Trophic state index of a lake system using IRS (P6-LISS III) satellite imagery

Abstract

Water pollution has now become a major threat to the existence of living beings and water quality monitoring is an effective step towards the restoration of water quality. Lakes are versatile ecosystems and their eutrophication is a serious problem. Carlson Trophic State Index (CTSI) provides an insight into the trophic condition of a lake. CTSI has been modified for the study area and is used in this study. Satellite imagery analysis now plays a prominent role in the quick assessment of water quality in a vast area. This study is an attempt to assess the trophic state index based on secchi disk depth and chlorophyll a of a lake system (Akkulam-Veli lake, Kerala, India) using Indian Remote Sensing (IRS) P6 LISS III imagery. Field data were collected on the date of the overpass of the satellite. Multiple regression equation is found to yield superior results than the simple regression equations using spectral ratios and radiance from the individual bands, for the prediction of trophic state index from satellite imagery. The trophic state index based on secchi disk depth, derived from the satellite imagery, provides an accurate prediction of the trophic status of the lake. IRS P6-LISS III imagery can be effectively used for the assessment of the trophic condition of a lake system.

Ecological Risk Assessment of a Tropical Lake System

“…The rest of the stations indicated 'low degree of contamination' with mCd values from 1.52. These results are in agreement with previous results reported earlier that the Akkulam side of the lake is more polluted than Veli side (Sheela et al, 2010;Swarnalatha et al, 2013a). In this study it was found that 63.6% of observations in the Akkulam side recorded mCd > 1.5 indicating 'low degree of contamination' whereas only 33.3% of observations in Veli side were under 'low degree of contamination'.…”

Assessment of Pollution Status of a Coastal Lake System using Satellite Imagery

“…The Lake mouth remains open usually for 10 to 14 days, depending upon the influx of land drainage to the Lake. This episode repeats six to eight times a year [21].…”

“…Satellite imagery is georeferenced into WGS 84 coordinates, and resampled using the nearest neighbor. The water spread area of the AV Lake, is created using ERDAS [21]. The raw digital numbers of the imagery is converted into radiance using ERDAS Imagine 9.1.…”

“…The water quality is 'bad' in the Akkulam Lake and is 'medium' in the Veli Lake during monsoon and post monsoon. Sheela et al [20] revealed that the AV Lake is in hyper eutrophic condition.…”

Sensoriamento remoto como ferramenta de monitoramento da qualidade da água do Lago Paranoá (DF)

“…Técnicas convencionais de avaliação serão, em médio prazo, de difícil aplicação, dada a grande área conjunta ocupada pelos reservatórios em território brasileiro (NOVO & TUNDISI, 1988). Estudos têm demonstrado que o sensoriamento remoto pode ser usado tanto na estimativa de parâmetros individuais de qualidade da água (VENTURA, 2013) quanto na determinação do seu estado trófico (SAUSEN & PEREIRA, 1986;SHEELA et al, 2011). Eles já relataram a aplicabilidade das bandas TM1, TM2, TM3 e TM4 em estudos de parâmetros ambientais em ambientes aquáticos (LILLESAND et al, 1983;NOVO & TUNDISI, 1988;MITTENZWEY;GITELSON;KONDRATIEV, 1992;CHENG & LEI, 2001;WALDRON;STEEVES;FINN, 2001 Além disso, ações antrópicas vêm resultando em vários materiais que são carreados para o lago, como lixo urbano, restos de materiais de construção, partículas de asfalto liberadas das estradas, materiais orgânicos de fazendas e matas, agrotóxicos das áreas cultivadas e partículas de solo exposto e livre das estradas não pavimentadas (FRANZ et al, 2014).…”