Knowledge of the patterns of location of retail stores in urban areas supports the development of effective urban planning and the reasonable allocation of commercial facilities. Using point of interest data and consumer survey data in three main commercial districts in Changchun, China, this study investigates the spatial structures of commercial districts and the patterns of distribution of retail stores to assess the determinants of the development of retail stores in commercial districts. Kernel density estimation, nearest neighbor index, and Pearson’s correlation analysis were used for this study. The following conclusions are drawn. (1) The spatial distribution of retail stores in Changchun commercial districts generates the coexistence of a concentration in the core area and diffusion in the peripheral area. The emergence of shopping malls has challenged the traditional single-center structure, resulting in the transformation of commercial districts from single-center to multicenter layouts, while also producing a hierarchical trend in development. (2) The Chongqing Road and Hongqi Street commercial districts have a relatively high spatial concentration of retail stores. Retail stores in Guilin Road exhibit distinct characteristics, namely, stores selling textiles, clothing, and daily necessities show the highest concentration, and food, beverage, and tobacco outlets as well as integrated stores show the lowest concentration. (3) The selected locations of the differing categories of stores on Chongqing Road strongly correlate, and textile, clothing, and daily necessity stores show a high correlation with other retail categories. (4) Four main factors affect the development and spatial layout of retail in the commercial districts. First, the interaction between consumer behavior and location choice in retail stores promotes the evolution of retail formats and trends in the development of comprehensive, specialized, and hierarchical retail commercial spaces. Second, the retail format determines the spatial layouts and the historical inheritance of the format. Third, governmental planning and policies lead to the agglomeration and diffusion of commercial activities in different areas. Fourth, such spatial clustering effects are an external driving factor for integration and aggregation among retail formats.

As the main carrier of regional residential sewage, industrial wastewater and surface runoff emissions, urban rivers are most vulnerable to pollution and destruction. Taking the Dongsha River in the city of Baoji in Northwest China as an example, four river pollutants were monitored, and the improved Nemero index and factor information model were established to for risk assessment of river water pollution. While compared with other methods, the method is verified, and it is believed that this method is a good tool to evaluate the water pollution of urban rivers. Moreover, the source load mechanism of urban river pollution is discussed. Evaluation results show that for TP, risk of upstream is highest, and for COD and NH3N, risks of the middle are highest, while for PH, risk of downstream is highest. Overall, COD and ammonia nitrogen are a major pollutant in urban rivers, which pollutants originate from industry and agricultural wastewater discharge. The domestic sewage, solid waste and agricultural wastewater overflows also play an important role in the change of river water quality. These studies provide the basis for urban environmental planning and pollution control.

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