Vegetation Impact on the Morphodynamic Activity of the River Kapuas

Aims: To have the clear understanding of the causes behind the spatial variability of the morphodynamic activity of the river Kapuas, West Kalimantan, Indonesia.

Study Design: This study was designed to focus on the vegetation impact on the morphodynamic activity of the river Kapuas based on the Normalized Difference Vegetation Index (NDVI) using Landsat images.

Place and Duration of Study: Hydrology and Quantitative Water Management Group of Wageningen University and Research Centre, The Netherlands between September 2013 to March 2014.

Methodology: Landsat images from 1991 to 2013 were used to interpret the vegetation impact based on NDVI values. At first land cover of the entire river corridor was classified based on an unsupervised classification system and then NDVI map of the same area was plotted using ENVI4.8. Based on the land cover classifications, NDVI maps and some videos, captured from the study area using handheld GPS, vegetation types and corresponding NDVI values were detected.

Results: High NDVI values usually indicate vegetation of high biomass both above and below the ground. Vegetation reinforces the soil particle and holds the soil particle in position against erosion. This research shows that banks with a little vegetation having NDVI values of 0.45 or less are morphologically more active than the banks with dense vegetation having NDVI values over 0.45.

Conclusion: Vegetation has a positive impact on the morphodynamic activity of the river Kapuas. Vegetation with high NDVI values give comparatively more stable bank against erosion compared to vegetation with lower NDVI values, especially below 0.45.