesting dominant reproduction, being almost as related to the dominant’s young as they would have been to their own. Kin structure alone cannot account entirely for these monopolies, however, as they remained complete following the immigration of unrelated males and females. That subordinate females remain reproductively quiescent despite also showing comparable body condition to dominants, overlapping them substantially in age, and showing no evidence of elevated stress hormone levels raises the possibility that they exercise reproductive restraint due instead to a threat of action by dominants and/or deficits in offspring fitness that might arise if subordinates bred. Our findings highlight the complexity of the mechanisms that generate reproductive disparities in animal societies and the challenge of identifying them when skews are complete.     

Explicitness of consequence information in warnings

Four experiments were carried out to assess effects of product warning explicitness on purchase preferences and caution in use. Explicitness was defined as the specificity or detail with which potential injury consequences were described. All experiments employed a paradigm in which warnings varying in explicitness were described for familiar products. Subjects rated various perceptions of the products, purchase preferences, and intent to act cautiously in using the product. Results indicated that more explicit warnings were associated with greater levels of perceived dangerousness, hazard understanding, injury severity, and manufacturers' concern. While explicit warnings were also associated with an increased intent to act cautiously in using products, no clear relationship was found between explicitness and purchase preferences. It is recommended that product warnings should be explicit regarding injury consequences, especially where injuries may be severe. Given such information, product users, particularly those less familiar with a product, are more likely to exercise greater caution during use. Further, manufacturers' concern that explicit warnings may negatively impact sales appears to be unwarranted.     

Using ‘found’ data to augment a probability sample: Procedure and case study

While probability sampling has the advantage of permitting unbiased population estimates, many past and existing monitoring schemes do not employ probability sampling. We describe and demonstrate a general procedure for augmenting an existing probability sample with data from nonprobability-based surveys (found data). The procedure, first proposed by Overton (1990), uses sampling frame attributes to group the probability and found samples into similar subsets. Subsequently, this similarity is assumed to reflect the representativeness of the found sample for the matching subpopulation. Two methods of establishing similarity and producing estimates are described: pseudo-random and calibration. The pseudo-random method is used when the found sample can contribute additional information on variables already measured for the probability sample, thus increasing the effective sample size. The calibration method is used when the found sample contributes information that is unique to the found observations. For either approach, the found sample data yield observations that are treated as a probability sample, and population estimates are made according to a probability estimation protocol. To demonstrate these approaches, we applied them to found and probability samples of stream discharge data for the southeastern US.     

A framework for evaluating the impact of the IUCN Red List of threatened species

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, a species extinction risk assessment tool, has been guiding conservation efforts for over 5 decades. It is widely assumed to have been instrumental in preventing species from moving closer to extinction and driving recoveries. However, the impact of the IUCN Red List in guiding conservation has not been evaluated. We conducted, transcribed, and coded interviews with experts who use the IUCN Red List across a range of sectors to understand how the list is used in conservation. We developed a theory of change to illustrate how and why change is expected to occur along causal pathways contributing to the long-term goal of the IUCN Red List and an evaluation framework with indicators for measuring the impact of the IUCN Red List in generating scientific knowledge, raising awareness among stakeholders, designating priority conservation sites, allocating funding and resources, influencing development of legislation and policy, and guiding targeted conservation action (key themes). Red-list assessments were the primary input leading to outputs (scientific knowledge, raised awareness), outcomes (better informed priority setting, access to funding and resource availability, improved legislation and policy), and impact (implemented conservation action leading to positive change) that have resulted in achievement of IUCN Red List goals. To explore feasibility of attributing the difference made by the IUCN Red List across themes, we studied increased scientific knowledge, raised awareness, access to funding and resource allocation, and increased conservation activity. The feasibility exploration showed increased scientific knowledge over time identified through positive trends in publications referring to the IUCN Red List in the literature; raised awareness of the list following high IUCN activity identified by peaks in online search activity; an increased proportion of conservation funding bodies requesting IUCN Red List status in the application process; and, based on interviews with Amphibian Specialist Group members, red-list assessments were essential in connecting relevant stakeholders and ensuring conservation action. Although we identified the IUCN Red List as a vital tool in global conservation efforts, it was challenging to measure specific impacts because of its ubiquitous nature. We are the first to identify the influence of the IUCN Red List on conservation.     

Solid recovery rate of food waste recycling in South Korea

Source-separated collection system of household food waste has been implemented national wide in South Korea. Food waste recycling rate that means conversion rate to recycle is over 90 % in present. However, over the value of 90 %, we need to enhance the efficiency of food waste recycling process. We analyzed material flow of 24 food waste recycling facilities and calculated solid recovery rate to key-process. We found that 3–13 % of the solids from food waste outflows with foreign materials and 27–33 % of the solids outflow with wastewater. As a result, solid recovery rates are 65.3, 60.9, and 56.3 % in wet feed facility, dry feed facility, and composting facility, respectively. Alternative ways to recovery solid from wastewater or collection tools to exclude plastic bags, salt, and moisture content are required to make food waste recycling more efficient.