SWMM-Based Assessment of Urban Mountain Stormwater Management Effects under Different LID Scenarios

The types of urban mountains are diverse, and the surrounding environment is complex. The conditions of runoff generation and convergence in different regions of the same mountain vary. Using the Lijia Mountain in China’s Nanjing City as a case study, this study investigates the effects of such mountain-region-based LID (Low Impact Development) systems. Based on the hydrological analysis of this mountain region, SWMM (Storm Water Management Model) software is used to model and compare the runoff control effects of two LID systems schemes, namely segmental detention and retention and terminal detention and retention. The study’s findings demonstrate that the terminal detention and retention scheme can effectively delay the time of peak flooding and partly reduce peak discharge. In contrast, the segmental detention and retention scheme has a limited delay effect on flood peaks but significantly reduces the peak discharge. This research breaks through the limitations of the previous construction of a single LID scheme for mountainous regions in built-up urban areas. It serves as a theoretical model and technical reference for selecting LID scenarios in response to different mountain conditions.

Study on Feng Shui (Geomantic) Suitability Evaluation of Mausoleums in Nanjing City Based on GIS

Taking the mausoleums in the main urban area of Nanjing city as the study object, with the support of GIS technology, this paper extracts eight influencing factors (surface roughness, elevation, surface cutting depth, surface peaks, outfall, river system, slope, and aspect) corresponding to geomantic elements (“Long”, “Sha”, “Shui”, and “Xue”) in the geographical environments of mausoleums. The AHP is applied in the correlation weight method to calculate the weights of the eight influencing factors, while the information content method is applied in the grading method to calculate the numerical index of each factor. The feng shui (geomantic) suitability of the mausoleums in the main urban area of Nanjing is evaluated using the AHP-weighted information content method and by combining expert knowledge and experience with mathematical statistical techniques. According to the feng shui (geomantic) suitability evaluation results obtained for the mausoleums in the study area, the relatively low-suitability area accounts for 14.55% of the entire study area, the low-suitability area accounts for 25.40%, the suitable area accounts for 29.13%, the relatively high-suitability area accounts for 22.00%, and the high-suitability area accounts for 8.92%. Finally, through a sensitivity analysis of the model, a verification analysis applied using random mausoleums and a feng shui (geomantic) analysis of the Ming Xiaoling Mausoleum, the feng shui (geomantic) suitability evaluation results obtained for the mausoleums analyzed herein are found to be consistent with the actual distribution of the mausoleum sites. The research shows that the AHP-weighted information method based on GIS is suitable for evaluating the feng shui (geomantic) suitability of mausoleums.

Predicting the Metro Scenario-based Spatiotemporal Evolution of Land Use Using CA-Kalman Filter Model: a Case Study of Nanjing City, China

The expansion of metro system can bring varying degrees of impact to the surrounding environment. To study this complex system problem, this paper discusses the temporal and spatial impact by metro system from the perspective of land use change simulation and scenario analysis. The traditional cellular automata (CA) model can realize the simulation of land use change under various scenarios through system dynamics or Markov chain to control the long-term demand forecasting. However, this type of model ignores the filtering of noise data from imageries and increases uncertainty of the system. Therefore, based on the Future Land Use Simulation (FLUS) model, this paper integrates Kalman filter to control the stochastic process of the state-space system, and predicts the spatio-temporal evolution of land use change impacted by metro system in Nanjing from 2019 to 2035. The results show that: (1) The proposed CA-Kalman filter model can realize the optimized simulation of land use change with good accuracy; (2) Urban patches impacted by metro system will emerge from the existing urban boundaries at the cost of occupation of cultivated land, although there is still significant expansion of urban land and construction land, it will reach the upper limit in 2050.

Strategies of Improving the Efficiency of Allocating Parking Slots in Shudeli Community of Nanjing City

Due to the continuous growth of the amount of vehicles that households possess, the scarcity of easily accessible parking slots has gradually become a universal issue, especially in old communities that are usually lack of standardized administration. Thus, how to enhance the efficiency of arranging parking slots within limited public areas has become a concerned social issue in Chinese cities nowadays. As a zealous and supportive member of Shudeli community, the author tries to find the most suitable strategies of improving the efficiency of allocating parking slots here by learning from existing advanced community planning from both foreign and domestic researchers, while applying the knowledge of Economics and Business Management to obtain a final scheme which fits the local circumstances best.

Microbial-Induced Carbonate Precipitation Improves Physical and Structural Properties of Nanjing Ancient City Walls

The preservation and restoration of heritage sites have always been of key focus in the field of cultural relics. Current restoration methods mainly involve physical or chemical techniques, which are in many cases intrusive, destructive, and irreversible. Hereby, we introduce a novel biological strategy (microbial-induced carbonate precipitation (MICP)) to repair natural and simulated surface cracks on six hundred years’ old wall bricks (part of the Nanjing City Min Dynasty ancient wall, China). X-ray micro computed tomography (X-ray micro-CT) was employed to non-destructively visualize the internal structure of the MICP-treated brick cubes. The results showed that MICP can effectively repair both natural and simulated cracks present on the brick’s surface. The compressive strength of the MICP-treated brick cubes was significantly higher than that of the untreated control cubes (33.56 ± 9.07 vs. 19.00 ± 1.98 kN, respectively). MICP significantly increased the softening coefficient and decreased the water absorption rate (p < 0.05), indicating that the water resistance of the wall bricks can be improved after treatment. The 3D images from X-ray micro-CT, a method that could non-destructively assess the internals of such cultural structures, showed that MICP can effectively repair ancient relics, promoting durability and limiting degradation without affecting the structure. X-ray diffraction analyses showed that MICP generates the same calcite form as that of original bricks, indicating that MICP filler is compatible with the ancient city wall brick. These findings are in line with the concept of contemporary heritage preservation.

Revisiting China’s Sponge City Planning Approach: Lessons From a Case Study on Qinhuai District, Nanjing

Integrating sustainable urban water management into the urban planning process is essential for developing water-resilient cities. To this end, the central government of the People’s Republic of China initiated the “Sponge City” programme. However, challenges and gaps exist in current urban planning practice. The operationalizable planning approach to realise the multiple objectives of Sponge City is missing in the existing guidelines. Using a local example of Sponge City planning in Nanjing City as a case study, this paper outlines the current Sponge City approach from the perspectives of planning content and planning process. A qualitative comparative analysis between Nanjing’s Sponge City planning and Auckland Water Sensitive Design, as well as an evaluation of the Sponge City approach through the lens of Dutch urban water management, identified key missing elements that would enhance the current Sponge City planning approach. Examples include targets for pluvial flood protection, a strategy for planning interventions, and tools for interdisciplinary cooperation in the planning process. This enhanced approach was successfully applied in the Sponge City planning for Qinhuai District, Nanjing City. Nevertheless, challenges on data availability and the decision-makers’ mindsets called for more efforts on the interface of research and policy development for upscaling the Sponge City approach.