Research

Quantifying sediment fluxes in the Mahakam delta using remote sensing

Coastal areas have problems with the changing environment due to human activities, which might lead to environmental degradation.  One indicator is sediment, which here is described as total suspended matter (TSM) or also known as suspended particulate matter (SPM).  TSM consists of organic and inorganic material, including phytoplankton, detritus (dead organic material) and other non-pigmented material.  Remote sensing has advantages for monitoring vast areas simultaneously.  Using remote sensing as a tool to monitor the distribution of TSM concentration in the coastal area is a challenging subject within the Ocean Optics research activities.

The major objective of this research is to monitor variability of Total Suspended Matter (TSM) concentration of Delta Mahakam in space and time using remote sensing.  The Mahakam delta has been selected, because it is a unique delta which has been developing by the fluvial and tidal activities. Evidence of fluvial and tidal channel (distributaries) in the delta, together with some information about the future abandonment channel, the most active channel and their activities related to tide, such as sediment distribution, make this area an interesting place to study.  Other information related to mangrove changes and human activities contribution to the degradation of delta environment adds some interesting discussion to the research.

The research method will include the use of an established model, so-called bio-optical model and the collection of in-situ and laboratory measurements of apparent optical properties (AOP) and inherent optical properties (IOP), along with the concentrations of water constituents (TSM and Chl).  The bio-optical model (i.e.: empirical and analytical approach) will be performed for algorithm development base on the result of AOP and IOP measurements, and the image will be processed using the best algorithm to extracted information about TSM distribution.  Evaluation and validation will be conducted during the field survey measurements, algorithm development and image processing.  Radar assessment to extract water extent information related with TSM concentration using sediment rating curves is going to be evaluated to obtain information during wet season (cloudy periods).  Delta development will be evaluated qualitatively using GIS analysis (e.g.: coastline changes) deduced from old bathymetry map (ca. 1900) and the information from satellite images.

The result is expected to contribute in understanding the optical properties of tropical turbid waters of Mahakam delta, as well as in the algorithm development using bio-optical model for this region.  In addition to that, the result is also expected in finding indications on the environmental degradation related to the water quality and the presence of shrimps/fish ponds.  Finally, the results of coastline changes analysis (ca. during 100 years period) is expected to contribute in understanding the delta development in space and time. This research is part of the East Kalimantan Programme (EKP) research cluster project, sponsored by The Foundation for the Advancement of Tropical Research (WOTRO), The Royal Netherlands Academy of Arts and Sciences (KNAW), and The Netherlands Organization of Scientific Research (NWO).

More information about the project on http://www.eastkalimantan.org/index.html

Figure 1: Laboratory analysis.

Figure 4: Research location in Mahakam Delta Indonesia.