Miracle-dz/UniFAR-FTUs huggingface dataset:
UNIT HYDROGRAPHS FOR DEVELOPING DESIGN FLOOD HYDROGRAPHS

ABSTRACT: In Illinois, a procedure has been developed to derive unit hydrographs for generating 100-year and probable maximum flood hydrographs, on the basis of 11 parameters that define the hydrograph shape very well. Regional regressions of these parameters with basin factors show very high correlation. Thus satisfactory values of parameters can be determined for ungaged areas or those with a few years' record. The nonlinearity in unit hydrographs derived from usual floods is largely attributed to mixing within-channel and overbank-flow flood events. To minimize the effects of nonlinearity and to derive unit hydrographa suitable for calculating spillway design floods, use of the proposed method of developing such hydrographs is recommended.
La erupción submarina de La Restinga en la isla de El Hierro, Canarias: Octubre 2011-Marzo 2012

The first signs of renewed volcanic activity at El Hierro began in July 2011 with the occurrence of abundant, low-magnitude earthquakes. The increasing seismicity culminated on October 10, 2011, with the onset of a submarine eruption about 2 km offshore from La Restinga, the southernmost village on El Hierro. The analysis of seismic and deformation records prior to, and throughout, the eruption allowed the reconstruction of its main phases: 1) ascent of magma and migration of hypocentres from beneath the northern coast (El Golfo) towards the south rift zone, close to La Restinga, probably marking the hydraulic fracturing and the opening of the eruptive conduit; and 2) onset and development of a volcanic eruption indicated by sustained and prolonged harmonic tremor whose intensity varied with time. The features monitored during the eruption include location, depth and morphological evolution of the eruptive source and emission of floating volcanic bombs. These bombs initially showed white, vesiculated cores (originated by partial melting of underlying pre-volcanic sediments upon which the island of El Hierro was constructed) and black basanite rims, and later exclusively hollow basanitic lava balloons. The eruptive products have been matched with a fissural submarine eruption without ever having attained surtseyan explosiveness. The eruption has been active for about five months and ended in March 2012, thus becoming the second longest reported historical eruption in the Canary Islands after the Timanfaya eruption in Lanzarote (1730-1736). This eruption provided the first opportunity in 40 years to manage a volcanic crisis in the Canary Islands and to assess the interpretations and decisions taken, thereby gaining experience for improved management of future volcanic activity. Seismicity and deformation during the eruption were recorded and analysed by the Instituto Geografico Nacional (IGN). Unfortunately, a lack of systematic sampling of erupted pyroclasts and lavas, as well as the sporadic monitoring of the depth and growth of the submarine vent by deployment of a research vessel, hampered a comprehensive assessment of hazards posed during volcanic activity. Thus, available scientific data and advice were not as high quality as they could have been, thereby limiting the authorities in making the proper decisions at crucial points during the crisis. The response in 2011-12 to the El Hierro eruption has demonstrated that adequate infrastructure and technical means exist in the Canary Islands for the early detection of potential eruptive hazards. However, it also has taught us that having detailed emergency management plans may be of limited value without an accompanying continuous, well-integrated scientific monitoring effort (open to national and international collaboration) during all stages of an eruption.
The NHDPlus dataset, watershed subdivision and SWAT model performance

Abstract The Soil and Water Assessment Tool (SWAT) has been developed to evaluate the effectiveness of agricultural management practices on watershed water quality. Many studies have indicated that watershed subdivision can affect the accuracy of model predictions. Most of them used the minimum drainage area (MDA) to delineate sub-watersheds, and varied the value of MDA depending on the size of the watershed being modelled. Instead of MDA, we use the National Hydrography Dataset Plus (NHDPlus)—an integration of the best features of the National Hydrography Dataset (NHD), Watershed Boundary Dataset (WBD), National Elevation Dataset (NED), and the National Land Cover Dataset (NLCD)—to delineate the watershed. The Kaskaskia River watershed in Illinois, USA, was selected to investigate the individual effects of sub-watershed and hydrologic response unit (HRU) delineations on predicted streamflow, total suspended sediment (TSS) and total nitrogen (TN) losses at two USGS gauges. In addition, an MDA of 3000 ha, and four levels of stream (the 2nd, 3rd, 4th and 5th order) were evaluated. Three levels of HRU threshold (5%, 10% and 15%) were used for each stream order model. The results show that stream order had little effect on predicted streamflow, but a great impact on TSS and TN losses, and the impact of HRU delineation became greater when a higher stream order was used to delineate the watershed. For higher stream order, fewer streams were recognized in SWAT simulations, which resulted in less sediment routing and channel processes, which, in turn, led to less deposition in the channels; thus high sediment losses were obtained at the watershed outlet. However, fewer channel processes led to less in-stream N processes; thus lower TN losses. Overall, the SWAT simulations performed the best when the 2nd stream order was used for delineations comparing with USGS observed data, followed by the 3rd stream order. Therefore, to fully depict the watershed characteristics to perform SWAT simulations, a stream order higher than 3rd order is not recommended for watershed delineation. Editor D. Koutsoyiannis; Associate editor C. Perrin
Speckle filtering in satellite SAR change detection imagery

Repeat-pass Synthetic Aperture Radar (SAR) imagery is useful for change detection. A disadvantage of SAR is the system-inherent speckle noise. This can be reduced by filtering. Various filter types and methods are described in the literature, but not one fits the speckle noise in change detection imagery. A new method is therefore developed in this paper. The new method is based on filtering the logarithmic-scaled ratio of SAR images. Logarithmic scaling changes the multiplicative speckle noise in the ratio-image into additive noise and alters the distribution, which simplifies and optimizes the subsequent filter process. The filter in the new method consists of an additive LLMMSE filter (Kuan et al. 1985), preceded by a structure detection stage for a better contour preserving performance. Testing the new method on a repeat-pass satellite SAR image-set gave an accurate overview of changes compared to a colour-composite of both images, other optical remote sensing images and maps of the same area.
Decadal climate variability in a coupled atmosphere‐ocean climate model of moderate complexity

In this study we determined characteristic temporal modes of atmospheric variability at the decadal and interdecadal timescales. This was done on the basis of 1000 year long integrations of a global coupled atmosphere-ocean climate model of moderate complexity including the troposphere, stratosphere, and mesosphere. The applied model resolves explicitely the basic features of the large-scale long-term atmospheric and oceanic variables. The synoptic-scale processes are described in terms of autocorrelation and crosscorrelation functions. The paper includes an extended description and validation of the model as well as the results of analyses of two 1000 year long model integrations. One model run has been performed with the fully coupled model of the atmosphere-ocean system. The performed time-frequency analyses of atmospheric fields reveal strong decadal and interdecadal modes with periods of about 9, 18, and 30 years. To quantify the influence of the ocean on atmospheric variations an additional run with seasonally varying prescribed sea surface temperatures has been carried out, which is characterized by strong decadal modes with periods of about 9 years. The comparison of both runs suggests that decadal variability can be understood as an inherent atmospheric mode due to the nonlinear dynamics of the large-scale atmospheric circulation patterns whereas interdecadal climate variability has to be regarded as coupled atmosphere-ocean modes.
Observations of a Loop Current Frontal Eddy Intrusion Onto the

Hydrographic and satellite data from the west Florida shelf between April 1–7, 1982 showed the intrusion of a Loop Current frontal eddy onto the shelf. Data were examined to describe the structure of this feature and study effects of its intrusion on water masses in the outer shelf region. A frontal eddy, consisting of a warm filament separated from the main current by a region of cooler water, propagated southeastward at 30 cm/s intruding onto the shelf near 26°N between April 4 and 6. Temperature-salinity (T-S) properties revealed that water in the filament was Loop Current water that had been contiguous with 80 m deeper Loop Current water in the main body of the current; water in the cold region was Continental Edge water, a transitional water mass with cooler, fresher T-S characteristics. Upwelling of deeper Loop Current water occurred under this region, and elevated nutrient concentrations were found in the upwelled dome under the cold region. Interleaving occurred along water mass boundaries enabling the exchange of heat and salt. This mixing and the supply of cool, nutrient-rich water to the outer shelf was the major consequence of the intrusion. The length scale and speed of this Loop Current frontal eddy was similar to Gulf Stream frontal eddies through the upwelling was not as intense as in intrusions of Gulf Stream frontal eddies.
A Seismic Stratigraphic Case History in the Eastern Barrow Subbasin, North West Shelf, Australia: Chapter 11

Regional chronostratigraphic correlations were developed within the Barrow Subbasin, a rift-margin basin associated with the breakup of eastern Gondwanaland. Three major Mesozoic-Cenozoic transgressive-regressive cycles were identified using excellent seismic control in an area of sparse well control. Each unit within these cycles could be seismically identified. Each cycle comprises a basal-transgressive sand unit, an overlying transgressive marine shale and a final regressive phase of fluvial-deltaic (or carbonate) progradation. Submarine channels and fans, associated with early and late stages of these cycles, have been recognized. The initial Triassic cycle and part of the second Early to Middle Jurassic cycle, were deposited prior to the main, Middle Callovian breakup period. Considerable uplift, erosion and sediment transport took place following this period, from off the eastern margin of the subbasin. In the Neocomian upper part of this second cycle, the sediment transport direction changed and extensive coarse clastic deposition infilled the basin from south to north. The third cycle, from Early to Late Cretaceous to Tertiary time, reflects the final dispersal of eastern Gondwanaland and the opening of the Indian Ocean with the development of a thick prograding carbonate wedge. Examples of the seismic sequences within each cycle are shown together with selected seismic facies maps. The methodology of developing these sequences and maps is given. A variety of stratigraphic traps have now been recognized - these traps rely on sands enclosed in turbidite sequences related to prograding fronts as well as to submarine canyons incised into the eastern shelf. Shaling out and updip pinchout of basal-transgressive units also sets up attractive targets. Some of these traps have now been drilled and their geological results confirmed the seismic stratigraphic interpretation.
The roles of competition, disturbance and nutrients on species composition, light interception and biomass production in a South African semi-arid savanna.

The long-term effects of burning frequency on herbaceous species composition were examined in semi-arid savanna vegetation near Alice, a small town in the Eastern Cape Province of South Africa. The trial was established in 1980 and treatments comprise an annual, biennial triennial, quadrennial, sexennial early spring burns and a no burn treatment, each with two replications in a Completely Randomized Design. Species composition was determined each year before burning, and the data collected between 1980 and 2008 was used in this study. A total of 20 grass species, several forbs and karroid species were also recorded. Nonmetric Multidimensional Scaling and the Bray-Curtis dissimilarity tests were used to test for compositional variation between burning treatments over time. In general, compositional change increased with fire frequency. Species abundances and distribution were influenced by fire treatments over time, whereby individual species were dispersed along gradients of increasing/decreasing fire frequency, and these also varied with sampling year. The triennial and quadrennial burns produced the longest NMS ordination distances between 1982 and 1983, signifying the highest magnitude of compositional change, which was also directional. These were followed by the no burn and sexennial burns, while the annual and biennial burns had the shortest ordination distances. Themeda triandra, a fire-tolerant species was most abundant in the annual, biennial and triennial plots, but gradually decreased with less frequent burning, while Melica decumbens was most dominant in the no burn and six-year burns, but gradually disappeared with increasing fire frequency. Several other species such as Digitaria eriantha, Eragrostis species, Panicum stapfianum and Sporobolus africanus were also abundant in most of the treatment plots. There was a highly significant variation in species abundances between 1980 and 2008 and the species abundances were also significantly influenced by burning treatments. The percentage dissimilarities for the annual and biennial burns (77.1 and 70.5 % respectively) were significantly higher than those of the triennial, quadrennial and sexennial burns respectively. The triennial and quadrennial burns exhibited the most diverse species composition after 28 years
Finding a proxy for wind stress over the coastal ocean

Wind stress forcing is a critical driver of oceanographic processes. In the absence of over-ocean wind measurements, re-analysis products and over-land measurements are often used. The present paper compares a unique wind-data series from an ocean mooring with two re-analysis products and data from six over-land sites in Sydney, Australia, to determine whether these data can infer over-ocean wind conditions. Four oceanographic moorings are located here; however, over-ocean meteorological observations are no longer available. Correlations between over-ocean and over-land sites wind stress were >0.8, whereas for re-analysis products, correlations ranged from 0.28 to 0.72. Re-analysis products were unable to resolve variability at the over-ocean site with periods shorter than 2 days, indicating that they are not appropriate wind proxies for the coastal ocean. Somewhat counter-intuitively, our results showed that proximity of over-land sites to the over-ocean site does not necessarily imply the highest correlation or the lowest error and careful site selection is required. An upwelling study showed that wind observations from selected over-land sites can accurately represent isotherm uplift in the coastal ocean. Threshold wind stress values that uplift isotherms at these over-land sites are provided, along with a recommendation for the use of the over-land site that best represents over-ocean wind conditions in this region.
Exploring the landscape of the National Forest : a walkers' guide to the landscape and natural environment of the National Forest

The National Forest offers a variety of landscape types, from extensive gently undulating clay lowlands dominated by mixed farming, to the hilly sandstone1 region in the central part. The coalfields, in Leicestershire and South Derbyshire, most notably demonstrate the great impact of man’s influence on the landscape. In the east Charnwood Forest, with its rolling hills and craggy knolls, presents us with a unique landscape that has been moulded over 600 million years. The rocks here date back to the Precambrian and contain some of the oldest known fossils. This book and map will help you to explore the region: its geology, landscape, biodiversity, archaeology and industrial and cultural heritage through a series of walks. You will have a fascinating glimpse of past variations in climate that show how England has moved around on the surface of the Earth by plate tectonics.There is evidence of a turbulent geological history that has included volcanoes, mountains, major earthquakes, rainforests, rivers, lakes, seas, deserts and glaciers. The book will also demonstrate how the geology of The National Forest has had a profound influence on the economy of the area, dating back over the centuries, with many industries largely dependent on the natural resources. Some are now no longer viable, such as coal mining, iron ore and lime, but others such as aggregate extraction, gypsum and brick clays, are still very prosperous. The effect of these industries has been to significantly change the landscape in many areas, most notably in the coalfields, but also the extensive aggregate extraction in Charnwood Forest.
Seismic velocity structure in the Hot Springs and Trifurcation areas of the San Jacinto fault zone, California, from double-difference tomography

S U M M A R Y We present tomographic images of crustal velocity structures in the complex Hot Springs and Trifurcation areas of the San Jacinto Fault Zone (SJFZ) based on double-difference inversions of earthquake arrival times. We invert for VP, VS and hypocentre location within 50 × 50 × 20 km3 volumes, using 266 969 P and 148 249 S arrival times. We obtain high-fidelity images of seismic velocities with resolution on the order of a few kilometres from 2 to 12 km depth and validate the results using checkerboard tests. Due to the relatively large proportion of S-wave arrival times, we also obtain stable maps of VP/VS ratios in both regions. The velocity of the Trifurcation Area as a whole is lower than adjacent unfaulted material. We interpret a 4-kmwide low velocity zone with high VP/VS ratio in the trifurcation itself as related to fault zone damage. We also observe clear velocity contrasts across the Buck Ridge, Clark and Coyote Creek segments of the SJFZ. The Anza segment of the SJFZ, to the NW of the trifurcation area, displays a strong (up to 27 per cent) contrast of VS from 2 to 9 km depth. In the Hot Springs area, a low velocity zone between the Claremont and Casa Loma Strands narrows with depth, with clear velocity contrasts observed across both segments. A roughly 10-km-wide zone of low velocity and low VP/VS ratio at the NW tip of the Hot Springs fault is indicative of either unconsolidated sediments associated with the San Jacinto basin, or fluid-filled cracks within a broad deformation zone. High VP/VS ratios along the Anza segment could indicate a preferred nucleation location for future large earthquakes, while the across-fault velocity contrast suggests a preferred northwest rupture propagation direction for such events.
Light‐absorbing soluble organic aerosol in Los Angeles and Atlanta: A contrast in secondary organic aerosol

Light absorption spectra and carbon mass of fine particle water‐soluble components were measured during the summer of 2010 in the Los Angeles (LA) basin, California, and Atlanta, Georgia. Fresh LA secondary organic carbon had a consistent brown color and a bulk absorption per soluble carbon mass at 365 nm that was 4 to 6 times higher than freshly‐formed Atlanta soluble organic carbon. Radiocarbon measurements of filter samples show that LA secondary organic aerosol (SOA) was mainly from fossil carbon and chemical analysis of aqueous filter extracts identified nitro‐aromatics as one component of LA brown SOA. Interpreting soluble brown carbon as a property of freshly‐formed anthropogenic SOA, the difference in absorption per carbon mass between these two cities suggests most fresh secondary water‐soluble organic carbon formed within Atlanta is not from an anthropogenic process similar to LA. Contrasting emissions of biogenic volatile organic compounds may account for these differences.
Subducting slabs stagnant in the mantle transition zone

The P wave velocity structure beneath the Western Pacific is found from the International Seismological Center first arrival data. Special attention was paid to the deep structure beneath the Wadati-Benioff zone. We discretized the whole mantle into blocks with finer blocks in the region of interest to obtain the velocities of all the blocks. This way of discretization minimizes a problem with tomographic studies of regional scale: difficulty in making corrections for the effects outside the region of interest. Our solution is iterative with the alternate step of the relocation of earthquakes, using the whole mantle model of Inoue et al. (1990) as a starting model. A first-order smoothness constraint was imposed to suppress the possible fluctuation of the solution around the initial model. The essential result depends little on whether the reference spherical model is smooth or discontinuous near 400- and 670-km depths. We examined the resolution by calculating the resolving kernels for selected blocks and by reconstructing the checkerboard test patterns of velocity perturbation and the test structures of subducting lithosphere. The resolution is depth dependent but in general good enough to see the slab configuration beneath the Southern Kurile-Japan-Izu-Bonin arcs and the Java arc. It is relatively poor beneath the Northern Kurile and Mariana arcs. The seismic image of subducting slab beneath the Southern Kurile to Bonin arcs bends to subhorizontal near the leading edge of the Wadati-Benioff zone and extends continentward over a distance of more than 1000 km. The subhorizontal portion of the slab connects a high-velocity blob to the bottom that reaches a depth of at least 800 km across the 670-km discontinuity under the Japan arc. Although the image of the Java slab directly penetrates the 670-km discontinuity, it then bends to a shallow dip with a considerable spread, reaching a depth of about 1200 km. These results suggest that descending slabs of lithosphere in the Western Pacific tend to be stagnant in the transition zone under a subtle control of the 670-km discontinuity. Although stagnant slab materials eventually descend into the lower mantle, they no longer maintain their original configuration below the 670-km discontinuity.
Enhancement of acidic gases in biomass burning impacted air masses over Canada

Biomass-burning impacted air masses sampled over central and eastern Canada during the summer of 1990 as part of ABLE 3B contained enhanced mixing ratios of gaseous HNO3, HCOOH, CH3COOH, and what appears to be (COOH)2. These aircraft-based samples were collected from a variety of fresh burning plumes and more aged haze layers from different source regions. Values of the enhancement factor, ΔX/ΔCO, where X represents an acidic gas, for combustion-impacted air masses sampled both near and farther away from the fires, were relatively uniform. However, comparison of carboxylic acid emission ratios measured in laboratory fires to field plume enhancement factors indicates significant in-plume production of HCOOH. Biomass-burning appears to be an important source of HNO3, HCOOH, and CH3COOH to the troposphere over subarctic Canada.