Some considerations on coastal processes relevant to sea level rise

The effects of potential sea level rise on the shoreline and shore environment have been briefly examined by considering the interactions between sea level rise and relevant coastal processes. These interactions have been reviewed beginning with a discussion of the need to reanalyze previous estimates of eustatic sea level rise and compaction effects in water level measurement. This is followed by considerations on sea level effects on coastal and estuarine tidal ranges, storm surge and water level response, and interaction with natural and constructed shoreline features. The desirability to reevaluate the well known Bruun Rule for estimating shoreline recession has been noted. The mechanics of ground and surface water intrusion with reference to sea level rise are then reviewed. This is followed by sedimentary processes in the estuaries including wetland response. Finally comments are included on some probable effects of sea level rise on coastal ecosystems. These interactions are complex and lead to shoreline evolution (under a sea level rise) which is highly site-specific. Models which determine shoreline change on the basis of inundation of terrestrial topography without considering relevant coastal processes are likely to lead to erroneous shoreline scenarios, particularly where the shoreline is composed of erodible sedimentary material. With some exceptions, present day knowledge of shoreline response to hydrodynamic forcing is inadequate for long-term quantitative predictions. A series of interrelated basic and applied research issues must be addressed in the coming decades to determine shoreline response to sea level change with an acceptable degree of confidence. (PDF contains 189 pages.

Leeds: a geological background for planning and development : 1:10000 sheets SE23NW, NE, SE and SE33NW, NE, SW, SE: parts of 1:50000 geological sheets 69 (Bradford), 70 (Leeds), 77 (Huddersfield) and 78 (Wakefield)

This study, carried out between 1989 and 1991, was commissioned by the Department of the Environment and funded jointly by the Department and the British Geological Survey. Its principal aim was to produce a synthesis of geological information relevant to the land-use planning for development and redevelopment for a large part of the Leeds district. This report is aimed at those involved in planning and development. Much of the information is provided on a series of thematic maps, each of which concentrates on a specific aspect of the geology relevant to landuse. These are suitable for use in forward planning for development and conservation, and as a background to desk studies, prepared in advance of specific development proposals. However, they must not be used in place of results of adequate site investigations when development is being considered. In addition to the information contained in the report, sources of other more detailed data are indicated

Stormwater-Pavement Interface in Cold Climates

This project relates to “managing stormwater runoff in cold climates” and addresses the feasibility of low-impact development at a regional demonstration site in eastern Washington. The studies relate to seven large permeable pavement systems. The findings for similar climates and soils are as follows: The draindown times for retention in Palouse or similar clay soils may handle many typical storms. On average, every square foot of a permeable pavement system installed also receives run-on from another square foot of impermeable pavement, doubling its impact on both stormwater quantity reduction and stormwater quality improvement. Most of the clogged sections on various applications were downslope of other areas. Permeable pavements installed in areas targeted for additional stormwater quantity control and quality improvement may be feasible. On average, the cleaning for installations is less frequent than annually. Power washing plus vacuuming appears to be an effective method for pervious concrete. Surface distress was usually where vehicles turned, or from placement activities. Preliminary studies on various surface treatments on pervious concrete show promise for added safety benefits under wintry conditions. Both detention-type and retention-type permeable pavement systems appear to have little negative impact on neighboring soils in the winter under the study conditions. However, further research is needed for different designs of retention-type systems to ensure that water volumes in the aggregate storage bed do not allow for sufficient water flow into neighboring soils that might result in ice lens formation or other negative impacts

Engineering geology of British rocks and soils : Lias Group

The report begins with an introduction and a detailed modern assessment of the geology of the Lias Group in terms of both stratigraphy and lithology. The modern lithostratigraphy is placed in the context of the old, and sometimes more familiar, usage. The next two chapters deal with the mineralogy of a suite of samples collected for the project, and an assessment of the nature and influence of weathering based on a detailed analysis of the Lias dataset held in the BGS National Geotechnical Properties Database. The following chapters cover geohazards associated with the Lias Group, and a brief overview of the wide variety of industrial applications for which the Lias is well known. The geotechnical database forms the basis of the penultimate chapter, geotechnical properties. The contents of the database are analysed, interpreted, presented in graphical form, and discussed in terms of statistical variation and in the light of likely engineering behaviour. The engineering geology of the Lias Group is discussed in the final chapter, borrowing from the preceding chapters. A comprehensive cited reference list and a bibliography are provided. In addition to the large number of technical data provided to BGS, a small data set has been generated by BGS laboratories, particularly in areas where the main database was deficient, and also in connection with associated BGS studies of the swelling and shrinkage properties of the Lias Group. The individual items of data making up the database are not attributed. However, the contribution of a wide range of consultancies, contractors, authorities, and individuals is acknowledged. It is hoped that this report will provide a source of useful information to a wide range of engineers, planners, scientists, and other interested parties concerned with Lias Group materials. It should be noted that whilst quantitative technical data are included in this report, these should not be used as a substitute for proper site investigation

Long-term Evaluation of Permanent Seeding and Mulching Practices

Vegetation cover is required on disturbed land resulting from construction activities. The West Virginia Division of Highways (WVDOH) specifications for seeding and mulching currently includes seed mixtures that contain species that are considered highly invasive by the West Virginia Division of Natural Resources (WVDNR). This work evaluated the use of experimental seed mixtures at roadside locations by considering two major objectives: i) evaluating long-term performance of experimental mixtures over multiple growing seasons, and ii) investigating sediment yield from vegetation cover practice.;First, vegetation growth and persistence from four small-scale field plots were monitored through the second and third growing seasons. The first field plot compared vegetation resulting from current WVDOH seed mixtures to new native and low invasive experimental seed mixtures. The second field plot tested experimental seed mixtures and WVDOH mixtures at a high elevation location to determine success of an experimental high elevation mixture. The third field plot was prepared by varying seed bed preparation techniques: i) planting in existing soil using hydraulic erosion control product, ii) planting in existing soil using straw mulch, iii) planting in topsoil using hydraulic erosion control product, and iv) planting in topsoil using straw mulch. The final plot was prepared by varying soil amendments (e.g. planting in existing soil, topsoil, and two hydraulic growth mediums) and compared resulting vegetation of an experimental mowable areas mixture planted throughout the entire plot. All experimental mixtures, except experimental high elevation mixture, were found to perform as well or better than current WVDOH seed mixtures. There was no significant difference between seed bed preparation with respect to resulting ground cover or biomass. Soil amendments were found to be comparable alternatives to topsoil and are being recommended to WVDOH specifications.;Second, runoff collection devices were constructed and deployed at one subplot of each of the four varying seed bed preparations. The traps collected runoff from storm events, and the runoff was analyzed for nutrients and sediment yield. Field-measured sediment yield was compared to estimated sediment yield that was calculated using the Modified Universal Soil Loss Equation (MUSLE). Limitations of the study did not allow accurate comparisons between the MUSLE and actual sediment yield. However, lack of runoff during one storm event proved that vegetation from all seed bed preparations completely prevents runoff from small storm events (≤ 0.5 in (1.27 cm)). Future work should include monitoring of experimental mixtures over further growing seasons

Behaviour of compacted silt used to construct flood embankment

This paper investigates the unsaturated mechanical behaviour of a fill material sampled from flood embankments located along the Bengawan Solo River in Indonesia. In order to gain a better understanding of this fill material, in situ tests were carried out alongside an extensive laboratory programme. Two different phenomena related to changes in moisture content of the embankment fill material are experimentally studied herein: (a) volumetric collapse and (b) variation in shear strength with suction. At low densities, similar to those found in situ, the material exhibited significant volumetric collapse behaviour. Triaxial tests carried out under saturated, suction-controlled and constant water content conditions indicate that the shear strength of the material increased with suction; in particular the effective angle of friction increased from 24.9 degrees under saturated conditions to 35.8 degrees under air-dried conditions

Tracking machinery to investigate the effect of compaction during sugar cane harvesting

The Australian sugar industry is a major part of the agricultural sector within Queensland and New South Wales. Through research it was noticed that there was no easy way for producers to evaluate the traffic pathways through the field. Therefore an investigation was devised to track the machinery during sugar cane harvesting to determine the potential increase in bulk density and therefore the decrease in plant production. A field trial was conducted in the Bundaberg region to assess the validity of such a program constructed to use GPS (global positioning system) data gathered from the load-out bins. Manual observations of the load-out bins during harvesting were also conducted to help validate the program. It was concluded that the program reported the correct answer, but was not running correctly due to limitations. The program was developed to report the number of times the growing bed was crossed and to help identify the potential loss of production in terms of sugar cane yield. From the measurements taken as part of the field trial, an average increase of 0.153tonne/m3 was witnessed within the traffic lanes. From this data, a yield decrease of 5% was inferred and subsequently a profit reduction of $0.03 per metre of growing bed crossed

A study on ground improvement using a combination of stone and concrete columns

Stone column is a cost-effective ground improvement technique that is typically employed for low-rise buildings and road embankments. This technique mainly uses naturally occurring materials as its load transferring medium. However, stone columns have some constraints because of the loose interactions between their aggregates which can lead to uncontrolled settlements, especially in soft soils. As a result, their performance is usually improved by the inclusion of geosynthetics either in layers or as a confinement. However, there was a lack of studies that used a binder within the stone column aggregates with a view to limit the bulging/lateral spreading of its aggregates in such soils. In this study, the upper portion of the stone columns was replaced by different grades of unreinforced concrete. The length of the concrete, as well as the depth of the soil beneath the columns, were varied. The effects of these different variables, when the resulting column was subjected to an applied load, were investigated. The optimum configuration of the above was identified and its resulting change in performance when it was combined with a reinforced bedding layer was studied. Considering application/installation procedures on site, it was best deemed to install and test a geosynthetic-reinforced bedding layer on top of, rather than within, the stone column. It was observed that increasing the grades of concrete did not have any consistent influence on the performance of the resulting columns when there was a considerable layer of soil beneath them. The hybrid stone columns (combination of stone and concrete) performed better than the normal stone column and even to a full concrete column of the same length in several cases. Physical modelling revealed that the bulging length ranges from 2.0-2.4D (D is the diameter of the column). Test results for the optimum hybrid stone column yielded a maximum load improvement factor of 3 to 6 folds (200% to 500% increase in bearing capacity) depending on their respective configuration compared to the unreinforced soil. The improvement factor was further increased to 9.9-fold (nearly 900% increase in bearing capacity) when the optimum hybrid stone column was tested in combination with a reinforced bedding layer. The findings from this research can be used to enhance and promote the stone column ground improvement technique while still providing an economical advantage as well

River Wyre salmon and sea trout spawning habitat restoration / creation project. Final report April 1995

Adult salmon and sea trout rod catches in the River Wyre have been subject to considerable variability over the years. Annual rod catches ranging from 6 to 401 have been reported since records began in 1905. It has long been suspected that the physical nature of the catchment, combined with anthropogenic influences, has resulted in a deleterious effect on the Wyre fishery. Acidification problems in the head water streams (Marshaw Wyre and Tarnbrook Wyre) have been reported and are thought to threaten salmon juvenile survival. The construction of Abbeystead Reservoir and an increased tendency towards rapidly rising water levels during storms (flashiness) 1 are thought to have a significant impact on spawning gravel quality and quantity, both of which are thought to be deteriorating. As part of an overall desire to maintain and improve the migratory salmonid population in the River Wyre, this project has been commissioned to investigate remedial action which may improve and enhance spawning success, leading to an eventual improvement in the status of adult stocks. The primary objective is to establish whether the quantity and/or quality of available spawning gravels are limiting migratory salmonid productivity. The investigations undertaken confirm the general observation that useable spawning gravels appear to be in short supply in the River Wyre, and may be the limiting factor influencing returning adult stock