Study of a highly modified coastal lake by side-scan sonar, modelling and remote sensing

Abstract

Lake Massaciuccoli and the associated wetlands are a heavily contaminated, highly modified coastal lagoon area within the coastal plain of Tuscany, Italy. In the last few decades, there have been increasing problems of: 1) eutrophication due to fertilizers used in the catchment area leaching into the lake; 2) increased turbidity due to runoff of sediments from the agricultural fields; 3) salinization due to influx of sea water through channels connecting the lake to the sea and through permeation through the barrier island; and 4) reduced influx of freshwater from the freshwater network, due to water use for irrigation and changes in rainfall patterns. The Lake and the surrounding wetlands are an important habitat for several endangered flora and fauna, including migrating birds, and as such have been designated as site of Community Importance and reclaimed as a nature reserve. In this work we describe the results of the first phase of a survey of the lake bottom carried out on the lake in summer 2003, using conventional echosounding techniques in combination with a novel side-scan sonar. The results underline the relevance of the areas affected by sand excavation both for the mass balance of the lake and for the type of ecosystem, and are compared with measurements of water parameters taken during complementary campaigns. We also examine how our survey can be used for the implementation of a dynamical model of the lake circulation and sediment transport, and in support of a program for the rejuvenation and careful management of the area. Finally, we discuss the plans for an airborne remote sensing campaign to map the water quality of the lake to be tentatively carried out on the area in late Spring 2004, in combination with further side-scan radar investigations.

More information

Identifiers

Catalogue record

Export record