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91.
Climate change and river flooding: Part 2 sensitivity characterisation for british catchments and example vulnerability assessments 总被引:4,自引:0,他引:4
This paper is the second of a series describing a scenario-neutral methodology to assess the sensitivity and vulnerability of British catchments to changes in flooding due to climate change. In paper one, nine flood sensitivity types were identified from response surfaces generated for 154 catchments. The response surfaces describe changes in 20-year return period flood peaks (RP20) in response to a large set of changes in precipitation, temperature and potential evapotranspiration. In this paper, a recursive partitioning algorithm is used to link families of sensitivity types to catchment properties, via a decision tree. The tree shows 85 % success characterising the four sensitivity families, using five properties and nine paths. Catchment annual average rainfall is the primary partitioning factor, with drier catchments having a more variable response to climate (precipitation) change than wetter catchments and higher catchment losses and permeability being aggravating factors. The full sensitivity-exposure-vulnerability methodology is illustrated for two catchments: sensitivity is estimated by using the decision tree to identify the sensitivity family (and its associated average response surface); exposure is defined from a set of climate model projections and combined with the response surface to estimate the resulting impacts (changes in RP20); vulnerability under a range of adaptive capacity thresholds is estimated from the set of impacts. Even though they are geographically close, the two catchments show differing vulnerability to climate change, due to their differing properties. This demonstrates that generalised response surfaces characterised by catchment properties are useful screening tools to quantify the vulnerability of catchments to climate change without the need to undertake a full climate change impact study. 相似文献
92.
Christopher J. Jarchow William J. Waugh Kamel Didan Armando Barreto-Muñoz Stefanie Herrmann Pamela L. Nagler 《水文研究》2020,34(12):2739-2749
Because groundwater recharge in dry regions is generally low, arid and semiarid environments have been considered well-suited for long-term isolation of hazardous materials (e.g., radioactive waste). In these dry regions, water lost (transpired) by plants and evaporated from the soil surface, collectively termed evapotranspiration (ET), is usually the primary discharge component in the water balance. Therefore, vegetation can potentially affect groundwater flow and contaminant transport at waste disposal sites. We studied vegetation health and ET dynamics at a Uranium Mill Tailings Radiation Control Act (UMTRCA) disposal site in Shiprock, New Mexico, where a floodplain alluvial aquifer was contaminated by mill effluent. Vegetation on the floodplain was predominantly deep-rooted, non-native tamarisk shrubs (Tamarix sp.). After the introduction of the tamarisk beetle (Diorhabda sp.) as a biocontrol agent, the health of the invasive tamarisk on the Shiprock floodplain declined. We used Landsat normalized difference vegetation index (NDVI) data to measure greenness and a remote sensing algorithm to estimate landscape-scale ET along the floodplain of the UMTRCA site in Shiprock prior to (2000–2009) and after (2010–2018) beetle establishment. Using groundwater level data collected from 2011 to 2014, we also assessed the role of ET in explaining seasonal variations in depth to water of the floodplain. Growing season scaled NDVI decreased 30% (p < .001), while ET decreased 26% from the pre- to post-beetle period and seasonal ET estimates were significantly correlated with groundwater levels from 2011 to 2014 (r2 = .71; p = .009). Tamarisk greenness (a proxy for health) was significantly affected by Diorhabda but has partially recovered since 2012. Despite this, increased ET demand in the summer/fall period might reduce contaminant transport to the San Juan River during this period. 相似文献
93.
Christian Sue Bastien Delacou Jean‐Daniel Champagnac Cecile Allanic Martin Burkhard 《地学学报》2007,19(3):182-188
Neotectonics of the Western and Central Alps is characterized by ongoing widespread extension in the highest zones of the chain and transcurrent/compressive tectonics at the external limits of the belt. The overall geodetically measured deformations also indicate extension across the Western Alps. There is a good qualitative coherency between seismotectonic and geodetic approaches. Here we attempt to quantify the seismic part of the deformation. The seismic strain is compared to the deformation derived from geodesy. In sub‐areas of homogeneous seismic stress/strain, we computed the total seismic moment tensor and related strain tensor. This study provides new quantitative elements about the ongoing geodynamic processes in the alpine belt. The important discrepancies obtained between seismic strains and geodetically‐measured deformations raise the issue of aseismic deformation in the Alps, which could be related to elastic loading, creeping and/or a slower ductile‐style deformation. 相似文献
94.
O. I. Wong E. V. Ryan-Weber D. A. Garcia-Appadoo R. L. Webster L. Staveley-Smith M. A. Zwaan M. J. Meyer D. G. Barnes V. A. Kilborn R. Bhathal W. J. G. de Blok M. J. Disney M. T. Doyle M. J. Drinkwater R. D. Ekers K. C. Freeman B. K. Gibson S. Gurovich J. Harnett P. A. Henning H. Jerjen M. J. Kesteven P. M. Knezek B. S. Koribalski S. Mader M. Marquarding R. F. Minchin J. O'Brien M. E. Putman S. D. Ryder E. M. Sadler J. Stevens I. M. Stewart F. Stootman M. Waugh 《Monthly notices of the Royal Astronomical Society》2006,371(4):1855-1864
95.
We describe the process used in the fisheries management system of the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) to minimise seabird bycatch, and the risk-assessment methodology developed to assist this. We examine the progress of several Regional Fishery Management Organisations in taking steps to address seabird bycatch. CCAMLR has the most advanced system of management among the RFMOS covered in this review, and has made the most demonstrable progress in reducing seabird bycatch levels in its longline fisheries. A combination of proven mitigation measures, extensive monitoring by independent observers, annual expert review of seabird bycatch rates and evolving fishery and mitigation practices have been instrumental in reducing seabird bycatch in CCAMLR fisheries. 相似文献
96.
Kyung-Min Nam Caleb J. Waugh Sergey Paltsev John M. Reilly Valerie J. Karplus 《Global Environmental Change》2013,23(6):1648-1661
Air pollution has been recognized as a significant problem in China. In its Twelfth Five Year Plan, China proposes to reduce SO2 and NOx emissions significantly, and here we investigate the cost of achieving those reductions and the implications of doing so for CO2 emissions. We extend the analysis through 2050, and either hold emissions policy targets at the level specified in the Plan, or continue to reduce them gradually. We apply a computable general equilibrium model of the Chinese economy that includes a representation of pollution abatement derived from detailed assessment of abatement technology and costs. We find that China's SO2 and NOx emissions control targets would have substantial effects on CO2 emissions leading to emissions savings far beyond those we estimate would be needed to meet its CO2 intensity targets. However, the cost of achieving and maintaining the pollution targets can be quite high given the growing economy. In fact, we find that the near term pollution targets can be met while still expanding the use of coal, but if they are, then there is a lock-in effect that makes it more costly to maintain or further reduce emissions. That is, if firms were to look ahead to tighter targets, they would make different technology choices in the near term, largely turning away from increased use of coal immediately. 相似文献
97.
This is the text of a letter sent by the President of the RAS to Lord Sainsbury of Turville, Parliamentary Under Secretary of State for Science, following the Discussion Meeting on ESO. 相似文献
98.
The evolution of minor structures during the growth of major folds and thrusts, in the Chartreuse district of the French Subalpine thrust belt, shows that each thrust evolved through a phase of distributed faulting, major thrust propagation and displacement, followed by distributed shear modification of the hanging-wall fold. Microstructural studies suggest that the distributed faulting phases, early and late in the history, were characterized by strain rates limited by diffusive mass transfer processes ( c . 10-15 -10-16 s-1 ). Faulting whose rate is limited by DMT is too slow on its own to accommodate the regional time-averaged shortening rates for the thrust belt as a whole, implying that the slow thrusts operated in tandem with those major, fast thrusts where deformation was primarily cataclastic. Consequently each thrust anticline experienced a displacement rate cycle and an array of thrust anticlines must amplify simultaneously. These interpretations raise important issues for the dynamics of fault populations, the evolution of thrust wedges and the history of fluid migration in thrust belts. 相似文献
99.
The New Zealand snapper Chrysophrys auratus is the object of a major fishery and contributes approximately 30% of the annual landed weight of fin‐fish. Samples of 65 fish from 7 localities on the New Zealand coast were analysed for mercury. Though there is an increase in mercury concentration with size of fish, the larger, older individuals with relatively high mercury levels contribute only a small proportion to the landed catch. Therefore, in establishing the average concentration of mercury in fish, due weight should be accorded to the differences in size composition of the catch. On this basis the average levels of mercury in snapper offered for human consumption are of the order of 0.25 ppm. As this is only half the “permissible safe level” of most other countries where fish consumption is much higher, the risk to the New Zealand consumer is negligible. 相似文献
100.
Dietary samples collected at Campbell Island in summer 1997 indicate that southern blue whiting (Micromesistius australis) formed the bulk of the food of black‐browed albatrosses (Diomedea melanophrys impavida) during the chick‐rearing period. Birds preyed upon a single size class of fish with a mode at 80–90 mm standard length; fish were 4–5 months old and belonged to the 0+ age group. Satellite tracking showed that, when performing trips of short duration, adult albatrosses foraged within the 1000 m depth contour in the subantarctic zone north of Campbell Island. The feeding ecology of albatrosses thus suggests that juvenile (0+) southern blue whiting are pelagic and occur in dense schools in the top 5 m of the water column over the Campbell Plateau during the summer months. The high reliance of birds on juvenile southern blue whiting during the chick‐rearing period has implications for the management of the southern blue whiting fishery and the conservation of black‐browed albatrosses and other marine predators occurring in the New Zealand subantarctic area. 相似文献