Remote sensing for Mapping TSM concentration in Mahakam Delta: an analytical approach

摘要

The Indonesian coastal zones have always been under heavy pressures, including those fromudfisheries, oil industries and sea transportation. The presence of these activities carry a largeudportion of risk in damaging the environment as well as in destroying the marine resources,udleading to the need for an integrated management approach based on an environmentaludinformation system that is comprehensive and multi-disciplinary in nature. The Mahakam Deltaudhas the same general problems as other coastal regions in Indonesia. The method is based on bioudoptical modeling. The forward water analysis comprised the laboratory measurements of waterudquality (TSM and Chl) and Inherent Optical Properties (IOPs) to derive Spesific Inherent Opticaludproperties (SIOPs). SIOPs (of water, TSM, Chl and CDOM), coefficient f and B were used touddeveloped R(0-) model. The inverse atmosphere analysis comprised the image preprocessing (i.e.udgeometric correction, atmospheric correction, air-water interface correction). The last step isudinverse water analysis, which comprised the development of algorithm and image processing touddevelop TSM concentration maps. The spectrometer measurements collected in the field wereudused for obtaining the subsurface irradiance reflectance. The subsurface irradiance reflectanceudR(0-) is the ratio of upwelling (Ewu) and downwelling irradiance (Ewd) just beneath the waterudsurface. There are some discrepancies from matching R(0-) model and R(0-) measured in theudfield, especially in the blue region and NIR region. The reason of the discrepancies could be dueudto the fact that the Q factor (the angular distribution factor of spectral radiance) is still notudunderstood completely. This model is very susceptible to the decrease of the proportional factorudf, and to the increase of the backscattering probability B. The results indicates that red band ofudsatellite sensor is sensitive to detect higher TSM concentration. For Mahakam Delta, red bandudalgorithm was used to derive TSM map, since higher TSM concentration occurred in the delta.