Preliminary study on remote sensing techniques to estimate water quality parameters at Lake Maninjau and Singkarak

Lake as a component of water resources plays an important role to support agriculture, fisheries, hydropower, domestic and tourism activities. The high dynamic changes in climatic and anthropogenicrequire themonitoring of water quality parameters for lake management. To the contrary, the remote locations, limitations in human resources and financial support are theproblems in lake management. Therefore, it is necessaryto develop faster, accurate and less expensive methods/techniques to estimate water quality parameters in lakes. In this study, remote sensing data with a SAMO-LUT (semi-analitycal model-optimizing and look-up-table) method were proposed to estimate chlorophyll a (Chl-a) concentration, tripton concentration (TR), absorption coefficient at 440 nm of CDOM (colored disolved organic matter) and Secchi Depth (SD) at lakes Maninjau and Singkarak. The results shows that the Chl-a concentrations at lakes Maninjau and Singkarak ranged from 35 to 45 mg m and from 2.5 to 10 mg m -3 -3, respectively. At the same time, the tripton concentrations at lakes Maninjau and Singkarak ranged from 2.5 to 5.5 g m, respectively. The absorption coefficient of CDOM for 440 nm at Lake Maninjau ranged from 0.05 to 0.7 m -3 and from 0 to 6.5 g m -3 , while at Lake Singkarak ranged from 0.3 to 1 m -1 -1 . Although these results havenot yet been validated with the in situ measurements, it seems that the algorithm could give the reasonable resutls. In addition, the SD algorithm showed high correlation between estimation and measurement (r =0.985). These results suggest that remote sensing tecniques can provide a faster, reasonable as well as low cost method to monitor water quality in lakes.