Knowledge gaps in our perceptual model of Great Britain's hydrology     

Thorsten Wagener  Simon J. Dadson  David M. Hannah  Gemma Coxon  Keith Beven  John P. Bloomfield  Wouter Buytaert  Hannah Cloke  Paul Bates  Joseph Holden  Louise Parry  Rob Lamb  Nick A. Chappell  Matthew Fry  Gareth Old 《水文研究》2021,35(7):e14288

There is a no lack of significant open questions in the field of hydrology. How will hydrological connectivity between freshwater bodies be altered by future human alterations to the hydrological cycle? Where does water go when it rains? Or what is the future space–time variability of flood and drought events? However, the answers to these questions will vary with location due to the specific and often poorly understood local boundary conditions and system properties that control the functional behaviour of a catchment or any other hydrologic control volume. We suggest that an open, shared and evolving perceptual model of a region's hydrology is critical to tailor our science questions, as it would be for any other study domain from the plot to the continental scale. In this opinion piece, we begin to discuss the elements of and point out some knowledge gaps in the perceptual model of the terrestrial water cycle of Great Britain. We discuss six major knowledge gaps and propose four key ways to reduce them. While the specific knowledge gaps in our perceptual model do not necessarily transfer to other places, we believe that the development of such perceptual models should be at the core of the debate for all hydrologic communities, and we encourage others to have a similar debate for their hydrologic domain.  相似文献   

Observations and Impacts from the 2010 Chilean and 2011 Japanese Tsunamis in California (USA)   总被引：3，自引：0，他引：3  

Rick I. Wilson  Amanda R. Admire  Jose C. Borrero  Lori A. Dengler  Mark R. Legg  Patrick Lynett  Timothy P. McCrink  Kevin M. Miller  Andy Ritchie  Kara Sterling  Paul M. Whitmore 《Pure and Applied Geophysics》2013,170(6-8):1127-1147

The coast of California was significantly impacted by two recent teletsunami events, one originating off the coast of Chile on February 27, 2010 and the other off Japan on March 11, 2011. These tsunamis caused extensive inundation and damage along the coast of their respective source regions. For the 2010 tsunami, the NOAA West Coast/Alaska Tsunami Warning Center issued a state-wide Tsunami Advisory based on forecasted tsunami amplitudes ranging from 0.18 to 1.43 m with the highest amplitudes predicted for central and southern California. For the 2011 tsunami, a Tsunami Warning was issued north of Point Conception and a Tsunami Advisory south of that location, with forecasted amplitudes ranging from 0.3 to 2.5 m, the highest expected for Crescent City. Because both teletsunamis arrived during low tide, the potential for significant inundation of dry land was greatly reduced during both events. However, both events created rapid water-level fluctuations and strong currents within harbors and along beaches, causing extensive damage in a number of harbors and challenging emergency managers in coastal jurisdictions. Field personnel were deployed prior to each tsunami to observe and measure physical effects at the coast. Post-event survey teams and questionnaires were used to gather information from both a physical effects and emergency response perspective. During the 2010 tsunami, a maximum tsunami amplitude of 1.2 m was observed at Pismo Beach, and over $3-million worth of damage to boats and docks occurred in nearly a dozen harbors, most significantly in Santa Cruz, Ventura, Mission Bay, and northern Shelter Island in San Diego Bay. During the 2011 tsunami, the maximum amplitude was measured at 2.47 m in Crescent City Harbor with over $50-million in damage to two dozen harbors. Those most significantly affected were Crescent City, Noyo River, Santa Cruz, Moss Landing, and southern Shelter Island. During both events, people on docks and near the ocean became at risk to injury with one fatality occurring during the 2011 tsunami at the mouth of the Klamath River. Evaluations of maximum forecasted tsunami amplitudes indicate that the average percent error was 38 and 28 % for the 2010 and 2011 events, respectively. Due to these recent events, the California tsunami program is developing products that will help: (1) the maritime community better understand tsunami hazards within their harbors, as well as if and where boats should go offshore to be safe, and (2) emergency managers develop evacuation plans for relatively small “Warning” level events where extensive evacuation is not required. Because tsunami-induced currents were responsible for most of the damage in these two events, modeled current velocity estimates should be incorporated into future forecast products from the warning centers.  相似文献   

Spatial variability of precipitation regimes over Turkey     

Faize Sariş  David M. Hannah  Warren J. Eastwood 《水文科学杂志》2013,58(2):234-249

Abstract

This study aims to predict the daily precipitation from meteorological data from Turkey using the wavelet—neural network method, which combines two methods: discrete wavelet transform (DWT) and artificial neural networks (ANN). The wavelet—ANN model provides a good fit with the observed data, in particular for zero precipitation in the summer months, and for the peaks in the testing period. The results indicate that wavelet—ANN model estimations are significantly superior to those obtained by either a conventional ANN model or a multi linear regression model. In particular, the improvement provided by the new approach in estimating the peak values had a noticeably high positive effect on the performance evaluation criteria. Inclusion of the summed sub-series in the ANN input layer brings a new perspective to the discussions related to the physics involved in the ANN structure.  相似文献   

Mainstreaming adaptation to climate change in Least Developed Countries (LDCs)     

Saleemul Huq  Hannah Reid  Mama Konate  Atiq Rahman  Youba Sokona  Florence Crick 《Climate Policy》2013,13(1):25-43

Abstract

The Least Developed Countries (LDCs) are a group of 49 of the world's poorest countries. They have contributed least to the emission of greenhouse gases (GHGs) but they are most vulnerable to the effects of climate change. This is due to their location in some of the most vulnerable regions of the world and their low capacities to adapt to these changes. Adaptation to climate change has become an important policy priority in the international negotiations on climate change in recent years. However, it has yet to become a major policy issue within developing countries, especially the LDCs. This article focuses on two LDCs, namely Bangladesh and Mali, where progress has been made regarding identifying potential adaptation options. For example, Bangladesh already has effective disaster response systems, and strategies to deal with reduced freshwater availability, and Mali has a well-developed programme for providing agro-hydro-meteorological assistance to communities in times of drought. However, much remains to be done in terms of mainstreaming adaptation to climate change within the national policymaking processes of these countries. Policymakers need targeting and, to facilitate this, scientific research must be translated into appropriate language and timescales.  相似文献   

Remote sensing in hydrology   总被引：4，自引：0，他引：4  

Thomas J. Schmugge  William P. Kustas  Jerry C. Ritchie  Thomas J. Jackson  Al Rango 《Advances in water resources》2002,25(8-12)

Remote sensing provides a means of observing hydrological state variables over large areas. The ones which we will consider in this paper are land surface temperature from thermal infrared data, surface soil moisture from passive microwave data, snow cover using both visible and microwave data, water quality using visible and near-infrared data and estimating landscape surface roughness using lidar. Methods for estimating the hydrometeorlogical fluxes, evapotranspiration and snowmelt runoff, using these state variables are also described.  相似文献   

THE USE OF TRACERS TO STUDY SEDIMENT SOURCES IN THREE STREAMS IN NORTHEASTERN OREGON     

Gregory N. Nagle  Jerry C. Ritchie 《自然地理学》2013,34(4):348-366

This pilot study used sediment tracers to identify general source areas of channel bottom sediment within three tributaries of the Umatilla and upper Grande Ronde basins in northeastern Oregon. Land use in each stream was dominated by agriculture, logging, or grazing. The nuclear bomb-derived radionuclide ¹³⁷Cs, carbon, and nitrogen were used as tracers to fingerprint sediment sources. Sediment was collected from the stream bottom inside the active channels and compared to samples from the surface horizon and channel banks. Samples were processed to separate the <63 μm fraction and characterized on the basis of tracer concentrations. A simple mixing model was used to estimate the relative portion of channel bottom sediment derived from the surface horizon and channel banks. Calculations from the ¹³⁷Cs tracer indicated that channel banks accounted for 56%, 74%, and 93% of the bottom sediment in the three study drainages, although these figures have a high margin of error. ¹³⁷Cs proved unexpectedly useful in the identification of actively eroding alluvial deposits deposited since the mid-1950s in one study area, likely resulting from the floods of 1964 and 1965. [Key words: bank erosion, ¹³⁷Cs, sediment tracers, Columbia Basin, nonpoint sediment sources.]  相似文献   

Tourist behaviour,local values,and interpretation at Ulu<Emphasis Type="Underline">r</Emphasis>u: ‘The sacred deed at Australia’s mighty heart’     

Hannah Hueneke  Richard Baker 《GeoJournal》2009,74(5):477-490

This paper explores issues relating to multiple and changing values and uses of desert landscapes in the context of tourism at Uluru-Kata Tjuta National Park (UKTNP), co-managed by Aboriginal people and the Australian Government agency Parks Australia. More than 400,000 people visit the park each year, drawn mostly by the massive red monolith. To the local Aboriginal people, Anangu, this rock is Uluru, a complex of places with great spiritual importance. Since co-management, UKTNP has become a symbol of the reconciliation process between Aboriginal and settler Australians. Climbing the rock is a popular activity. Aboriginal co-managers ask visitors not to climb Uluru but rather to learn about their culture and home through their eyes. Park management aims to discourage climbing. This research investigated how visitors respond to the Anangu request not to climb, and why some climb while others do not. We argue that spatial and experiential aspects of the park support climbing at the expense of participation in other activities more attuned to Aboriginal understandings of landscape at Uluru.  相似文献   

Effects of habitat complexity on cannibalism rates in European green crabs (Carcinus maenas Linnaeus, 1758)          下载免费PDF全文

Hannah Gehrels  Paula Tummon Flynn  Ruth Cox  Pedro A. Quijón 《Marine Ecology》2017,38(5)

The habitat in which predator–prey interactions take place may have a profound influence on the outcome of those interactions. Cannibalism is an intriguing form of predation whereby foraging by predators may contribute to the regulation of their own populations.This is particularly interesting in the case of invasive species, like the widely distributed European green crab (Carcinus maenas). This study explores how habitat complexity influences cannibalism rates in green crab populations of Prince Edward Island, Atlantic Canada. Both laboratory and field experiments were conducted to measure feeding rates by individual adult green crabs on a standard number of smaller conspecifics. In the laboratory, experimental treatments mimicked unstructured to increasingly structured habitats: water, sandy bottom, oyster shells, mussel shells, oyster shells with sandy bottom and mussel shells with sandy bottom. In those trials, adult green crabs consumed several times more juveniles on unstructured habitats than on the most structured ones, with a gradual decrease in predation rates across increasingly complex habitats. Field inclusion experiments used the same approach and were conducted in sandy bottoms, sandy bottoms with a layer of oyster shells and sandy bottoms with a layer of mussel shells. These trials showed similar patterns of decreasing feeding rates across increasingly complex habitats, but differences among treatments were not significant. These results support the idea that complex habitats have the potential to mediate predator–prey interactions, including adult–juvenile cannibalism in green crabs.  相似文献   

Natural and Anthropogenic Geohazards in Greater London Observed from Geological and ERS-1/2 and ENVISAT Persistent Scatterers Ground Motion Data: Results from the EC FP7-SPACE PanGeo Project     

Francesca Cigna  Hannah Jordan  Luke Bateson  Harry McCormack  Claire Roberts 《Pure and Applied Geophysics》2015,172(11):2965-2995

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Generating dark matter halo merger trees     

Hannah Parkinson  Shaun Cole  John Helly 《Monthly notices of the Royal Astronomical Society》2008,383(2):557-564

We present a new Monte Carlo algorithm to generate merger trees describing the formation history of dark matter haloes. The algorithm is a modification of the algorithm of Cole et al. used in the galform semi-analytic galaxy formation model. As such, it is based on the Extended Press–Schechter theory and so should be applicable to hierarchical models with a wide range of power spectra and cosmological models. It is tuned to be in accurate agreement with the conditional mass functions found in the analysis of merger trees extracted from the Λ cold dark matter Millennium N -body simulation. We present a comparison of its predictions not only with these conditional mass functions, but also with additional statistics of the Millennium Simulation halo merger histories. In all cases, we find it to be in good agreement with the Millennium Simulation and thus it should prove to be a very useful tool for semi-analytic models of galaxy formation and for modelling hierarchical structure formation in general. We have made our merger tree generation code and code to navigate the trees available at http://star-www.dur.ac.uk/~cole/merger_trees .  相似文献