Assessment of the overall resource consumption of germanium wafer production for high concentration photovoltaics

The overall resource requirements for the production of germanium wafers for III–V multi-junction solar cells applied in concentrator photovoltaics have been assessed based on up to date process information. By employing the cumulative energy demand (CED) method and the cumulative exergy extraction from the natural environment (CEENE) method the following resources have been included in the assessment: fossil resources, nuclear resources, renewable resources, land resources, atmospheric resources, metal resources, mineral resources and water resources. The CED has been determined as 216 MJ and the CEENE has been determined as 258 MJ_ex. In addition partial energy and exergy payback times have been calculated for the base case, which entails the installation of the high concentration photovoltaics (HCPVs) in the Southwestern USA, resulting in payback times of around 4 days for the germanium wafer production. Due to applying concentration technology the germanium wafer accounts for only 3% of the overall resource consumption of an HCPV system. A scenario analysis on the electricity input to the wafer production and on the country of installation of the HCPV has been performed, showing the importance of these factors on the cumulative resource consumption of the wafer production and the partial payback times.     

Using the multiple capitals framework to connect indicators of regional cumulative impacts of mining and pastoralism in the Murray Darling Basin,Australia

It is commonly recognized that there are constraints to successful regional-scale assessment and monitoring of cumulative impacts because of challenges in the selection of coherent and measurable indicators of the effects. It has also been sensibly declared that the connections between components in a region are as important as the state of the elements themselves. These have previously been termed “linked” cumulative impacts/effects. These connections can be difficult to discern because of a complicated set of interactions and unexpected linkages. In this paper we diagnose that a significant cause of these constraints is the selection of indicators without due regard for their inter-relationships in the formulation of the indicator set. The paper examines whether the common “forms of capital”, i.e., natural (renewable and non-renewable), manufactured, social, human and financial capitals, framework is a potential organizing structure. We examine a large region in western NSW Australia where the predominant production systems are mining and grazing for production of wool, beef and lamb. Production in both is driven by consumption of a non-renewable resource, i.e., ore for mining and topsoil for grazing, the latter on the basis that loss rate estimates far exceed soil formation rates. We propose that the challenge of identifying connections of components within and between capital stores can be approached by explicitly separating stores of capital and the flows of capital between stores and between elements within stores, so-called capital fluxes. We attempt to acquire data from public sources for both capital stores and fluxes. The question of whether these data are a sufficient base for regional assessment, with particular reference to connections, is discussed. The well-described challenge of a comparative common currency for stores and fluxes is also discussed. We conclude that the data acquisition is relatively successful for stores and fluxes. A number of linked impacts are identified and discussed. The potential use of money as the common currency for stores and fluxes of capital is considered. The basic proposition is that replacement or preservation costs be used for this. We conclude that the study is sufficiently positive to consider further research in fully-coupled models of capital stores and fluxes.     

Progress in Enclave Tourism Study of Overseas: A Literature Review

Abstract

In response to the “isolated island” phenomenon emerging from the development of tourist resorts in China, this paper reviews the study of enclave tourism overseas, which has similar features to the resort “island”. Based on the literatures related to enclave tourism from Tourism Management and Annals of Tourism Research, this paper reviews the study of enclave tourism from the following aspects: definition discussion, theories used, causation of enclaves, characteristics and impacts of enclave tourism. The understanding of the overseas researches on enclave tourism would provide instructions for the study on the problems of Chinese resorts, such as enclavity and “island effects”, and suggest measures for the sustainable development of resorts in China. This paper is divided into three sections. Section 1 briefly introduces the development of enclave tourism in developing countries and the outline of enclave tourism study. Section 2 elaborates on the contents of enclave tourism research and gives deep insights into the study on concepts, characteristics, causations and effects respectively, which is the key part of this paper; Section 3 concludes the review and proposes suggestions for the enclave tourism study in China.     

我国海水利用现状及其对环境的影响

海水利用为解决全球水资源短缺提供了重要途径.本文综述了世界范围内海水利用方面的进展情况,评述了大生活用水和工业冷却水等海水直接利用及海水淡化过程对海洋环境的影响,特别是高温冷却海水和海水淡化浓盐水的排放以及化学物质的加入对海水水质、海洋生物的影响,并提出了预防和减轻这些影响的措施和方法.     

Modeling the Fate and Transport of Plunging Inflows to Onondaga Lake

The transport and fate of two plunging tributaries, Onondaga and Ninemile Creeks, in Onondaga Lake, New York, are quantified based on application of hydrodynamic/transport models. Short‐term transport is simulated with a three‐dimensional Estuary Lake and Coastal Ocean Model (ELCOM), while the longer term fate is represented by a previously validated one‐dimensional model (UFILS4). The validation of ELCOM for the vertical distribution of tributary inflow into the lake's water column is demonstrated for four dye tracer experiments. The models are applied for three years to represent the dynamics of transport and fate for the two tributaries, with ELCOM predictions serving as input for UFILS4. The models together quantify the distribution of these inflows between the upper mixed layer (UML) and stratified depths, and the subsequent transport from stratified depths to the UML by vertical mixing. Substantial short‐term variations are predicted for both tributaries in response to variability in hydrology and weather. Increased inflow to the UML is predicted for high runoff periods. The fraction of Ninemile Creek's inflow directly entering the UML is predicted to be 50% greater than for Onondaga Creek due to Ninemile's lower negative buoyancy. The plunging phenomenon has important water quality implications, by reducing the effective loading to the UML, particularly for constituents with large rates of loss/transformation relative to the rate of vertical transport from stratified depths.     

Bedded Sediment Conditions and Macroinvertebrate Responses in New Mexico Streams: A First Step in Establishing Sediment Criteria

Excess fine sediments in streambeds are among the most pervasive causes of degradation in streams of the United States. Simple criteria for acceptable streambed fines are elusive because streambed fines and biotic tolerances vary widely in the absence of human disturbances. In response to the need for sediment benchmarks that are protective of minimum aquatic life uses under the Clean Water Act, we undertook a case study using surveys of sediment, physical habitat, and macroinvertebrates from New Mexico streams. Our approach uses weight of evidence to develop suggested benchmarks for protective levels of surficial bedded sediments <0.06 mm (silt and finer) and <2.0 mm (sand and finer). We grouped streams into three ecoregions that were expected to produce similar naturally occurring streambed textures and patterns of response to human disturbances. Within ecoregions, we employed stressor response models to estimate fine sediment percentages and bed stability that are tolerated by resident macroinvertebrates. We then compared individual stream sediment data with distributions among least‐disturbed reference sites to determine deviation from natural conditions, accounting for natural variability across ecoregion, gradient, and drainage area. This approach for developing benchmark values could be applied more widely to provide a solid basis for developing bedded sediment criteria and other protective management strategies in other regions.     

On‐Site Exposure to Treated Wastewater Effluent Has Subtle Effects on Male Fathead Minnows and Pronounced Effects on Carp

This study tested the hypotheses that (1) exposure to treated Water Reclamation Plant (WRP) effluent will induce biological effects in exposed fish that are consistent with environmental estrogen (EE) exposure; and (2) seasonal differences in effluent composition will moderate biological effects. We conducted seven on‐site exposures using a mobile laboratory. Total estrogenicity of effluents was 10‐ to 20‐fold higher during spring than in fall. Common EEs including steroid estrogens, alkylphenols, and bisphenol‐A were ubiquitous. An unusual spike in total estrogenicity identified a combined sewer overflow event. Fathead minnows (Pimephales promelas) responded to exposure with subtle changes in vitellogenin concentrations and secondary sex characteristics. An opportunity to assess a common carp (Cyprinus carpio) population permanently sustained inside the Stickney WRP revealed pronounced exposure effects, but also the resilience of biological organisms even under long‐term exposure. In contrast to other studies, no histopathological changes were found. The mobile exposure laboratory proved capable of maintaining U.S. Environmental Protection Agency‐recommended exposure conditions while providing flexibility for rapid deployment at multiple sites with minimal operational disruption. Further studies using this platform hold promise to resolve the convoluted interactions between complex effluents and inherent biological complexity.     

四川马边彝族自治县土地利用/覆被变化分析

采用基于最大似然法的监督分类方法对四川省马边彝族自治县1988年和2001年两期Landsate5 TM影像进行解译,利用单项土地利用动态指数〖WTBX〗（LUDI）、双向土地利用动态指数（Ki）以及土地利用类型转移矩阵（Cx×y）〖WTBZ〗等定量分析方法分析解译结果,得到马边县13年间土地利用/覆被动态及转移特征,并对可能的生态影响进行了分析预测。结果显示：①次生林面积增加,针叶林面积有所下降,灌草地被农田大量取代;②城镇及居民点和次生林的动态最为活跃,转入面积明显高于转出面积;③中山区和亚高山区林地构成发生变化,高山草甸面积有所萎缩,河谷区的阔叶林带被次生林大量取代,低山河谷区的土地破碎化程度增加。研究表明,13年间马边土地利用/覆被变化具有动态高、转换活跃、空间性强以及人为活动干扰影响明显等特点。其中,低山丘陵区的灌草坡大量被农地替代、中山区和亚高山区次生林面积扩大应该作为生态退化的信号加以重视。另外,气候变化对马边森林植被演替可能产生的影响应在今后进行深入的分析研究     

Phosphorus Loadings Associated with a Park Tourist Attraction: Limnological Consequences of Feeding the Fish

The Linesville spillway of Pymatuning State Park is one of the most visited tourist attractions in Pennsylvania, USA, averaging more than 450,000 visitors · year⁻¹. Carp (Cyprinus carpio Linnaeus) and waterfowl congregate at the spillway where they are fed bread and other foods by park visitors. We hypothesized that the “breadthrowers” constitute a significant nutrient vector to the upper portion of Pymatuning Reservoir. In the summer of 2002, we estimated phosphorus loadings attributable to breadthrowers, and compared these values to background loadings from Linesville Creek, a major tributary to the upper reservoir. Items fed to fish included bread, donuts, bagels, canned corn, popcorn, corn chips, hot dogs, birthday cakes, and dog food. Phosphorus loading associated with park visitors feeding fish was estimated to be 3233 g day⁻¹, and estimated P export from the Linesville Creek watershed was 2235 g·day⁻¹. P loading attributable to breadthrowers exceeded that of the entire Linesville Creek watershed on 33 of the 35 days of study, with only a heavy rainfall event triggering watershed exports that exceeded spillway contributions. Averaged across 5 weeks, breadthrowers contributed 1.45-fold more P to Pymatuning Reservoir than the Linesville Creek watershed. If Linesville Creek P exports are extrapolated to the entire Sanctuary Lake watershed, spillway contributions of P added 48% to the non-point source watershed P entering the lake. Park visitors feeding fish at the Linesville Spillway are a significant source of nutrients entering Sanctuary Lake.     

SIMULATED IMPACTS OF EL NINO/SOUTHERN OSCILLATION ON UNITED STATES WATER RESOURCES1

ABSTRACT: The El Nino/Southern Oscillation (ENSO) phenomena alter global weather patterns with consequences for fresh water supply. ENSO events impact regions and their natural resource sectors around the globe. For example, in 1997 and 1998, a strong El Nino brought warm ocean temperatures, flooding, and record snowfall to the west coast of the United States. Research on ENSO events has improved long range climate predictions, affording the potential to reduce the damage and economic cost of these weather patterns. Here, using the Hydrologic Unit Model for the United States (HUMUS), we simulate the impacts of four types of ENSO states (Neutral, El Niño, La Niña, and strong El Niño) on water resources in the conterminous United States. The simulations show that La Niña conditions increase water yield across much of the country. We find that water yield increases during El Niño years across the south while declining in much of the rest of the country. However, under strong El Niño conditions, regional water yields are much higher than Neutral, especially along the West Coast. Strong El Niño is not simply an amplification of El Niño; it leads to strikingly different patterns of water resource response.