THE USE OF GIS IN THE DESIGN OF MANAGED REALIGNMENT SCHEMES

Abstract This paper describes a range of GIS techniques, which have been developed over the last 5 years and successfully employed in the design of over 15 realignment schemes in a range of UK estuaries. A proposed scheme in the Humber Estuary is used to illustrate the applicability of the methods. GIS is seen to be fundamental at all stages of the design process. This starts with establishing the historical site evolution, the current site elevations/gradients, the existing habitats and the nature conservation designations. The paper describes how topographic survey data can be combined with remotely sensed information to create a digital terrain model for the managed realignment scheme, which can then be adapted to create a new 'design' surface for the proposed scheme. Further explanation is given various aspects of scheme design, including (i) the prediction of the habitats which are likely to colonise the scheme, (ii) the need to maintain a sediment balance within the scheme, (iii) the calculation of tidal prisms, and; (iv) the mapping of sampling locations. The GIS analysis provides valuable information for the design, consultation and environmental assessment process. The ability to overlay various layers of information and to create 2 or 3D representations of the scheme, are seen to be particularly powerful GIS features

Uniendo ingeniería y ecología: la protección costera basada en ecosistemas

En un contexto de crecientes impactos y riesgos socio-económicos en las costas del planeta, la protección costera basada en ecosistemas surge como un nuevo paradigma que une los principios de protección, sostenibilidad y resiliencia, a la vez que proporciona múltiples beneficios. Este artículo ofrece una perspectiva sobre qué son y cómo se pueden utilizar las defensas naturales en el diseño, planificación y gestión de costas. La política pública muestra un creciente interés por su implementación general y el cuerpo de conocimiento y experiencia alrededor de la también denominada infraestructura ?verde? es creciente, pero aún existen importantes barreras que salvar. Una de ellas es estandarizar su diseño en términos ingenieriles, así como reconocer los aspectos que los diferencian respecto a enfoques tradicionales. La adaptación climática y la reducción de riesgos son áreas en las que su utilización puede ser más significativa, debido a la variedad de servicios que ofrecen. Tanto desde el punto de vista técnico como económico, existen argumentos sólidos para evitar la degradación de los ecosistemas, avanzando su restauración y conservación, como también desde la perspectiva de la defensa de las costas.In a context of increasing socio-economic impacts and risks in the coastal areas of the planet, coastal protection based on ecosystem features becomes a new paradigm that combines the principles of conservation, sustainability and resilience, while providing multiple benefits. This paper provides a perspective on what these are and how they can be used in the design, planning and management of the coastal zones. Policy-makers are calling for further uptake and implementation across the board and the body of knowledge and experience around the socalled ?green? infrastructure is growing, but there are still major barriers for a widespread uptake. One of them is to standardize designs in engineering terms, recognizing the different characteristics compared to traditional engineering solutions. Climate adaptation and risk reduction are areas where its use may be more significant, for the variety of services they offer. Both technically and economically, there are strong arguments to prevent degradation of ecosystems and to advance in their restoration and conservation, as well as from a coastal defense perspective

Methodologies for measuring and modelling coastal habitat change: saline lagoons of the Suffolk coast, eastern England

Thorough assessment of vulnerable coastal habitats, impacted by sea-level rise and anthropogenic pressures, requires both the accurate establishment of the evidence base for current status and scientifically-informed forward planning of expected future status. Coastal saline lagoons are transitional, ephemeral habitats of considerable conservation interest; under European legislation their status requires on-going maintenance of ‘favourable status’. Over decadal timescales, the seaward barriers that enclose saline lagoons migrate progressively landwards. Geo-referenced and digitised historic maps and aerial photographs are used to create a detailed trajectory of barrier migration and loss of lagoon area for three saline ‘broads’ on the rapidly retreating coastline of Suffolk, eastern England. The SCAPE shoreline response model is then employed to extend this trajectory, under a range of sea-level rise scenarios, to 2050 and 2095 and to predict saline lagoon ‘time to extinction’. Loss rates are likely to accelerate considerably after 2015 and a fundamental revision of UK saline lagoon creation targets is urgently required. The approach is generic and could be used to assess the evolutionary trajectories for other vulnerable coastal habitats, under a range of near-future environmental change scenarios