Faculty of Civil Engineering Subotica, University of Novi Sad, Kozaračka Street 2a, Subotica, 24000, Serbia.
Faculty of Water Sciences, National University of Public Service, Bajcsy-Zsilinszky utca 12-14, Baja, H-6500, Hungary.
Environ Monit Assess. 2020 Jan 30;192(2):149. doi: 10.1007/s10661-020-8074-z.
This paper presents the development, calibration and verification of a two-dimensional model for a Danube reach and its old cutoff meander. The considered meander was at one point separated from the main reach with a levee, which caused a series of unwanted environmental consequences. Aiming to stop the ongoing degradation of the meander, the validated model was engaged to investigate the effects different river works would have on its current state. The considered river works involved dredging in certain parts of the meander, while keeping in mind the negative effects these works can have on the environment, as well as possible widening of the existing opening in the levee. Numerical simulations showed that all the considered scenarios would result in a general increase of velocities, which is important from the aspect of sediment deposition. After a thorough evaluation of the results, it was found that by carefully selecting the locations where dredging should be conducted, no other interference is needed to put an end to the increasingly deteriorating situation in the meander. Computations confirmed that the suggested river works would increase the unit discharge in the entire meander, especially in its upstream part. The redistribution of flow around the island downstream of the levee (that formed during past years as a result of sediment deposition) was also predicted, where the flow would once again favor the left side of the island. This is a more natural path of flow that would aid the flushing of previously deposited sediment in this part of the meander.
本文介绍了多瑙河一段及其旧河道弯道的二维模型的开发、校准和验证。所考虑的弯道曾经被堤坝与主河道隔开，这导致了一系列不良的环境后果。为了阻止弯道的持续退化，验证后的模型被用于研究不同河道工程对其当前状态的影响。所考虑的河道工程包括在弯道的某些部分进行疏浚，同时考虑到这些工程可能对环境造成的负面影响，以及堤坝现有开口可能的拓宽。数值模拟表明，所有考虑的方案都将导致流速的普遍增加，这对于泥沙沉积方面非常重要。在对结果进行彻底评估后，发现通过仔细选择应进行疏浚的位置，无需进行其他干扰即可阻止弯道日益恶化的情况。计算结果证实，建议的河道工程将增加整个弯道的单位流量，特别是在其上游部分。还预测了堤坝下游岛屿周围的水流重新分布（这是过去几年由于泥沙沉积形成的），水流将再次有利于岛屿的左侧。这是一个更自然的水流路径，有助于冲刷弯道这部分以前沉积的泥沙。
