Tainan Hydraulics Laboratory,National Cheng Kung University, TAIWAN
5 F., 500 Anming Rd., Sec.3, Tainan City, Taiwan.
70955
http://iard.thl.ncku.edu.tw/en/​;
http://www.thl.ncku.edu.tw/english/introduction/i_org.2015B.htm
OutlineTainan Hydraulics Laboratory (THL) was founded by a joint venture between theNational Hydraulic Research Institute, Ministry of Economic Affairs (MOEA) and theTaiwan Provincial College of Engineer (predecessor of National Cheng Kung University(NCKU) in 1950. By 2015, T.H.L had about 150 full time researchers, technical engineers
and administrative staffs. The 9 divisions of THL are (1)Division of Field investigation;(2)Division of Physical Modeling; (3)Numerical Modeling and Geographical Information
Division; (4)Land-subsidence Prevention and Reclamation Corps; (5)Water Professions
Enterprise Information and Incubation Center; (6)Ocean Energy Research Center;(7)Division of International Affairs and Research Development; (8)Division of Human Assetand Administration Management; (9)Division of Project and Knowledge Management.
Missions of THL including:● Contributing research and investigation efforts to Hydraulics, Coastal and Oceanengineering.
● Establish domestic hydraulic and oceanic database and geographical informationsystem.
● Providing sufficient research data to government department, such as, Water
Resources Agency, and Industrial Development Bureau of Ministry of Economic
Affairs in Taiwan, and etc..
● Supporting National Cheng Kung University in teaching, research activities andexperiment training, in order to achieve a higher research level and to integrateindustrial, governmental, academic and research activities.
Research topics including: generation and transformation of wind waves, waves
and tidal currents, wave statistics, wave-structure interaction, coastal sediment transport,
coastal pollution, and offshore engineering.
THL also participated in major coastal engineering construction projects in Taiwan,such as offshore cage aquaculture study in Pintung County; simulation of tsunami waves;
EIA of offshore wind farm along the west coastline in Chang-Hwa county; construction ofdeep water harbor of Mailau; land reclamation and protection of eroded coastal areas in
Yulin county; mitigation of disasters caused by typhoon waves and tsunamis; sustainable
development of rich tidal power; wetland rehabilitation and utilizing ocean resources
around Taiwan.
Each year, researchers in THL publish research efforts on international journals andinternational conferences, which are Journal of Fluid Mechanics, ISOPE Journals,
1European Journal of Mechanics Fluid, Ocean Engineering, Coastal Engineering, Journalof Coastal Research, and etc. Researchers in THL also participate in international
conferences, such as IAHR World Conference of the International Association for
Hydro-Environment Engineering and Research, PACON Conference of the PacificCongress on Marine Science and Technology, the International Offshore and Polar
Engineering Conference (ISOPE), and the International Conference on Coastal
Engineering (ICCE).

Fig. 1 research facilities of THL (a) Long wave flume, 300m X 5m X 5.2m (b,c) Near Shore Basin (150m X60m)

International Collaboration
With solid research force, THL has established joint research collaborations withleading institutes in the world (Fig. 2). The establishment of international collaborations not
only strengthens research capabilities but also creates values for all collaborative partners.

Fig. 2 ​THL has established joint research collaborations with leading institutes in the world

Research and Achievement
2Situated in the highly potential typhoon impact region of West pacific, the coastal
area of Taiwan suffers frequent disaster caused by typhoons (3~4 events in a year).
Starting from 1976, the Water Resources Agency of Ministry of Economic Affairs publishedthe “ Proposal for Construction and Renovation of Sea Dikes in Taiwan”. Since then, sea
dikes are built in Taiwan to protect the livelihood, safety and property of the people living
along the coastal area.
The main function of the seawall is to defend coastal and estuarine areas fromstorm surge and wave impact. By the end of 2012, a total of 524 Kilometers of sea dikes
were built to protect the coastal areas in Taiwan, Penghu, Kinmen and Matsu. Whichmeans approximately 44% of Taiwan coastline covers by seawalls. This is 95.6% of thetotal sea dikes length of 548 Kilometers planned by Water Resources Agency in 1976. In
the “Sustainable Coastal Development Program” approved by Executive Yuan of Taiwan
in 2007, which points out that the sustainable development in coastal area should not
reduce the proportion of natural shoreline. The program also suggests the maintenanceand management of existing sea dikes should integrate with wave dissipation function,
ecology conservation and environment friendly, in addition to strengthen the safety ofdikes.
Tainan Hydraulics Laboratory makes efforts in research and development of coastal
engineering during past 60 years. The research results are applied to the development
and protection of the coastal zone along Taiwan accompany with the aforementioned
coast management policy released by Taiwanese government. For example, a series ofapplication research were conducted during past several years to evaluate theperformance of the seawalls along the southwest Taiwan for coastal zone protection.
Based on the research results, some suggestions about the improvement of coastal zone
environment were proposed. On the other hand, coastal erosion along Liaolo Bay which isa semi-circular beach and locates at the south coast of Kinmen Island was observed
during past years. Field and numerical experiments were conducted to discuss thehydrodynamics inside the bay. CMS-WAVE and CMS-FLOW models were setup andvalidated according to the collected field data. Then, the models were applied to simulate
the hydrodynamics inside the study site during typhoon events. Longshore current patternalong the semi-circular beach is sensitive to the incident wave. For wave approaching fromeast direction, the most affected region inside the bay by the wave locates on the west of
the beach. However, widespread impact on the whole beach was found when the wave
incident from south direction. Wave (1~2 m) travels from E~ESE direction at the bay
mouth usually occurs in winter and induces to consistently westward longshore current
along the beach with speed 0.2~0.4 m/s. High wave approached from SE~S direction
during the studied typhoon events which induced to strong transiently and complex current
patterns inside the bay beach with maximum speed up to more than 1.0 m/s (Fig. 3). A rip
circulation cell constantly found near the outcrop, which enhanced the strength of the rip
circulation. Besides, rip circulation cells occasionally found at some spots along the beachrespectively which depends on the incident wave energy and direction. Based on the study
on hydrodynamic and sediment transport inside the bay beach, a coastal protection project
was proposed to the airport authority.

3Fig. 3 snapshot of spatial wave heights and currents at a time (6:00 Sep., 20, 2010) during Typhoon Fanabio​o​(wind speed and direction: 14m/s, 140​
, wave height and direction: 9.12m, 112​).

Future Challenges
1. Sea Level rise around Taiwan under the impact of global warming.
2. Increasing number and strength of typhoons threatening Taiwan
3. Coastal erosion caused by natural and anthropogenic factors.
4. Severe Land subsidence caused by excessive pumping of groundwater in coastal
areas for fish farming.
Disaster Management Policy
In order to rehabilitate the coast, the coastal environment improvement in the future
should focus on “soft, environment and ecology friendly engineering” which will strengthen
the disaster prevention function of sea dikes, and at the same time satisfies the needs forwater zone utilization, recreation and ecology rehabilitation.
On the other hand, non-engineering measure should also include to reduce lossesof lives and properties caused by storm surge and extreme typhoon events. For example,
limit the land utilization in the coastal area and set up a buffer zone, etc. However, face thefuture challenges, a new disaster management policy is necessary to accomplish thedisaster risk reduction and resilience.

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