The new urbanization (NU) will lead to changed land use types, affecting the ecological environment and ecosystem service value (ESV). The NU is affected by the ecological environment because of resource scarcity when the ecological environment is damaged. NU levels and ESV were used to evaluate the degree of urbanization development and value provided by ecosystem services (ES), respectively, and to analyze their coupling and coordination relationships. This study shows that (1) the Nanchang city NU increases annually, at an accelerated rate, while the city scale continuously expands. Among the various NU subsystems, economy and spatial urbanization are primary, and the remaining subsystems are secondary. (2) In terms of the area of each land use in Nanchang, arable land is the most widely distributed, followed by forest land, and water. The land type with the greatest change was development land, followed by arable land. (3) ESV declined during the study period, with water and forest land being the main ESV components. Hydrological regulation had the greatest contribution among the individual services, while maintaining the nutrient cycle had the minimal contribution. The high-value areas of Nanchang ecology were mainly located in the northeast corner and the water location in the southeast, while the low-value areas were mainly located in the central Nanchang county area. (4) The coupling degree (CD) of Nanchang’s NU and ES showed an inverted U-shaped development trend, first increasing and then decreasing. The coupling coordination degree also showed the same trend and exhibited fluctuation in the evolution process.
A nonpoint source (NPS) loads evaluation method based on the Bayesian source apportionment mixing model was established in this research. The model assumed that (1) the pollutant concentration from each source mixed with the others in the monitoring section during transport, (2) transport only considered first-order attenuation, (3) point source pollution had relatively stable emissions, and (4) the measurement error was random, unrelated, and consistent with a normal distribution (mean of 0). All unknown parameters in the model were taken as random variables, and their posterior distributions were derived by Markov chain Monte Carlo procedures based on historical data, literature, and empirical information. The outflow system of the Huaihe River was adopted as a case study to verify the feasibility of the model. Gelman–Rubin, automatic frequency control statistics, and the determination coefficient (R2) verified the reliability. The results showed that the total loads of ammonia nitrogen (NH4+), chemical oxygen demand, total nitrogen, and total phosphorus from NPSs accounted for 16.35–27.58%, 18.78–25.69%, 21.68–29.71%, and 42.11–52.09%, respectively. The parameter sensitivity analysis showed that prior distribution of NPS concentration was the most sensitive one, which should be determined reasonably based on the empirical or historical information.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.