Application of Remote Sensing Techniques to study the Distribution of Mangroves along the Estuaries of Goa

Abstract

Aerial photographs were used to study the distribution of mangroves in the estuaries of Goa during 1978-79. The total area covered by 7 estuaries in Goa including the major Mandovi - Zuari estuarine complex, is approximately 12,000 ha of which the mangrove forests occupy ca. 2,000 hectares. About 900 ha of mangroves are found in the Zuari estuary, 700 ha along the Mandovi estuary and 200 ha in the Cumbarjua Canal. The mangrove vegetation is represented by 10 genera and 15 species. The dominant species are Rhizophora mucronata, Sonneratia alba and Avicennia officinalis. Other codominant species are R. apiculata, S. caseolaris, Kandelia rheedii, Bruguiera gymnorhiza, B. parviflora, Aegiceras corniculata, Excoecaria agallocha, Acanthus ilicifolius and Derris heterophylla. The other associated species are Thespesia populnea, Clerodendron inerme, halophila beccarii and Acrostichum aureum. R. mucronata, S. alba, Avicennia species are dominant in the polyhaline region while B. parviflora, B. gymnorhiza, Acanthus ilicifolius, Avicennia are common in mesohaline region. In the regions of low salinity (0.5 to 5 ppt), Kandelia rheedii, Sonneratia caseolaris are the only mangroves seen with their associate species Acrostichum aureum, Cyperus Sp. The fringing mangroves of Goa region are stable and there seems to be little human impact such as large-scale wood cutting or reclamation