Las Obras hidráulicas en los sistemas fluviales de la Costa Brava: preferencias locales y limitaciones de un modelo convencional de adaptación al riesgo de inundación

Este artículo tiene por finalidad analizar las medidas de adaptación al riesgo de inundación que se han realizado en el ámbito de la Costa Brava, con especial incidencia en el papel que han tenido las obras de infraestructura hidráulica en la prevención de avenidas. Se intenta comprobar hasta que punto la percepción local dominante sobre las obras hidráulicas como una de las formas más eficientes pera la prevención de inundaciones se contradice con las nuevas tendencias tanto en relación a los costes ecológicos de la construcción de estos dispositivos hidráulicos como al planeamiento urbanístico y fluvial, en general

Quantitative Assessment of Soil Physical Quality in Northern China Based on S-theory

ABSTRACT Quantitative assessment of soil physical quality is of great importance for eco-environmental pollution and soil quality studies. In this paper, based on the S-theory, data from 16 collection sites in the Haihe River Basin in northern China were used, and the effects of soil particle size distribution and bulk density on three important indices of theS-theory were investigated on a regional scale. The relationships between unsaturated hydraulic conductivityKi at the inflection point and S values (S/hi) were also studied using two different types of fitting equations. The results showed that the polynomial equation was better than the linear equation for describing the relationships between -log Ki and -logS, and -log Kiand -log (S/hi)2; and clay content was the most important factor affecting the soil physical quality index (S). The variation in the S index according to soil clay content was able to be fitted using a double-linear-line approach, with decrease in the S index being much faster for clay content less than 20 %. In contrast, the bulk density index was found to be less important than clay content. The average S index was 0.077, indicating that soil physical quality in the Haihe River Basin was good.

Estudi de les aigües salines a la conca del riu Llobregat i Cardener : implicacions ambientals

L’increment de la salinitat a les aigües subterrànies a prop de la zones de les explotacions mineres salines representa un problema ambiental amb moltes implicacions socio-econòmiques. La part mitja de la conca del riu Llobregat i Cardener és un clar exemple d’aquesta problemàtica. En molts casos l’origen de la salinitat és dubtós, ja que pot provenir del contacte de l’aigua de l’aqüífer amb formacions geològiques salines naturals o per l’afectació de les escombreres produïdes per l’explotació minera de potasses que es troba en aquesta regió. L’objectiu d’aquest treball és demostrar que el Ra pot ser un bon traçador per determinar l’origen de la salinitat de les aigües i complementar les analítiques químiques elementals i dels isòtops del sofre i de l’oxigen del sulfat (δ34SSO4 i δ18OSO4). La presència dels diversos isòtops del Ra en les aigües subterrànies dependrà de la geologia i del temps de residència de l’aigua dins l’aqüífer. L’anàlisi de 12 mostres de la comarca indica que el 226Ra és el millor dels isòtops del Ra que permet diferenciar l’origen de les aigües subterrànies.

Iowa’s Bridge and Highway Climate Change and Extreme Weather Vulnerability Assessment Pilot, HEPN-707, 2015

The Iowa Department of Transportation (DOT) is responsible for approximately 4,100 bridges and structures that are a part of the state’s primary highway system, which includes the Interstate, US, and Iowa highway routes. A pilot study was conducted for six bridges in two Iowa river basins—the Cedar River Basin and the South Skunk River Basin—to develop a methodology to evaluate their vulnerability to climate change and extreme weather. The six bridges had been either closed or severely stressed by record streamflow within the past seven years. An innovative methodology was developed to generate streamflow scenarios given climate change projections. The methodology selected appropriate rainfall projection data to feed into a streamflow model that generated continuous peak annual streamflow series for 1960 through 2100, which were used as input to PeakFQ to estimate return intervals for floods. The methodology evaluated the plausibility of rainfall projections and credibility of streamflow simulation while remaining consistent with U.S. Geological Survey (USGS) protocol for estimating the return interval for floods. The results were conveyed in an innovative graph that combined historical and scenario-based design metrics for use in bridge vulnerability analysis and engineering design. The pilot results determined the annual peak streamflow response to climate change likely will be basin-size dependent, four of the six pilot study bridges would be exposed to increased frequency of extreme streamflow and would have higher frequency of overtopping, the proposed design for replacing the Interstate 35 bridges over the South Skunk River south of Ames, Iowa is resilient to climate change, and some Iowa DOT bridge design policies could be reviewed to consider incorporating climate change information.

1208-005 North Raccoon Watershed Final Report

The Buena Vista SWCD is submitting this WIRB request on behalf of both Buena Vista and Pocahontas SWCDs. The two SWCDs are working jointly on a project that includes three existing Mississippi River Basin Imitative (MRBI) project areas in the North Raccoon River Watershed. The total project area is 280,654 crop acres. The MRBI project involves installing conservation practices through the EQIP program. Funding from MRBI will support costs of practice design, layout and checkout, however, there is no funding to market and sell the program and practices to landowners and producers in the project area. Both soil and water districts are financially supporting work currently being done to encourage signup for the approved practices. To effectively implement the MRBI project it is imperative that marketing and promotion through group meetings and one-on­ one contacts is completed. Funding from WIRB will allow the existing employee to spend the needed time on these promotional activities in both Buena Vista and Pocahontas County. Through this WIRB request these two SWCDs districts plan to apply over $800,000 worth of conservation practices that is funded through the MRBI program. The return from this investment of WIRB dollars is large. This is an opportunity to support a large amount of conservation work in the North Raccoon River Watershed, which, is also an important water source for the city Des Moines and provides recreational activities from Des Moines up to BY and Pocahontas Counties.

09008-005 Hewitt Creek Final Report

The primary goal of the Hewitt Creek watershed council is to have Hewitt-Hickory Creek removed from the Iowa impaired waters (303d) list. Hewitt Creek watershed, a livestock dense 23,005 acre sub-watershed of the Maquoketa River Basin, is 91.2% agricultural and 7.5% woodland. Since 2005, sixty-seven percent of 84 watershed farm operations participated in an organized watershed improvement effort using a performance­ based watershed management approach, reducing annual sediment delivery to the stream by 4,000 tons. Watershed residents realize that water quality improvement efforts require a long-term commitment in order to meet their watershed improvement goals and seek funding for an additional five years to continue their successful watershed improvement project. Cooperators will be provided incentives for improved environmental performance, along with incentives and technical support to address feedlot runoff issues and sub-surface nitrate-nitrogen loss. The Phosphorus Index, Soil Conditioning Index and cornstalk nitrate test will be used by producers as measures of performance to refine nutrient and soil loss management and to determine effective alternatives to reduce nutrient and sediment delivery. Twenty-five livestock operations will improve feedlot runoff control systems and five sub-surface bioreactors will be installed to reduce nitrate delivery from priority tile-drained fields. The Hewitt Creek council will seek additional cost-share funding for high-cost feedlot runoff control structures, sediment control basins and stream bank stabilization projects.

25-years of biomonitoring in two mediterranean streams (Llobregat and Besos basins, NE Spain)

Biological water quality changes in two Mediterranean river basins from a network of 42 sampling sites assessed since 1979 are presented. In order to characterize the biological quality, the index FBILL, designed to characterize these rivers" quality using aquatic macroinvertebrates, is used. When comparing the data from recent years to older ones, only two headwater sites from the 42 had improved their water quality to good or very good conditions. In the middle or low river basin sites or even in headwater localities were river flow is reduced, the important investment to build up sewage water treatment systems and plants (more than 70 in 15 years) allowed for a small recovery from poor or very poor conditions to moderate water quality. Nevertheless still a significant number (25 %) of the localities remain in poor conditions. The evolution of the quality in several points of both basins shows how the main problems for the recovery of the biological quality is due to the water diverted for small hydraulic plants, the presence of saline pollution in the Llobregat River, and the insufficient water depuration. In the smaller rivers, and specially the Besòs the lack of dilution flows from the treatment plants is the main problem for water quality recovery.

Propuesta de un protocolo de evaluación de la calidad ecológica de ríos andinos (CERA) y su aplicación a dos cuencas de Ecuador y Perú

ABSTRACT Proposal for an evaluation protocol of the ecological quality of Andean rivers (CERA) and its use in two basins in Ecuador and Peru A Rapid Protocol is presented for Evaluation of the Ecological Status of Andean Rivers (CERA) localized over 2000 m.a.s.l. from the Northern Andes (Venezuela) through the Altiplano in the Central Andes (Bolivia). This protocol was used in 45 sampling sites in the Guayllabamba River Basin in Ecuador and in 42 sampling sites in the Ca nete River Basin in Peru. Previously, and in order to test if the sampling stations may or not be considered reference stations, we constructed a method that assesses 24 basin attributes, hydrology, reach and riverbed and that uctuates from 24 to 120 points; sites with values higher than 100 were considered as potential reference sites. Besides the benthic macroinvertebrats" evaluation, the river habitat and riparian vegetation were also evaluated through of the application of the indices ABI (R´ os et al., submitted), IHF (Pardo et al., 2002) and QBR-And, respectively. The convenience of the initial allocation of the reference sites was evaluated as well. These indices have been properly adapted to the conditions and characteristics of the high Andes rivers. The results obtained for both basins were compared and discussed. Through the use of the CERA protocol, the particular perturbation gradients and the natural variability of the reference sites in both countries were recognized. RESUMEN Propuesta de un protocolo de evaluación de la calidad ecológica de ríos andinos (CERA) y su aplicaci´on a dos cuencas en Ecuador y Perú Se presenta un protocolo rápido de evaluación de la Calidad Ecológica de Ríos Andinos (CERA), situados sobre los 2000 m.s.n.m, desde los Andes del Norte (Venezuela) hasta el Altiplano de los Andes Centrales (Bolivia). Este protocolo ha sido aplicado en 45 estaciones de muestreo en la cuenca del río Guayllabamba en Ecuador y en 42 estaciones de muestreo en la cuenca del río Cañete en Perú. Previamente, para probar si las estaciones de muestreo pueden o no ser estaciones de referencia construimos un método que valora 24 atributos de cuenca, hidrología, tramo y lecho y que fluctúa de 24 a 120 puntos; valores superiores a 100 fueron considerados como sitios potencialmente de referencia. Además del estudio de los macroinvertebrados bentónicos, se evaluó el hábitat fluvial y la comunidad vegetal de ribera a través de la aplicación de los índices ABI (Ríos et al., sometido), IHF (Pardo et al., 2002) y QBR-And respectivamente; así como la conveniencia de la asignación inicial de las estaciones de referencia. Estos índices han sido adecuadamente adaptados a las condiciones y características propias de los ríos altoandinos. Los resultados obtenidos fueron comparados y discutidos entre ambas cuencas. Mediante la aplicación del protocolo CERA se han reconocido los respectivos gradientes de perturbación y la variabilidad natural de las estaciones de referencia en ambos países.

Reconstructing native American migrations from whole-genome and whole-exome data.

There is great scientific and popular interest in understanding the genetic history of populations in the Americas. We wish to understand when different regions of the continent were inhabited, where settlers came from, and how current inhabitants relate genetically to earlier populations. Recent studies unraveled parts of the genetic history of the continent using genotyping arrays and uniparental markers. The 1000 Genomes Project provides a unique opportunity for improving our understanding of population genetic history by providing over a hundred sequenced low coverage genomes and exomes from Colombian (CLM), Mexican-American (MXL), and Puerto Rican (PUR) populations. Here, we explore the genomic contributions of African, European, and especially Native American ancestry to these populations. Estimated Native American ancestry is 48% in MXL, 25% in CLM, and 13% in PUR. Native American ancestry in PUR is most closely related to populations surrounding the Orinoco River basin, confirming the Southern American ancestry of the Taíno people of the Caribbean. We present new methods to estimate the allele frequencies in the Native American fraction of the populations, and model their distribution using a demographic model for three ancestral Native American populations. These ancestral populations likely split in close succession: the most likely scenario, based on a peopling of the Americas 16 thousand years ago (kya), supports that the MXL Ancestors split 12.2kya, with a subsequent split of the ancestors to CLM and PUR 11.7kya. The model also features effective populations of 62,000 in Mexico, 8,700 in Colombia, and 1,900 in Puerto Rico. Modeling Identity-by-descent (IBD) and ancestry tract length, we show that post-contact populations also differ markedly in their effective sizes and migration patterns, with Puerto Rico showing the smallest effective size and the earlier migration from Europe. Finally, we compare IBD and ancestry assignments to find evidence for relatedness among European founders to the three populations.

Metais pesados em águas superficiais como estratégia de caracterização de bacias hidrográficas

The input of heavy metals concentrations determinated by ICP-AES, in samples of the Cambé river basin, was evaluated by using the Principal Component Analysis. The results distinguishes clearly one site, which is strongly influenced by almost all elements studied. Special attention was given to Pb, because of the presence of one battery industry in this area. Some downstream samples were associated with the same characteristics of this site, showing residual action of contaminants along the basin. Other sites presented influence of soil elements, plus Cr near a tannery industry. This study allowed to distinguish different sites in the upper basin of the Cambé (Londrina-PR-BR), in accordance to elements input.

Distribuição de compostos organoclorados nas águas e sedimentos da bacia do rio Piracicaba/SP - Brasil

The great utilization of synthetic and persistent xenobiotic cumulative compounds is the main causes of the deterioration of aquatic ecosystems. The one of objective of this work was the determination of the organochlorine levels in the Piracicaba river basin, situated at the center of São Paulo state. Four PCBs congeners, PCP and HCB were determined by GC-ECD in two different matrices: water and sediments. The pattern of the compound distribution indicated a dominance of PCP, HCB and PCB-200. The results indicated contamination in the sampling points located in Campinas, Piracicaba, Santa Bárbara d'Oeste and Sumaré cities.

Invasive species and habitat degradation in Iberian streams: an analysis of their role in freshwater fish diversity loss

Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives’ decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions

Imposicions estructurals en el drenatge de la conca del riu Onyar (Girona)

The Onyar River basin is situated in the depression of la Selva. His origins are related to tectonic activity during Neogen in this region. In his evolution, we note a slowly and continuous downfall which directs the morphodinamical behaviour. In this sense, the drainage network has a directional trend towards the north, as consecuence of fault systems, and specially the N-S oriented one. A fault of this system has an important influence in the basin morphology, directs the drainage towards the north and avoids a closely drainage in the basin

Experimental assessment of the effects of a Neotropical nocturnal piscivore on juvenile native and invasive fishes

We experimentally examined the predator-prey relationships between juvenile spotted sorubim Pseudoplastystoma corruscans and young-of-the-year invasive and native fish species of the Paraná River basin, Brazil. Three invasive (peacock bass Cichla piquiti, Nile tilapia Oreochromis niloticus, and channel catfish Ictalurus punctatus) and two native (yellowtail tetra Astyanax altiparanae and streaked prochilod Prochilodus lineatus) fish species were offered as prey to P. corruscans in 300 L aquaria with three habitat complexity treatments (0%, 50% and 100% structure-covered). Prey survival was variable through time and among species (C. piquiti < O. niloticus < A. altiparanae < P. lineatus < I. punctatus), depending largely on species-specific prey behavior but also on prey size and morphological defenses. Habitat complexity did not directly affect P. corruscans piscivory but some prey species changed their microhabitat use and shoaling behavior among habitat treatments in predator’s presence. Pseudoplatystoma corruscans preyed preferentially on smaller individuals of those invasive species with weak morphological defensive features that persisted in a non-shoaling behavior. Overall, our results contrast with those in a companion experiment using a diurnal predator, suggesting that nocturnal piscivores preferentially prey on different (rather diurnal) fish species and are less affected by habitat complexity. Our findings suggest that recovering the native populations of P. corruscans might help controling some fish species introduced to the Paraná River basin, particularly C. piquiti and O. niloticus, whose parental care is expected to be weak or null at night

Quantificação de fluxos de mercúrio gasoso na interface solo/atmosfera utilizando câmara de fluxo dinâmica: aplicação na bacia do Rio Negro

Gaseous mercury sampling conditions were optimized and a dynamic flux chamber was used to measure the air/surface exchange of mercury in some areas of the Negro river basin with different vegetal coverings. At the two forest sites (flooding and non-flooding), low mercury fluxes were observed: maximum of 3 pmol m-2 h-1 - day and minimum of -1 pmol m-2 h-1 - night. At the deforested site, the mercury fluxes were higher and always positive: maximum of 26 pmol m-2 h-1 - day and 17 pmol m-2 h-1 - night. Our results showed that deforestation could be responsible for significantly increasing soil Hg emissions, mainly because of the high soil temperatures reached at deforested sites.