Characteristics and dynamics of multiple intertidal bars,north Lincolnshire,England     

Selma van Houwelingen  Gerhard Masselink  Joanna Bullard 《地球表面变化过程与地形》2006,31(4):428-443

Multiple intertidal bars and troughs, often referred to as ‘ridges and runnels’, are significant features on many macrotidal sandy beaches. Along the coastline of England and Wales, they are particularly prevalent in the vicinity of estuaries, where the nearshore gradient is gentle and a large surplus of sediment is generally present. This paper examines the dynamics of such bar systems along the north Lincolnshire coast. A digital elevation model of the intertidal morphology obtained using LIDAR demonstrates that three to five intertidal bars are consistently present with a spacing of approximately 100 m. The largest and most pronounced bars (height = 0·5–0·8 m) are found around mean sea level, whereas the least developed bars (height = 0·2–0·5 m) occur in the lower intertidal zone. Annual aerial photographs of the intertidal bar morphology were inspected to try to track individual bars from year to year to derive bar migration rates; however, there is little resemblance between concurrent photographs, and ‘resetting’ of the intertidal profile occurs on an annual basis. Three‐dimensional beach surveys were conducted monthly at three locations along the north Lincolnshire coast over a one‐year period. The intertidal bar morphology responds strongly to the seasonal variation in the forcing conditions, and bars are least numerous and flattest during the more energetic winter months. Morphological changes over the monthly time scale are strongly affected by longshore sediment transport processes and the intertidal bar morphology can migrate along the beach at rates of up to 30 m per month. The behaviour of intertidal bars is complex and varies over a range of spatial and temporal scales in response to a combination of forcing factors (e.g. incident wave energy, different types of wave processes, longshore and cross‐shore sediment transport), relaxation time and morphodynamic feedback. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

P.G. Fookes, E.M. Lee and G. Milligan, Editors, Geomorphology for Engineers, Whittles Publishing, Dunbeath, Scotland, UK (2005) xxi + 851 pp., $229.95 hardback, USA ISBN 0-8493-9641-7; ISBN 1-870325-03-6.     

Joanna C. Curran   《Geomorphology》2007,86(3-4):537-538

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Trace element soil contamination from smelters in the Illawarra region,New South Wales,Australia     

Jafari  Yasaman  Jones  Brian G.  Pacheco  Joanna C.  Umoru  Sultan 《Environmental Earth Sciences》2020,79(15):1-11

Boundaries of densely populated areas can approach with time to old subsurface repositories of radioactive waste due to growth of settlement territories. P  相似文献   

Population dynamics and condition index of natural stock of blood cockle,Tegillarca granosa(Mollusca,Bivalvia,Arcidae) in the Marudu Bay,Malaysia     

Joanna W. Doinsing  Vienna Anastasia Admodisastro  Laditah Duisan  Julian Ransangan 《海洋学报(英文版)》2021,40(8):89-97

The population parameters of blood cockles, Tegillarca granosa in the intertidal zone of Marudu Bay, Sabah,Malaysia were investigated based on monthly length-weight frequency data(July 2017 to June 2018). A total of 279 cockle individuals with shell length and weight ranging from 27.7 mm to 82.2 mm and 13.11 g to 192.7 g were subjected to analysis. T. granosa in Marudu Bay showed a consistent moderately high condition index 4.98±0.86 throughout the year. The exponent b of the length-weight relationship was 2.6 demonstrating negative allometric growth. The estimated asymptotic length(L_∞), growth coefficient(K) and growth performance(?) of the T.granosa population in Marudu Bay were estimated at 86.68 mm, 0.98 a~(-1) and 3.87, respectively. The observed maximum shell length was 82.55 mm and the predicted maximum shell length was 84.44 mm with estimated maximum life span(t_(max)) of 3.06 years. The estimated mean lengths at the end of 2, 4, 6, 8, 10 and 12 months of age were 21.31 mm, 31.16 mm, 39.53 mm, 46.63 mm, 52.67 mm and 57.79 mm. Total, natural, and fishing mortalities were estimated at 2.39 a~(-1), 1.32 a~(-1) and 1.07 a~(-1). The exploitation level(E) was 0.45. Results of the current study also demonstrated that T. granosa in the Marudu Bay has two major recruitment peaks; one in March and another in October. The exploitation level revealed that natural stock of T. granosa in the Marudu Bay was approaching the maximum exploitation level. If such trend continues or demand for T. granosa is increasing,coupled with no effective fisheries management in place, possibility of the T. granosa population in the Marudu Bay to collapse is likely to elevate.  相似文献   

The dynamic effects of sediment availability on the relationship between wind speed and dust concentration          下载免费PDF全文

Tom Mockford  Joanna E. Bullard  Throstur Thorsteinsson 《地球表面变化过程与地形》2018,43(11):2484-2492

Where sediment supply is unlimited, previous research suggests that a strong, positive relationship between wind speed and dust concentration exists at the event scale. This relationship can break down if sediment availability is limited or changes during an event. This paper explores the dynamic effects of sediment availability on the relationship between wind speed and dust concentration using data from nine high‐latitude dust events recorded in Iceland. Of these events, six showed a strong positive relationship between wind speed and dust concentration. For the remainder, the relationship breaks down periodically during the event due to changing surface moisture conditions and atmospheric humidity. Results suggest a need to understand how spatial and temporal changes in humidity, surface soil moisture, soil texture and threshold velocity interact and control sediment availability for dust emissions in all environments, including at high latitudes. Copyright © 2018 John Wiley & Sons, Ltd.  相似文献   

Assessment of climate change and associated impact on selected sectors in Poland     

Zbigniew W. Kundzewicz  Mikołaj Piniewski  Abdelkader Mezghani  Tomasz Okruszko  Iwona Pińskwar  Ignacy Kardel  Øystein Hov  Mateusz Szcześniak  Małgorzata Szwed  Rasmus E. Benestad  Paweł Marcinkowski  Dariusz Graczyk  Andreas Dobler  Eirik J. Førland  Joanna O’Keefe  Adam Choryński  Kajsa M. Parding  Jan Erik Haugen 《Acta Geophysica》2018,66(6):1509-1523

The present paper offers a brief assessment of climate change and associated impact in Poland, based on selected results of the Polish–Norwegian CHASE-PL project. Impacts are examined in selected sectors, such as water resources, natural hazard risk reduction, environment, agriculture and health. Results of change detection in long time series of observed climate and climate impact variables in Poland are presented. Also, projections of climate variability and change are provided for time horizons of 2021–2050 and 2071–2100 for two emission scenarios, RCP4.5 and RCP8.5 in comparison with control period, 1971–2000. Based on climate projections, examination of future impacts on sectors is also carried out. Selected uncertainty issues relevant to observations, understanding and projections are tackled as well.  相似文献   

Factors Influencing Helophyte Distribution in Lakes (Eastern Poland)     

Joanna Sender  Urban  Danuta  Różańska-Boczula  Monika  Garbowski  Magda 《Water Resources》2020,47(2):315-324

Water Resources - The aim of the study was to show which morphometric traits of lakes influence the development of the rush zone of lakes and how buffer zone management influences analyzed features...  相似文献   

Implications of Nontraditional Housing Arrangements for Urban Water Management in the United States Intermountain West     

Matthew J. Barnett  Douglas Jackson-Smith  Joanna Endter-Wada 《社会与自然资源》2019,32(5):508-529

Homeowners living in single-family detached housing have dominated the literature exploring drivers of residential water use. Meanwhile, rentals, multiunit buildings, and residences governed by private associations are an increasingly important component of the American residential landscape. We used data from a large sample of households in northern Utah cities to explore the effects of these nontraditional housing arrangements on water use decision-making, attitudes and behaviors, and their implications for urban water management. After accounting for the sociodemographic characteristics of respondent households, we found that residents of nontraditional housing arrangements are much less likely to have authority over key water use decisions, and differ significantly from residents of traditional housing in regards to water use perceptions and concerns, self-reported water behaviors, and support for various local water policy options. Traditional approaches to urban residential water management should be adapted to renters, residents in multiunit buildings, and members of community associations.  相似文献   

Alkaline phosphatase activity in the western English Channel: Elevations induced by high summertime rainfall     

Andrew P. Rees  Sam B. Hope  Claire E. Widdicombe  Joanna L. Dixon  E. Malcolm S. Woodward  Mark F. Fitzsimons   《Estuarine, Coastal and Shelf Science》2009,81(4):569-574

Alkaline phosphatase activity (APA) was determined in bulk particulate material and in a single-cell (ELF) assay at station L4 in the western English Channel during the summer of 2007. Throughout this period, the UK experienced its heaviest summertime rainfall since records began in 1914; with the result that riverine run-off into coastal waters was also elevated relative to long-term averages. Between May and August 2007, three distinct periods of elevated river run-off were observed which resulted in salinity minima at L4 on days 141, 190 and 232. An extended period of high river run-off between days 170 and 210 was responsible for decreases in near-surface salinity at L4 from 35.2068 to a minimum on day 190 of 34.7422. This contributed to the development of haline stratification which supported the development of an intense bloom of the centric diatom Chaetoceros debelis, with maximum observed chlorophyll a concentration of 8.69 μg l⁻¹. Minima in salinity, and maxima in chlorophyll concentration on day 190 were coincident with a peak in river-derived dissolved inorganic nitrogen (DIN) of 1.9 μmol l⁻¹ which was >5 times greater than the summertime mean and 24 times the concentrations experienced at L4 on weeks immediately before and after. There was no accompanying increase in dissolved inorganic phosphorus (DIP), and the DIN:DIP ratio increased to 49. With the inherent phosphorus stress that this caused, rates of APA increased from <4 to 42.4 nmolP l⁻¹ h⁻¹. ELF analysis on day 197 identified two taxa actively expressing alkaline phosphatase: the dinoflagellate Prorocentrum micans and ciliate Tiarana sp.  相似文献   

New Zealand oceans governance: Calming turbulent waters?     

Joanna Vince  Marcus Haward 《Marine Policy》2009

In March 2000, New Zealand began the development of a national oceans policy. The oceans policy has weathered a number of challenges, most notably the dispute between Maori and the Crown over title to coastal land and water. This dispute stalled the development process in mid 2003 until work recommenced in November 2005. This paper analyses developments in New Zealand oceans governance, identifying the interaction between state, community and market as important influences that can help explain complexities of policy development, lack of sectoral integration and a change in policy direction.  相似文献