We prove the first bifurcation result of time quasi-periodic
traveling
wave solutions for space periodic water waves with vorticity. In particular, we prove the existence of small amplitude time ...quasi-periodic solutions of the gravity-capillary water waves equations with
constant vorticity
, for a bidimensional fluid over a flat bottom delimited by a space-periodic free interface. These quasi-periodic solutions exist for all the values of depth, gravity and vorticity, and restrict the surface tension to a Borel set of asymptotically full Lebesgue measure.
Various methods have been proposed in the literature to predict the rainfall conditions that are likely to trigger landslides in a given area. Most of these methods, however, only consider the ...rainfall events that resulted in landslides and provide deterministic thresholds with a single possible output (landslide or no‐landslide) for a given input (rainfall conditions). Such a deterministic view is not always suited to landslides. Slope stability, in fact, is not ruled by rainfall alone and failure conditions are commonly achieved with a combination of numerous relevant factors. When different outputs (landslide or no‐landslide) can be obtained for the same input a probabilistic approach is preferable. In this work we propose a new method for evaluating rainfall thresholds based on Bayesian probability. The method is simple, statistically rigorous, and returns a value of landslide probability (from 0 to 1) for each combination of the selected rainfall variables. The proposed approach was applied to the Emilia‐Romagna Region of Italy taking advantage of the historical landslide archive, which includes more than 4000 events for which the date of occurrence is known with daily accuracy. The results show that landsliding in the study area is strongly related to rainfall event parameters (duration, intensity, total rainfall) while antecedent rainfall seems to be less important. The distribution of landslide probability in the rainfall duration‐intensity shows an abrupt increase at certain duration‐intensity values which indicates a radical change of state of the system and suggests the existence of a real physical threshold.
Key Points
A probabilistic approach is needed to evaluate landslide rainfall thresholds
Bayes theorem is suited to this purpose
Landslide probability is strongly related to the event rainfall
Sustainably balancing biofuel crop production with food, feed, and fiber on agricultural lands will require developing new cropping strategies. Double- and/or relay-cropping winter camelina (Camelina ...sativa L.) with soybean Glycine max (L.) Merr. may be a means to produce an energy and food crop on the same land in a single year. A study was conducted between 2009 and 2011 in west central Minnesota to evaluate yields, seed quality, economics, and within field energy balance of winter camelina-soybean double- and relay-cropping systems compared to a conventional mono-cropped full-season soybean. Systems included methods to hasten camelina harvest (e.g., swathing and desiccating) to promote early soybean growth. Camelina seed yields were unaffected by cropping system and ranged from 1.1 to 1.3 Mg ha-1. Relay-cropped soybean yields were greater than double-cropped soybean and were 58 to 83% of that for the mono-cropped control. Seed oil and protein content of double- and relay-cropped soybean were comparable to, and combined seed oil yield for the dual crop systems was as much as 50% greater than, the mono-cropped soybean. Net economic returns for the relay-crop system were competitive with that of the full-season soybean. Moreover, energy outputs of the relay-crop system were as high as or higher than a sole soybean crop, but energy efficiency was less for the dual cropping systems due to greater inputs. Results indicate that dual cropping of winter camelina with soybean is agronomically viable for the upper Midwest and might be an attractive system to growers seeking a “cash” cover crop.
Abstract
We use subhalo abundance and age distribution matching to create magnitude-limited mock galaxy catalogs at
z
∼ 0.43, 0.52, and 0.63 with
z
-band and 3.4
μ
m
W
1-band absolute magnitudes and
...r
−
z
and
r
−
W
1 colors. From these magnitude-limited mocks, we select mock luminous red galaxy (LRG) samples according to the (
r
−
z
)-based (optical) and (
r
−
W
1)-based (infrared) selection criteria for the LRG sample of the Dark Energy Spectroscopic Instrument (DESI) survey. Our models reproduce the number densities, luminosity functions, color distributions, and projected clustering of the DESI Legacy Surveys that are the basis for DESI LRG target selection. We predict the halo occupation statistics of both optical and IR DESI LRGs at fixed cosmology and assess the differences between the two LRG samples. We find that IR-based SHAM modeling represents the differences between the optical and IR LRG populations better than using the
z
band and that age distribution matching overpredicts the clustering of LRGs, implying that galaxy color is uncorrelated with halo age in the LRG regime. Both the optical and IR DESI LRG target selections exclude some of the most luminous galaxies that would appear to be LRGs based on their position on the red sequence in optical color–magnitude space. Both selections also yield populations with a nontrivial LRG–halo connection that does not reach unity for the most massive halos. We find that the IR selection achieves greater completeness (≳90%) than the optical selection across all redshift bins studied.
In dolomitic headwater catchments, intense rainstorms of short duration produce runoff discharges that often trigger debris flows on the scree slopes at the base of rock cliffs. In order to measure ...these discharges, we placed a measuring facility at the outlet (elevation 1770 m a.s.l.) of a small, rocky headwater catchment (area ∼0.032 km2, average slope ∼320%) located in the Venetian Dolomites (North Eastern Italian Alps). The facility consists of an approximately rectangular basin, ending with a sharp‐crested weir. Six runoff events were recorded in the period 2011–2014, providing a unique opportunity for characterizing the hydrological response of the catchment. The measured hydrographs display impulsive shapes, with an abrupt raise up to the peak, followed by a rapidly decreasing tail, until a nearly constant plateau is eventually reached. This behavior can be simulated by means of a distributed hydrological model if the excess rainfall is determined accurately. We show that using the Soil Conservation Service Curve‐Number (SCS‐CN) method and assuming a constant routing velocity invariably results in an underestimated peak flow and a delayed peak time. A satisfactory prediction of the impulsive hydrograph shape, including peak value and timing, is obtained only by combining the SCS‐CN procedure with a simplified version of the Horton equation, and simulating runoff routing along the channel network through a matched diffusivity kinematic wave model. The robustness of the proposed methodology is tested through a comparison between simulated and observed timings of runoff or debris flow occurrence in two neighboring alpine basins.
Key Points:
Hydrological response to convective rainfalls in headwater rocky catchments is impulsive and mainly ruled by excess infiltration
Combining SCS‐CN method for estimating excess rainfall and constant velocity for routing, the observed hydrographs cannot be reproduced
Observed peaked hydrographs need a simplified Hortonian equation and the Muskingum‐Cunge scheme along network to be simulated
ABSTRACT We test for galactic conformity at to a projected distance of 5 Mpc using spectroscopic redshifts from the PRism MUlti-object Survey (PRIMUS). Our sample consists of ∼60,000 galaxies in five ...separate fields covering a total of ∼5.5 square degrees, which allows us to account for cosmic variance. We identify star-forming and quiescent "isolated primary" (i.e., central) galaxies using isolation criteria and cuts in specific star formation rate. We match the redshift and stellar mass distributions of these samples to control for correlations between quiescent fraction and redshift and stellar mass. We detect a significant (>3 ) one-halo conformity signal, or an excess of star-forming neighbors around star-forming central galaxies, of ∼5% on scales of 0-1 Mpc and a 2.5 two-halo signal of ∼1% on scales of 1-3 Mpc. These signals are weaker than those detected in the Sloan Digital Sky Survey and are consistent with galactic conformity being the result of large-scale tidal fields and reflecting assembly bias. We also measure the star-forming fraction of central galaxies at fixed stellar mass as a function of large-scale environment and find that central galaxies are more likely to be quenched in overdense environments, independent of stellar mass. However, we find that environment does not affect the star formation efficiency of central galaxies, as long as they are forming stars. We test for redshift and stellar mass dependence of the conformity signal within our sample and show that large volumes and multiple fields are required at intermediate redshift to adequately account for cosmic variance.
Land subsidence in urban areas is a highly significant and globally widespread geological hazard. This type of ground deformation process commonly occurs in rapidly expanding cities due to the ...combined effects of structural loading from built infrastructures and excessive groundwater withdrawals due to the increasing water demand of growing populations and industries. In this study, we perform a detailed analysis of ongoing subsidence in Bologna (Italy), with respect to historical pumping trends and a 3D geological model of the subsurface. Since the 1960s, the city of Bologna has experienced severe subsidence attributed to the overexploitation of aquifers for civil water use. Ground deformation peaked in the 1970s, with documented maximum rates of approximately 100 mm/year, causing structural and infrastructural damages. Over the years, the subsidence process has been intensively monitored by local authorities, collecting extensive ground displacement measurements employing different and increasingly sophisticated techniques, including topographic levelling and satellite interferometry. Long-term data are essential for a comprehensive understanding of the subsidence process evolution and for calibrating numerical or statistical predictive models. Therefore, we developed a methodology to integrate ground-based and remotely sensed monitoring data and produce cumulative ground displacement time series and maps, capturing the long-term temporal evolution and spatial distribution of the subsidence process, respectively. The long-term deformation field reconstructed consistently aligns with the 3D geological model of the area, and the produced cumulative displacement curves consistently match the pluriannual trends observed in groundwater level and pumping monitoring time series.
We present a new method for the automatic classification of Persistent Scatters Interferometry (PSI) time series based on a conditional sequence of statistical tests. Time series are classified into ...distinctive predefined target trends, such as uncorrelated, linear, quadratic, bilinear and discontinuous, that describe different styles of ground deformation. Our automatic analysis overcomes limits related to the visual classification of PSI time series, which cannot be carried out systematically for large datasets. The method has been tested with reference to landslides using PSI datasets covering the northern Apennines of Italy. The clear distinction between the relative frequency of uncorrelated, linear and non-linear time series with respect to mean velocity distribution suggests that different target trends are related to different physical processes that are likely to control slope movements. The spatial distribution of classified time series is also consistent with respect the known distribution of flat areas, slopes and landslides in the tests area. Classified time series enhances the radar interpretation of slope movements at the site scale, pointing out significant advantages in comparison with the conventional analysis based solely on the mean velocity. The test application also warns against potentially misleading classification outputs in case of datasets affected by systematic errors. Although the method was developed and tested to investigate landslides, it should be also useful for the analysis of other ground deformation processes such as subsidence, swelling/shrinkage of soils, or uplifts due to deep injections in reservoirs.
The transport and deposition mechanisms of debris flows are still poorly understood due to the complexity of the interactions governing the behavior of water–sediment mixtures. Empirical–statistical ...methods can therefore be used, instead of more sophisticated numerical methods, to predict the depositional behavior of these highly dangerous gravitational movements. We use widely accepted semi-empirical scaling relations and propose an automated procedure (DFLOWZ) to estimate the area potentially inundated by a debris flow event. Beside a digital elevation model (DEM), the procedure has only two input requirements: the debris flow volume and the possible flow-path. The procedure is implemented in Matlab and a Graphical User Interface helps to visualize initial conditions, flow propagation and final results. Different hypothesis about the depositional behavior of an event can be tested together with the possible effect of simple remedial measures. Uncertainties associated to scaling relations can be treated and their impact on results evaluated. Our freeware application aims to facilitate and speed up the process of susceptibility mapping. We discuss limits and advantages of the method in order to inform inexperienced users.
•Debris flow inundated area can be estimated using scaling relationships.•We provide a free, open-source program to evaluate debris flow hazard.•The model considers the uncertainties in scaling relationships and input data.•A Graphical User Interface facilitate the process of susceptibility mapping.
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