Enhanced nitrogen and phosphorus flows in a mixed land use basin: drivers and consequences

Rapid increase in accumulation of phosphorus (P) relative to nitrogen (N) has been observed in human-impacted regions, but the reasons are largely unknown. We developed an Integrated Nutrient Flow Analysis (INFA) model in order to assess the changes in nutrient flows of the Chaohu Lake basin from 1978 to 2015. Results show that the increase in total N input is slower than that of P (3.5-fold versus 4.2-fold) during 1978–2015, while total N loss increases much faster than that of P (3.1-fold versus 2.3-fold). We found a decline trend in the N:P ratio of nutrient input and accumulation since the mid-1990s. The decline in N:P ratio of nutrient loss to waterbodies in the basin is correlated (p < 0.05) with TN:TP of water concentration in Chaohu Lake, which may be related to the frequent algal blooms in the P-limited lake by supplying more P than N. Using an extended STIRPAT model, we found that nutrient use efficiency, urban rate, diet choice and population are key factors driving the change in nutrient flows, which contribute over 90% to the total change. This study confirms that human activities decrease N:P in regional environment and demonstrates the importance of P management to balance nutrient for improving water quality. The method in this study has a wide application for many other mixed land use regions to address nutrient flows imbalance problems and to explore nutrient management options

Phosphorus footprint in China over the 1961–2050 period: historical perspective and future prospect

The phosphorus footprint (PF) is a novel concept to analyze human burdens on phosphorus resources. However, research on PF approach is still limited, and current several PF studies include incomplete phosphorus sources and have limited quantitative interpretation about the drivers of PF changes, which can help understand future trends of PF. This study develops a more comprehensive PF model by considering crop, livestock and aquatic food, and non-food goods, which covers the mainly phosphorus containing products consumed by human. The model is applied to quantify China's PF from 1961 to 2014, and the results of the model are also used to analyze the factors driving the PF changes and explored China's PF scenarios for 2050 using an econometric analysis model (STIRPAT). The result shows that China's PF increased over 11-fold, from 0.9 to 10.6 Tg between 1961 and 2014. The PF of livestock food dominated China's PF, accounting for 57% of the total in 1961 and 45% in 2014. The key factors driving the increase in China's PF are the increase in population and urbanization rate, with contributions of 38% and 33%, respectively. We showed that in the baseline scenario, China's PF would increase by 70% during 2014–2050 and cause the depletion of China's phosphate reserves in 2045. However, in the best case scenario, China's PF would decrease by 15% in 2050 compared with that in 2014, and it would have 50% of current phosphate reserve remaining by 2050. Several mitigation measures are then proposed by considering China's realities from both production and consumption perspective, which can provide valuable policy insights to other rapid developing countries to mitigate the P footprint

R/S method for evaluation of pollutant time series in environmental quality assessment

The significance of the fluctuation and randomness of the time series of each pollutant in environmental quality assessment is described for the first time in this paper. A comparative study was made of three different computing methods: the same starting point method, the striding averaging method, and the stagger phase averaging method. All of them can be used to calculate the Hurst index, which quantifies fluctuation and randomness. This study used real water quality data from Shazhu monitoring station on Taihu Lake in Wuxi, Jiangsu Province. The results show that, of the three methods, the stagger phase averaging method is best for calculating the Hurst index of a pollutant time series from the perspective of statistical regularity

Supporting data to A process-based model to quantify the generation pattern of water pollutant loads at high resolution and track the subsequent pathway to collection and discharge

This dataset includes parameters for point sources (industrial production, residential and commercial consumption) and activity data for artificial drainage activities. Please see the publication for more details

Understanding consumers’ behavior intention of recycling mobile phone through formal channels in China: The effect of privacy concern

The aim of this paper is to explore consumers’ intention of recycling obsolete mobile phone through formal channels in China. Taking Jiangsu Province as an example, the survey results revealed that although nearly half of consumers prefer to save their obsoleted mobile phones at residence, those who are willing to participate in recycling prefer formal recycling channels instead of informal ones. To explore the determinants of formal recycling intention from the perspective of consumers’ psychological characteristics, an integrative model based on the theory of planned behavior was established, in which the effect of consumers’ privacy concern was thoroughly explored. The results indicated that recycling attitude, subjective norm, perceived behavioral control, and moral norm are all positively influential factors. Inconsistent with prior studies, consumers’ privacy concern is found to have a direct positive rather than a negative effect on formal recycling intention. It also has a negative moderating effect on the relationship between subjective norm and formal recycling intention. Therefore, to promote consumers’ formal recycling behavior of obsolete mobile phones, a series of measures are proposed to influence these psychological factors in the model. First, a positive social atmosphere for participation in formal recycling should be vigorously created. Then, further efforts are required to increase the publicity and availability of formal recycling channels. Furthermore, joint efforts should be made for privacy information protection during formal recycling processes, including establishing certification standards for secure data erasure, further routinizing recycling processes and establishing a credible image to obtain consumers’ trust by formal recycling enterprises, etc

High-resolution maps of intensive and extensive livestock production in China

Reliable and detailed information on livestock distribution is essential for studies of food security, environmental change, and even sustainable development. However, insufficient accuracy and inadequate validation currently remain in high-resolution livestock distribution datasets primarily resulting from using spatially-continuous models and deficient data. This study presents, for the first time to our knowledge, a spatially detailed dataset on intensive (point) and extensive (30”× 30” grid) livestock production in China (HIEL-China) in 2017 based on an improved model and multi-scale data. Technical validation shows high accuracy in spatial distribution and farm-size simulation. Based on the more reliable depiction of livestock farms, we addressed the obvious underestimation of livestock density in previous datasets, and found different structures of livestock production systems in urban, peri-urban and rural areas. This study accordingly contributes to an essential data basis for livestock-associated analyses targeting at sustainable development of food systems, especially for the largest contributor to global livestock production

Eco-efficiency analysis of industrial system in China: A data envelopment analysis approach

Eco-efficiency is an instrument for sustainability analysis, indicating how efficient the economic activity is with regard to nature's goods and services. This paper conducts an eco-efficiency analysis for regional industrial systems in China by developing data envelopment analysis (DEA) based models. Using real data of 30 provinces in China, an empirical study is employed to illustrate the pattern of regional industrial systems' eco-efficiency. The results indicate that Tianjing, Shanghai, Guangdong, Beijing, Hainan and Qinghai are relatively eco-efficient. The results also show that, provinces with higher level GDP per capita will have higher eco-efficiency relatively with an exception of Hainan and Qinghai. The study provides deeper insights into the causes of eco-inefficiency, and gives further implications on environmental protection strategies in China. In the article, we also discuss the advantages and disadvantages of using DEA in eco-efficiency analysis and areas that require further work are presented.Eco-efficiency Industrial system Data envelopment analysis (DEA) China

Intensification of phosphorus cycling in china since the 1600s

Phosphorus (P) is an essential nutrient for living systems with emerging sustainability challenges related to supply uncertainty and aquatic eutrophication. However, its long-term temporal dynamics and subsequent effects on freshwater ecosystems are still unclear. Here, we quantify the P pathways across China over the past four centuries with a life cycle process-balanced model and evaluate the concomitant potential for eutrophication with a spatial resolution of 5 arc-minutes in 2012. We find that P cycling in China has been artificially intensified during this period to sustain the increasing population and its demand for animal protein-based diets, with continuous accumulations in inland waters and lands. In the past decade, China\u27s international trade of P involves net exports of P chemicals and net imports of downstream crops, specifically soybeans from the United States, Brazil, and Argentina. The contribution of crop products to per capita food P demand, namely, the P directly consumed by humans, declined from over 98% before the 1950s to 76% in 2012, even though there was little change in per capita food P demand. Anthropogenic P losses to freshwater and their eutrophication potential clustered in wealthy coastal regions with dense populations. We estimate that Chinese P reserve depletion could be postponed for over 20 y by more efficient life cycle P management. Our results highlight the importance of closing the P cycle to achieve the cobenefits of P resource conservation and eutrophication mitigation in the world\u27s most rapidly developing economy