Presence and spatial distribution of emerging contaminants (drugs of abuse) in protected agroecological systems (L’Albufera de Valencia Coastal Wetland, Spain)

The Mediterranean wetlands are unique in biological diversity and provide multiple benefits, constituting a great water reserve for the planet and producing biomass and nutrients for the trophic chain. However, the increasing human impact and socio-economic development in recent decades have caused important losses in these ecosystems. This work was carried out in the Natural Park of L’Albufera (Valencia, Spain), which includes a coastal lagoon, marshlands, dunes and pinewoods, surrounded by rice fields and orchard in its non-urbanized part. Despite this great ecological value, it suffers impacts derived from the high human and industrial occupation and the hydrological contributions of the connected irrigation systems. The study focused on the development of a combined methodology, based on environmental forensics principles, with the aim of identifying the presence, flow paths and spatial distribution of illicit drugs entering the Natural Park. It is organized around two major procedures: analysis of 16 water samples and application of Geographical Information Systems (GIS) integrating different sources and data formats, as analysis of 14 drugs of abuse by Liquid Chromatography-Mass Spectrometry techniques, and social and environmental data in either GIS layers or tabular digital formats. Results show that, at present, most analyzed drugs have been identified in all sample points. Besides the population distribution pattern, the traditional irrigation system connected to sewage treatment plant (STP) locations is the way by which illicit substances are introduced into the Natural Park waters.     

X‐shooter: What stands behind the good performance

One year of operations demonstrated the high level of scientific performance of the X‐shooter spectrograph. The excellent science opened by this instrument is described in various papers within this volume. The purpose of this contribution is to briefly describe the novel technical solution adopted in the design and construction phase of X‐shooter that made it a successful instrument and the aforementioned science possible (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Wind influence on surface current variability in the Ibiza Channel from HF Radar

Surface current variability is investigated using 2.5 years of continuous velocity measurements from an high frequency radar (HFR) located in the Ibiza Channel (Western Mediterranean Sea). The Ibiza Channel is identified as a key geographical feature for the exchange of water masses but still poorly documented. Operational, quality controlled, HFR derived velocities are provided by the Balearic Islands Coastal Observing and Forecasting System (SOCIB). They are assessed by performing statistical comparisons with current-meter, ADCP, and surface lagrangian drifters. HFR system does not show significant bias, and its accuracy is in accordance with previous studies performed in other areas. The main surface circulation patterns are deduced from an EOF analysis. The first three modes represent almost 70 % of the total variability. A cross-correlation analysis between zonal and meridional wind components and the temporal amplitudes of the first three modes reveal that the first two modes are mainly driven by local winds, with immediate effects of wind forcing and veering following Ekman effect. The first mode (37 % of total variability) is the response of meridional wind while the second mode (24 % of total variability) is linked primarily with zonal winds. The third and higher order modes are related to mesoscale circulation features. HFR derived surface transport presents a markedly seasonal variability being mostly southwards. Its comparison with Ekman-induced transport shows that wind contribution to the total surface transport is on average around 65 %.     

An alternative method for calculation of Rayleigh and Love wave phase velocities by using three-component records on a single circular array without a central station

A method for the computation of phase velocities of surface waves from microtremor waveforms is shown. The technique starts from simultaneous three-component records obtained in a circular array without a central station. Then, Fourier spectra of vertical, radial and tangential components of motion are calculated for each station and considered as complex-valuated functions of the azimuthal coordinate. A couple of intermediate real physical quantities, B and C , can be defined from the 0- and ±1-order coefficients of the Fourier series expansion of such functions. Finally, phase velocities of Rayleigh and Love waves can be retrieved from B and C by solving respective one-unknown equations. The basic assumption is the possibility of expanding the wavefield as a sum of plane surface waves with Rayleigh and Love wavenumbers being univocal functions of the circular frequency. The method is tested in synthetic ambient noise wavefields confirming its reliability and robustness for passive seismic surveying.     

Simplified longitudinal seismic response of tunnels linings subjected to surface waves

This paper presents an engineering approach for analysing the longitudinal behaviour of tunnels subjected to earthquakes. The tunnel is modelled as a Timoshenko beam connected to the far soil by means of continuous elastic support (Winkler model). Seismic free-field inputs, such as those caused by surface waves travelling parallel to the tunnel axis, were imposed at the base of the springs of the Winkler model, generating bending moments and shear forces on the cross-sections of the tunnel. Closed-form expressions of the tunnel displacements, shear forces, and bending moments were determined at any tunnel section in terms of the seismic excitation, tunnel geometry and material properties, and subgrade reaction modulus of the soil. A dimensional analysis was carried out to ascertain directly the maximum tunnel displacement, bending moment, and shear force.     

Assessment of 80 years of ancient‐badlands restoration in Saldaña,Spain

This paper presents the history of badland generated in the Saldaña region, Spain; as well as the main responses eight decades after the start of restoration – in terms of vegetation, soil and erosive processes. The restoration consisted of intense reforestation and construction of more than 100 check dams and numerous wattle fences. Presently, the dense vegetation (87% cover) contrasts markedly with the degraded landscape from the early 20th century (5% cover). The thickness of litter and the natural presence of some species (Quercus pyrenaica, Paeonia broteroi and Lactarius deliciosus) clearly indicate the recovery of the site. The development of the forest cover shows that the intervention has the potential to recover almost 90% of the area. There is also evidence of soil regeneration, although some properties (erodibility, resistance to penetration and shear‐strength resistance) are not that different between the forested and degraded areas. In the restored zones, runoff is negligible, since a thick layer of moss covers the spillways of all the check dams. Erosion has almost been stopped by the effects of vegetation cover, litter and higher infiltration rates (infiltration rate in forested slopes is 43.4 times greater than in bare slopes). Sediment detachment, such as landslides, mudflows and piping, still occur, but are restricted to the degraded zones. Furthermore, even when sediments are mobilized from the upper degraded hillslopes during the larger storms events (2000–2010), check dams and the lower elevation restored forest‐buffers effectively work to reduce the sediment yield into the Carrión River by almost three orders of magnitude (<10² mg L^‐1), compared with data from the 1930s and 1940s (>10⁵ mg L^‐1). Copyright © 2014 John Wiley & Sons, Ltd.     

Growing season expansion and related changes in monthly temperature and growing degree days in the Inter-Montane Desert of the San Luis Valley, Colorado

Most climate change studies on high elevation ecosystems identify changes in biota, while several report abiotic factors. However, very few report expansion of the freeze-free period, or discuss monthly changes of temperature and growing degree days (GDD) during the growing season. This study provides initial data on agriculturally-related aspects of climate change during the growing season (M-J-J-A-S) in the inter-montane desert of the San Luis Valley (SLV), Colorado. Temperature data were gathered from 7 climate stations within the SLV. Based on ordinal days, the last vernal freeze is occurring (p?<?0.05) earlier at 3 stations than in prior years, ranging between 5.52 and 11.86?days during 1981–2007. Significantly-later autumnal freezes are occurring at 5 stations by 5.95–18.10?days, while expansion of the freeze-free period was significantly longer at all stations by 7.20–24.21?days. The freeze-free period averaged about 93?days prior to the 1980s, but now averages about 107?days. Increases (p?<?0.05) in daily mean, maximum, minimum temperature occurred at nearly all stations for each month. Increases in GDD₁₀, GDD_4.4 (potato) and GDD_5.5 (alfalfa) also occurred at nearly all stations for all months during 1994–2007. Higher temperatures increase the number of GDD, quickening crop growth and maturity, and potentially reducing yield and quality unless varieties are adapted to changes and water is available for the season extension and increased evapotranspiration.