Use of terrestrial photogrammetry for monitoring and measuring bank erosion

This paper examines the use of terrestrial photogrammetry as a technique for measuring bank erosion in a rapidly changing fluvial environment. It has been recognized that there are a number of advantages when applying photogrammetric techniques to geomorphological situations. In this study the enhancement of spatial sampling combined with the ability to capture additional information, such as soil moisture, on film, is of particular importance in enabling the identification of specific processes involved in bank erosion as well as detailed volumetric analysis of losses. Metric terrestrial photography was taken of the river bank on several dates, and data were abstracted by the use of analytical photogrammetry. This enabled the generation of digital terrain models from which morphological and volumetric changes could be assessed. © 1997 John Wiley & Sons, Ltd.     

How ready is ready? Measuring physical preparedness for severe storms

This paper investigates use of inventories, or checklists of activities, as an emergency management tool to motivate preparedness action in individuals. It develops the inventory concept to provide the foundation for a more targeted approach to storm preparation communication and community engagement. It also examines the potential efficacy of alternatives to paper-based checklists, such as web or smartphone applications. Academic and grey literature was reviewed to collect activities for a storm inventory for emergency agencies to measure individual preparedness and for individuals to measure their preparation progress. The resulting master list was refined for application and tested for useability in a pilot study of semi-structured interviews in a storm-susceptible community in Queensland, Australia. Also, clustering items by type of preparedness activity reveal where strengths and weaknesses exist in individual preparedness. For instance, preparation for leaving and safety planning were shown to be the areas of weakest activity in the pilot sample, while preparation of the house for a storm was the strongest area. In addition, behaviour change literature shows potential for effective use of an inventory-based smartphone application in motivating preparation activity. Data collected by a storm preparedness smartphone application could show where a communication or engagement program for targeted communities should be focused. It is supported by health literature that identifies preferences of individuals to make progress on complex tasks in stages, the value of lists to achievement of goals and demonstrated increase in uptake of activities prompted by smartphone applications over web or paper-based diaries.

     

Instrumentation Development for In Situ 40Ar/39Ar Planetary Geochronology

The chronology of the Solar System, particularly the timing of formation of extra‐terrestrial bodies and their features, is an outstanding problem in planetary science. Although various chronological methods for in situ geochronology have been proposed (e.g., Rb‐Sr, K‐Ar), and even applied (K‐Ar), the reliability, accuracy, and applicability of the ⁴⁰Ar/³⁹Ar method makes it by far the most desirable chronometer for dating extra‐terrestrial bodies. The method however relies on the neutron irradiation of samples, and thus a neutron source. Herein, we discuss the challenges and feasibility of deploying a passive neutron source to planetary surfaces for the in situ application of the ⁴⁰Ar/³⁹Ar chronometer. Requirements in generating and shielding neutrons, as well as analysing samples are described, along with an exploration of limitations such as mass, power and cost. Two potential solutions for the in situ extra‐terrestrial deployment of the ⁴⁰Ar/³⁹Ar method are presented. Although this represents a challenging task, developing the technology to apply the ⁴⁰Ar/³⁹Ar method on planetary surfaces would represent a major advance towards constraining the timescale of solar system formation and evolution.     

Development and Testing of a Field Screening Method Based on Bubbling Extraction and Photoionization Detection for Measurement of Benzene and Total VOCs

A field screening method was developed for rapid measurement of benzene and gasoline range total petroleum hydrocarbons (TPHg) concentrations in groundwater. The method is based on collecting photoionization detector (PID) measurements from vapor samples. The vapor samples are collected by bubbling air through groundwater samples (air sparging) with a constant volume, temperature and sparging rate. The level of accuracy, sensitivity, precision, and statistical significance of the estimated concentrations, derived from the screening method, are comparable to conventional laboratory analytical results at concentrations equal to or greater than 150 µg/L for benzene and greater than 50 µg/L for TPHg. The method's concentration estimations can assist in making real‐time decisions regarding location of dissolved plumes and light nonaqueous phase liquid (LNAPL) source zones at many fuel release sites. The screening method was tested in the laboratory and in the field with 208 and 107 samples, respectively. The study concludes that the screening method can be used as a tool to aid in completing a site conceptual model as well as analyzing groundwater from monitoring wells.     

Length‐mass models for some common New Zealand littoral‐benthic macroinvertebrates,with a note on within‐taxon variability in parameter values among published models

Regression models are developed and presented to predict dry mass (mg) from two linear dimensions (mm) for 17 benthic macroinvertebrate taxa common to littoral zones of New Zealand lakes. We also provide regression models to predict body length from head capsule width for the major insect taxa. Dry mass was best explained as a power function of all linear dimensions: M = aL _b .Parameters are presented in the log₁₀‐transformed linear form of this power function. Body length was a simple linear function of head capsule width for all insect taxa, hence parameters for these models are presented as untransformed values. We also provide family level models for the Chironomidae, and compare our chironomid body length‐mass model with other published Chrionomidae length‐mass models. There was a very high degree of variability in parameter values among published length‐mass models for the family Chironomidae (mean coefficient of variation for mass at length = 148%). We discuss the potential causes and implications of this variability.     

Seamount Characteristics and Mine-Site Model Applied to Exploration- and Mining-Lease-Block Selection for Cobalt-Rich Ferromanganese Crusts

Regulations are being developed through the International Seabed Authority (ISBA) for the exploration and mining of cobalt-rich ferromanganese crusts. This paper lays out geologic and geomorphologic criteria that can be used to determine the size and number of exploration and mine-site blocks that will be the focus of much discussion within the ISBA Council deliberations. The surface areas of 155 volcanic edifices in the central equatorial Pacific were measured and used to develop a mine-site model. The mine-site model considers areas above 2,500 m water depth as permissive, and narrows the general area available for exploration and mining to 20% of that permissive area. It is calculated that about eighteen 100 km² exploration blocks, each composed of five 20 km² contiguous sub-blocks, would be adequate to identify a 260 km² 20-year-mine site; the mine site would be composed of thirteen of the 20 km² sub-blocks. In this hypothetical example, the 260 km² mine site would be spread over four volcanic edifices and comprise 3.7% of the permissive area of the four edifices and 0.01% of the total area of those four edifices. The eighteen 100 km² exploration blocks would be selected from a limited geographic area. That confinement area is defined as having a long dimension of not more than 1,000 km and an area of not more than 300,000 km².     

Ecosystem under pressure: ballast water discharge into Galveston Bay, Texas (USA) from 2005 to 2010

Ballast water exchange processes facilitate the dispersal and unnatural geographic expansion of phytoplankton, including harmful algal bloom species. From 2005 to 2010, over 45,000 vessels (≈ 8000 annually) travelled across Galveston Bay (Texas, USA) to the deep-water ports of Houston (10th largest in the world), Texas City and Galveston. These vessels (primarily tankers and bulkers) discharged ≈ 1.2 × 10(8) metrictons of ballast water; equivalent to ≈ 3.4% of the total volume of the Bay. Over half of the ballast water discharged had a coastwise origin, 96% being from US waters. Galveston Bay has fewer non-indigenous species but receives a higher volume of ballast water discharge, relative to the highly invaded Chesapeake and San Francisco Bays. Given the magnitude of shipping traffic, the role of Galveston Bay, both as a recipient and donor region of non-indigenous phytoplankton species is discussed here in terms of the invasibility risk to this system by way of ballast water.     

Reproductive characteristics and steroid levels in the scleractinian coral Oculina patagonica inhabiting contaminated sites along the Israeli Mediterranean coast

In this study we compared reproductive characteristics and steroid hormone levels in the non-indigenous scleractinian coral, Oculina patagonica, inhabiting contaminated vs. uncontaminated reference sites along the Israeli Mediterranean coast. Our results indicate significantly higher steroid levels in both seawater and coral tissue samples from contaminated sites as compared to reference sites, suggesting that corals tend to accumulate steroids from the surrounding waters. Despite their higher steroid levels, corals from the contaminated sites showed reproductive potential comparable to those of the reference sites. Interestingly, a clear distinction could be seen between corals exposed to pollution for long vs. short durations, with the latter showing a failure to complete gametogenesis. This suggests that reproduction in O. patagonica is susceptible to acute rather than chronic stress. The involvement of adjustment/adaptation processes may explain this species tolerance, and may reflect the ability of O. patagonica to successfully invade new areas in the Mediterranean Sea.     

Contrasting rainfall generated debris flows from adjacent watersheds at Forest Falls, southern California, USA

Debris flows are widespread and common in many steeply sloping areas of southern California. The San Bernardino Mountains community of Forest Falls is probably subject to the most frequently documented debris flows in southern California. Debris flows at Forest Falls are generated during short-duration high-intensity rains that mobilize surface material. Except for debris flows on two consecutive days in November 1965, all the documented historic debris flows have occurred during high-intensity summer rainfall, locally referred to as ‘monsoon’ or ‘cloudburst’ rains. Velocities of the moving debris range from about 5 km/h to about 90 km/h. Velocity of a moving flow appears to be essentially a function of the water content of the flow. Low velocity debris flows are characterized by steep snouts that, when stopped, have only small amounts of water draining from the flow. In marked contrast are high-velocity debris flows whose deposits more resemble fluvial deposits. In the Forest Falls area two adjacent drainage basins, Snow Creek and Rattlesnake Creek, have considerably different histories of debris flows. Snow Creek basin, with an area about three times as large as Rattlesnake Creek basin, has a well developed debris flow channel with broad levees. Most of the debris flows in Snow Creek have greater water content and attain higher velocities than those of Rattlesnake Creek. Most debris flows are in relative equilibrium with the geometry of the channel morphology. Exceptionally high-velocity flows, however, overshoot the channel walls at particularly tight channel curves. After overshooting the channel, the flows degrade the adjacent levee surface and remove trees and structures in the immediate path, before spreading out with decreasing velocity. As the velocity decreases the clasts in the debris flows pulverize the up-slope side of the trees and often imbed clasts in them. Debris flows in Rattlesnake Creek are relatively slow moving and commonly stop in the channel. After the channel is blocked, subsequent debris flows cut a new channel upstream from the blockage that results in the deposition of new debris-flow deposits on the lower part of the fan. Shifting the location of debris flows on the Rattlesnake Creek fan tends to prevent trees from becoming mature. Dense growths of conifer seedlings sprout in the spring on the late summer debris flow deposits. This repeated process results in stands of even-aged trees whose age records the age of the debris flows.