On the spatio-temporal analysis of hydrological droughts from global hydrological models

The recent concerns for world-wide extreme events related to climate change have motivated the development of large scale models that simulate the global water cycle. In this context, analysis of hydrological extremes is important and requires the adaptation of identification methods used for river basin models. This paper presents two methodologies that extend the tools to analyze spatio-temporal drought development and characteristics using large scale gridded time series of hydrometeorological data. The methodologies are classified as non-contiguous and contiguous drought area analyses (i.e. NCDA and CDA). The NCDA presents time series of percentages of areas in drought at the global scale and for pre-defined regions of known hydroclimatology. The CDA is introduced as a complementary method that generates information on the spatial coherence of drought events at the global scale. Spatial drought events are found through CDA by clustering patterns (contiguous areas). In this study the global hydrological model WaterGAP was used to illustrate the methodology development. Global gridded time series of subsurface runoff (resolution 0.5°) simulated with the WaterGAP model from land points were used. The NCDA and CDA were developed to identify drought events in runoff. The percentages of area in drought calculated with both methods show complementary information on the spatial and temporal events for the last decades of the 20th century. The NCDA provides relevant information on the average number of droughts, duration and severity (deficit volume) for pre-defined regions (globe, 2 selected hydroclimatic regions). Additionally, the CDA provides information on the number of spatially linked areas in drought, maximum spatial event and their geographic location on the globe. Some results capture the overall spatio-temporal drought extremes over the last decades of the 20th century. Events like the El Niño Southern Oscillation (ENSO) in South America and the pan-European drought in 1976 appeared clearly in both analyses. The methodologies introduced provide an important basis for the global characterization of droughts, model inter-comparison of drought identified from global hydrological models and spatial event analyse

Meteorological Drought Forecasting Based on Climate Signals Using Artificial Neural Network – A Case Study in Khanhhoa Province Vietnam

AbstractIn Khanhhoa Province (Vietnam) long-lasting droughts often occur, causing negative consequences for this region, so accurate drought forecasting is of paramount importance. Normally, drought index forecasting model uses previously lagged observations of the index itself and rainfall as input variables. Recently, climate signals are being also used as potential predictors. In this study, we use 3-month, 6-month, and 12-month of Standardized Precipitation Evapotranspiration Index (SPEI), with a calculation time during the period from 1977 to 2014. This paper aims at examining the lagged climate signals to predict SPEI at Khanhhoa province, using artificial neural network. Climate signals indices from Indian Ocean and Pacific Ocean surrounding study area were analysed to select five predictors for the model. These were combined with local variables (lagged SPEI and rainfall) and used as input variables in 16 different models for different forecast horizons. The results show that adding climate signals can achieve better prediction. Climate signals can be also used solely as predictors without using local variables – in this case they explain the variation SPEI (longer horizons, e.g.12-month) reaching 61 – 80%. The developed model can benefit developing long-term policies for reservoir and irrigation regulation and plant alternation schemes in the context of drought hazard

Cyanobacterial calcite cementation in a tidal channel of the Bay of Cadiz Natural Park

A study of the carbonated crust located in a tidal channel close to a hypersaline tidal lagoon of the Nature area of the Bay of Cádiz has been done. A textural, mineralogical, and an experimental study, including O2 y pH measurements have been conducted during a period of a month and a tidal cycle in four different locations along the channel. The results of the mineralogical and textural study and those from the microelectrodes, show how the photosynthetic activity of biofilms dominated by cyanobacteria and diatoms growing in the sediment surface seems to control the calcite precipitation on the intertidal sediments. Although bacterial remains are rarely preserved in beachrocks, this study shows how bacterial activity should be taken into account in beachrock development in coastal environmentsMinisterio de Educación y Ciencia, proyecto MICROBENTOS (CTM2006-04015/MAR

Labor Force and Economic Changes in Cuba

The labor adjustments and the economic changes present limitations, and if left unchanged, are likely to hinder Cuba’s prospects for successful economic reforms. The present article examines recent labor adjustments in Cuba and presents a balanced analysis of the new economic measures. This article demonstrates that while recent labor force and economic changes in Cuba represent a step in the right direction, these reform measures face a series of challenges that will require profound policy transformations and greater flexibility on the part of the Government

Labor Force and Economic Changes in Cuba

The labor adjustments and the economic changes present limitations, and if left unchanged, are likely to hinder Cuba’s prospects for successful economic reforms. The present article examines recent labor adjustments in Cuba and presents a balanced analysis of the new economic measures. This article demonstrates that while recent labor force and economic changes in Cuba represent a step in the right direction, these reform measures face a series of challenges that will require profound policy transformations and greater flexibility on the part of the Government

Individual or Common Good? Voluntary Data Sharing to Inform Disease Surveillance Systems in Food Animals

Livestock producers have traditionally been reluctant to share information related to their business, including data on health status of their animals, which, sometimes, has impaired the ability to implement surveillance programs. However, during the last decade, swine producers in the United States (US) and other countries have voluntarily begun to share data for the control and elimination of specific infectious diseases, such as the porcine reproductive and respiratory syndrome virus (PRRSv). Those surveillance programs have played a pivotal role in bringing producers and veterinarians together for the benefit of the industry. Examples of situations in which producers have decided to voluntarily share data for extended periods of time to support applied research and, ultimately, disease control in the absence of a regulatory framework have rarely been documented in the peer-reviewed literature. Here, we provide evidence of a national program for voluntary sharing of disease status data that has helped the implementation of surveillance activities that, ultimately, allowed the generation of critically important scientific information to better support disease control activities. Altogether, this effort has supported, and is supporting, the design and implementation of prevention and control approaches for the most economically devastating swine disease affecting the US. The program, which has been voluntarily sustained and supported over an extended period of time by the swine industry in the absence of any regulatory framework and that includes data on approximately 50% of the sow population in the US, represents a unique example of a livestock industry self-organized surveillance program to generate scientific-driven solutions for emerging swine health issues in North America

Benthic metabolism and nutrient dynamics of a hyperturbid and hypernutrified estuary

The biogeochemical role of the sediments in the Guadalquivir River estuary, a vital region in the SW Iberian Peninsula, has been considerably neglected. The benthic microalgae (microphytobenthos, MPB) inhabiting the sediment surface could contribute to the autochthonous primary production and influence nutrient recycling in this hyper-turbid and hypernutrified estuary. Sediment–water column fluxes of O2 and dissolved inorganic nitrogen species (DIN = NH4+ + NO3− + NO2−) were assessed in laboratory incubations of sediment cores from Bonanza (mouth) and Lebrija (middle) during a 1-year study. Vertical profiles down to the 10-cm depth of photosynthetic pigments, organic C, total nitrogen, DIN, Fe2+, SO42−, and dissolved inorganic carbon (DIC) were also measured. Chlorophyll a in the sediment surface was higher at the estuarine mouth, exhibiting a seasonal pattern at both sites with highest values in winter and lowest in summer. Net community production (NCP) was higher in Bonanza compared with Lebrija and showed positive values most of the year, indicating that MPB contributed to the overall autochthonous primary production of the estuary. Seasonal changes in chlorophyll a and NCP were not parallel, suggesting different ecological controls. The sediment was generally a net sink of NO3− and NH4+ in both sites, with several fold higher rates for NO3− uptake. MPB N demand could account for the entire sediment DIN uptake in Bonanza and 21% in Lebrija. The remaining high NO3− uptake rates indicate that they sustain elevated sediment denitrification rates. In contrast, rates of anaerobic oxidation of organic matter by Fe reduction and SO42− reduction, estimated from Fe2+ and SO42− vertical concentration profiles, were several orders of magnitude lower than the estimated water column-dependent denitrification rates. Overall, this study shows the importance of MPB in the Guadalquivir Estuary and the potential dominant role of denitrification in the anaerobic mineralization of organic matter

Rainfall–interception–evaporation–runoff relationships in a semi-arid catchment, northern Limpopo basin, Zimbabwe

Characterizing the response of a catchment to rainfall, in terms of the production of runoff vs the interception, transpiration and evaporation of water, is the first important step in understanding water resource availability in a catchment. This is particularly important in small semi-arid catchments, where a few intense rainfall events may generate much of the season’s runoff. The ephemeral Zhulube catchment (30 km2) in the northern Limpopo basin was instrumented and modelled in order to elucidate the dominant hydrological processes. Discharge events were disconnected, with short recession curves, probably caused by the shallow soils in the Tshazi sub-catchment, which dry out rapidly, and the presence of a dambo in the Gobalidanke sub-catchment. Two different flow event types were observed, with the larger floods showing longer recessions being associated with higher (antecedent) precipitation. The differences could be related to: (a) intensity of rainfall, or (b) different soil conditions. Interception is an important process in the water balance of the catchment, accounting for an estimated 32% of rainfall in the 2007/08 season, but as much as 56% in the drier 2006/07 season. An extended version of the HBV model was developed (designated HBVx), introducing an interception storage and with all routines run in semi-distributed mode. After extensive manual calibration, the HBVx simulation satisfactorily showed the disconnected nature of the flows. The generally low Nash-Sutcliffe coefficients can be explained by the model failing to simulate the two different observed flow types differently. The importance of incorporating interception into rainfall–runoff is demonstrated by the substantial improvement in objective function values obtained. This exceeds the gains made by changing from lumped to semi-distributed mode, supported by 1 000 000 Monte Carlo simulations. There was also an important improvement in the daily volume error. The best simulation, supported by field observations in the Gobalidanke sub-catchment, suggested that discharge was driven mainly by flow from saturation overland flow. Hortonian overland flow, as interpreted from field observations in the Tshazi subcatchment, was not simulated so well. A limitation of the model is its inability to address temporal variability in soil characteristics and more complex runoff generation processes. The model suggests episodic groundwater recharge with annual recharge of 100 mm year-1, which is similar to that reported by other studies in Zimbabw

Índice de transparencia corporativa aplicado al sector microfinanciero

La presente investigación tiene como objetivo la construcción de un Índice de Transparencia Corporativa que pueda ser aplicado en el sector financiero y microfinanciero. La propuesta se realiza tomando como base la metodología de la OCDE que establece las pautas para diseñar y construir índices compuestos, considerando el uso de ponderaciones por dimensión, factor y variable en base al juicio de expertos. El Índice de Transparencia Corporativa propuesto mide el nivel de divulgación de información por internet y cuenta con información estructurada para el sector microfinanciero del Perú a través de seis dimensiones, 17 factores y 60 variables. Estas dimensiones explican el concepto integral de la Transparencia Corporativa y evalúa el nivel de divulgación de información de las organizaciones hacia sus principales grupos de interés. Las seis dimensiones del ITC planteado son: legalidad, información financiera y contable, información comercial, accesibilidad, integridad y credibilidad; las cuales fueron diseñadas tomando como referencia modelos de transparencia corporativa aplicados al sector financiero y validadas con el apoyo de expertos en el sector. La validación de este índice se realizó seleccionando diferentes entidades microfinancieras mediante un muestreo por cuotas, donde se establecieron cinco categorías: cajas municipales de ahorro y crédito, financieras, EDPYMES, cajas rurales y un banco. Se consideró un tamaño de muestra de 16 empresas, cuyos parámetros de selección establecen elegir entidades con el mayor número de colocaciones por categoría, que se encuentran económicamente activas y que mantienen dominio activo en sus páginas web. Los resultados obtenidos muestran a la Financiera Confianza en la posición número uno del ranking, ya que obtuvo 92 puntos porcentuales sobre un total de 100 en el ITC lo que corresponde a un nivel de transparencia muy alto y la EDPYME BBVA Consumer Finance se ubica en la última posición con 26 puntos porcentuales.This research aims to build a Corporate Transparency Index that can be applied in the financial and microfinance sector. The proposal is made based on the OCDE methodology that sets the guidelines for designing and building composite indexes, considering the use of weights by dimension, factor and variable based on expert judgment. The proposed Corporate Transparency Index measures the level of information dissemination on the internet and has structured information for the microfinance sector in Peru through six dimensions, 17 factors and 60 variables. These dimensions explain the comprehensive concept of Corporate Transparency and assess the level of information dissemination of organizations to their main stakeholders. The six dimensions of the ITC proposed are: legality, financial and accounting information, commercial information, accessibility, integrity and credibility; which were designed based on corporate transparency models applied to the financial sector and validated with the support of experts in the sector. The validation of this index was carried out by selecting different microfinance entities through a sampling by quotas, where five categories were established: municipal savings and credit, financial, EDPYMES, rural savings banks and a bank. A sample size of 16 companies was considered, whose selection parameters establish entities with the highest number of placements by category, which are economically active and that maintain active dominance in their web pages. The results obtained show the Financial Trust in the number one position in the ranking, since it obtained 92 percentage points out of a total of 100 in the ITC, which corresponds to a very high level of transparency and the EDPYME BBVA Consumer Finance is located in the Last position with 26 percentage points.Tesi

A multiproxy study distinguishes environmental change from diagenetic alteration in the recent sedimentary record of the inner Cadiz Bay (SW Spain)

In this study, we reconstruct the recent environmental evolution of the inner Cadiz Bay using sedimentary records reaching back as far as AD 1700. We report lithological descriptions of the sediments and extensive mineralogical and geochemical analyses. An extraction technique that identifies different Fe phases provides an assessment of diagenetic alteration, which allows an estimation of the original organic matter inputs to the inner Cadiz Bay. Downcore variations in Corg/N ratios, δ13Corg and δ15N are related to changes in organic matter sources and the trophic state of the water column. The downcore records of selected trace metals (e.g. Pb, Zn and Cu) are interpreted to reflect changes in heavy metal pollution in the bay, while records of other elements (e.g. Mn and P) are likely overprinted by diagenetic alteration. Major environmental shifts took place during the 20th century, when the population around Cadiz Bay increased exponentially. Increases in sediment accumulation rates, organic matter inputs and heavy metal contents, in parallel with increases in δ13Corg and δ15N over this period, are interpreted as direct effects of the increasing anthropogenic influence in the area. The results of this study suggest that multiproxy approaches and detailed consideration of diagenetic overprinting are required to reconstruct past environmental conditions from coastal sediments