Decision and Planning Support System for Integrated Coastal Zone Management. The Case of Kaštela Bay, Croatia.

Francesca Santoro

Interdepartmental Centre IDEAS, University Ca' Foscari of Venice, (IT)

To meet the challenges of progressing integrated coastal zone management (ICZM) and governance, baseline and interdisciplinary research is required. This will contribute to the resolution of the conflicting requirements of multi-users needs. The strategies of ICZM should be based on integrating oceanographic, fisheries, biological research with the requirements of sustainable resource use, maritime transport and offshore industries, and environmental protection. ICZM should embrace strategic integration of initiatives enabling the resolution of conflicts arising from the multiple uses and multiple stakeholders and decision-makers present in the coastal areas.
Planners and decision-makers in the coastal zones, have to broaden their view to understand and incorporate the impacts of their decisions on different stakeholders groups and socio-economic sectors. To assist them in this task information systems and more specifically decision and planning support systems can be powerful tools for the understanding of the inter-relationships between natural and socio-economic variables and hence result in improved decision-making.
This poster will present the case of Kaštela Bay, which is a semi-enclosed bay situated along the eastern coast of the Adriatic Sea in the Croatian Dalmatian region.
The micro-region of Split is the largest demographic and economic centre in Dalmatia, with the most intensive development in the second half of the 20th century. There are two factors of its great contribution: demographic increase and economy development. However, during the time these two factors have lead to great ecological problems: increase of air pollution, water-flow pollution, as well as sea and soil pollution. Environmental changes in the Kaštela Bay and in the port of Split have come to the extreme proportion as far back as in the 1980.
The aim of the Kaštela Bay Planning and Decision Support System is to develop a system able to implement processes of sustainable governance of coastal area.
The development of the system involved in the first stages the organisation of stakeholder workshops to create a common platform to build on.
It is a modular system which is composed by an information module, an analytical module and an evaluation one. The analytical module is composed by an integrated models system:

• The Split Sewer System Hydraulic Model using MOUSE (Danish Hydraulic Institute - DHI)
• The River Cetina Hydraulic Model using MIKE11 DHI
• The Coastal Area Model using RMA2, RMA4 - SMS (Surface water Modelling System) - Environmental Modelling System Inc. Utah.

The input in the coastal area are calculated as discharges from the Split Sewer System in terms of COD, SS and Total Nitrogen, for the other municipalities the inputs have been evaluated through a parametric estimation based on the Split model results. The inputs from the River Cetina are calculated through the MIKE11 model. The results of the models constitute the input for the coastal circulation and water quality model (RMA2-4).
This simulation models are able to generate scenarios, i.e. alternative images of the futures, which can help in seeing how the uncertain future might unfold and how the future might be influenced by the decisions we make today. Once the different development scenarios have been generated the system is able to evaluate them. In order to find the "optimal" intervention (or policy or project), three criteria should be applied: efficiency, equity and ecological sustainability. Multi criteria analysis appears to be the method of choice for a sustainability-oriented evaluation of intervention scenarios.