Dam sediment tracking using spectrometry and Landsat 8 satellite image, Taleghan Basin, Iran

Area of Science:

• Environmental Science
• Geology
• Remote Sensing

Background:

• Reservoir sedimentation reduces water storage and intensifies river erosion.
• Identifying sediment origins is key to effective control and prevention strategies.
• Advanced techniques like GIS and remote sensing offer high accuracy in sediment source detection.

Purpose of the Study:

• To detect the primary sediment sources impacting Taleghan Dam in northern Iran.
• To integrate geographic information system (GIS) and remote sensing (RS) for sediment origin analysis.
• To identify vulnerable geological formations contributing to dam sedimentation for conservation efforts.

Main Methods:

• Collected sediment samples from the basin outlet for laboratory analysis.
• Determined mineral composition using X-ray diffraction and spectral signatures using spectroscopy.
• Applied mixture-tuned matched filtering (MTMF) on satellite imagery, integrating results with geological maps to pinpoint sediment origins.

Main Results:

• Mineralogical analysis identified specific trace minerals, with sample 4 containing 6% Illite.
• Remote sensing and GIS integration successfully mapped sediment origins.
• Identified key geological formations contributing to sedimentation: mudstone, siltstone, conglomerate, Karaj Formation (Poldokhtar section), acidic tuffs, volcanic lavas, upper red formation (mudstone and gypsum), and Cambrian dolomites.

Conclusions:

• The study successfully identified the primary geological origins of sediment in Taleghan Dam.
• Vulnerable formations like mudstone, siltstone, and conglomerate require conservation to mitigate erosion and sedimentation.
• Integrated GIS and RS provide a powerful tool for understanding and managing reservoir sedimentation issues.