Research News
Researchers reveal consequences of hydropower dams on tiger and jaguar habitat
Flooding of forest habitats caused by hydropower development poses an important threat to tiger and jaguar populations. New research suggests that hydroelectric reservoirs may have caused the loss of more than one-fifth of the global population of tigers.The damming of rivers to generate electricity has recently expanded worldwide. Currently, at least 3,700 hydroelectric dams are planned or under construction, many in tropical forest areas. Although the impacts of these dams on freshwater biodiversity are known to be great, the effects on terrestrial species are less well understood.Associate Professor Luke Gibson and Dr. Ana Filipa Palmeirim from the Southern University of Science and Technology (SUSTech) have examined the impacts of hydropower development on two apex predator species: tigers and jaguars. They identified the locations of existing and planned hydropower dams within the geographic distributions of both species. Then, they used published records of the population densities of the species to estimate the number of individuals lost due to the flooding of the forest habitat by hydropower reservoirs.Their study, entitled “Impacts of hydropower on the habitat of jaguars and tigers,” was published in Communications Biology, a high-quality research and Nature series journal across all areas of biology.Figure 1. Chiew Larn reservoir flooded 165 square kilometers of tropical forests in southern Thailand. Shortly after the inundation of this hydroelectric reservoir, tigers disappeared from the landscape.In total, the authors found 164 dams intersecting the distribution of jaguars, flooding a total of 25,397 km2 of jaguar habitat. For tigers, a total of 421 dams were found, amounting to a total of 13,750 km2 habitat lost. Assuming tigers or jaguars could not survive in the aftermath of the flooding of these habitats, this habitat loss is equivalent to 915 individual jaguars, or 0.53% of the global population, and 729 individual tigers, or 20.8-22.8% of the global population.Figure 2. Tigers in Sumatra are a critically endangered subspecies, which face additional threats from two hydropower dams planned to be constructed within their habitat.While existing hydropower projects disproportionately affect tigers, future hydropower growth will more strongly affect jaguars, with 10x more dams (429 vs. 41) planned or under construction within the distribution of jaguars compared to those within tiger habitats.The authors of this study also examined the trade-off between hydroelectricity generation and population losses for jaguars in Brazil. For existing hydropower dams, every 100 MW or hydroelectricity was found to cause the loss of 0.54 jaguars. However, in the future, this ratio will nearly double (0.97 jaguars per 100 MW) as dams must be positioned in flatter areas where the footprint of hydroelectric reservoirs will be greater.Figure 3. Balbina Dam flooded 3,129 square kilometers of tropical rainforest in the Brazilian Amazon. This hydroelectric reservoir is located in the core of the distribution of jaguars.In conclusion, the researchers recommend that hydropower development should avoid topographically flat areas such as the Amazon basin, where hydropower reservoirs have flooded expansive jaguar habitats, and priority conservation areas for tigers, where several hydroelectric dams are planned.Dr. Ana Filipa Palmeirim, a former postdoctoral researcher in Associate Prof. Luke Gibson’s team, is the first author of this paper. Associate Prof. Luke Gibson is the corresponding author.This study was supported by the National Talent Program and the Shenzhen Government.Paper link:
Researchers develop advanced air quality modeling technique to help mitigate ozone pollution in China
Tropospheric ozone is a trace gas and major air pollutant with adverse impacts on human and ecosystem health. Ozone pollution in China leads to about 180,000 deaths every year, and recent observations show that ozone pollution is worsening. Because of the nonlinear chemistry of ozone formation, mitigation of ozone has been proven difficult.Assistant Professor Huizhong Shen’s team from the School of Environmental Science and Engineering at the Southern University of Science and Technology (SUSTech) and Zhe Sun from the Centre for Atmospheric Science, Yusuf Hamied Department of Chemistry at the University of Cambridge have explored this issue.In this study, they developed a new method to numerically investigate the nonlinear chemistry of ozone formation. Compared to past methods, their approach can capture more accurately the nonlinear responses of ozone to its precursors’ emissions (i.e., nitrogen oxides (NOx) and volatile organic compounds (VOCs) and thus facilitates policy-making for ozone mitigation.Their research, entitled “Novel Method for Ozone Isopleth Construction and Diagnosis for the Ozone Control Strategy of Chinese Cities,” was published in Environmental Science & Technology, an impactful environmental science and environmental technology research journal.Ozone isopleths depict the ozone response to NOx and VOCs and have been widely used to diagnose ozone formation. Accurately constructing ozone isopleths is challenging and usually requires hundreds of model simulations or a large number of measurements. In this study, the researchers used a high-order integral method (HIM) to generate ozone isopleths numerically based on an advanced sensitivity analysis technique, i.e., the high-order decoupled direct method (HDDM). HIM integrates a small number of HDDM simulations and can generate ozone isopleths more accurately and efficiently than conventional approaches (e.g., the brute force).Figure 1. Schematic of the coordinate system transformation and the high-order integral method (HIM) to generate ozone isopleths. “sqrt” denotes square-root transformation.Based on this method, they investigated the ozone pollution in China. They discovered that, in 2017, 97% of the residents in China experienced at least one day in excess of Chinese Level-II Ambient Air Quality Standards for ozone. Different cities respond differently to NOX and VOC emission changes, as reflected by the different patterns of their ozone isopleths (Figure 2). For example, in Beijing and Guangzhou, reducing VOCs effectively reduces ozone mitigation, while reducing NOx increases ozone. Moderately or less developed cities are more divided in their ozone isopleths patterns. Still, their ozone isopleths indicate that in most such cities, reducing NOx could be equally or more effective compared to reducing VOCs. Yuxi in Yunnan province (Figure 2), as a representative of a less-developed city, falls deep into the NOx-limited regime, meaning that reducing NOx is much more effective than reducing VOCs to ozone mitigation.Figure 2. Ozone isopleths for six representative cities. The black cross marks the ozone concentration under 100% of NOx and VOC emissions, i.e., the current positions (2017) on the isopleths. The black dashed line is where the sensitivity to NOx emission changes is zero (above which, increased NOx emissions decrease ozone). The solid black line is where the VOC and NOx emission sensitivities are the same.Prof. Shen’s team further investigated the temporal trends in ozone concentration, the sensitivity of ozone to NOx emission (SN), and the sensitivity of ozone to VOC emission (SV) in China with a focus on four representative regions: the Jing-Jin-Ji metropolitan area (JJJ, located in the north of NCP), Yangtze River Delta (YRD), Pearl River Delta (PRD), and the Cheng-Yu metropolitan area (CY). Temporally, ozone concentration across China peaks in May (Figure 3). Similar peaks in May were also evident in YRD, PRD, and CY. Both modeled and observed ozone concentrations exhibit multiple peaks over PRD. SN summit in June-July-August across all China regions except PRD, which displays multiple peaks. SV, on the other hand, shows a trough in most regions in the summer. This is attributed to the strong solar radiations in summer that endow the photolysis of NOx with a predominant position over the contribution from VOCs. Therefore, the ozone sensitivities from VOCs were suppressed.The ratio of SN to SV generally peaks in summer, suggesting that a NOx-limited regime is of higher frequency to occur in summer. An exception is PRD, where SN/SV ratios are mostly negative throughout the study period. Considerable variability of the ratios is evident within each region, as illustrated by the shaded areas in Figure 3.Figure 3. Daily variations in maximum daily average 8 hour (MDA8h) ozone concentrations, SN, SV, and SN/SV in China and four target regions during the ozone season in 2017. Variables are shown as population-weighted levels in the regions. The solid line indicates the median level; the shaded area with the dark color presents the inter-quartile range covering 50% population; the shaded area with the light color denotes the 95% interval.The ozone responses to emissions of precursors vary widely across individual cities. In densely populated metropolitan areas such as JJJ, YRD, and PRD, NOx reduction increases ozone in the short term. Ambient ozone pollution in the eastern region generally is limited by VOCs, while in the west by NOx. The city-specific ozone isopleths generated by HIM are instrumental in forming hybrid and differentiated strategies for ozone abatement in China.Assistant Professor Huizhong Shen from SUSTech and Zhe Sun from the University of Cambridge are the co-first authors of this paper. Huizhong Shen is also the corresponding author.This work is supported by the National Natural Science Foundation of China (NSFC), the Shenzhen Environmental Monitoring Center, the U.S. Environmental Protection Agency, the U.S. National Science Foundation, and the Center for Computational Science and Engineering at SUSTech.Paper link:
Researchers provide solutions to big data and water management challenges
The advent of big data era brings brand-new opportunities and challenges to water resources research. Data crowdsourcing is an emerging approach that supports data acquisition from individual citizens, which opens new doors for big data collection and application in water science.In hydrology monitoring, data crowdsourcing has become a research hotspot in recent years. However, little attention has been paid to hydro data crowdsourcing features and their implications for policy making.Professor Yi Zheng’s group from the School of Environmental Science and Engineering at the Southern University of Science and Technology (SUSTech) recently published two papers in Water Resources Research, a top academic journal in the field of hydrology and water resources.The two papers solved one challenge in water science apiece; one is about artificial intelligence (AI) application in the context of hydrological big data, while the other focuses on a long-standing puzzle in water resources management.In the first paper, entitled “Automatic Quality Control of Crowdsourced Rainfall Data with Multiple Noises: A Machine Learning Approach,” Prof. Zheng’s group proposed a machine learning approach for automatic crowdsourced data quality control (CSQC) using both supervised and unsupervised algorithms.CSQC can detect and remove noisy data inputs in spatially and temporally discrete crowdsourced observations from both fixed-point sensors (e.g., surveillance cameras) and moving sensors (e.g., moving cars/pedestrians), significantly reducing the overall rainfall estimate errors. In addition, supervised multilayer perception-based CSCC shows surprisingly good transferability. It also has great performance in reducing errors when directly applied (without retraining) to Chicago and Miami, where climate conditions are significantly different from where the model was trained (San Diego).This study provides important technical supports for the collection and application of rainfall crowdsourcing data. It brings scientific implications in promoting the applications of big data, artificial intelligence, and the internet of things in smart city construction.Figure 1. Quality control of crowdsourced rainfall data using machine learningGeng Niu, a Ph.D. candidate under the joint Ph.D. program of SUSTech and Peking University (PKU), is the first author of this paper. Prof. Yi Zheng and Dr. Yang Pan from the University of Illinois Urbana-Champaign are the co-corresponding authors.The work was financially supported by the National Natural Science Foundation of China (NSFC), Shenzhen Science and Technology Innovation Commission, and the China Scholarship Council (CSC). Providing a new perspective to IE paradoxThe paradox of irrigation efficiency (IE), that is, higher efficiency rarely reduces, even increases irrigation water consumption, has long been recognized since the last century. However, issues surrounding the existence of the IE paradox and underlying mechanisms are of continuing debate. In addition to geographic differences in the natural environment and social economy, another important reason leading to the controversy is the lack of consensus regarding IE definition and the absence of scientifically rigorous assessment of IE.In the second paper, entitled “Improving the Scientific Understanding of the Paradox of Irrigation Efficiency: An Integrated Modeling Approach to Assessing Basin-Scale Irrigation Efficiency,” Prof. Zheng’s group developed a new basin-scale IE index to explicitly account for the role of return flow and groundwater’s direct contributions to crop evapotranspiration.Based on multiscale water balance, they proposed a new method for quantifying basin-scale IE via integrated surface water-groundwater modeling. The Zhangye Basin (Gansu Province, China), sitting in the center of the Hexi Corridor, was chosen as the study area, where irrigated agriculture and ecosystems compete against each other for limited water resources.With the proposed index and method, Prof. Zheng’s group unraveled the spatiotemporal variations of IE and the governing mechanisms over this typical inland arid basin, and identified opportunities to enhance IE and save water at the basin scale. This study provides a methodological foundation and a brand-new perspective for overcoming the misunderstanding of the IE paradox.Figure 2. Calculating basin-scale irrigation efficiency via integrated surface water-groundwater modelingRui Xiong, a Ph.D. candidate under the joint Ph.D. program of SUSTech and Hong Kong University of Science and Technology (HKUST), is the first author of this paper. Professor Yi Zheng is the corresponding author.The work was financially supported by the NSFC, the Strategic Priority Research Program of the Chinese Academy of Sciences, and the State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control. Paper links (In order of appearance above):Water Resources Research: Resources Research:
New findings on effect of climate change on hydrology of Tibetan Plateau
The Tibetan Plateau has recently experienced noticeable climate changes. As a consequence, this has changed atmospheric and hydrological cycles and reshaped the local environment. The visible impacts of climate change on the Tibetan Plateau are obvious: increased rainfall, melting glaciers, rising lakes, etc. However, the impacts on the groundwater and the Tibetian people living there have attracted less attention.A group of scholars from the School of Environmental Science and Engineering at the Southern University of Science and Technology (SUSTech) has recently analyzed the effects of climate change in the Tibetan Plateau. Associate Professor Xingxing Kuang’s team has published five papers in top journals in environmental science such as Environmental Research Letters and Journal of Environmental Management and top journals in hydrological science such as Journal of Hydrology.The first paper, entitled “Increasing annual streamflow and groundwater storage in response to climate warming in the Yangtze River source region,” was published in Environmental Research Letters. This study selected long-term (1962–2012) streamflow records and permafrost data in the Yangtze River source region to analyze streamflow variations and groundwater storage in response to climate warming.Their results showed that the main period scales of annual streamflow and winter baseflow are 37 years and 34 years, respectively. The rising air temperature is the primary cause for the increased streamflow instead of precipitation and evaporation. Permafrost thawing and increasing temperature are the direct and indirect causes of the increasing groundwater storage (Figure 1).These findings are significant in investigating the hydrological processes and water resources management in mountainous alpine regions in response to climate change.Figure 1. Variations of permafrost area and groundwater storage during 1962–2012The second paper, entitled “Water quality and health risk assessment of the water bodies in the Yamdrok-Tso basin, southern Tibetan Plateau,” was published in the Journal of Environmental Management.In this study, Professor Kuang’s team looked at the lake waterbodies’ quality status and health risk. They observed this in the national nature reserve, the Yamdrok-Tso basin, in the southern Tibetan Plateau. They were assessed by 25 water parameters, corresponding pollution index, water quality index, and health risk index.The group’s results showed that the lake water bodies were at a low pollution level with respect to heavy metal(loid)s. The water quality of most areas met the regulation of the China National Standard for water resources in national nature reserves. Health risk assessment showed that potential hazards existed in this region when the residents are under long-term exposure to the lake water through oral and dermal pathways. Children and adults are mostly exposed to As and F for non-carcinogenic and As for carcinogenic risks.This study could help to further understand the heavy metal(loid)s mobility and health hazard in the lake water of the southern Tibetan Plateau. Their findings could also contribute to making targeted regulations in the national nature reserves (NNR) for effectively managing water resources.Figure 2. Water quality status and health risk of the lake water bodies in the Yamdrok-Tso basin, southern Tibetan PlateauThe third paper, entitled “A simple and efficient method for correction of basin-scale evapotranspiration (ET) on the Tibetan Plateau,” was published in Remote Sensing. In this study, the researchers proposed a simple and efficient method to correct basin-scale ET in seven sub-basins on the Tibetan Plateau.A reasonable, accurate, and corrected ET was obtained on the Tibetan Plateau. The corrected ET improved the correlation coefficients and reduced the biases and root-mean-square errors (RMSEs). The ET on the Tibetan Plateau decreased from southeast to northwest. There was a general increasing trend of ET on the Tibetan Plateau, with an average value of 1.2 mm/yr over the period from 2003–2014 (Figure 3). These results contribute to a better understanding of the hydrological cycle of the plateau.Figure 3. Distribution of corrected ET trends in the sub-basins on the Tibetan Plateau (2003-2014)The fourth paper, entitled “A preliminary investigation on the climate-discharge relationship in the upper region of the Yarlung Zangbo River basin,” was published in the Journal of Hydrology. This study analyzed the annual and seasonal variability of the river discharge in the upper region of the Yarlung Zangbo River basin. It investigated the climate-discharge relationship and projected the trend of river discharge from 2021 to 2100 using a distributed hydrological model (Soil and Water Assessment Tool, SWAT).River discharge is one of the key elements of the global water cycle. However, observation and projection of river discharge are still lacking in alpine areas. This research showed that river discharge did not show the same trend as precipitation at either an annual or seasonal scale, which indicates that precipitation might not be the primary source of river discharge (Figure 4).Meltwater from snow, glacier, and frozen soil could contribute a large percentage of river discharge. The projected river discharge would vary significantly over the years with different changing rates in response to different scenarios of climate change. This study contributes to investigating the unusual climate-discharge relationship that is different from that in the whole river basin.Figure 4. Comparisons of observations (black points) and simulations in both OC and SC cases based on grid-based data (g) and station observations (s)The fifth paper, entitled “Analysis of the groundwater flow system in a high-altitude headwater region under rapid climate warming: Lhasa River Basin, Tibetan Plateau,” was published in the Journal of Hydrology: Regional Studies. Taking the Lhasa River Basin (LRB) as an example, Prof. Kuang’s team developed a numerical groundwater flow model to characterize the groundwater flow pattern and simulate the groundwater’s recharge and discharge.They also quantified the impact of climate change on the groundwater flow system in the LRB (Figure 5). Results show that more than 80% of the groundwater flows within 300 m below the ground surface. The groundwater flow system is dominated by flow path distances of less than 10 km and between 10 and100 years.The projected interannual fluctuations of baseflow in the LRB will increase, and the groundwater’s response in mountainous areas to climate change will be more sensitive than in other areas.Figure 5. Simulated hydraulic head distributions in the LRB for typical four years (2020, 2040, 2060, 2100) in response to different climate change scenariosWenxuan Yi from the China University of Geosciences (Beijing), and Can Wang, Yuqing Feng, Suning Liu, and Jiachang Chen, all members of Prof. Xingxing Kuang’s group at SUSTech, are the first authors of the five papers, in order of their appearance above. Xingxing Kuang is the corresponding author or co-corresponding author for all the papers.These studies were funded by the National Natural Science Foundation of China (NSFC). Paper link (In order of appearance above):Environmental Research Letters: of Environmental Management: Sensing: of Hydrology: of Hydrology: Regional Studies:
First-ever satellite mapping of lake ice over Northern Temperate Zone (NTZ) unveiled
Widespread reductions in lake ice have been detected worldwide, yet spatially detailed characterization of global lake ice is currently unavailable.Using more than half a million Landsat satellite images obtained over the past thirty-five years, a group of researchers from SUSTech provided the first long-term wall-to-wall mapping of lake ice cover over the entire Northern Temperate Zone (NTZ). The mapping comprised of more than 33,000 lakes, representing 48% of the global lake area in total.Dr. Lian Feng’s Group from the School of Environmental Science and Engineering (ESE) at SUSTech conducted this research. They tracked spatially detailed changes in lake ice across the entire NTZ and examined how ice change patterns have differed geographically and temporally in response to climate change. In doing so, they achieved new developments in ice cover changes in over 33,000 lakes across the NTZ.Their research paper, entitled “High-Resolution Mapping of Ice Cover Changes in Over 33,000 Lakes Across the North Temperate Zone,” was published in Geophysical Research Letters, a high-impact journal documenting major advances in geoscience.Nearly half of the world’s lakes periodically freeze. The phenology of lake ice influences not only physical conditions (such as heat storage, temperature, mixing) but also provides important opportunities for transportation, recreation, and fishing. Recently, widespread reductions in lake ice have been detected due to recent climate warming, and this problem will become more severe in the future due to ongoing warming trends and escalating climate extremes. However, few field records are available, and the thermodynamics of lakes are difficult to characterize separately due to lake-specific features. Therefore, a spatially detailed quantification of the changes in lake ice at the global scale is extremely needed.This study provides the first long-term wall-to-wall mapping of lake ice cover over the entire Northern Hemisphere temperate zone using 0.55 million Landsat images from 1985 to 2020 (Figure 1). The study also finds a remarkable reduction in median ice cover occurrence from 61% to 43%. Extensive lake ice retreats are located in central and southern Europe, the northern US, and central and southeastern Asia (Figure 2).Figure 1. Cross-period differences for ICOFigure 2. Coefficient of variation (CV) of ICO between the 4-time periodsThere is a strong logistic regression relationship between surface temperature and ICO (Figure 3). The air temperature of lakes in Europe fluctuated around 0°C and had small interquartile ranges, satisfactorily explaining why lakes in Europe show more significant variations in ice cover than those in Asia and North America.In addition, logistic regression curves of lakes in the Tibet Plateau (Region 1) and the Yangtze River (Region 2) are different from others. It may be caused by the exceptional lake conditions and human activities. For example, the depth of lakes in the Tibet Plateau can exceed 100m. Most of the lakes in the Yangtze River are shallow, exhibit great interannual changes in water depth, and have suffered from extensive human activities in recent decades.Figure 3. Scatter plot between ICO and the corresponding mean surface temperatureXinchi Wang, a master’s student in Dr. Lian Feng’s group at SUSTech, is the first author of this research paper. Dr. Feng is the corresponding author of this paper.This study was supported by the National Natural Science Foundation of China (NSFC), the Strategic Priority Research Program of the Chinese Academy of Sciences, and the Shenzhen Science and Technology Innovation Committee.Paper link: 
SUSTech’s Junguo LIU awarded as the Paul A. Witherspoon Lecturer
The American Geophysical Union (AGU) recently announced its list of AGU awards/honors for renowned experts in various fields in 2021. Seventy-eight scientists from all over the world received accolades, including thirty awards for named lectureships to recognize distinguished scientists with proven leadership in their fields of science.Junguo LIU, Chair Professor of the School of Environmental Sciences and Engineering at the Southern University of Science and Technology (SUSTech) and member of the European Academy of Sciences, received the Paul A. Witherspoon Lecture in the Hydrology Section. He is the first Asian scholar to receive the award since its formation.Junguo LIU is a recipient of the Outstanding Young Scientist from the National Science Foundation of China and has long been engaged in scientific research and teaching water resources and ecological restoration. He proposed the three-dimensional water shortage theory and the ecological restoration theory in protecting and utilizing water resources. His innovative research work has had an important impact in the field of water resources at home and abroad.He is the first hydrologist and Chinese scientist to receive the Outstanding Young Scientist Award by the European Geosciences Union (EGU) and the first Chinese scientist to receive the Technology Communication Award from the Society for Ecological Restoration (SER). In 2020, he received the World Academy of Science (TWAS) Award and the Science and Technology Award by the Chinese Soil and Water Conservation Society (CSWCS).Established in 1919 with more than 62,000 members from 137 countries, AGU is the world’s largest society in Earth Sciences. AGU’s activities are focused on the organization and dissemination of scientific information in the interdisciplinary and international fields within the Earth and space sciences.The Paul A. Witherspoon Lecture is presented annually. It recognizes significant and innovative contributions by mid-career scientists to the hydrologic sciences through research aimed at socially important problems and through mentoring of young scientists.Related link:
SUSTech scholars win Young Scientist Award from Chinese Society for Environmental Sciences
The Chinese Society for Environmental Sciences (CSES) recently announced its list of candidates for the 4th CSES Young Scientist Award. Assistant Professor Jun-Jian WANG from the School of Environmental Science and Engineering (ESE) at the Southern University of Science and Technology (SUSTech) won the Young Scientist Gold Award, and Associate Professor Hong CHEN won the Young Scientist Excellence Award.Dr. Jun-Jian WANG joined SUSTech in 2017. He is dedicated to developing and applying cutting-edge and molecular-level analyses of natural organic matter and pollutants to study the critical impacts of global change and anthropogenic disturbance on the plant-soil-water system and environmental quality. He received more than 10 research grants, including National Science Fund for Excellent Young Scholars of China and Natural Science Fund for Distinguished Young Scholars of Guangdong Province. He has published more than 60 papers in top-tier journals, including Nature Communications, New Phytologist, Environmental Science & Technology, and Water Research. He is serving as an associate editor of the Journal of Environmental Quality and on the editorial boards of the Frontier in Soil Science, Chinese Chemical Letters, and Journal of Agricultural Resources and Environment. He has also served as an international reviewer for National Science Foundation (US) and France National Research Agency (ANR) proposals.Dr. Hong CHEN joined SUSTech in 2018. He is mainly engaged in research on resource recycling and utilization chemistry. He has published more than 100 papers in renowned journals such as Nature Materials, Science Advances, PNAS, and Nature Communications, with a total number of more than 4,620 citations. Earlier this year, he also won the Gold Award from the Guangdong Society of Environmental Sciences (GDSES). The Young Scientist Award of CSES was first established in 2018 to reward outstanding young scientists under 40 years of age engaged in environmental science and technology research. The accolade is awarded yearly, with thirty recipients being honored with the prize. 
SUSTech's Yan ZHENG selected as Fellow of American Geophysical Union
On September 28, 2021, the American Geophysical Union (AGU) announced the 2021 Class of Fellows.Amongst them included Chair Professor Yan ZHENG of the School of Environmental Science and Engineering (ESE) at the Southern University of Science and Technology (SUSTech).She became the 22nd scientist from China (including Hong Kong, Macao, and Taiwan) to receive this honor. Worldwide, 59 scientists in the field of Earth and space sciences will become AGU fellows in 2021.Yan ZHENG joined ESE at SUSTech in 2016. She received her Ph.D. degree from the Department of Earth and Environmental Sciences at Columbia University in 1999 and was elected as a Fellow of the Geological Society of America in 2010.AGU was founded in 1919, with more than 130,000 members worldwide in Earth and space sciences. The AGU Fellow is one of the highest honors in the international Earth and space sciences research community. It recognizes individuals who have made outstanding contributions through scientific research, education, science communication, and outreach.
SUSTech researchers publish study on typhoon redistributed microplastics in coastal areas and uniformed plastisphere community
The increasing microplastic pollution, together with the plastisphere-associated ecological threats in coastal areas, have aroused global concern. Tropical cyclones have increased in both frequency and intensity under global warming, causing an intense impact on the microplastics distribution and the structure of coastal ecosystems. However, until most currently, the extent to which typhoon impacts the microplastics and plastisphere community remains poorly known.Recently, researchers from the Southern University of Science and Technology (SUSTech) published a paper on the subject. Their study, entitled “Typhoon-induced turbulence redistributed microplastics in coastal areas and reformed plastisphere community,” was published in the journal Water Research.The emergence of plastic has provided huge social benefits but also brought serious environmental problems. Due to the long half-life and the hydrophobic surface of plastics, it is generally believed that microplastics can be served as vehicles to promote microbial colonization and biofilm formation, the so-called “plastisphere”, and eventually become a pelagic habitat for microorganisms. At the same time, microplastics provide more ways for the long-distance transmission of potentially pathogenic microorganisms, posting ecological impacts on the original ecosystem.Extreme storm events, such as tropical cyclones (i.e., tropical storms and typhoons), can significantly affect coastal ecosystems. However, limited studies have been conducted to investigate the effect of typhoons on microplastic abundance, composition, and distribution to date. Given the growing ecological concerns aroused by increasingly frequent and severe tropical cyclones, such effort is of no doubt inadequate to clarify the impacts of typhoons on the coastal microplastic distribution.Furthermore, even though plastisphere has been recognized to modify the environmental fate of microplastic particles, no study has demonstrated the influence of typhoons on plastisphere to date. Therefore, more research is urgently needed to better understand how typhoons impact the microplastic distribution in the environment and ultimately impact ecosystem function by regulating plastisphere composition.Figure 1. Mean (±SD) abundance of microplastics in surface water (a) and sediments (b) collected in Shenzhen coastal areas before and after a typhoon (B: before the typhoon; A: after the typhoon). The bar plot at the upright corner shows differences in microplastic abundance before and after typhoon (paired-sample t-test). Correlation analysis of microplastic abundance in surface water (c) and sediment (d) before and after the typhoon.Figure 2. The microplastic characteristics before and after the typhoon (B: before the typhoon; A: after the typhoon). (a) Distribution of size, color, and shape of microplastics in surface water and sediment. (b) PCoA biplot shows the differences in microplastic characteristics before and after the typhoon for water and sediment samples.The study found a significant typhoon-induced increase in microplastic abundance in surface water, whereas an opposite trend was observed in sediment. Despite the evident transportation of microplastics from sediment to surface water by agitation, a possible microplastics influx was introduced by typhoons, as evidenced by the prominent attribution of unknown force in source tracking analysis.Additionally, typhoons have adeptly uniformed the plastisphere community in the sediment along the 190km coastal line overnight. A significant increase of nitrogen fixer, Bradyrhizobiaceae, was observed ubiquitously after a typhoon, which might alter the nitrogen cycling and increase the eutrophic condition of the coastal ecological system. Together, this study expanded the knowledge about the impact of a typhoon-induced influx of microplastics on coastal biogeochemical cycling.Figure 3. Bacterial community diversity of plastisphere and their shaping factors (B: before the typhoon; A: after the typhoon). (a) Bacterial community composition of plastisphere displayed at the phylum level. (b) Alpha diversity profiles of plastisphere community. Shannon and Pielou’s Evenness indices comprehensively denote the richness and homogeneity of the bacterial community. (c) Principal coordinate analysis of the plastisphere communities. (d) Bray–Curtis db-RDA plots displaying the relationships between plastisphere communities and microplastic characteristics.Figure 4. Spearman correlation between the relative abundance of each OTU and microplastic characteristics. OTU_1 was the most abundant taxon and affiliated with Bradyrhizobiaceae. The bar plot shows differences in the relative abundance of OTU_1 between before and after the typhoon.Liming Chen, a postdoctoral fellow, and Jiangpeng Li, a Ph.D. student, are the co-first authors of this paper. Associate Professor Yuanyuan Tang and Assistant Professor Yu Xia from the School of Environmental Science and Engineering at SUSTech are the co-corresponding authors.The study was supported by the National Natural Science Foundation of China (NSFC), Natural Science Foundation of Guangdong Province, State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, and the Center for Computational Science and Engineering at SUSTech.Paper link: contact information:Associate Professor Yuanyuan Tang: Professor Yu Xia:
SUSTech's Junguo Liu co-authors paper on food waste and its environmental impact
Recently, Chair Professor Junguo Liu from the School of Environmental Science and Engineering at the Southern University of Science and Technology (SUSTech) co-authored a paper in Nature Food, an online journal publishing top-tier food-related research in the natural, applied, and social sciences. The paper was entitled “China's food loss and waste embodies increasing environmental impacts.”In recent years, food loss and waste have become a global problem, which has attracted widespread attention from academia, government, and the public. Food loss and waste are closely related to food security, food safety, nutrition and health, resources, environment, economy, and society. They are considered to be major environmental issues for the sustainable development of the global food system. However, monitoring and benchmarking food loss and waste reduction is often constrained by the lack of reliable and consistent data, especially for emerging economies. This research is based on the large-scale field investigations conducted by the Ministry of Agriculture and Rural Affairs and the Chinese Academy of Sciences (CAS) from 2013 to 2018 on food losses in the supply chain, food waste in households, and catering industries. It quantifies the food loss and waste of major agrifood products along the entire farm-to-fork chain in China.Figure 1. Food flow and waste in China’s supply chain from the farm to the tableThe result shows that 27% of food annually produced for human consumption in the country (349 ± 4 Mt) is lost or wasted. 45% of this is associated with postharvest handling and storage and 17% with consumption activities. The paper also shows that the land, water, carbon, nitrogen, and phosphorus footprints associated with total food loss and waste are similar to those of a medium-sized country, such as the United Kingdoms, in the case of carbon footprint.Figure 2. Land footprint, water footprint, carbon footprint, nitrogen footprint, and phosphorus footprint of food waste in ChinaThese results highlight that food loss and waste in China have a greater impact on resources and the environment. Reducing food waste at the consumption stage has a significant effect on reducing various environmental footprints.This paper is the work of a collaborative effort between researchers from the Chinese Academy of Sciences (CAS), the University of Southern Denmark, Ministry of Agriculture (MOA) of the People’s Republic of China, Wuhan University, the University of Pennsylvania, and SUSTech.It is worth mentioning that Junguo Liu was one of the earliest scholars in China who paid attention to food waste and its environmental impact. In 2013, as the first corresponding author, he published an article entitled “Food Loss and Waste in China and their Implication for Water and Land” in Environmental Science and Technology (ES&T). The results showed that food waste and food loss have a huge environmental impact on water and land resources. The food waste rate in China is 19% (+5%), which is far lower than the waste rate in the United States and European countries. The study found that the food waste rate in Chinese canteens and households is only 5-7%, but the food waste rate in restaurants is as high as 19%. This shows that Chinese food culture and habits play an important role in influencing the rate of food waste.Paper links: