Flood Mitigation Using an Innovative Flood Control Scheme in a Large Lake: Dongting Lake, China
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applied sciences Article Flood Mitigation Using an Innovative Flood Control Scheme in a Large Lake: Dongting Lake, China Yizhuang Liu 1,2 , Shu-Qing Yang 2, Changbo Jiang 1,3,4,*, Muttucumaru Sivakumar 2 , Keith Enever 5, Yuannan Long 1,3,4 , Bin Deng 1,3,4, Usman Khalil 2 and Lingshi Yin 1 1 School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha 4100114, China; [email protected] (Y.L.); [email protected] (Y.L.); [email protected] (B.D.); [email protected] (L.Y.) 2 School of Civil, Mining and Environmental Engineering, University of Wollongong, NSW 2522, Australia; [email protected] (S.-Q.Y.); [email protected] (M.S.); [email protected] (U.K.) 3 Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha 410114, China 4 Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha 410114, China 5 School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, NSW 2522, Australia; [email protected] * Correspondence: [email protected]; Tel.: +86-0731-85258437 Received: 6 May 2019; Accepted: 13 June 2019; Published: 17 June 2019 Featured Application: The Innovative flood control scheme could be applied to the flood-prone lake areas to mitigate the flood disaster. Abstract: A large lake plays an important role in mitigating flood disasters in its nearby regions during the flooding period; however, the effect is limited, because most of its storage capacity becomes dead storage prior to the arrival of the flood wave. In the current study, an innovative flood control scheme (IFCS) is applied to Dongting Lake (the second largest freshwater lake in China) to alleviate flood disasters. MIKE 21 FM was used to examine its feasibility to mitigate flood disasters. One of the largest floods in the 20th century, the 1998-type flood, was modelled and the maximum water levels with/without IFCS were compared. The result shows that the effective flood control storage could be at least doubled when compared with the natural condition once IFCS was applied. The peak flood level in the Dongting Lake could be lowered by at least 0.32 m at the Chenglingji station in the same flood passage of Dongting Lake. The case study reveals that, after applying IFCS, the hydraulic gates play a very important role in floodwater regulation and further study should be conducted to find the optimized operation for each gate in the flood control scheme system. Keywords: flood mitigation; Dongting Lake; flood control capacity; peak water level 1. Introduction Flood disaster causes the greatest losses among natural hazards and it has become more severe and most frequent in recent years due to climate change, urbanization, and water infrastructures. [1–3]. Economic losses from flood hazards have considerably increased over the recent decades [4]. Great floods result in great losses to the world as well as in China. During 1990–1998, most of the global significant flood disasters occurred in China [1], especially in China’s Yangtze River Basin, where about 40% of the national GDP in China is produced due to its abundant water. On the other hand, its economic development is constrained by these flood disasters, according to the Flood chronology of China. Appl. Sci. 2019, 9, 2465; doi:10.3390/app9122465 www.mdpi.com/journal/applsci Appl. Sci. 2019, 9, x 2 of 16 Appl.its economic Sci. 2019, 9 development, 2465 is constrained by these flood disasters, according to the Flood chronology2 of 16 of China. Upstream dams on rivers (e.g., Three Gorges Dam (TGD, China) [5], Hoover Dam (America) [6], and WivenhoeUpstream Dam dams (Australia) on rivers (e.g., [7], etc.) Three can Gorges greatly Dam regulate (TGD, the China) inflow [5 from], Hoover their Damcatchments, (America) which [6], canand Wivenhoeeffectively Damreduce (Australia) flooding. [7 However,], etc.) can greatlyfloodwa regulateter from the the inflow vast fromdownstream their catchments, area cannot which be regulated,can effectively as there reduce is no flooding. dam to control However, the flow. floodwater Relatively, from the the downstream vast downstream river valleys, area cannotas well beas theregulated, delta, have as there a higher is no population dam to control density the and flow. properties Relatively, and theany downstream floods can cause river huge valleys, losses, as thus well excessiveas the delta, floodwater have a higher management population is most density important. and properties For example, and any there floods are two can dams cause with huge a losses, flood thus excessive floodwater management is most important. For example, there are two dams with a control capacity of 1.97 billion m3 in the Brisbane River catchment, but Brisbane city on the river delta flood control capacity of 1.97 billion m3 in the Brisbane River catchment, but Brisbane city on the river was flooded twice in the 20th century, and the city was flooded again, leading to 35 deaths and $2.55 billiondelta was economic flooded loss twice in 2011 in the [7]. 20th The century, TGD is andone of the the city largest wasflooded dams in again, the world, leading with to a 35 flood deaths control and $2.55 billion economic loss in 2011 [7]. The TGD is one of the largest dams in the world, with a flood capacity of 22.1 billion m3, but it only controls 56% of the Yangtze River catchment area (see the 3 shadowedcontrol capacity area in of Figure 22.1 billion 1); floodwater m , but it onlyfrom controls the downstream 56% of the area Yangtze cannot River be controlled, catchment areaeven (see where the theshadowed mega-cities, area inlike Figure Wuhan,1); floodwater Nanjing, and from Shangh the downstreamai, are situated. area cannot When bethe controlled, floods come even from where the middlethe mega-cities, or lower likepart Wuhan,of the Yangtze Nanjing, River and basin, Shanghai, the TGD are situated.cannot effectively When the regulate floods comethe floodwater from the formiddle the purpose or lower of part disaster of the mitigati Yangtzeon, River as happened basin, the TGDin Brisbane cannot in eff 2011.ectively Therefore, regulate it the is worthwhile floodwater for to investigatethe purpose the of flood disaster control mitigation, strategy as in happened the downstre in Brisbaneam area in of 2011. the dam. Therefore, In the itcurrent is worthwhile study, we to takeinvestigate the Dongting the flood Lake, control which strategy is located in the downstream downstream of area the ofTGD, the dam.as an Inexample the current to investigate study, we how take athe lake Dongting can achieve Lake, a which more iseffective located role downstream in mitigating of the a TGD,flood asdisaster an example in the tomiddle investigate or low how part a lakeof a largecan achieve river. a more effective role in mitigating a flood disaster in the middle or low part of a large river. Figure 1. YangtzeYangtze River basin. Generally, a large lake (i.e., the mean surface area is greater than 500 km2 [8]) plays an important Generally, a large lake (i.e., the mean surface area is greater than 500 km2 [8]) plays an important buffer role for temporal floodwater detention during flood seasons [9,10]. However, a flood disaster buffer role for temporal floodwater detention during flood seasons [9,10]. However, a flood disaster still occurs when the incoming excessive floodwater is higher than a lake’s effective storage capacity, still occurs when the incoming excessive floodwater is higher than a lake’s effective storage capacity, which usually becomes very small relative to its total storage, because safe floodwater occupies most of which usually becomes very small relative to its total storage, because safe floodwater occupies most its total storage (small/medium scale flood) as the dead storage before the peak flood wave arrives [11]. of its total storage (small/medium scale flood) as the dead storage before the peak flood wave arrives For example, the severe flood-period of 1998 in China resulted in 3600 deaths and wreaked more than [11]. For example, the severe flood-period of 1998 in China resulted in 3600 deaths and wreaked more $30 billion in damages [1], even though its upstream dams and downstream lakes played some role than $30 billion in damages [1], even though its upstream dams and downstream lakes played some rolein mitigating in mitigating the loss.the loss. An An innovative innovative flood flood control control scheme scheme (IFCS) (IFCS) proposed proposed by by Yang Yang [11 [11,12],12] could could be beused used to mitigateto mitigate the the flood flood disasters disasters in ain large a large lake lake to improveto improve the the eff ectiveeffective flood flood control control capacity capacity of ofthe the lake lake to reduceto reduce the the flooding flooding loss. loss. The The IFCS IFCS consists consists of a by-passof a by-pass canal canal with connectingwith connecting sluice sluice gates gatesaround around the lake, the whichlake, which can be can used be toused mitigate to mitigate flood disastersflood disasters by properly by properly operating operating the sluice the sluice gates. In this paper, the feasibility study of applying the new flood control scheme (IFCS) to the Dongting gates. LakeIn was this conducted paper, the while feasibility using thestudy hydrodynamic of applying modulethe new offlood MIKE control 21 FM scheme (flow model)(IFCS) withto the a Dongtinglong-time simulationLake was conducted (June to September while using 1998). the The hydrodynamic main objectives module were to:of MIKE (1) investigate 21 FM (flow the flooding model) processwith a long-time in Dongting simulation Lake; (2)(June apply to September and design 1998).