Constructing the landscape security pattern of urban stormwater in Nanjing, China

Stormwater management must address three direct threats to urban ecological security during the urbanisation of China: waterlogging, water pollution and shortages of water resources. Based on the theory of landscape security patterns, macro-level stormwater landscape security patterns (SLSPs) associated with regional flood security, runoff pollution control security structures and water resource utilisation can be set up to solve urban stormwater and environmental problems. The objective of this study was to construct the SLSP of the Tiebei area in Nanjing, east China. A high-precision digital terrain model and a digital orthophoto map were obtained using portable, unmanned aerial vehicle remote sensing technology and Pix4Dmapper software. These data were integrated in an ArcGIS platform and used to calculate runoff flow direction and flow accumulation, measure runoff pollution levels and determine priority areas for water resources protection. Combined with regional planning of the Tiebei area, the SLSP was effectively and efficiently constructed. This study also examined current management and use of urban stormwater and addressed the important bases for ecological flood prevention, regional planning and site design of the urban landscape.