Conceptual Patterns for Water Resources Information Systems

Water Resources Information Systems (WRIS) present different types of problems during the data storage and analysis phases, related with the complex nature of the environmental data spacio-temporal phenomena. There are many questions to deal with, such as geographic representation of environmental variables, large timeseries management, measurements and observations related with different hydrologic phenomena recording and the integration of simulations models to information systems. Conceptual models allow us to understand and simplify problems in a specific domain. These problems can be expressed through analysis patterns, which reflect conceptual structures of an application domain speeding up the development of the abstract analysis model. This model will be able to capture the main requirements from real world problems. This type of patterns, are used in the present paper to define conceptual microarchitectures that allow the appropriate representation of environmental information in WRIS. Accordingly, the physic domain environmental objects are initially identified and an architecture style is defined, allowing this way the integration of WRIS with another interacting systems. The representation of the hydrological phenomena spatial component, is made by means of the conceptual Framework GeoFrame specialization

Les tourbières de la Terre de Feu en Argentine : un patrimoine naturel très menacé

Les tourbières de la partie argentine de la grande île de la Terre de Feu couvrent 2600 km2, une superficie qui représente 90% de l'ensemble des étendues tourbeuses du pays. Trois grands types ont été identifiés : les tourbières bombées à Sphagnum, les tourbières de couverture, les tourbières basses à cypéracées. Leur flore et les archives paléoécologiques conservées dans la tourbe confèrent à ces écosystèmes humides un intérêt patrimonial incontestable auquel s'ajoute leur importance dans le fonctionnement hydrologique des bassins versants et l'attrait qu'il représente pour les touristes du fait de leur originalité paysagère. L'emprise humaine sur les tourbières de la Terre de Feu est demeurée longtemps négligeable. Mais ces dernières années les menaces qui pèsent sur leur intégrité se sont multipliées : extraction de tourbe, développement urbain, construction d'infrastructures routières et maintien d’une forte pression des cheptels bovins et ovins. Ce sont les conséquences de l'activité extractrice qui sont les plus préoccupantes. En six ans, la quantité de tourbe extraite a été multipliée par quatre et l'absence de politique conservatoire laisse présager une croissance notable des quantités produites dans les années à venir. Il est urgent de réfléchir à une gestion plus rationnelle et durable de la ressource. Des adaptations de la législation sont nécessaires pour permettre la protection des sites les plus remarquables, d'une part et imposer la restauration des sites endommagés par l'extraction, d'autre part.Fens and peat-bogs of Tierra del Fuego (Argentina) : a natural heritages under major threats Mires cover approximately 2 600 km2 of the Argentinean part of the large island of Tierra del Fuego;  This represents 90% of the country’s total surface of mires. Three types of area are analysed : Ombragenous Sphagnum mires, Carex fens, and blanket mires.  Peat-lands and their related ecosystems represent an important natural heritage.  They also play a significant role in water basin regulation and constitute an original form of landscape, representing a major tourist attraction.  Over a long period these areas were little affected by human activity.  However, more recently various threats have arisen.  These include peat mining, overgrazing, urban development, and road construction.  In particular, peat extraction has quadrupled over the past six years and the absence of conservation policies implies that this trend will continue.  It is vital to reflect on a more rational and sustainable management of this resource.  Changes to legislation are necessary to allow, on the one hand, the protection of the most outstanding sites and, on the other, the restoration of the worst damaged areas

Status of breeding birds at Observatorio and Goffré Islands, Argentina

Continental islands are often sites of low diversity and endemism, as well as important areas for the protection of bird populations, especially seabirds. On Isla Observatorio and the Año Nuevo Islands, in the Southwestern Atlantic, the latest assessment of avifauna dates from more than 20 years ago. In this study, we use a combination of methods to update the status of the main seabird colonies and the most abundant avian terrestrial predator at Observatorio and Goffré Islands during the breeding season. In only 4.5 km2, the islands would harbour ~ 90,000 breeding seabirds. Seabird colonies occupied different areas of the islands and varied in their population status, with Imperial Shags (Leucocarbo atriceps) showing an increase and Southern Giant Petrels (Macronectes giganteus) a decrease according to the last surveys. Magellanic Penguin (Spheniscus magellanicus) population estimations also suggest a decrease but the last survey was based on total, and not on occupied nest sites. We recorded and assessed one new breeding species: The globally near-threatened Striated Caracara (Phalcoboenus australis), which has an important breeding population of around 15 territorial pairs at Observatorio Island. These islands appear to be an important regional bird site and future studies would determine their trends and threats, especially those related with invasive species.Postprin

Journal of Hydrology

Through a systematic modelling analysis for focus catchments in Costa Rica (131 km2), Ecuador (10 km2), Chile (0.35 km2) and Argentina (12.9 km2), the hypothesis is tested that, as the size of the hydrological event increases, the effect of forest cover on the peak discharge becomes less important. For each focus catchment, a 1000-year synthetic rainfall time series was generated, representative of the current climate. This time series was used to run SHETRAN hydrological models for each catchment with two contrasting land use scenarios (generally with and without a forest cover). The corresponding maximum daily discharges for the contrasting scenarios were then compared to show the extent to which the two responses converged as the size of the peak discharge increased. For a given forest catchment discharge there could be a range of larger non-forest catchment discharges, depending on antecedent soil moisture content. The simulations show consistently for the rainfall dominated sites that the width of this range either remains constant or narrows as discharge increases, indicating either relative or absolute convergence of the responses. The pattern is more difficult to distinguish for a snowmelt regime but a relative convergence of response still appears possible. The results therefore support the test hypothesis. However, the pattern is complicated by factors such as catchment scale, soil depth, antecedent moisture content and land management. Forests may also still offer significant flood mitigation benefits for moderate (and more frequent) rainfall events and they protect against soil erosion and sediment transport for a wide range of events.Cuencavolumen 40