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WP4: Water and sediment distribution at lowland river junctions: the Mahakam Lakes region

Research group
Project leaders:
Dr. A.J.F. Hoitink
Dr. Safwan Hadi

Researcher:
Ir B. Vermeulen


Other participants:
Prof. Dr. Peter A. Troch
Dr. Zheng Bing Wang
Dr. Dirk H. Hoekman
Mr. M. Schroevers, MSc

3. Summary of the project
River junctions are nodal points where river channels confluence or diverge. Over the past decades much research has been focused on channel junctions in braided rivers. These are morphologically highly dynamic alluvial environments, which occur typically in steep upstream river reaches. Physical analyses of channel junctions in lowland rivers are relatively few. Especially bifurcation processes controlling the water and sediment distribution over lowland distributaries are not well understood. The distribution function of river bifurcations is captured in nodal point relations used for one-dimensional morphodynamical models, which relate water and sediment flow rates. These relations can be used to analyze the stability of a bifurcation, which can be defined as the likeliness that both the downstream branches remain open. The present objective is to include more physical processes in existing nodal point relations, and to analyse the effect of local morphodynamic changes on the stability of a bifurcation.
It is proposed to analyze river junctions in the Mahakam Lakes region, which is an extremely flat area that seldom reaches 10 m above mean sealevel. As a result of the small bed level gradient the Mahakam River is meandering with a tendency to anastomose. On opposite sides the Mahakam is connected to about 30 shallow lakes, which modulate the water discharge. Although no evidence exists to date, it is assumed that the Mahakam Lakes alternately feed and drain the Mahakam, preventing extreme floods or low flow conditions. Accordingly, river junctions may alternately be regarded as a bifurcation (divergence) and a confluence. The functioning of the channel junctions in the Mahakam Lake region will be analysed ultimately aiming to establish the vulnerability of the hydraulic connection between the lakes and the Mahakam River, which discharges into the economically important Mahakam Delta.
The proposed methods include field measurements, satellite radar remote sensing for observation of water surface elevation and width, theoretical analysis and morphodynamic modelling. The proposed field campaign encompasses bathymetric surveys, installation of water level gauges and ADCP measurements of flow and sediment transport. A two-dimensional morphodynamic model will be used after calibration to simulate morphometric changes of the bifurcations between the Mahakam river and the connecting channels to the three main lakes. The nodal point relations will be used in the network model setup in WP10 of the research cluster.

4. Detailed description of the project
a. Scientific Background
Open channel river junctions
Open channel junctions are major elements of lowland river systems, which include confluences and bifurcations. Bifurcations, also called a diversion if the main channel has the same direction upstream and downstream of the bifurcation, distribute water and sediment over the downstream river branches and often originate from an avulsion. They can morphologically develop in time and feature helical flow cell depending on the junction angles (cf. Gurrran et al., 1997). Confluences result where two initial streams meet. They are also characterised pronounced lateral flow structures, often related to discordance of the upstream channels (Best and Roy, 1991; Biron et al., 1996; De Serres et al., 1999). There has been a strong growth in the scientific interest in the role of channel junctions, especially as components of braiding rivers. Substantial progress has been made to understand flow processes, sediment transport and channel geometrical influences in junctions in river braids (Mosley, 1976; Ashmore et al., 1992; Best and Ashworth, 1987; Richardson and Thorne, 2001).
Although commonly treated together, channel junctions within braiding rivers can be inherently different from junctions of meandering or straight river reaches, which can be part a dentritic river network. Aspects that may hamper a direct comparison regard the substantial influences of sediment mobility associated with the degree of consolidation, growth of riparian vegetation, non-uniformity of the bed material, and lateral bed level variations. Meandering and straight river reaches occur typically in lowland areas where bed slopes are small and the flow is subcritical, whereas braided rivers are often found in upstream regions with a large bed slope, where flow conditions can be super-critical. Understanding the functioning of lowland river junctions generally requires analysis of larger spatial and time scales and to focus on details of the local environmental characteristics.
In one-dimensional morphodynamical models of a river network, bifurcations are represented by a nodal point relation relating water and sediment flow rates (Wang et al., 1995; Bolla Pittaluga et al., 2003). Wang et al. (1995) propose a nodal point relation, starting from a bifurcation where the downstream two branches debouch into the same lake. Their analysis relies on the assumption that the sediment distributing function of a bifurcation is fully dependent on the main parameters of the upstream and two downstream branches, including bed slope, channel width, water depth and bed roughness. The proposed nodal point relation assumes proportionality between the ratio between the sediment transports into the downstream branches and a power of the discharge ratio. The nodal point relation allowed for a stability analysis predicting the requisites for both branches to remain open, or to close. For a small exponent in the nodal point relation, only one of the two branches tends to remain open. In a quasi two-dimensional approach, Bolla Pittaluga et al. (2003) further elaborated the study by Wang et al. (1995) accounting for the influence of a transverse bed slope. It was established that the associated transverse exchange of sediment stabilizes the bifurcations, provided that the Shields parameter remains below the threshold for incipient sediment motion.
De Heer and Mosselman (2004) argue that the study of Bolla Pittaluga et al. (2003) is merely a next step towards a generic nodal point relation that accounts for all relevant bifurcation characteristics. Neglected aspects include the bifurcation angle, roundness of the upstream walls of the channel entrances and mobility of the sediment. De Heer and Mosselman (2004) stress that nodal point relations change if the local geometry of the bifurcation changes, i.e. the stability analyses of Wang et al. (1995) and Bolla Pittaluga et al. (2003) apply for a fixed bifurcation. From this it is herein concluded that the stability problem of river bifurcations is ill defined, as the local morphology of a bifurcation may change in case of gradual closure of one of the downstream branches. The tendency favoring closure of a branch could be counteracted by a morphology change of the bifurcation. A knowledge gap exists about the stability of non-fixed bifurcations. The present approach towards filling this gap is to analyze the effect of local morphodynamic processes at a bifurcation on the corresponding nodal point relation. It is proposed to do this by taking a relatively pristine area as an example, viz. the Mahakam Lakes region.

b. Specific Objective(s)
The present proposal aims to increase the understanding of the hydraulic and morphological controlling mechanisms determining the stability of non-fixed lowland river bifurcations. To this end it is proposed to analyse the discharge distribution function and morphological stability of river junctions in the Mahakam Lakes region East Kalimantan.

Regional setting
The 920 km long Mahakam River drains about 75,000 km2 of the upper Kutai Basin. From available rainfall data and the size of the drainage basin, a mean water discharge was evaluated by Allen and Chambers (1998) on the order of 3000 m3 s-1, with large seasonal variations. The catchment of the Mahakam can be divided into four physiogeographic regions, viz. the western mountains, an upland area fringing them, a central floodplain and a narrow strip of hills parallel to the coast (cf. Christensen, 1992). The central floodplain area, which hosts over 30 lakes, is located in an extremely flat area slightly above present sealevel with a complex hydrology, ecology and geology. The Mahakam has an extremely high sinuosity in this area and tends to anastomose. The midstream area, generally referred to as the Mahakam Lakes region, has the capacity to impact the water and sediment households in the entire river basin. Flood discharges of up to 5000 m3 s-1 may occur in the central part of the catchment (Roberts and Sydow, 2003).
The lakes and surrounding wetlands directly act as a buffer or trap of sediment contained in the many streams that debouch into the lakes. The shallow lakes, which have depths between 0.4 and 3.0 m, are known to become shallower at an unknown rate, presumably as a result of an imbalance between sediment input and slow subsidence, related to neotectonic activity. Indirectly, The lakes create a buffer capacity causing the dampening of the flood surges (Allen and Chambers, 1998) and effectively level off Mahakam river floods, explaining a relatively constant discharge for lower reaches of the Mahakam river and delta system (Storms et al., 2005). This has severe implications for the sediment transport capacity of the Mahakam River and the associated sediment loads caused by scour.
The connection between the Mahakam River and the wetland area is clearly defined by a limited number of short connecting channels of a limited width (Remote sensing images in Google Earth give a clear overview). The hydraulic interconnection seems fragile and depends largely on the morphometry of the channels and the channel junctions. The junctions between the Mahakam River and the connecting channels generally act as a bifurcation, but may be a confluence at the time of low flow conditions. The latter conception has been inferred from discharge data, but to the author's knowledge no direct evidence from observations in the connecting channels exists. Three of the lakes are significantly larger the others. In view of the overall aim, the following specified objectives are formulated:

  1. Establish the mechanisms controlling the distribution of water and sediment at the junctions between the Mahakam river and the channels connecting the three major lakes.

  2. Derive nodal point relations capturing the basic aspects that determine the distribution of water and sediment.

  3. Determine the influence of morphodynamic processes on the nodal point relations found.

  4. Establish the stability of the junctions that determines the vulnerability of the hydraulic connection between the Mahakam River and the lakes.

c. Workplan
Extensive field campaigns are planned in the wet season of 2006/2007 and in the dry season of 2007, consisting of:

  • detailed bathymetry mapping on the basis of echo soundings

  • surface elevation measurements with arrays of self-contained pressure sensors

  • hydrographic surveys using an Acoustic Doppler Current Profiler (ADCP), optical backscatter (OBS) sensors and water sampling

  • sediment sampling to asses the resistance of boundary sediments to erosion processes

  • characterization of riparian vegetation

Kostaschuk et al. (2005) recently provided a discussion on measuring flow velocity, suspended load transport and bedload transport with an ADCP (see also Kostaschuk et al., 2004). Measuring bedload and suspended load transport requires using bottom tracking and acoustic backscatter data from the ADCP (respectively). Both options are relatively new and especially obtaining measurements of sediment transport near the bed is still under discussion. Kostaschuk et al. (2005) indicate that the main problem relates to the large beam width near the bed, implying a large sampling diameter. This is particularly relevant in case of sand dunes or other bed forms within the acoustic beams. The advantages compared to single point sediment samplers regard the facts that the ADCP is non-intrusive, flow and sediment transport are measured simultaneously at the same location, the need to anchor a vessel is eliminated and array data is obtained. These factors allow analyzing spatial variations over a large region, assuring a short duration of the surveys. Dinehart and Burau (2005) give an example of a river junction area of about 200 by 200 m that is covered by an ADCP survey in less the half an hour. It is planned to combine ADCP and OBS measurements of suspended sediment concentration, which provide complimentary data (Hoitink and Hoekstra, 2005). Repeated ADCP/OBS surveys of flow velocity and sediment transport will each time be started and ended by taking pump samples, providing in situ calibration data.
Remote sensing images will be employed to obtain a delineation of the channels of the central Mahakam Lakes region at river stages coinciding with the passovers of the ALOS satellite, which is planned to be launched in December 2005 and covers peninsular SE Asia (see also point 8 about integration). Radar altimeter data will be used to for river level observation. The PALSAR L-band radar aboard the ALOS is delivers a series of 8 observations (45 days interval) during the first year at 100 m resolution, and additional coverages at 50 m resolution during the whole mission period. Special products with 10 m resolution will be requested, which are expected to yield surface width information.
In the phase after fieldwork a theoretical study is planned to elaborate the work of Wang et al. (1995) and Bolla Pittaluga et al. (2003), to include more physics in the existing nodal point relations as suggested by De Heer and Mosselman (2004). It is foreseen that a stability analysis will be performed much in the same way as Wang et al. (1995) and Bolla Pittaluga et al. (2003). Subsequently, a three-dimensional morphological model (viz. Delft3D) will be used to establish the initial morphological changes of the bifurcations under consideration. Records of satellite radar data and aerial photographs may yield information on ongoing planform changes of the river junctions. These morphology and planform changes will in turn be used to establish how the parameters in the nodal point relations change with changing morphology. The final step will be to determine how the stability of the bifurcations alters when the parameters in the nodal point relations change. This will yield an overall appreciation of the vulnerability of the hydraulic connection between the Mahakam River and the lakes.

d. Scientific Relevance
See points a, b and c.

5. Participation in a graduate School ('onderzoeksschool')
The PhD candidate will participate in the SENSE Research School for Socio-Economic and Natural Sciences of the Environment.

6. Scientific performance of members of the research group(s)

  • Hoitink, A.J.F., Hoekstra, P., and Van Maren, D.S.(in press). Comment on "On the role of diurnal tides in contributing to asymmetries in tidal probability distribution functions in areas of predominantly semi-diurnal tide" by P.L. Woodworth, D.L. Blackman, D.T. Pugh and J.M. Vassie. To appear in Estuarine, Coastal and Shelf Science.

  • Storms, J.E.A., R.M. Hoogendoorn, M.A.C. Dam, A.J.F. Hoitink and S.B. Kroonenberg (2005) Late-Holocene evolution of the Mahakam delta, East Kalimantan, Indonesia. Sedimentary Geology 180(3-4) 149-166

  • Hoitink, A.J.F., & Hoekstra, P. (2005). Observations of suspended sediment from ADCP and OBS measurements in a mud-dominated environment. Coastal Engineering, 52(2), 103-118.

  • Maren, D.S. van, Hoekstra, P., & Hoitink, A.J.F. (2004). Tidal flow asymmetry in the diurnal regime: bed load transport and morphologic changes around the Red River Delta. Ocean dynamics, 54(3), 424-434.

  • Hoitink, A.J.F. (2004). Tidally-induced clouds of suspended sediment connected to shallow-water coral reefs. Marine Geology, 208(1), 13-31.

  • Hoitink, A.J.F., Hoekstra, P., & Maren, D.S. van (2003). Flow assymmetry associated with astronomical tides: Implications for the residual transport of sediment. Journal of Geophysical Research, 108(C10), 3315-3315.

  • Hoitink, A.J.F., & Hoekstra, P. (2003). Hydrodynamic control of the supply of reworked terrigenous sediment to coral reefs in the Bay of Banten (NW Java, Indonesia). Estuarine, Coastal & Shelf Science, 58(4), 743-755.

  • Alan Frendy Koropitan, Safwan Hadi, Ivonne M. Radjawane: "Three-Dimensional Simulation of Tidal Current in Lampung Bay: Diagnostic Numerical Experiments" International Journal Remote Sensing and Earth Science (I JReSES) Vol. I No. 2, 2004.

  • Alan F. Koropitan; Richardus Kaswadji; Ivonne M. Radjawane; Safwan Hadi: “Aquatic Ecosystem Modeling in Pelabuhan Ratu Bay”. Proceedings of the Pan Ocean Remote Sensing Conference (PORSEC), Bali, Indonesia, 2002

  • Nining N.S.; Safwan Hadi; M. Yusuf: “Upwelling in the Southern Coast of Java and its Relation to Seasonal Ocean Circulation by Using a Three– Dimensional Ocean Model”. Proceedings of the Pan Ocean Remote Sensing Conference (PORSEC), Bali, Indonesia, 2002.

  • H. Latief; Safwan Hadi, Fumihiko Imamura: “Numerical Model for Tsunami Inundation Area and Its Sediment Transport in Pancer Bay”. International Workshop on Tsunami Risk and Its Reduction in the Asia–Pacific Region; 2002.

  • Safwan Hadi: "Submarine Tailings Disposal in The Perspective of Oceanography". Proceedings 2001 Indonesian mining Association Conference and Exhibition, Nov. 7-8, 2001, Jakarta.

  • Hamzah Latief, Safwan Hadi, Haris Sunendar, Aditya R. Gusman: "Tsunami Assement Around The Sunda Strait". Proceeding International Seminar/Workshop on Tsunami, Jakarta and Anyer August 26-29, 2003.

  • Nining S.N, Safwan Hadi, Agus Supangat, Mustaid Yusuf, and Dian N. Handiani: "Fishing Ground Prediction in Indonesian Water Based on Upwelling Regions and Its Relation to Seasonal Circulation". Final Report, The Asahi Glass Foundation, 2004.

  • Safwan Hadi and Nining S.N: " Numerical Simulation of Suspended Sedimen Transport caused by Sands Mining in Riau Island Waters". Proceeding of the Thirteenth Workshop of OMISAR (WOM-13) on the Application and Networking of Satellite Data, Bali, Indonesia, 5-9 October 2004.

  • Totok Suprijo, Safwan Hadi, and Nining S.N: " Preeliminary Results on Seasonal Salt Water Intrusion Modelling of Mahakam Estuary". INSTANT Workshop."Oceanography of Indonesian Seas", Bali, Indonesia, December 9-10, 2004.

  • Wood, E.F.; Lin, D.S.; Mancini, M.; Thongs, D.; Troch, P.; Jackson, T.; Famiglietti, J.; Engman, E.T. (1992). Intercomparison Between Passive Microwave and Active Radar Remote Sensing and Hydrologic Modeling for Soil Moisture, Adv. Space Res., 13(5), 5,167-5,176.

  • Lin, D.S.; Wood, E.F.; Mancini, M; Troch, P.; Jackson, T. (1993). Comparisons of Remotely Sensed and Model Simulated Soil Moisture Over a Heterogeneous Watershed, Remote Sensing of Environment, 48, 159-171.

  • Altese, E.; Bolognani, O.; Mancini, M.; Troch, P.A. (1996). Retrieving Soil Moisture Over Bare Soil From ERS-1 Synthetic Aperture Radar Data: Sensitivity Analysis Based on a Theoretical Surface Scattering Model and Field Data, Water Resources Research, 32(3), 653-661.

  • Troch, P.A.; Su, Z.; De Troch, F.P. (1996). Remote Sensing of Surface Soil Moisture Using EMAC/ESAR Data, Earth Observation Quarterly, ESA, (53), 17-21.

  • Su, Z.; Troch, P.A.; De Troch, F.P. (1997). Remote Sensing of Soil Moisture Using EMAC/ESAR Data, International Journal of Remote Sensing, 18(10), 2105-2124.

  • Schoups, G.; Troch, P.A.; Verhoest, N. (1998). Soil Moisture Influences on the Radar Backscattering of Sugar Beet Fields, Remote Sensing of the Environment, 65, 184-194.

  • Verhoest, N.; Troch, P.A.; Paniconi, C.; De Troch, F.P. (1998). Mapping basin scale variable source areas from multitemporal remotely sensed observations of soil moisture behaviour, Water Resources Research, 34(12), 3235-3244.

  • Mancini, M.; Hoeben, R.; Troch, P.A. (1999). Multifrequency radar observations of bare surface soil moisture content, a laboratory experiment, Water Resources Research, 35(6), 1827-1838.

  • Hoeben, R.; Troch, P.A. (2000). Assimilation of active microwave observation data for soil moisture profile estimation, Water Resources Research, 36(10), 2805-2819.

  • Van Loon, E.E.; Troch, P.A. (2002). Tikhonov regularization as a tool for assimilating soil moisture data in distributed hydrological models, Hydrological Processes, 16, 531-556.

  • Schuurmans, J.M.; Troch, P.A.; Veldhuizen, A.A.; Bastiaanssen, W.; Bierkens, M. (2003). Assimilating remotely sensed latent heat fluxes in a distributed hydrological model, Advances in Water Resources, 26(2), 151-159.

  • Troch, P.A.; Paniconi, C.; McLaughlin, D. (2003). Preface: Catchment-scale hydrological modeling and data assimilation, Advances in Water Resources, 26(2), 131-135.

  • Marciano, R. Z.B. Wang, A. Hibma, H.J. de Vriend and A. Defina, Modelling of fractal channel patterns in short tidal basins, Journal of Geophysical Research, VOL. 110, F01001, doi:10.1029/2003JF000092, 2005

  • Wang, Z.B., C. Jeuken, H. Gerritsen, H.J. de Vriend, B.A. Kornman, Morphology and asymmetry of vertical tide in the Westerschelde Estuary, Continental Shelf Research, Volume/Issue 22/17 pp. 2599-2609.

  • Wang, Z.B., Karssen, B., Fokkink, R.J. and A. Langerak (1998) A dynamic/empirical model for long-term morphological development of estuaries, In: Physics of estuaries and coastal seas, Dronkers, J. and Scheffers, M.B.A.M. (ed.) Balkema, Rotterdam

  • Wang, Z.B., Fokkink, R.J., De Vries, M., and Langerak, A. (1995) Stability of river bifurcations in 1D morphological models, Journal of Hydraulic Research, Vol. 33, No. 6,

  • Fokkink, R.J., Wang, Z.B. and Schropp, M.H.I. (1995) On 1D morphodynamic network models, 6th IAHR conference in London,

  • Wang, Z.B., Fokkink, R.J. and Fokkink, W.J. (1995) A relation between partitions and number of divisors, Mathematical Monthly 102(4) 345-346

  • Wang, Z.B. (1992) Theoretical analysis on depth-integrated modelling of suspended transports, Journal of Hydraulic Research, vol. 30. Nr. 3.

  • Wojcik, R., P. Torfs and P. Warmerdam (2003) Application of Parzen Densities to probabilistic Rainfall-Runoff Modelling. J Hydrol Hydromech, 51, 175-186

  • Quiñones, M.J., and D.H. Hoekman, 2004, Exploration of factors limiting biomass estimation by polarimetric radar in tropical forests, IEEE Transactions on Geoscience and Remote Sensing, Vol.42, No.1, January 2004, pp.86-104.

  • Hoekman, D.H., and M.A.M. Vissers, 2003, A new polarimetric classification approach evaluated for agricultural crops, IEEE Transactions on Geoscience and Remote Sensing, Vol.41, No.12, December 2003, pp.2881-2889.

  • Del Frate, F., G. Schiavon, D. Solimini, M. Borgeaud, D.H. Hoekman, and M.A.M. Vissers, 2003, Crop classification using multi-configuration C-band SAR data, IEEE Transactions on Geoscience and Remote Sensing, Vol.41, No.7, July 2003, pp.1611-1619.

  • Hoekman, D.H. and M.J. Quiñones, 2002, Biophysical Forest Type Characterisation in the Colombian Amazon by Airborne Polarimetric SAR, IEEE Transactions on Geoscience and Remote Sensing, Vol.40, No.6, pp.1288-1300, June Issue.

  • Varekamp, C., and D.H. Hoekman, 2002, High-resolution InSAR image simulation for forest canopies, 2002, IEEE Transactions on Geoscience and Remote Sensing, Vol.40, No.7, pp.1648-1655, July Issue.

  • Hoekman, D.H. and C. Varekamp, 2001, Observation of tropical rain forest trees by airborne high resolution interferometric radar, IEEE Transactions on Geoscience and Remote Sensing, Vol.39, No.3, pp.584-594.

  • Varekamp, C and D.H. Hoekman, 2001, Segmentation of high-resolution InSAR data of tropical forest using Fourier parameterised deformable models, International Journal of Remote Sensing, Vol.22, No.12, pp.2339-2350.

  • Woodhouse, I.H. and D.H. Hoekman, 2000, Determining land surface parameters from the ERS-windscatterometer, IEEE Transactions on Geoscience and Remote Sensing, Vol.38, pp.126-140.

  • Hoekman, D.H. and M.J. Quiñones, 2000, Land cover type and biomass classification using AirSAR data for evaluation of monitoring scenarios in the Colombian Amazon, IEEE Transactions on Geoscience and Remote Sensing, Vol.38, pp.685-696.

7. Literature references

  • Allen, G. P. and Chambers, J. L. C. (1998). Sedimentation in the Modern and Miocene Mahakam delta. Jakarta, Indonesian Petroleum Association. 236

  • Alsdorf, D.E., J.M. Melack, T. Dunne, L.A.K. Mertes, L.L.Hess and L.C. Smith (2000) Interferometric radar measurements of water level changes on the Amazon flood plain. Nature 404, pp 174 – 177

  • Best, J.L.; Ashworth, PJ Scour in large braided rivers, and the recognition of sequence stratigraphic boundaries Nature, 387 (6630): 275-277 1997

  • Best, J.L. and Roy, A.G. (1991). Mixing-layer distortion at the confluence of channels of different depth. Nature 350 (6317): 411-413.

  • Biron, P; Best, J.L.; Roy, A.G. 1996. Effects of bed discordance on flow dynamics at open channel confluences. Journal of Hydraulic Engineering-ASCE 122 (12): 676-682.

  • Bolla Pittaluga, M., R. Repetto and M. Tubino. Channel bifurcation in braided rivers: Equilibrium configurations and stability. Water Resources Research 39(3), 1046, doi:10.1029/2001WR001112

  • Christensen, M.S. (1992) Investigations on the Ecology and Fish Fauna of the Mahakam River in East Kalimantan ) Borneo, Indonesia. Int Revue ges. Hydrobiol. 77(4) 593-608

  • De Heer, A. and E. Mosselman (2004) Flow structure and beldoad distribution at alluvial diversions. River Flow 2004: Proceedings of the Second International Conference on Fluvial Hydraulics, Greco, Carravetta, & Della Morte (eds.), Vol. 2, 1429-1439, Balkema

  • De Serres, B; Roy, A.G.; Biron, P.M.; Best, J.L.. 1999. Three-dimensional structure of flow at a confluence of river channels with discordant beds. Geomorphology 26 (4): 313-335.

  • Dinehart, R.L. and J.R. Burau (in press) Repeated surfvay by acoustic Doppler current profiler for flow and sediment dynamics in a tidal river. Journal of Hydrology.

  • Federici, B; Paola, C. 2003. Dynamics of channel bifurcations in noncohesive sediments. Journal of Hydraulic Engineering 39 (6): art. no.-1162.

  • Gurram, S.K., K.S. Karki and W.H. Hager (1997) Subcritial Junction Flow. Journal of Hydraulic Engineering

  • Hoitink, A.J.F., & Hoekstra, P. (2005). Observations of suspended sediment from ADCP and OBS measurements in a mud-dominated environment. Coastal Engineering, 52(2), 103-118.

  • Kostaschuk, R.; Best, J.; Villard, P.; Peakall, J; Franklin, M. 2005. Measuring flow velocity and sediment transport with an acoustic Doppler current profiler. Geomorphology 68 (1-2): 25-37.

  • Kostaschuk, R.; Villard, P.; Best, J. 2004. Measuring velocity and shear stress over dunes with an acoustic Doppler profiler. Journal Of Hydraulic Engineering-Asce 130 (9): 932-936.

  • Mosley, 1976. An experimental study of channel confluences. Journal of Geology 84, 535-562.

  • Parsons, D.R. 2003. Discussion of "Three-dimensional numerical study of flows in open-channel junctions" by Jianchun Huang, Larry J. Weber, and Yong G. Lai. Journal of Hydraulic Engineering-Asce 129 (10): 822-823.

  • Richardson, W.R. and Thorne, C.R. Multiple thread flow and channel bifurcation in a braided river: Brahmaputra-Jamuna River, Bangladesh. Geomorphology 38, 185-196

  • Roberts, H. H. and Sydow, J. (2003). Late Quaternary stratigraphy and sedimentology of the offshore Mahakam delta, East Kalimantan (Indonesia). Tropical deltas of Southeast Asia, Sedimentology, Stratigraphy and Petroleum Geology. F. H. Sidi, D. Nummedal, P. Imbert, H. Darman and H. W. Posamentier. Tulsa, SEPM special publication. 76: 125-145.Ashmore, P.E.; Ferguson, R.I.; Prestegaard, K.L.; Ashworth, PJ.; Paola, C. 1992. Secondary flow in anabranch confluences of a braided, gravel-bed stream. Earth Surface Processes And Landforms 17 (3): 299-311.

  • Storms, J.E.A., R.M. Hoogendoorn, M.A.C. Dam, A.J.F. Hoitink and S.B. Kroonenberg (2005) Late-Holocene evolution of the Mahakam delta, East Kalimantan, Indonesia. Sedimentary Geology 180(3-4) 149-166

  • Wang Z.B., Fokkink R.J., De Vries M.; Langerak, A. Stability of river bifurcations in 1D morphodynamic models; Journal of Hydraulic Research 33 (6): 739-750 1995

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