Over the last decades, the People’s Republic of China experience large economic development, which have led to severe shortages of usable land. To counteract this, the Chinese central government promoted the development of coastal provinces by reclaiming large sections of coastal zones. One of these regions is Nantong Binhai Park or Tongzhou Bay on the Jiangsu coast. This region is characterized with large intertidal mudflats and tidal channels and has a high potential for the development of agri-aquaculture as well as the construction of a deep-sea port. However, these intertidal mudflats are a vital part of ecosystems and support numerous species, such as several endangered migratory shorebirds within the East Asian–Australasian Flyway. Acknowledging the importance of both port development and existing endangered ecosystems, a more integrated coastal design is needed. Possible solution could be found through the Building with Nature approach, in which natural processes and ecological needs are included in the design. This requires a good understanding of the governing processes as well as the requirements from society, ecology and engineering perspectives. In this thesis, a preliminary study was performed into a more sustainable alternative for the planned Tongzhou Bay Port, in which a basic connection was made between engineering and ecological point of view. A hydro-morphodynamic numerical model was made available and further developed for the modelling of the governing processes in the development of the intertidal mudflats at Tongzhou Bay. The model showed satisfactory results with respect to observations and net flow and transport features were closer analyzed. The different ecosystem types at Tongzhou Bay were quantified with ecotope classification and further validated with satellite-tracked data of two endangered shorebird species. Based on this validation, high-value ecotopes were determined based on these species and was used as an indication for the performance of alternative port configurations with respect to ecology. With a better understanding of the governing processes for the development of the intertidal mudflats and ecotopes, a series of alternative port designs were conceived through several design cycle iterations. Guiding principles were the preservation of high-value ecotopes, the enhancement of these area’s development and the potential area created for future port development by each variant. Results showed that by understanding natural transport and siltation patterns, not only could alternative port configurations lead to the preservation of existing high-value ecotopes, but a stronger development of these areas with respect to the natural development could be realized as well. The preliminary results of this thesis show the potential of more sustainable alternative port designs through the Building-with-Nature principle, in creating benefits for both economic and ecological development of Tongzhou Bay.

The People's Republic of China experienced large socio-economic development over the last decades, which was mainly concentrated in coastal regions. Jiangsu Province is among these regions, which shows large socio-economic differences between north and south. The Chinese Central Government has allocated Binhai County as a new coastal development zone to lessen inequality. New infrastructure (e.g. Binhai Port) was constructed and industrialisation increased in order to boost local development. Binhai County is located at the Abandoned Yellow River Delta. In 1855, the Yellow River shifted its course which cut off sediment supply to the delta. Major land retreat was stopped by the construction of sea dikes from the 1930's. Ongoing erosion is undermining the present sea defence and endangers the hinterland. The erosion along the delta has engaged the disappearance of mudflat area. Furthermore, large development in southern Jiangsu has led to constraints in usable land for which large mudflat areas were reclaimed. Multiple research pointed the negative effects of reclamation activities on ecology (e.g. decline of shorebird populations). After recognition of the importance of mudflats by the Chinese Central Government, the national policy was set to protect and restore mudflats along the Chinese coast. The erosive features of the Abandoned Yellow River Delta (AYRD) needs counteracting measures. Within this research it is aimed to integrate a multi-purpose design in which engineering and ecology are mutually enhanced. Following the Building with Nature guidelines multiple innovative solutions can be presented. Within this research it is aimed to protect the delta by implementation of islands in front of the coast. Furthermore, it is aimed to enhance mudflat growth which adds ecological value to the delta area. It is expected that by implementation of islands a reduced energetic environment is created in which fine sediment can settle. The Jiangsu Regional Model (JRM) was made available for this research, which is based on Delft3D software. An outcrop has been made at the area of interest which was refined (3:1) and further referred to as the Abandoned Yellow River Delta Model (AYRDM). The hydrodynamical forcing was completed by the addition of waves. The AYRDM was set-up with three sediment fractions from which one added cohesive fraction. The production simulation was set-up for ten morphological years by using a morphological factor of 50. The better obtained understanding of the governing processes optimised island configuration design. Fifteen configurations were designed and subdivided over two series: the Basic- and Exploratory series of eight- and seven configurations respectively. The Basic series was set-up with a systematic approach in order to represent the concept of barrier islands. The Exploratory series comprehend designs based on the entrapment of sediment by using sediment transport patterns. The definition of a mudflat was set from -0.88 m to all above, relative to mean sea level in order to measure mudflat growth. The findings within the reference production simulation (without the implementation of islands) showed a flood dominant environment in which flood direction is south. Hence, south- and offshore directed residual sediment transport were observed along the AYRD. The outgoing sediment flux from the AYRDM increased by 2.2E7 ton/year when waves were included. The addition of waves increased the average grain size by 26 µm at siltation areas due to sediment stirring and cross-shore transport. The effect of island configurations showed most favourable sediment entrapment when elongated islands and small inlet widths were applied. The shallows induce larger friction on tidal movement for which current velocities and herewith sediment transport capacity is reduced over distance. Hence, depositional areas were found to be radially deflected to the south. Secondary flow, due to eddy formation, showed significant streaming induced sediment transport behind the islands ends. Small bed slopes induce larger distances between islands and mainland China, which holds for relatively larger mudflat areas. Wave penetration was reduced significantly when islands were implemented, which created a less energetic environment. The largest increase of mudflat relative to the reference simulation is 59.8 km2 after ten morphological years by implementing 16 km2 of island area. The findings within this study are representative for the Abandoned Yellow River Delta area and show the potential of islands in order to protect the delta and create additional ecological/recreational benefits alongside.