Miracle-dz/UniFAR-FTUs huggingface dataset:
Analysis of runoff extremes using spatial hierarchical Bayesian modeling

A spatial hierarchical Bayesian method is developed to model the extreme runoffs over two spatial domains in Columbia River Basin, USA. This method combines the limited number of data from different locations. The two spatial domains contain 31 and 20 gage stations, respectively, with daily streamflow records ranging from 30 to over 130 years. The generalized Pareto distribution (GPD) is employed for the analysis of extremes. Temporally independent data are generated using declustering procedure, where runoff extremes are first grouped into clusters and then the maximum of each cluster is retained. The GPD scale parameter is modeled based on a Gaussian geostatistical process and additional variables including the latitude, longitude, elevation, and drainage area are incorporated by means of a hierarchy. Metropolis‐Hasting within Gibbs Sampler is used to infer the parameters of the GPD and the geostatistical process to estimate the return levels across the basins. The performance of the hierarchical Bayesian model is evaluated by comparing the estimates of 100 year return level floods with the maximum likelihood estimates at sites that are not used during the parameter inference process. Various prior distributions are used to assess the sensitivity of the posterior distributions. The selected model is then employed to estimate floods with different return levels in time slices of 15 years in order to detect possible trends in runoff extremes. The results show cyclic variations in the spatial average of the 100 year return level floods across the basins with consistent increasing trends distinguishable in some areas.
Through a Beer Glass Darkly

Pour yourself a glass of beer and look closely at the rising bubbles. Careful examination shows that they are seldom distributed uniformly throughout the liquid. Instead, streams of bubbles appear to rise from certain spots on the surface of the glass. Closer inspection reveals that the bubbles rapidly grow in size as they ascend, the volume of each bubble often doubling or more by the time it reaches the top of the glass. In addition, the speed of the bubbles increases as they travel upward.
Geo-referencing forest field plots by co-registration of terrestrial and airborne laser scanning data

Remote sensing plays an important role within the field of forest inventory. Airborne laser scanning (ALS) has become an effective tool for acquiring forest inventory data. In most ALS-based forest inventories, accurately positioned field plots are used in the process of relating ALS data to field-observed biophysical properties. The geo-referencing of these field plots is typically carried out by means of differential global navigation satellite systems (dGNSS), and often relies on logging times of 15–20 min to ensure adequate accuracy under different forest conditions. Terrestrial laser scanning (TLS) has been proposed as a possible tool for collection of field data in forest inventories and can facilitate rapid acquisition of these data. In the present study, a novel method for co-registration of TLS and ALS data by posterior analysis of remote-sensing data – rather than using dGNSS – was proposed and then tested on 71 plots in a boreal forest. The method relies on an initial position obtained with a recreational-grade GPS receiver, in addition to analysis of the ALS and TLS data. First, individual tree positions were derived from the remote-sensing data. A search algorithm was then used to find the best match for the TLS-derived trees among the ALS-derived trees within a search area, defined relative to the initial position. The accuracy of co-registration was assessed by comparison with an accurately measured reference position. With a search radius of 25 m and using low-density ALS data (0.7 points m−2), 82% and 51% of the TLS scans were co-registered with positional errors within 1 m and 0.5 m, respectively. By using ALS data of medium density (7.5 points m−2), 87% and 78% of the scans were co-registered with errors within 1 m and 0.5 m of the reference position, respectively. These results are promising and the method can facilitate rapid acquisition and geo-referencing of field data. Robust methods to identify and handle erroneous matches are, however, required before it is suitable for operational use.
Mapping submarine sand waves with multiband imaging radar: 1. Model development and sensitivity analysis

In 1989 and 1991, unexpected modulations caused by submarine sand waves were observed with the airborne imaging radar (AIR), a P, L, and C band synthetic aperture radar. The measurements were performed in a sand wave area off the Dutch coast. The sand waves have an asymmetric, sawtooth-shaped profile with the steep slope oriented toward the northeast. During the experiments, wind and current had opposite directions: the wind was directed toward the northeast and the current toward the southwest. Under these conditions, existing models for the imaging mechanism predict that the modulation depth decreases with increasing radar frequency and that the steep slopes show up as dark lines in radar images. The AIR images show a relation between modulation depth and radar frequency as predicted. However, only the P band image of 1989 shows the steep slopes of the sand waves as dark lines. The P band image of 1991 and the L band images of 1989 and 1991 show a sawtooth-shaped modulation which cannot be explained by existing theory. A new model is developed that is one dimensional in position space and fully two dimensional in wavenumber space. The radar cross section is calculated using both first-order Bragg and an integral equation scattering model in which the cross section originates from a spectral band rather than a single value. The new model contains two improvements over previous ones. First, wave blocking or, better, wave reflection is included, though in an approximate manner. It is shown to be of importance at P band only. Second, the contribution to the radar cross section from waves moving both to and from the radar is included, whereas some previous models consider only one of these contributions. This explains the observed modulations, at least qualitatively, under the assumptions that the angular distribution of short waves is almost constant and that waves moving against the wind have small relaxation rates.
Spatial distribution of storm wave energy dissipation for the assessment of beach morphodynamics

ABSTRACT Guisado-Pintado, E. , Malvárez, G. , Navas, F. , Carrero, R. , 2014. Storms based morphodynamics from wave energy dissipation for beach characterisation. In: Green, A.N. and Cooper, J.A. G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 259–265, ISSN 0749-0208. High energy events are responsible for most significant and visible changes in beach morphology and sediment disposal in a short temporal scale. Storms are associated with damage to the coastal ecosystem and societal services such as severe shoreline erosion, collapse of coastal infrastructures and properties (ports, seawalls). These also affect the effectiveness of coastal defence works such as beach nourishment. In a scenario of climate change, with predictions of sea level rise and an increase in storminess being the most important threats affecting the coastal environments, the understanding of wave climate and the role of high energy events are of key importance. In this paper an index for the characterisation of modal regimes and extreme wave events, based on a 10-year wave hindcast on a 1-hour basis, is developed to characterize wave storms regime of the Andalusia region of southern Spain. Results of the implementation of this method are presented through two case studies; one concerning a low-energy environment located on the Mediterranean coast and other for the higher energy Atlantic coast. Analysis and characterisation of the wave parameters during modal and storm conditions and the study of the spatial distribution of wave energy dissipation patterns, among other hydrodynamic parameter such as wave orbital velocity, are carried out and implemented through a morphodynamic index for nearshore environments. Results show the variability of wave energy dissipation patterns among both study sites, the role of the nearshore topography and the adaptation of the surf zone in wave hydrodynamic processes. Further, the morphodynamic resilience helps in identifying the potential for changing behaviour in energy dissipation and morphological effects derived from high energy events when compared with low-energy modal conditions.
Seismic sensor array for monitoring an avalanche start zone: design, deployment and preliminary results

Abstract In snow, acoustic emissions originate from the breaking of bonds between snow crystals and the formation of cracks. Previous research has shown that acoustic signals emanate from a natural snowpack. The relation between these signals and the stability of the snowpack has thus far remained elusive. Studies on other hazardous gravitational processes suggest that damage accumulation precedes major failure. If increased cracking activity could be detected in snow this might be used for avalanche prediction. We report on the development of a seismic sensor array to continuously monitor acoustic emissions in an avalanche start zone. During three winters, over 1400 sensor days of continuous acoustic data were collected. With the aid of automatic cameras and a microphone the main types of background noise were identified. Seismic signals generated by avalanches were also identified. Spectrograms from seismic signals generated by avalanches exhibit a unique triangular shape unlike any source of background noise, suggesting that automatic detection and classification of events is possible. Furthermore, discriminating between loose-snow and snow-slab avalanches is possible. Thus far we have not identified precursor events for natural dry-snow slab avalanche release. Detailed investigation of one dry-snow slab avalanche showed that signals observed prior to the release originated from background noise or small loose-snow avalanches.
Urban Storm Sewer Design: Approach in Consideration of Sediments

Sediment transport in sewers has different aspects to be analyzed and the paper describes primarily the transport at “limit deposition,” the concept of “self-cleansing” sewers, and transport over small mobile (loose) beds. A new model for the transport at limit deposition criterion was developed based on physical concepts for extrapolation for sewers larger than 500 mm in diameter. This model leads to more economical solutions than previously developed best-fit deterministic models. The transport phenomenon over mobile beds is modeled based upon the classical dimensionless parameters of bed shear stress and transport using the Meyer–Peter and Muller method normally used in the studies of alluvial channels. These studies were conducted using uniform sediment materials to understand the effect of sediment size on transport phenomena and then the effect of sediment gradation was focused upon.
Field Measurements of Air and Water Pressures in a Heterogeneous Forest‐Reclaimed Lignitic Mine Soil

Soil matric and air pressures can significantly affect each other especially if the soil‐gas phase becomes disconnected from the atmosphere. Such effects were presumed to be one possible explanation for observed preferential flow patterns in a mine soil. The objective of this study was to evaluate interactions between soil‐air and water pressures in situ under field conditions. In a 2.5‐m‐wide mine soil pit, nine soil air pressure probes were horizontally installed 27 cm apart in a row at 80 cm depth and augmented by two rows of tensiometers, one row 10 cm below and one row 10 cm above the air probes. Field data were recorded for 3 wk in autumn 2001. At two of the nine measurement positions, deviations of soil air from atmospheric pressure were observed. Solely at these two positions, water‐saturated conditions were found and drainage could be collected using a cell lysimeter, indicating that these air probes were disconnected from aboveground air. After accounting for soil temperature effects, the fluctuations in soil air pressure were found to correspond with those of the ambient soil water pressure during infiltration events. The gradual decrease of soil air pressure after the event might be induced by suction effects of draining soil water in the flow finger with the soil water pressures remaining above the air entry pressure of the soil. Results suggest that effects of flow on soil air pressure can occur locally. In this heterogeneous mine soil, the air–water pressure interactions were restricted to soil regions that coincided with preferential flow paths.
Effects of pine straw harvesting on quantity and quality of surface runoff

ABSTRACT: Pine needles (straw) are an attractive landscape mulching material that protects the soil surface against erosion, conserves soil moisture, moderates soil temperature, and inhibits weed growth; yet it retains a loose, open structure that allows air, fertilizer, and water to easily penetrate the soil surface. Such characteristics have made pine straw a valuable commodity, but the loss of those mulching benefits from pine forests has raised concerns about effects on watersheds where pine straw is harvested. For example, pine straw absorbs the impact of raindrops and slows the speed of runoff, so its removal may increase soil erosion and nutrient losses, and decrease water-holding capacity of the forest floor. To test this hypothesis, three pine-straw harvesting practices and a control treatment (no straw harvest) were compared to determine harvesting effects on water, soil, and nutrient losses in runoff. The 24 plots (six replications of each treatment) were constructed in an established (16 yrs) loblolly pine (Pinus taeda L.) stand that had tree spacing of 3.0 m by 1.5 m (10 ft by 5 ft), and basal area of 41.3 m2 ha−1 (180 ft2 ac−1). Each plot (2 m by 1 m or 6.6 ft by 3.3 ft) had four percent slope, aluminum borders, and a runoff collector. Simulated rainfall was applied [5 cm h−1 (2 in h−1)] to produce 20 minutes of runoff from each plot. Annual pine straw harvesting clearly increased runoff, soil erosion from 0.5 to 91.6 kg ha−1 (0.4 to 81.7 Ib ac−1), and losses of phosphorus (P), carbon (C), and total Kjeldahl nitrogen (N) in runoff; but these losses were partially controlled by less-frequent harvesting, and declined to control levels when pine straw had accumulated for two years.
The morphology and evolution of coronae on Venus

Coronae on Venus are large, circular to ovoidal surface features that have distinctive tectonic, volcanic, and topographic expressions. They range in diameter from less than 200 km to at least 1000 km. New data from the Magellan spacecraft have shown coronae to be among the dominant tectonic forms on the planet and have revealed their morphology in unprecedented detail. Typical coronae are dominated by concentric tectonic features and have a raised rim, a central region higher than the surounding plains but in many instances lower than the rim, and, commonly, a peripheral depression or “moat”. Some coronae also show significant amounts of radial tectonic structure, and in most cases this predates the concentric features. In addition, there are other features on Venus, recognized for the first time in Magellan data, that consist of domical rises with intense radial tectonic patterns and little or no concentric structure. All of these features commonly are associated with moderate to large quantities of volcanism. In fact, some radially fractured domes have undergone so much volcanism that volcanic construction appears to have played a significant role in establishing their topography. We explore a model of corona formation that links these forms into a genetic sequence. The model begins with the ascent of a mantle diapir. Upward mantle flow driven by its ascent forces the lithosphere above the diapir upward, producing a gentle dome with a radiating pattern of extensional fractures. As the diapir impinges on the underside of the lithosphere it flattens and spreads, transforming the uplift to a more flat-topped shape. In this flattened, near-surface configuration the diapir can cool rapidly. With the resultant loss of buoyancy the raised plateau can relax to form a central sag, a raised rim, and a depressed moat. Concentric tectonic features develop primarily during the latter stages of corona formation and hence are best preserved on mature coronae. Volcanism takes place during all phases of the uplift and may diminish as the relaxation occurs. Our analyses to date suggest that this scenario is broadly consistent with many of the coronae on Venus. However, there is enormous diversity in corona morphology, and features are present that require substantial deviations from this simple model. In particular, some circular depressions appear corona like in synthetic aperature radar images but may in fact be large calderas. Some of the variations observed in corona morphology may ultimately be interpretable in terms of variations in the behavior of individual diapirs and in the local properties of the Venusian lithosphere.
A latest Cretaceous hotspot and the southeasterly tilt of Britain

The southeasterly regional dip of England and Wales is usually ascribed to Miocene movements. Loss of up to 2 km of cover from northern England, shown by apatite fission track analysis, has been related to uplift and erosion induced by a mantle hotspot, but its effects were far more widespread than considered hitherto. Outcrop patterns throughout much of England, Wales and eastern Ireland can be related to a hotspot beneath the Irish Sea. Uplift occurred within the late Maastrichtian and erosion continued into the late Palaeogene. After post-Oligocene down-faulting of the Irish sea, the modern drainage was initiated on the eroded surface. Unconformities provide the best means of dating orogenic movements; in some localities the time interval between the youngest rocks preserved beneath the unconformity and the oldest preserved above may be small enough to enable the dating of fold movements to be determined with some precision. Thus in southeastern Britain the major E-W structures of the Hampshire Basin, the Weald and the London Basin can be dated as Miocene, as rocks of Oligocene age are involved in the folding in the Hampshire Basin and Pliocene sands rest in erosional pockets of the Chalk of SE England. Because fold movements tend to affect large areas of the crust at discrete intervals of time, the southeasterly tilt of Britain, evident from the fact that a NW-SE transect from Anglesey to London crosses outcrops of rocks getting progressively younger from the Precambrian of Anglesey to the Tertiary of the London Basin, has
CEO Compensation, Board of Directors and Corporate Governance in European Companies

In this Ph.D. thesis we analyze the composition of the board of directors as key corporate governance mechanism in Europe. In the first chapter we present stylized features of firms? corporate governance in the main Western European Economies (the group E-17), comparing economic determinants, governance structures and institutional frameworks among countries, and along the time dimension. We describe the evolution of the European Corporate Sector in the last decade, stressing the importance of the harmonization process that has been going on since the beginning of this century. We also present key academic contributions in the field of corporate governance studies, both worldwide and in Europe. In the second chapter we analyze how the use of committees improves board efficiency and how it contributes to increase firm value. In the third chapter we analyze how European firms use board independence and CEO compensation as alternative corporate governance mechanisms. In our study, we find that firms that combine independent advising committees and independent boards are those with higher firm value. We also find a positive relation between board independence and the use of CEO equity linked compensation. Overall in our study we show that although board independence alone is not statistically related to firm value, the use of independent board of directors combined with additional instruments (such as advising committees and equity linked compensation) is associated with higher firm valuation in Europe.
Geochemistry and Petrogenesis of the Tongshankou and Yinzu Adakitic Intrusive Rocks and the Associated Porphyry Copper‐Molybdenum Mineralization in Southeast Hubei, East China

Abstract. The late Jurassic Tongshankou and Yinzu plutons in southeast Hubei have been investigated for their contrasting metal mineralization features. The former is closely associated with porphyry Cu‐Mo mineralization, while the latter is barren of metal mineralization, althouth both are located very close to each other. The Tongshankou granodiorite porphyries and the Yinzu granodiorites are geochemically similar to adakites, e.g., high Al2O3 and Sr contents and La/Yb and Sr/Y ratios, enriched in Na2O, depleted in Y and Yb, very weak Eu anomalies and positive Sr anomalies. However, different geochemi‐cal characteristics exist between the two plutons: the Tongshankou adakitic rocks (1) are relatively enriched in SiO2, K2O, MgO, Cr, Ni, and Sr and depleted in Y and Yb; (2) have higher degree REE differentiation; (3) have positive Eu anomalies in contrast with very weak negative or unclear Eu anomalies in the Yinzu rocks; and (4) isotopically have relatively higher ePNd(t) values (‐5.19 to ‐5.38) and lower initial 87Sr/86Sr ratios (0.7060 to 0.7062), while the Yinzu adakitic rocks have relatively lower ePNd(t) values (‐7.22 to ‐8.67) and higher initial 87Sr/86Sr ratios (0.7065 to 0.7074).
Inflation Expectations and Monetary Policy Design : Evidence from the Laboratory ∗

Using laboratory experiments within a New Keynesian macro framework, we explore the interaction between the formation of inflation expectations and monetary policy design. The central question in this paper is how to design monetary policy in an environment characterized by heterogeneous expectations. Rules that use actual rather than forecasted inflation produce lower inflation variability and reduce expectational cycles. Inflation forecast targeting rule where a reaction coeffi cient equals 4 produces lower inflation variability than rules with reaction coeffi cients 1.5 and 1.35. The difference between the latter two is not significant. However, this result heavily depends on the subjects’ predominant expectation formation mechanism. JEL: C91, C92, E37, E52