Thesis colloquium Md. Monowar Hossain

This research is adopted with the following research questions:
i) Does bank vegetation influence morphological activity of Kapuas? ii) Are soil types and soil moisture interlinked to the morphodynamic activity in different reaches of the River Kapuas? iii) Do catchment topography and bed slope influence the morphodynamic variability of Kapuas throughout the entire length? iv) Does the Lake Sentarum Nasional Park exert influences on the morphodynamic variability of Kapuas?

Organisator Hydrology and Quantitative Water Management

vr 14 maart 2014 10:00 tot 11:00

Locatie Lumen, building number 100
Droevendaalsesteeg 3a
6708 PB Wageningen
+31 317 481 700
Zaal/kamer Lumen 2

Explaining spatial variability in morphodynamic activity in different reaches of the river Kapuas

Supervisors: Ton Hoitink, Jan Clevers and Dirk Hoekman

The Kapuas is the longest river in Indonesia. Morphologically it is very active, especially in the upstream parts of the river. Based on observations from delineated river banks in the period between 1973 and 2013, previous research showed the spatial variability of bank erosion and accretion over a large part of the river. The causes of spatial variability in morphodynamic activity of the Kapuas are not yet well understood. This study aims to explain the spatial variability in morphdynamic behavior of the Kapuas River. Bank vegetation, flood occurrence, soil types, river bed slope, the topographical shape of the catchment and the presence of lakes within the river corridor were investigated using Landsat images, radar images, SRTM data and the world soil map. Landsat images from 1991 to 2013 were used to investigate vegetation impacts based on NDVI. PALSAR images taken between 2007 to 2010 were used to investigate flood occurrence as well as the influence of lakes on the morphodynamic activity of the river. The Kapuas bed slope and catchment topographical shape, delineated from SRTM data, were used to interpret their effects on the morphodynamic variability in different reaches along the river. Results show that banks with little vegetation, having NDVI values of 0.45 or less, are morphologically more active than banks with dense vegetation, having NDVI values over 0.45. This study concludes that the Kapuas River is morphologically more active in a flat area which is more often flooded than its surroundings, where peat soils are prevalent. The lakes may have a role in fixing the downstream position of the river at the junction of the river with the connecting channel.