Shimin Fang

Understanding the spatial distribution and associated factors of sustainable environmental development (SED) is crucial for effectively formulating action plans aimed at achieving the environment-related Sustainable Development Goals (SDGs). Because of spatial heterogeneity characterized by non-uniform distributions of SED within a region, the use of a single or aggregated value at the national or provincial scale in existing research obscures internal variabilities and fails to adequately reveal the spatial disparities in the progress of environment-related SDGs. Consequently, this study aims to investigate the spatially heterogeneous patterns of SED in prefecture-level cities within the Yangtze River Economic Belt (YREB), China—a critical economic zone characterized by stark intra-regional disparities and pressing environmental challenges. To achieve this objective, the SED index is first constructed using principal component weighted aggregation to quantify the SED status, local Moran’s I is then employed to identify heterogenous patters of the spatial distribution patterns of SED, and geographical random forest is utilized to explore spatially varying association patterns between SED and influences factors. In the YREB, the findings indicate the following key insights: (1) SED has generally shown a positive trend across most cities from 2013 to 2021, with approximately 30% experiencing a downward trend, particularly in Jiangxi, Hubei, and Hunan Provinces; (2) the number of high- or low-value aggregation clusters has decreased, concurrent with an increase in spatial variability; (3) human activity disturbance and population density have been identified as significant factors influencing SED, with a notable impact in cities across Sichuan, Chongqing, Guizhou, and Hubei Provinces. This research contributes technical support and a scientific foundation for evaluating and enhancing SED.

Urban topsoil is not only an essential part of the urban ecosystem, but also a powerful carrier of pollutants in the urban environment. In this paper, 130 topsoil samples from urban area of Xinyang in central-eastern China were selected, the aim is to quantitatively investigate the concentrations, pollution levels, and sources apportionment of 8 heavy metals (HMs, encompassing arsenic (As), cobalt (Co), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), vanadium (V), and zinc (Zn)) via geochemical method. The main conclusions are as follows. (1) The eight HMs in the topsoil have been artificially enriched to varying degrees, which are lower than the street dust levels sampled in pairs. (2) Cu, Zn, and Pb were significantly contaminated, and As, Co, Ni, Cr, and V were relatively low levels of contamination. Overall, comprehensive pollution levels were particularly severe, with 30.0%, 39.2%, and 30.8% for slight, moderate, and serious pollution, respectively. (3) Co, Ni, V, and Cr predominantly originated from natural sources, the percentage contribution of which is 6.3%; Pb, As, Cu, and Zn were predominantly derived from traffic-derived sources, with a percentage contribution of 93.7%. Thus, the first-order source of HMs in the topsoil originates from traffic-induced activities, similar to the case of street dust. Our findings can be beneficial in providing local governments with a reference to formulate environmental pollution controls, and also provide a case study for environmental pollution control in the other livable cities in China.