Development of a marine G.I.S. with the view on the monitoring and modelling of the Guayas estuary and the Estero Salado in Ecuador

It is the aim of this research to quantify and correlate in space and time certain actual aspects of the geo-bio-physico-chemical equilibrium in the Guayas estuary and the Estero Salado tidal channel, by means of a functional geographical information system (G.I.S.). The channels are located at a transitional marine environment in the intersection of two important fronts that can be described in terms of the autogenic input of climate, geomorphology, hydrology, tectonics, sedimentary, biological, estuarine, tidal, and ocean dynamics, and the anthropogenic front built up by the extended agricultural, domestic and industrial -including harbour-activities in the Ecuadorian Central-West and South. A major component of this study is the development of a PC-based functional G.I.S. with software packages Intergraph MGE (Modular G.I.S. Environment, versions 6 & 7) and Bentley MicroStation Geographics with as data attributes a set of parameters that describe benthic and pelagic communities, chemical, physical and sedimentological aspects. The graphic component is made of digital navigation charts of the area, topologically verified, and conforming the chart datum. Other supporting aids are the review of historical data and the flexibility of object-oriented development environment tools available with Microsoft Access database to provide trend indicator graphics. This approach of study has resulted in a valuable support for the comparison of events along the seasons and establishing their functional relationship with other variables, among other useful definitions of criteria. Ultimately the production of maps with this criteria is meant for giving the authorities a decision-making tool for sustainable management purposes.