Effects of a Low-Head Dam Removal on River Morphology and Riparian Vegetation: A Case Study of Gongreung River
ABSTRACT
The long term existence of a low-head dam in the river channel significantly affects river geomorphology and river ecosystem. Because more and more low-head dam structures have deteriorated in recent years, the attention for low-head dam removal is increasing as one of alternatives for river restoration. Thus, this study intends to investigate the impacts of low-head dam removal on river geomorphology and riparian vegetation with developing a quantitative method to predict the changes of river morphology as well as invasion, growth, expansion and destruction of riparian vegetation after a low-head dam removal. To verify the numerical simulation model, the low-head dam removal case in Gongreung River was employed with investigation of low-head dam removal responses on river geomorphology and riparian vegetation. Following the low-head dam removal, the results of monitoring and numerical simulation indicated that new sand bars has formed as well as increasing the extent of existing sand bars in the upstream of the low-head dam. The sand bars have been colonized in a year after the low-head dam removal by grass type plants. After a decade to several decades, the riparian vegetation in sand bars often developed to tree type plants in several low-head dam removal cases. As other cases, Gongreung River also showed the growth of tree type plants in 5 years after the removal.
The long term existence of a low-head dam in the river channel significantly affects river geomorphology and river ecosystem. Because more and more low-head dam structures have deteriorated in recent years, the attention for low-head dam removal is increasing as one of alternatives for river restoration. Thus, this study intends to investigate the impacts of low-head dam removal on river geomorphology and riparian vegetation with developing a quantitative method to predict the changes of river morphology as well as invasion, growth, expansion and destruction of riparian vegetation after a low-head dam removal. To verify the numerical simulation model, the low-head dam removal case in Gongreung River was employed with investigation of low-head dam removal responses on river geomorphology and riparian vegetation. Following the low-head dam removal, the results of monitoring and numerical simulation indicated that new sand bars has formed as well as increasing the extent of existing sand bars in the upstream of the low-head dam. The sand bars have been colonized in a year after the low-head dam removal by grass type plants. After a decade to several decades, the riparian vegetation in sand bars often developed to tree type plants in several low-head dam removal cases. As other cases, Gongreung River also showed the growth of tree type plants in 5 years after the removal.
Cite this paper
Kim, S. , Toda, Y. and Tsujimoto, T. (2014) Effects of a Low-Head Dam Removal on River Morphology and Riparian Vegetation: A Case Study of Gongreung River. Journal of Water Resource and Protection, 6, 1682-1690. doi: 10.4236/jwarp.2014.618151.
Kim, S. , Toda, Y. and Tsujimoto, T. (2014) Effects of a Low-Head Dam Removal on River Morphology and Riparian Vegetation: A Case Study of Gongreung River. Journal of Water Resource and Protection, 6, 1682-1690. doi: 10.4236/jwarp.2014.618151.
References
[1] Doyle, M.W., Stanley, E.H., Orr, C.H., Selle, A.R., Sethi, S.A. and Harbor, J.M. (2005) Stream Ecosystem Response to Small Dam Removal: Lessons from the Heartland. Geomorphology, 71, 227-244.
http://dx.doi.org/10.1016/j.geomorph.2004.04.011 [2] Sawaske, S.R. and Freyberg, D.L. (2012) A Comparison of Past Small Dam Removals in Highly Sediment-Impacted Systems in the US. Geomorphology, 151, 50-58.
http://dx.doi.org/10.1016/j.geomorph.2012.01.013 [3] Pizzuto, J. (2002) Effects of Dam Removal on River form and Process. BioScience, 52, 683-691.
http://dx.doi.org/10.1641/0006-3568(2002)052[0683:EODROR]2.0.CO;2 [4] Doyle, M.W., Stanley, E.H. and Harbor, J.M. (2003) Channel Adjustments Following Two Dam Removals in Wisconsin. Water Resources Research, 39, 1011. http://dx.doi.org/10.1029/2002WR001714 [5] Shafroth, P.B., Friedman, J.M., Auble, G.T., Scott, M.L. and Braatne, J.H. (2002) Potential Responses of Riparian Vegetation to Dam Removal. BioScience, 52, 703-712.
http://dx.doi.org/10.1641/0006-3568(2002)052[0703:PRORVT]2.0.CO;2 [6] Orr, C.H. and Stanley, E.H. (2006) Vegetation Development and Restoration Potential of Drained Reservoirs Following Dam Removal in Wisconsin. River Research and Applications, 22, 281-295. http://dx.doi.org/10.1002/rra.891 [7] Meyer-Peter, E. and Muller, R. (1948) Formulas for Bed Load Transport. Proceedings of 2nd meeting of the International Association for Hydraulic Structures Research, Delft, 7 June 1948, 39-64. [8] Hasegawa, K. (1981) Bank-Erosion Discharge Based on a Non-Equilibrium Theory. Proceedings of JSCE, 316, 37-52. (In Japanese) [9] Jensen, P.B. (1932) Die Stoffproduktion der Pflanzen. Fischer. [10] Yagisawa, J., Tanaka, N. (2009) Dynamic Growth Model of River Vegetation Considering the Destruction by Floods and Regeneration Process of Trees. Annual Journal of Hydraulic Engineering, 53, 1171-1176. (In Japanese) [11] Toda, T., Kim, S.N., Tsujimoto, T. (2014) Relation between Sandbar Mode and Vegetation Expansion in Sand-Bed River. Proceedings of River Flow 2014, Lausanne, 3-5 September 2014, 429. [12] Toda, Y., Ikeda, S., Kumagai, K., Asano, T. (2005) Effects of Flood Flow on Flood Plain Soil and Riparian Vegetation in a Gravel River. Journal of Hydraulic engineering, 131, 950-960.
http://dx.doi.org/10.1061/(ASCE)0733-9429(2005)131:11(950)
[1] Doyle, M.W., Stanley, E.H., Orr, C.H., Selle, A.R., Sethi, S.A. and Harbor, J.M. (2005) Stream Ecosystem Response to Small Dam Removal: Lessons from the Heartland. Geomorphology, 71, 227-244.
http://dx.doi.org/10.1016/j.geomorph.2004.04.011 [2] Sawaske, S.R. and Freyberg, D.L. (2012) A Comparison of Past Small Dam Removals in Highly Sediment-Impacted Systems in the US. Geomorphology, 151, 50-58.
http://dx.doi.org/10.1016/j.geomorph.2012.01.013 [3] Pizzuto, J. (2002) Effects of Dam Removal on River form and Process. BioScience, 52, 683-691.
http://dx.doi.org/10.1641/0006-3568(2002)052[0683:EODROR]2.0.CO;2 [4] Doyle, M.W., Stanley, E.H. and Harbor, J.M. (2003) Channel Adjustments Following Two Dam Removals in Wisconsin. Water Resources Research, 39, 1011. http://dx.doi.org/10.1029/2002WR001714 [5] Shafroth, P.B., Friedman, J.M., Auble, G.T., Scott, M.L. and Braatne, J.H. (2002) Potential Responses of Riparian Vegetation to Dam Removal. BioScience, 52, 703-712.
http://dx.doi.org/10.1641/0006-3568(2002)052[0703:PRORVT]2.0.CO;2 [6] Orr, C.H. and Stanley, E.H. (2006) Vegetation Development and Restoration Potential of Drained Reservoirs Following Dam Removal in Wisconsin. River Research and Applications, 22, 281-295. http://dx.doi.org/10.1002/rra.891 [7] Meyer-Peter, E. and Muller, R. (1948) Formulas for Bed Load Transport. Proceedings of 2nd meeting of the International Association for Hydraulic Structures Research, Delft, 7 June 1948, 39-64. [8] Hasegawa, K. (1981) Bank-Erosion Discharge Based on a Non-Equilibrium Theory. Proceedings of JSCE, 316, 37-52. (In Japanese) [9] Jensen, P.B. (1932) Die Stoffproduktion der Pflanzen. Fischer. [10] Yagisawa, J., Tanaka, N. (2009) Dynamic Growth Model of River Vegetation Considering the Destruction by Floods and Regeneration Process of Trees. Annual Journal of Hydraulic Engineering, 53, 1171-1176. (In Japanese) [11] Toda, T., Kim, S.N., Tsujimoto, T. (2014) Relation between Sandbar Mode and Vegetation Expansion in Sand-Bed River. Proceedings of River Flow 2014, Lausanne, 3-5 September 2014, 429. [12] Toda, Y., Ikeda, S., Kumagai, K., Asano, T. (2005) Effects of Flood Flow on Flood Plain Soil and Riparian Vegetation in a Gravel River. Journal of Hydraulic engineering, 131, 950-960.
http://dx.doi.org/10.1061/(ASCE)0733-9429(2005)131:11(950)