Mortgage Foreclosures,Race, and Postrecession Lending

This article examines the effect of high foreclosure rates on postrecession lending. Our hypothesis is that high neighborhood foreclosure rates will have a significant and positive effect on the likelihood of mortgage loan denial. In a case study on Toledo, Ohio, we explore the role of foreclosure activity, race, and racial disparities in lending practices and how they differ across neighborhoods. Our results suggest that applicants in high-foreclosure neighborhoods have a greater likelihood of loan denial (ceteris paribus). We also find that minority applicants face a higher probability of loan denial in high-foreclosure minority neighborhoods. Overall, the results depict highly variable lending practices where race seems to make a difference albeit in a small subset of neighborhoods deeply affected by the foreclosure crisis. There is also some indication of a chilling effect on minority loan applicants in Toledo during the postrecession period. Key Words: foreclosure, logistic regression, mortgage lending, neighborhood contingency, race discrimination.     

Depth Correlated Benthic Faunal Quantity and Infaunal Burrow Structures on the Slopes of a Marine Depression

In the northern part of the Kattegat, western Sweden, a series of marine depressions remain since the last glaciation. One of these, the well-oxygenated Alkor Deep, is about 3 km long and 800 m wide and with a depth of 138 m. Random depth-stratified sampling was made along four transects on the slopes including benthic macrofauna (0·1 m²grab samples) and sediment profile imaging. A significant positive correlation was found between depth and the faunal variables abundance and biomass. Deposit feeders such as Maldane sarsi, Heteromastus filiformis andAbra alba were among the dominants and may have been supported by down-slope advected organic material. In many images, pockets and extensive burrows were seen in the sediment that appeared to be constructed by the crustaceans Calocaris macandreae and Maera loveni. The ecological significance of their irrigation of the sediment is discussed. Due to the faunal activity deep down in the sediments of the slopes, the mean apparent redox potential discontinuity (RPD) was found as deep as between 8·0 and 11·3 cm depth, and RPD was significantly positively correlated with water depth. On the slopes there appears to be a balance between the input of organic material and the capacity of the benthic organisms to assimilate that carbon.     

Estimation and evaluation of real-time precipitable water vapor from GLONASS and GPS

The revitalized Russian GLONASS system provides new potential for real-time retrieval of zenith tropospheric delays (ZTD) and precipitable water vapor (PWV) in order to support time-critical meteorological applications such as nowcasting or severe weather event monitoring. In this study, we develop a method of real-time ZTD/PWV retrieval based on GLONASS and/or GPS observations. The performance of ZTD and PWV derived from GLONASS data using real-time precise point positioning (PPP) technique is carefully investigated and evaluated. The potential of combining GLONASS and GPS data for ZTD/PWV retrieving is assessed as well. The GLONASS and GPS observations of about half a year for 80 globally distributed stations from the IGS (International GNSS Service) network are processed. The results show that the real-time GLONASS ZTD series agree quite well with the GPS ZTD series in general: the RMS of ZTD differences is about 8 mm (about 1.2 mm in PWV). Furthermore, for an inter-technique validation, the real-time ZTD estimated from GLONASS-only, GPS-only, and the GPS/GLONASS combined solutions are compared with those derived from very long baseline interferometry (VLBI) at colocated GNSS/VLBI stations. The comparison shows that GLONASS can contribute to real-time meteorological applications, with almost the same accuracy as GPS. More accurate and reliable water vapor values, about 1.5–2.3 mm in PWV, can be achieved when GLONASS observations are combined with the GPS ones in the real-time PPP data processing. The comparison with radiosonde data further confirms the performance of GLONASS-derived real-time PWV and the benefit of adding GLONASS to stand-alone GPS processing.     

Identifying soft sediments at sea using GIS-modelled predictor variables and Sediment Profile Image (SPI) measured response variables

Macrofauna composition and diversity in soft sediments are commonly used as “health indicators” in various pollution monitoring programmes worldwide. Hence, finding a modelling method for predicting the presence of soft sediments and enable production of digital maps of where soft sediments are likely to be found would be valuable for developing a cost-effective sampling design. This study presents a first-generation model that can predict where to find soft sediments in coastal areas with a complex topography and a mosaic of seabed habitat types. We used geophysical data that were quantitative, objectively defined (through GIS modelling) and integrated over time. We analysed, using a Generalised Additive Model (GAM) and the model-selection approach Akaike Information Criterion (AIC), the influence of in-situ measured depth and GIS-modelled terrain structures, wave exposure and current speed on the distribution of soft sediment measured using a Sediment Profile Image (SPI) camera. Our analyses showed that the probability of finding soft sediment was best determined by depth, terrain curvature and median current speed at the seafloor. These predictors were used to develop a spatial predictive GIS-model/-map (for parts of Skagerrak, Norway, with a spatial resolution of 25 m × 25 m) of the probability of soft seabed occurrence.     

Evaluating preprocessing methods of digital elevation models for hydrological modelling

With the introduction of high‐resolution digital elevation models, it is possible to use digital terrain analysis to extract small streams. In order to map streams correctly, it is necessary to remove errors and artificial sinks in the digital elevation models. This step is known as preprocessing and will allow water to move across a digital landscape. However, new challenges are introduced with increasing resolution because the effect of anthropogenic artefacts such as road embankments and bridges increases with increased resolution. These are problematic during the preprocessing step because they are elevated above the surrounding landscape and act as artificial dams. The aims of this study were to evaluate the effect of different preprocessing methods such as breaching and filling on digital elevation models with different resolutions (2, 4, 8, and 16 m) and to evaluate which preprocessing methods most accurately route water across road impoundments at actual culvert locations. A unique dataset with over 30,000 field‐mapped road culverts was used to assess the accuracy of stream networks derived from digital elevation models using different preprocessing methods. Our results showed that the accuracy of stream networks increases with increasing resolution. Breaching created the most accurate stream networks on all resolutions, whereas filling was the least accurate. Burning streams from the topographic map across roads from the topographic map increased the accuracy for all methods and resolutions. In addition, the impact in terms of change in area and absolute volume between original and preprocessed digital elevation models was smaller for breaching than for filling. With the appropriate methods, it is possible to extract accurate stream networks from high‐resolution digital elevation models with extensive road networks, thus providing forest managers with stream networks that can be used when planning operations in wet areas or areas near streams to prevent rutting, sediment transport, and mercury export.     

Satellite SAR observation of shallow bottom topography of the east Australia Sea

INTRODUCTIONOne of the interesting oceanographic features detected with SAR is the shallow bottom toPOgraphic feature and bathymetry nearshore. The knowledge on sea bottom toPOgraphy is of vitalimPOrtance not only for shipping, fishery and all kinds of offshore activities, but also for the calibration and validation of morphodynamic models which are currently under development. Traditional bathymetric surveys consume time and cost. SAR remote sensing of oceanography may offeran altern…     

Balance Between Autotrophic and Heterotrophic Components and Processes in Microbenthic Communities of Sandy Sediments: A Field Study

The microscopic community of a microtidal sandy sediment on the Swedish west coast was studiedin situat two depths (0·5 and 4 m) on four occasions (January, April, August and October). Biomass of microalgae, bacteria, ciliates and meiofauna, as well as primary and bacterial productivity, were quantified. Meiofaunal grazing on algae and bacteria was measured simultaneously by radiolabelling intact sediment cores. Autotrophic biomass dominated the microbial community at both depths and on all sampling occasions, accounting for 47–87% of the microbial biomass. Meiofauna contributed 10–47%, while bacteria and ciliates together made up less than 6%. The microflora was dominated by attached (epipsammic) diatoms, but occasional ‘ blooms ’ of motile species occurred. Vital cells of planktonic diatoms contributed to benthic algal biomass in spring. Primary productivity exceeded bacterial productivity in April and August at both depths, while the balance was reversed in October and January. Meiofauna grazed between 2 and 12% of the algal biomass per day, and between 0·3 and 37% of the bacterial biomass. Almost an order of magnitude more algal (17–138 mg C m⁻²) than bacterial (0·1–33 mg C m⁻²) carbon was grazed daily. At the shallow site, primary productivity always exceeded grazing rates on algae, whereas at the deeper site, grazing exceeded primary productivity in October and January. Bacterial productivity exceeded grazing at both depths on all four occasions. Thus, meiofaunal grazing seasonally controlled microalgal, but not bacterial, biomass. These results suggest that, during summer, only a minor fraction (<10%) of the daily microbenthic primary production appears to enter the ‘ small food web ’ through meiofauna. During spring and autumn, however, a much larger fraction (≈30–60%) of primary production may pass through meiofauna. During winter, meiofaunal grazing is a less important link in the shallow zone, but at sublittoral depths, algal productivity may be limiting, and meiofauna depend on other food sources, such as bacteria and detritus.