bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aerial photography and digital photogrammetry for landslide monitoring
Authors: Walstra J. , Chandler J. H. , Dixon N. , Dijkstra T. A. 
Published: November 2007

Abstract
A review is given of the techniques that are available to extract relevant information from multi-temporal aerial photographs for use in the monitoring stage of landslide assessments. It is shown that aerial photograph interpretation reveals qualitative information on surface characteristics, which is helpful in detecting landslide features and inferring the mechanisms involved. Photogrammetrically derived products can be used to quantify these processes, providing distinctive advantages. Comparison of digital elevation models (DEMs) from different times provides detailed information on changes in surface topography, whereas orthophotos can be used to measure horizontal displacements. The various factors influencing the quality of the products are also identified. Examples from a case study on the Mam Tor landslide are used to illustrate the benefits of the different approaches.
Geomorphology and urban geology of Bukavu (R.D. Congo): interaction between slope instability and human settlement
Authors: Trefois P. , Moeyersons J. , Lavreau J. , Alimasi D. , Badryio I. , Mitima B. , Mundala M. , Munganga D. O. , Nahimana L. 
Published: November 2007

Abstract
The city of Bukavu, on the south coast of Lake Kivu in the Democratic Republic of Congo, suffers from frequent landsliding, which leads to continual damage and destruction of buildings, roads, waterworks and sewerage infrastructure. Thirty-one landslides identified on aerial photographs of 1954 and 1973 are located outside the Bukavu micro-rift and are related to actively incising rivers. Their origin is thought to be due to increases in hydrostatic pressure. Six landslides occur within the Bukavu micro-rift, four of which are much larger and wider than other slope failures in the study region. These large landslides are adjacent to, or crossed by, active faults. They fall far below the topographic threshold envelope, a relationship of slopes at the head of the slide and the surface area drained into it, indicating seismic or anthropomorphic triggering. The Bukavu landslides still reactivate occasionally. Deforestation, followed by a large increase in the population, have been indirect causes of the reactivated mass wasting processes. On the steep slopes in the south of the city the high density of newly built houses has led to reduced water infiltration and enhanced runoff, causing landslides and mudflows. Very high spatial resolution IKONOS satellite images have recently been used as base maps for geohazard assessments of Bukavu. A geographical information system (GIS) has been developed for Bukavu's planners: this shows the locations of buildings, roads and tracks, the river network, the water distribution system and the sewerage infrastructure, as well as areas of slope instability.
Landslide susceptibility assessment for St. Thomas, Jamaica, using geographical information system and remote sensing methods
Authors: Miller S. , Harris N. , Williams L. , Bhalai S. 
Published: November 2007

Abstract
The St. Thomas district of Jamaica is prone to slope failure, which has resulted in extensive damage and in some cases loss of life. To reduce the effect from landslides, there was an urgent need to map and assess areas that may be prone to future failure. The interpretation of aerial photographs, together with geomorphological mapping and field surveys, was used to produce inventory maps of the landslides. The factors conditioning the slopes for failure were assessed and a weighting value was assigned to them. The weighting was achieved by using the principle of Bayesian conditional probability. The weighted factors were combined in a geographical information system (GIS) to produce a landslide susceptibility model for the study area. Comparison of the model with the existing landslides showed that 97% of the landslides fell within the high and very high susceptibility zones of the model. Comparison of the model with landslides that occurred during 2002, and that were not used in the construction of the model, shows that 83 of the 89 slides that occurred fell within the high and very high susceptibility zones. The landslide susceptibility model will be one of the first steps in assessing the risks that landslides pose to lives and new developments (housing, agriculture, physical infrastructure) in the region.
Applications of remote sensing for geohazard mapping in coastal and riverine environments
Authors: Teeuw R. 
Published: November 2007

Abstract
This paper reviews various types of remote sensing that can be applied to mapping and monitoring riverine and coastal geohazards. It focuses on flooding, ground instability, erosion and sedimentation, mainly drawing on examples from the UK. Both airborne and space-borne systems are examined, with assessments of the merits, limitations and relative costs of each system. Remote sensing offers a wide range of useful techniques for mapping coastal and riverine features, particularly where there are access problems associated with sites prone to flooding or slope instability.
Application of hyperspectral remote sensing data in the monitoring of the environmental impact of hazardous waste derived from abandoned mine sites
Authors: Ferrier G. , Rumsby B. , Pope R. 
Published: November 2007

Abstract
The release of hazardous mine waste from abandoned gold mining areas is a major global environmental problem. The complexity of the processes, the scale of the mine sites, problems with accessibility and the lack of site information mean that field-based survey methods are often too costly and provide incomplete coverage. The results of a study of an abandoned gold mine at Rodalquilar in southern Spain have demonstrated the potential of airborne-mounted hyperspectral remote sensing instruments to resolve the distributions of mine waste and secondary iron species on the mine site and in adjacent rivers. The advantages of using higher spatial resolution hyperspectral data in identifying secondary iron species and resolving geomorphological settings of mine waste accumulations were also demonstrated. Integration of laboratory-derived correlations of secondary iron species, cyanide and heavy metals concentrations with the results of the remote sensing study allowed the identification of locations of hazardous materials over the study area and a more accurate understanding of the environmental status of the Rodalquilar area.
Collaboration between hepatic and intratumoral prodrug activation in a P450 prodrug-activation gene therapy model for cancer treatment
Authors: Ma Jie , Waxman David J. 
Published: November 2007

Abstract
Presently, we investigate the mechanisms whereby intratumoral expression of a cyclophosphamide-activating hepatic cytochrome P450 gene enhances therapeutic activity when cyclophosphamide is given on an every 6-day (metronomic) schedule. In P450-deficient 9L gliosarcomas grown in severe combined immunodeficient mice, metronomic cyclophosphamide substantially decreased tumor microvessel density and induced a ∼70% loss of endothelial cells that began after the second cyclophosphamide treatment. These responses were accompanied by increased expression of the endogenous angiogenesis inhibitor thrombospondin-1 in tumor-associated host cells but by decreased expression in 9L tumor cells. These antiangiogenic responses preceded tumor regression and are likely key to the therapeutic activity of metronomic cyclophosphamide. Unexpectedly, 9L/2B11 tumors, grown from 9L cells infected with retrovirus encoding the cyclophosphamide-activating P450 2B11, exhibited antiangiogenic responses very similar to 9L tumors. This indicates that the tumor endothelial cell population is well exposed to liver-activated cyclophosphamide metabolites and that intratumoral P450 confers limited additional anti–endothelial cell bystander activity. In contrast, an increase in apoptosis, which preceded the antiangiogenic response, was substantially enhanced by intratumoral P450 2B11 expression. 9L/2B11 tumor regression was accompanied by an overall loss of tumor cellularity and by substantial enlargement of remaining P450-immunoreactive tumor cells as the number of P450-positive tumor cell decreased and the P450 protein content declined with cyclophosphamide treatment. We conclude that metronomic cyclophosphamide regresses P450-expressing tumors by two independent but complementary mechanisms: increased tumor cell killing via intratumoral P450-catalyzed prodrug activation, coupled with strong antiangiogenic activity, which is primarily associated with hepatic prodrug activation. [Mol Cancer Ther 2007;6(11):2879–90]
Vertical Motions in Precipitation Bands in Three Winter Cyclones
Authors: Cronce Marcia , Rauber Robert M. , Knupp Kevin R. , Jewett Brian F. , Walters Justin T. , Phillips Dustin 
Published: November 2007

Abstract
The University of Alabama in Huntsville Mobile Integrated Profiling System 915-MHz profiler was deployed in January and February of 2004 to measure vertical air velocities in finescale precipitation bands in winter cyclones. The profiler was placed to sample the “wraparound” quadrant of three winter cyclones in the central and southern United States, and it obtained high-resolution measurements of the vertical structure of a series of bands in each storm. The data revealed bands that were up to 6 km deep, 10–50 km wide, and spaced about 5–20 km apart. Measurements of vertical air motion w within these bands were retrieved from the Doppler spectra using the lower-bound method, adapted to account for the effects of spectral broadening caused by the horizontal wind, wind shear, and turbulence. Derived vertical air motions ranged from −4.3 to 6.7 m s−1, with an uncertainty of about ±0.6 m s−1. Approximately 29% of the 1515 total derived values were negative, 35% exceeded 1 m s−1, and 9% exceeded 2.0 m s−1. These values are consistent with studies in the Pacific Northwest, except that more extreme values were observed in one band than have been previously reported. There was a high correlation between values of signal-to-noise ratio (SNR) and w within each band (0.60 ≤ r ≤ 0.85), in the composite of bands from each cyclone (0.59 ≤ r ≤ 0.79), and in the overall analysis (r = 0.68). The strongest updrafts were typically between 2.0 and 4.0 m s−1 and were located near the center of each band in regions of high SNR. Regions of downdrafts within the bands had maximum values between −1.0 and −4.3 m s−1 and were typically located along the edges of the bands in regions of low SNR. These results are consistent with snow growth and sublimation processes. The magnitudes of the vertical velocities in the core of the bands were comparable to theoretical predictions for moist symmetric instability (MSI) under inviscid conditions but would appear to be somewhat larger than expected for MSI when turbulent mixing is considered, suggesting that other instabilities, such as potential instability, may have contributed to the band development in these storms.
The Characterization of Ice Cloud Properties from Doppler Radar Measurements
Authors: Delanoë Julien , Protat A. , Bouniol D. , Heymsfield Andrew , Bansemer Aaron , Brown Philip 
Published: November 2007

Abstract
The paper describes an original method that is complementary to the radar–lidar algorithm method to characterize ice cloud properties. The method makes use of two measurements from a Doppler cloud radar (35 or 95 GHz), namely, the radar reflectivity and the Doppler velocity, to recover the effective radius of crystals, the terminal fall velocity of hydrometeors, the ice water content, and the visible extinction from which the optical depth can be estimated. This radar method relies on the concept of scaling the ice particle size distribution. An error analysis using an extensive in situ airborne microphysical database shows that the expected errors on ice water content and extinction are around 30%–40% and 60%, respectively, including both a calibration error and a bias on the terminal fall velocity of the particles, which all translate into errors in the retrieval of the density–diameter and area–diameter relationships. Comparisons with the radar–lidar method in areas sampled by the two instruments also demonstrate the accuracy of this new method for retrieval of the cloud properties, with a roughly unbiased estimate of all cloud properties with respect to the radar–lidar method. This method is being systematically applied to the cloud radar measurements collected over the three-instrumented sites of the European Cloudnet project to validate the representation of ice clouds in numerical weather prediction models and to build a cloud climatology.
Spatiotemporal Trends in Episodic Ozone Pollution in the Lower Fraser Valley, British Columbia, in Relation to Mesoscale Atmospheric Circulation Patterns and Emissions
Authors: Ainslie B. , Steyn D. G. 
Published: November 2007

Abstract
A cluster analysis of wind measurements from two meteorological stations in the Lower Fraser Valley, British Columbia, Canada, has been performed to identify mesoscale circulation regimes that are common to days on which ozone mixing ratios at one or more measuring stations in the region’s fixed monitoring network exceed the National Ambient Air Quality Objective of 82 ppb. The analysis, using 20 yr of data (1984–2003), identifies the following four regimes: two with morning winds at the coastal Vancouver International Airport (YVR) meteorological station from the northwest direction and two with southerly YVR morning winds. Not all exceedance days are associated with sea-breeze circulations, but days with southerly morning winds have a higher proportion of well-developed sea-breeze circulations. Composite synoptic patterns associated with each regime all show high pressure over the eastern Pacific Ocean with a thermal trough over Washington State and southwestern British Columbia. Composite ozone patterns, corresponding to each mesoscale circulation regime and taken at the hour of maximum ozone concentration, show similar general features, including strong ozone titration in and around the urban source regions and higher values downwind. This suggests that precursor buildup, prior to the exceedance day, plays an important role in the spatial ozone pattern on exceedance days. A simple multiple linear regression of the plume centroid with the number of days elapsed from the start of the analysis period suggests the centroid of the ozone plume has shifted eastward since 1990. There also appears to be a north–south shift in the ozone plume. It is impossible to tell if these shifts are due to changes in emission levels or to changes in spatial emission patterns, because both changes have occurred over the study period.
High-Resolution Spatial Modeling of Daily Weather Elements for a Catchment in the Oregon Cascade Mountains, United States
Authors: Daly Christopher , Smith Jonathan W. , Smith Joseph I. , McKane Robert B. 
Published: November 2007

Abstract
High-quality, daily meteorological data at high spatial resolution are essential for a variety of hydrologic and ecological modeling applications that support environmental risk assessments and decision making. This paper describes the development, application, and assessment of methods to construct daily high-resolution (∼50-m cell size) meteorological grids for the 2003 calendar year in the Upper South Santiam Watershed (USSW), a 500-km2 mountainous catchment draining the western slope of the Oregon Cascade Mountains. Elevations within the USSW ranged from 194 to 1650 m. Meteorological elements modeled were minimum and maximum temperature; total precipitation, rainfall, and snowfall; and solar radiation and radiation-adjusted maximum temperature. The Parameter–Elevation Regressions on Independent Slopes Model (PRISM) was used to interpolate minimum and maximum temperature and precipitation. The separation of precipitation into rainfall and snowfall components used a temperature-based regression function. Solar radiation was simulated with the Image-Processing Workbench. Radiation-based adjustments to maximum temperature employed equations developed from data in the nearby H. J. Andrews Experimental Forest. The restrictive terrain of the USSW promoted cold-air drainage and temperature inversions by reducing large-scale airflow. Inversions were prominent nearly all year for minimum temperature and were noticeable even for maximum temperature during the autumn and winter. Precipitation generally increased with elevation over the USSW. In 2003, precipitation was nearly always in the form of rain at the lowest elevations but was about 50% snow at the highest elevations. Solar radiation followed a complex pattern related to terrain slope, aspect, and position relative to other terrain features. Clear, sunny days with a large proportion of direct radiation exhibited the greatest contrast in radiation totals, whereas cloudy days with primarily diffuse radiation showed little contrast. Radiation-adjusted maximum temperatures showed similar patterns. The lack of a high-quality observed dataset was a major issue in the interpolation of precipitation and solar radiation. However, observed data available for the USSW were superior to those available for most mountainous regions in the western United States. In this sense, the methods and results presented here can inform others performing similar studies in other mountainous regions.
A Variational Scheme for Retrieving Rainfall Rate and Hail Reflectivity Fraction from Polarization Radar
Authors: Hogan Robin J. 
Published: November 2007

Abstract
Polarization radar offers the promise of much more accurate rainfall-rate R estimates than are possible from radar reflectivity factor Z alone, not only by better characterization of the drop size distribution, but also by more reliable correction for attenuation and the identification of hail. However, practical attempts to implement retrieval algorithms have been hampered by the difficulty in coping with the inherent noise in the polarization parameters. In this paper, a variational retrieval scheme is described that overcomes these problems by employing a forward model for differential reflectivity Zdr and differential phase shift ϕdp and iteratively refining the coefficient a in the relationship Z = aRb such that the difference between the forward model and the measurements is minimized in a least squares sense. Two methods are used to ensure that a varies smoothly in both range and azimuth. In range, a is represented by a set of cubic-spline basis functions; in azimuth, the retrieval at one ray is used as a constraint on the next. The result of this smoothing is that the retrieval is tolerant of random errors in Zdr of up to 1 dB and in ϕdp of up to 5°. Correction for attenuation is achieved simply and effectively by including its effects in the forward model. If hail is present then the forward model is unable to match the observations of Zdr and ϕdp simultaneously. This enables a first pass of the retrieval to be used to identify the radar pixels that contain hail, followed by a second pass in which the fraction of the Z in those gates that is due to hail is retrieved, this time with the scheme being able to forward-model both Zdr and ϕdp accurately. The scheme is tested on S-band radar data from southern England in cases of rain, spherical hail, oblate hail, and mixtures of rain and hail. It is found to be robust and stable, even in the presence of differential phase shift on backscatter.
Effect of Direct Radiative Forcing of Asian Dust on the Meteorological Fields in East Asia during an Asian Dust Event Period
Authors: Ahn Hyun-Ju , Park Soon-Ung , Chang Lim-Seok 
Published: November 2007

Abstract
Coupled and noncoupled models in a grid of 60 × 60 km2 in the eastern Asian domain have been employed to examine the effect of the direct radiative forcing of the Asian dust aerosol on meteorological fields for an intense Asian dust event observed in eastern Asia on 18–23 March 2002. The coupled model consists of the modified fifth-generation Pennsylvania State University–National Center for Atmospheric Research (NCAR) Mesoscale Model (MM5) with direct radiative forcing of the Asian dust aerosol through the NCAR Column Radiation Model and the Asian Dust Aerosol Model. The noncoupled model is MM5 without the direct radiative forcing of the Asian dust aerosol. The results indicate that the radiative cooling of the dust aerosol over the high-dust-concentration (HDC) region induces sinking motion and positive pressure perturbation near the surface, whereas the radiative warming of the aerosol near the top of the HDC layer induces rising motion and negative pressure perturbation, thereby enhancing the stable stratification in the dust layer. The induced positive pressure perturbation near the surface causes a dipole shape of the pressure perturbation field by forming a negative pressure perturbation toward the low pressure center downstream near the surface. This negative pressure perturbation is so deep and wide that the perturbation of the meteorological fields extends in the wide and deep regions away from the HDC region. The associated secondary circulation of this pressure perturbation reduces the low-level wind speed in the upstream HDC region but strengthens the downstream wind speed, resulting in reduction of dust emission in the upstream source region and downstream enhancement. Some of the dust aerosols lifted to the higher level by the synoptic rising motion are transported to the downstream direction more quickly with the upper-level strong wind, resulting in a bent-over shape of dust cloud in the downstream region with a maximum concentration near the surface and a secondary maximum in the upper level. The radiative flux convergence between these maximum dust layers produces a warm layer, thereby further enhancing the stable stratification.
Dynamic Surface Interface Exchanges of Mercury: A Review and Compartmentalized Modeling Framework
Authors: Bash Jesse O. , Bresnahan Patricia , Miller David R. 
Published: November 2007

Abstract
This paper presents a review of recent natural surface mercury exchange research in the context of a new modeling framework. The literature indicates that the mercury biogeochemical flux is more dynamic than the current models predict, with interacting multimedia storage and processes. Although several natural mercury emissions models have been created and incorporated into air quality models (AQMs), none are coupled with air quality models on a mass balance basis, and all lack the capacity to explain processes that involve the transport of mercury across atmosphere–surface media concentration gradients. Existing natural mercury emission models treat the surface as both an infinite source and infinite sink for emissions and deposition, respectively, and estimate emissions through the following three pathways: soil, vegetation, and surface waters. The use of these three transport pathways, but with compartmentalized surface storage in a surface–vegetation–atmosphere transport (SVAT) resistance model, is suggested. Surface water fluxes will be modeled using a two-film diffusion model coupled to a surface water photochemical model. This updated framework will allow both the parameterization of the transport of mercury across atmosphere–surface media concentration gradients and the accumulation/depletion of mercury in the surface media. However, several key parameters need further experimental verification before the proposed modeling framework can be implemented in an AQM. These include soil organic mercury interactions, bioavailability, cuticular transport of mercury, atmospheric surface compensation points for different vegetation species, and enhanced soil diffusion resulting from pressure perturbations.