Yongjun Yang

Enhanced recycling network for spent e-bicycle batteries: A case study in Xuzhou, China

Electric bicycles (e-bicycles) are a primary means of commuting in China because of their light weight, speed, and low maintenance costs. Owing to short service life and environmental pollution hazards, recycling and reuse of e-bicycle batteries has always been a focus of industry and academia. As a typical case of both production and use of large electric bicycles, 113 major sellers, 378 corporate and individual buyers, 147 large e-bicycle repair centers, and 1317 e-bicycle owners in Xuzhou City were investigated in order to understand the sales, use, recycling, and disposal of spent e-bicycle batteries. The findings show that the existing distempered recycling system is the main limitation of spent battery recovery, and the actual recovery rate of spent batteries is lower than the estimated output (QW) for the years 2011-2014. Electric bicycle sellers play a fundamental role in the collection of spent batteries in Xuzhou, accounting for 42.3±8.3% of all batteries recovered. The widespread use of lithium batteries in recent years has resulted in a reduction in spent battery recycling because of lower battery prices. Furthermore, consumer preferences are another important factor affecting the actual recovery rate according to survey results evaluated using canonical correspondence analysis. In this paper, we suggest that a reverse logistics network system for spent battery recycling should be established in the future; in addition, enhancing producer responsibility, increasing publicity, raising of public awareness, developing green public transport, and reducing dependence on e-bicycles also should be pursued. This study seeks to provide guidance for planning construction and management policies for an effective spent battery recycling system in China and other developing countries.

Incorporating ecological vulnerability assessment into rehabilitation planning for a post-mining area

A practical issue is present in sustaining and rehabilitating the ecologically vulnerable post-mining area in which the environmental condition varies spatially and therefore influenced by multiple factors. This paper attempts to integrate the ecological vulnerability assessment and rehabilitation treatment to assist land managers in revealing vulnerable features along with developing treatments of vulnerability mitigation. Using a post-mining site in a mountainous area in western China as study area, an indicator system and framework for assessing and reducing vulnerability were developed based on a vulnerability analysis. Geo-informatics, such as satellite image processing and spatial analysis, were employed to perform the assessment and planning. It was found that higher exposure and sensitivity are the main causes of increased vulnerability in a seriously disturbed post-mining area. Rehabilitation treatments were arranged spatially and structurally based on the framework of vulnerability mitigation. A pre-evaluation of the effectiveness shows this type of rehabilitation has a convergence effect that clusters and lowers the ecological vulnerability index (EVI). The average value of EVI will be reduced by 15.02% if the minimum standards of rehabilitation can be completed. Altogether, an integration of rehabilitation treatments and the quantification of vulnerability in a spatially explicit manner are critical for planners to gain more insight into ecological vulnerability in post-mining area, which provides guidance to simplify rehabilitation planning with respect to vulnerability mitigation.

A GIS-Based Web Approach for Serving Land Price Information

Participants in the land market are usually hampered to browse and analyze the land price information due to the lack of information sources and available analysis tools. A service-oriented GIS-based web system was developed to provide a practical solution, its essential data sources contain basic geographic elements and benchmark land price (BLP)-related information. Core models for land price analysis were implemented, including land price index, spatial distribution, and parcel appraisal. The system was developed based on a four-level Browse Server (B/S) architecture using GIS and web service technologies, which enables the publishing, browsing, and analysis of the land price information via the Internet. With effective functionalities, the system has been employed in a project for updating BLP in a case study city located in China. The main advantage of the GIS-based web approach lies in its integration of spatial-temporal analysis models and web GIS technology, which allows more investors and administrators with limited domain knowledge to obtain further understanding on the change pattern and spatial distribution of land price by an online means. The experience in the case study city demonstrates that the approach has strong practicality for land price information services.

Enhancing municipal solid waste recycling through reorganizing waste pickers: A case study in Nanjing, China:

Waste pickers (WPs) play an indispensable role by helping to control municipal solid waste (MSW). However, they constitute the entry-level workforce of the waste recycling industry and receive little attention from the general public. In China, approximately 4 million WPs make their living by collecting MSW recyclable materials. To assess the role of WPs, an extensive social survey including urban management decision-makers, recycling industrial circle insiders, WPs, as well as common citizen respondents has been conducted in the city of Nanjing, China. The results confirmed that 70–80% of recyclable MSW materials were collected by WPs in the informal sector, which are an integral component of the waste recycling system. In Nanjing, the recyclable material collected annually by WPs is about 505,000 tons, which creates annual economic value of about 78.6–84.7 million USD. However, WPs account for only 6.8–7.3% of the entire industrial chain of the recycling economy. In Nanjing, WPs are able to save an annual MSW disposal cost of about 17.6–22.0 million USD. The resource recovery rate is also increased by 1.9–8.0%. The survey results support the experience of establishing a community-based semi-official picker organizational framework, accompanied by relevant laws, regulations, and preferential policies that would improve the resource recovery rate and pickers’ living and working conditions in order to achieve more effective and hazard-free MSW resource utilization. It is anticipated that the results of this research will be instrumental for the improvement of the MSW recycling system and WP management in other cities in China and other developing countries.

Influence of CO2 leakage from oil-producing wells on crop growth based on improved CASA model

ABSTRACT As a significant application of CO2 geological storage technology, CO2-enhanced oil recovery (CO2-EOR) considers impacts on ecosystems due to the risk of CO2 leakage from oil-producing wells. It is critical to clarify the relationship between CO2 leakage and vegetation growth, because large numbers of wells are situated in the midst of cropland. In this study, we calculated the net primary productivity (NPP) of crops to examine the correlation between oil-producing wells and crop growth using Pleiades’ high-spatial resolution remote-sensing imaging in a CO2-EOR experimental area in Shandong Province, China, basing our methods on the improved Carnegie–Ames–Stanford approach (CASA) model. Atmospheric CO2 concentrations at varying distances from one of the producing wells were collected by wireless sensors and hand-held equipment, and analysis was conducted in regard to the impact of CO2 leakage from producing wells on crop growth according to a simple sampling method. The results indicated that increased CO2 concentration resulting from leakage from producing wells has a slightly positive influence on crop productivity, with the influence ranges correlated with wind direction and velocity. The variance of NPP resulting from increased CO2 concentration and wind direction ranged from 5.0 to 33.7%.

Regime shift and redevelopment of a mining area’s socio-ecological system under resilience thinking: a case study in Shanxi Province, China

Theory related to resilience thinking proposes that complex systems evolve in nested adaptive cycles. However, concrete examples are needed to instantiate this proposition and show what merit it might have in practice. This empirical study used a mesoscale landscape that has experienced mining activity and has faced challenges related to environmental protection and sustainable development. Adopting the perspective of resilience thinking, this study investigated the historical dynamics of a post-mining area in Shanxi Province and considered its future development. In the studied area, the main income source was found to have shifted from agriculture to coal mining activity between 1983 and 2010, with more than 41% of the land being used for mining operations. Such activity degraded the net primary productivity of the local ecosystem. The socio-ecological system experienced two states: traditional agriculture and mining. The evolution of the past adaptive cycles was mainly driven by coal exploitation and environmental degradation within the mining area, as well as the cross-scale interactions of economic events and coal policy changes outside the mining area. As a result of exhausted coal resources and small-scale mining closures, the socio-ecological system is currently in a poverty trap. Based on an assessment of the socio-ecological system’s strengths, weaknesses, opportunities, and threats, a new eco-agriculture can be considered an option for future transformation. The post-mining landscape is apparently a coupled socio-ecological system characterized by panarchy and temporal dynamics. Internal resources and cross-scale interactions, such as the regional-scale demand for agricultural products, could help reorganize the stagnant system. This case study shows that a mesoscale landscape can be a sally port for the application and operation of resilience-thinking-related theory, such as panarchy. This concrete example manifests the proposition that complex systems undergo cycles of renewal and collapse and can be nested in adaptive cycles. The merit of this proposition is not just that it helps to establish a theoretical understanding of the dynamics of complex systems; more importantly, it also generates practical measures to manage such dynamics. This case study supports the existence and importance of regional resilience in maintaining or restoring local economies. On these grounds, we propose that resilience thinking can act as a mental model and practical tool for understanding the historical dynamics of stagnant systems, such as legacy mining sites, and navigate their transitions.