IDENTIFICATION AND CLASSIFICATION OF LAKE BOTTOM SURFACE AND AQUATIC VEGETATION IN LAUT TAWAR LAKE, ACEH
Abstract: Identification and
classification of benthic habitats in Lake of Laut Tawar, Aceh by using hydro
acoustic method can provide data and information on types of substrate and
aquatic vegetation in a short time and wide spatial coverage, as done in the
present work. Data acoustic collection was performed in 2013 using quantitative
echosounder with split beam frequency of 120 kHz, and through a visual
observation. The later is destined to look at the bottom types and macrophytes
that lie on the line transect of acoustic survey. Analysis of data is to
extract the value of bottom volume backscattering for each transect of 0.5-1
km. Classification of the bottom type was done based on the value of Sv using
geospatial models. Results show the interval value of Sv for soft bottom ranged
between -24.00 dB and -32.00 dB, the type of hard bottom (e.g. rocks, rocky
sand substrate) ranged between -14.00 dB and -22.00 dB, whereas the Sv value of
macrophyte ranged between- 45.00 dB and -54.00 dB. The percent covers were
about 42.90%, 44.71% and 12.93% for hard bottom type, soft bottom and
macrophytes, respectively. The types of aquatic vegetation commonly found in
the lake were two genera belonging Hydrocharitaceaea and Gramineae. The current
work is still lack of information on the classification of organisms into
genera scales. Therefore, more signal verification and algorithms verification
would be needed in order to estimate macrophytes biomass by comparing with
other visual observation.
Keywords: Bottom surface; Laut
Tawar Lake; macrophytes; hydro acoustic methods
Author: Zulkarnaen Fahmi,
Husnah
Journal Code: jpperikanangg150016