Delivery of upper-basin sediment to the lower neuse river,North Carolina,U.S.A.

Extensive storage of upper-basin Piedmont sediment and apparent low sediment supply to streams in lower-basin Coastal Plain areas generates questions as to the source of alluvium in lower reaches of rivers of the U.S. Atlantic drainage. This was investigated on the Neuse River, North Carolina, using a mineralogical indicator of sediment source areas. The utility of mica flakes for discriminating between Piedmont and non-Piedmont sources of sediment in the lower Coastal Plain reaches of the Neuse was established on the basis of an examination of the U.S. National Soils Database and of 26 soil surveys of the North Carolina Coastal Plain. From the Neuse River estuary to 48 km upstream there are no mica flakes in floodplain soils or in river bank and channel shelf sediments. Mica flakes become more common upstream. This suggests that a very small proportion of the sediment eroded in the Piedmont portion of the watershed is delivered to the river mouth. The small amounts which presumably do reach the lower Coastal Plain are so diluted by Coastal Plain-derived alluvium that no Piedmont origin can be discerned. This demonstrates a dominantly Coastal Plain source and underscores the importance of storage and discontinuous transport in fluvial sediment systems. More importantly, results suggest that upper- and lower-basin sediment dynamics are not only non-linearly related, but may be virtually decoupled.     

Effects of climate change on coastal fresh groundwater resources

This study evaluates the impacts of climate change on fresh groundwater resources specifically salinity intrusion in water resources stressed coastal aquifers. Our assessment used the Hadley Centre climate model, HadCM3 with high and low emission scenarios (SRES A2 and B2) for years 2000–2099. In both scenarios, the annual fresh groundwater resources losses indicate an increasing long-term trend in all stressed areas, except in the northern Africa/Sahara region. We also found that precipitation and temperature individually did not show good correlations with fresh groundwater loss. However, the relationship between the aridity index and fresh groundwater loss exhibited a strong negative correlation. We also discuss the impacts of loss of fresh groundwater resources on socio-economic activities, mainly population growth and per capita fresh groundwater resources.     

Chronology of an oyster reef on the coast of Bohai Bay, China: Constraints from optical dating using different luminescence signals from fine quartz and polymineral fine grains of coastal sediments

Fossil oyster reefs are indicators of past sea levels, and their formation is usually dated by means of radiocarbon. However, radiocarbon dating of the shells from coastal areas may be complicated by the varying sources of carbon. Here we applied optical dating methods to date the samples from above and below a fossil oyster bed in a section on the coast of Bohai Bay, China. The optical ages of the sediments were used to constrain the oyster bed. Single-aliquot regenerative-dose procedures using the OSL signal from fine grain quartz, the IRSL and post-IR OSL signals from polymineral fine grains were employed to determine equivalent dose (D_e). The behaviors of the different luminescence signals from quartz and polymineral grains during D_e measurements were examined. The results showed that the quartz OSL signal is more reliable than the polymineral IRSL and post-IR OSL signals with respect to dating for these coastal samples. The optical ages indicated that the oyster reef formed between ca. 6.2 and 5.0 ka.     

Holocone paleovegetation and paleohydrology of a prairie pothold in southern Saskatchewan, Canada

The Andrews site represents one of countless prairie potholes found in areas of hummocky moraine on the northern Great Plains. Sediments from a depth of 5.8 to 3.1 m at this 'kettle-fill' site in the Missouri Coteau upland of southern Saskatchewan, Canada, provides a record of vegetation, climate, and hydrologic changes within a small, ca 30 m diameter, closed-drainage basin from ca 10.2 to 5.8 ka. Plant macrofossil analyses of 67 samples, 6 ¹⁴C ages, and stratigraphy were used to identify 5 zones, representing the paleohydrological changes that followed deglaciation in southern Saskatchewan.Results of this study indicate that with the melting of residual stagnant ice a pond (>2 m deep) with abundant aquatic, emergent, and shoreline plants developed in the basin at ca 10.2 ka and persisted until at least ca 8.8 ka. During this time there was a shift in upland vegetation from a white spruce forest (Zone II) to a deciduous parkland at ca 10 ka (Zone III). As climate warmed, brackish and alkaline conditions developed coincident with shallowing of the pond at the end of Zone III. The perennial water phase ended at ca 8.8 ka and was followed by a low-water stand lasting ca 1100 years. Prairie fires and slopewash from unstable slopes were dominant sedimentological processes until ca 7.7 ka (Zone IV). Water levels began to rise and between ca 7.7 and 5.8 ka a semi-permanent pond was established in a grassland setting (Zone V). After ca 5.8 ka this prairie pothole wetland became ephemeral, to the point that plant macrofossils could not be preserved, a situation continuing today. Interactions between climate change, variability in local groundwater supply, and sedimentological processes likely account for the paleohydrologic events reconstructed at the Andrews site.     

Sea level,climate change and coastal evolution in Morar,northwest Scotland

Analyses of geomorphologically contrasting sites in Morar, NW Scotland, describe the forcing mechanisms of coastal change. Isolation basins (i.e. basins behind rock sills and now isolated from the sea following isostatic uplift) accumulated continuous marine and freshwater sediments from c.12 to 2 ka BP. Raised dune, marsh and wetland sites register breaching, migration and stability of dunes from c. 9 to 2 ka BP. High-resolution methods designed to address issues of macroscale and microscale sea-level changes and patterns of storminess include 1-mm sampling for pollen, dinocyst and diatom analyses, infra-red photography, X-ray photography and thin-section analysis. The data enhance the record of relative sea-level change for the area. Major phases of landward migration of the coast occurred during the period of low sea-level rise in the mid-Holocene as the rate of rise decreased from c. 3 to < 1 mm/year. Relative sea-level change controls the broad pattern of coastal evolution at each site; local site-specific factors contribute to short-term process change. There is no record of extreme events such as tsunami. Within a system of dynamic metastable equilibrium, the Holocene records show that site-specific factors determine the exact timing of system breakdown, e.g. dune breaching, superimposed on regional sea-level rise. The global average sea-level rise of 3 to 6 mm/yr by AD 2050 predicted by IPCC would only partly be offset in the Morar area by isostatic uplift of about 1 mm/yr. A change from relative sea-level fall to sea-level rise, in areas where the regional rate of uplift no longer offsets global processes, is a critical factor in the management of coastal resources.     

Evaluating infiltration losses in a Mediterranean wetland: Las Tablas de Daimiel National Park,Spain

Las Tablas de Daimiel National Park is a series of wetlands which naturally originated from groundwater discharges from the Mancha Occidental aquifer, Spain. Despite the relatively large size of this aquifer, 30 years of intensive groundwater pumping have significantly depleted the water table. As a result, wetlands only remain functional due to artificial inflows. Infiltration loss is therefore a key parameter to evaluate how much water is needed to maintain ecosystem functionality. Although yearly infiltration estimates existed prior to this work, these did not take into account key parameters such as the temporal evolution of the flooded area. This paper presents a more concrete estimate of the average infiltration losses. Infiltration is calculated as the closure term of daily water balances during a period of time where all other elements were known to an acceptable accuracy. A validation mechanism is provided to check the potential utility of the calculated infiltration in wetland management practices. Copyright © 2008 John Wiley & Sons, Ltd.     

Wetlands with controlled drainage and sub‐irrigation systems—modelling of the water balance

Over the past centuries, the agricultural use of wetlands in Central Europe has required interference with the natural wetland water balance. Often this has consisted of drainage measures alone. In low‐precipitation areas, it has also involved the operation of combined drainage and sub‐irrigation systems. Model studies conducted as part of planning processes, or with a view to finding out the impact of changing climate conditions on the water balance of wetlands, must take these facts into account. For this reason, a water balance model has been devised for wetlands whose water balance is governed by water resources management systems. It is based on the WBalMo model system. Special modules were integrated into WBalMo to calculate the water balance of wetland areas (WABI module) and to regulate inflow partitioning within the wetland (REGINF module). When calculating the water balance, the WABI module takes into account precipitation and potential evapotranspiration, groundwater levels below surface, soil types, land‐use classes, inflows via the running water system, and data for target water levels. It provides actual evapotranspiration, discharge into the running water system, and groundwater levels in the area. The example of the Spreewald, a major wetland area in north‐eastern Germany, was used to design and test the WBalMo Spreewald model. The comparison of measured and calculated water balance parameters of the wetland area confirms the suitability of the model for water balance studies in wetlands with complex water resources management systems. The results reveal the strong influence of water management on the water balance of such areas. The model system has proved to be excellently suited for planning and carrying out water management measures aimed at the sustainable development of wetlands. Furthermore, scenario analyses can be used to assess the impact of global change on the water balance of wetlands. Copyright © 2006 John Wiley & Sons, Ltd.     

Each fisherman is different: Taking the environmental perception of small-scale fishermen into account to manage marine protected areas

One of the reasons for the failure of some Marine Protected Areas (MPAs) is the lack of respect for their boundaries and regulations, which intensifies the need to assess the attitudes of stakeholders affected by MPAs. To this end, it is necessary to know the perception and behavior of resource users in these areas in relation to the management process. This study addressed the perception of different groups of fishermen in three MPAs that allow sustainable use of resources on the Brazilian northeastern coast. The perception analysis was based on four aspects: biodiversity conservation, flexibility and adaptability of fishermen, participation in management and opinions about the MPA. The interviewed fishermen (n=100) were classified into natives or immigrants,≥than 40 years old or <40, predominant use of selective or nonselective fishing gear and part or full time fishermen. The results showed that younger fishermen and the ones who use selective fishing gear presented a more conservation prone perception; nonselective fishermen and part-time fishermen were more flexible and adaptable to changes; and younger fishermen tended to agree more with the establishment of the MPAs. Taking these differences in perceptions among fishermen into account could serve as a basis for improvements in the management and conservation of fishing resources, besides helping predict possible future behavior due to changes in management policies.     

Biogeographic assessments: A framework for information synthesis in marine spatial planning

This paper presents the Biogeographic Assessment Framework (BAF), a decision support process for marine spatial planning (MSP), developed through two decades of close collaborations between scientists and marine managers. Spatial planning is a considerable challenge for marine stewardship agencies because of the need to synthesize information on complex socio-ecological patterns across geographically broad spatial scales. This challenge is compounded by relatively short time-frames for implementation and limited financial and technological resources. To address this pragmatically, BAF provides a rapid, flexible and multi-disciplinary approach to integrate geospatial information into formats and visualization tools readily useable for spatial planning. Central to BAF is four sequential components: (1) Planning; (2) Data Evaluation; (3) Ecosystem Characterization; and (4) Management Applications. The framework has been applied to support the development of several marine spatial plans in the United States and Territories. This paper describes the structure of the BAF framework and the associated analytical techniques. Two management applications are provided to demonstrate the utility of BAF in supporting decision making in MSP.     

Deterministic and ensemble storm surge prediction for Atlantic Canada with lead times of hours to ten days

Regional deterministic and ensemble surge prediction systems (RDSPS and RESPS respectively) are used to forecast sea levels off the east of Canada and northeast US. The surge models for the RDSPS and RESPS have grid spacings of 1/30° and 1/12° respectively. The models are driven by surface air pressure and 10 m winds generated by operational global deterministic and ensemble prediction systems that are run operationally by the Canadian Meteorological Centre. Surge forecasts are evaluated for the period 1 March, 2013 to 31 March 2014. Based on traditional statistics (e.g., standard deviation of the difference between observations and predictions) both systems are shown to have skill in forecasting surges six days into the future. It is shown however that skill exists beyond six days if allowance is made for errors in the timing of large surges. The usefulness of the RESPS is demonstrated for two positive surges (important for coastal flooding and erosion) and a negative surge (important for safe navigation in shallow water). It is shown that the RESPS can identify events not forecast by the RDSPS, and can also add useful additional information on the timing of the surge, an important consideration in tidally dominated waters. Several new types of display are used to illustrate the sort of information that can be generated by the RESPS to support the issuers of warnings of unusually high and low total water levels.