Storage dynamics, hydrological connectivity and flux ages in a karst catchment : Conceptual modelling using stable isotopes

This research was supported by The UK-China Critical Zone Observatory (CZO) Programme (41571130071), the National Natural Scientific Foundation of China (41571020, 41601013), the National 973 Program of China (2015CB452701), the National Key Research and development Program of China (2016YFC0502602), the Fundamental Research Funds for the Central Universities (2016B04814) and the UK Natural Environment Research Council (NE/N007468/1). In addition, we thank Sylvain Kuppel, the two anonymous reviewers, Thom Bogaard and the editor for their constructive comments which significantly improved the manuscript. The isotope data as well as rainfall and flow measurements used for this paper can be shared after the ending of our project (2019) according to the project executive policy. Anyone who would like to use the data can contact the corresponding author after signing the agreement. The data were obtained through a purchasing agreement for this study. GIS data in this study are available.Peer reviewedPublisher PD

Characterizing the variability of transit time distributions and young water fractions in karst catchments using flux tracking

Open access via the Jisc Wiley Agreeement National Natural Science Foundation of China (GrantNumber(s): 41571130071, 41971028) National Key Research and development Program of China (GrantNumber(s): 2016YFC0502602) UK Natural Environment Research Council (GrantNumber(s): NE/N007468/1)Peer reviewedPublisher PD

Effects of passive-storage conceptualization on modeling hydrological function and isotope dynamics in the flow system of a cockpit karst landscape

Funding Information: This research was supported by the National Natural Science Foundation of China (grant nos. 42030506 and 41971028). We thank Natalie Orlowski, the two reviewers (Catherine Bertrand and the anonymous reviewer) and Thom Bogaard for their constructive comments that significantly improved the manuscript. Funding Information: Acknowledgements. This research was supported by the National Natural Science Foundation of China (grant nos. 42030506 and 41971028). We thank Natalie Orlowski, the two reviewers (Catherine Bertrand and the anonymous reviewer) and Thom Bogaard for their constructive comments that significantly improved the manuscript. Financial support. This research has been supported by the National Natural Science Foundation of China (grant nos. 42030506 and 41971028). Publisher Copyright: Copyright © 2022 Guangxuan Li et al.Peer reviewedPublisher PD

Precise Hong Kong Geoid HKGEOID-2000

Abstract: This paper briefly discusses the data and methodology used in the construction of a Hong Kong local geoid of centimeter accuracy HKGEOID-2000. The results have been published in the website of Department of Land obtain the Surveying and Geo-Informatics, the Hong Kong Polytechnic University for public use. Users can directly geoidal height of a point by inputting its geodetic coordinates (in ITRF96 reference frame) or the HK1980 grid coordinates. Examples are given to illustrate the procedures

Different responses of incidence-weighted and abundance-weighted multiple facets of macroinvertebrate beta diversity to urbanization in a subtropical river system

Urbanization is one of the major drivers of biotic homogenization (i.e., decrease in beta diversity) in freshwater systems. However, only a few studies have simultaneously examined how urbanization affects multiple facets (i. e., taxonomic, functional and phylogenetic) of beta diversity and its underlying ecological drivers in urban river macroinvertebrates. Here, we distinguished the patterns and ecological mechanisms of multiple facets of macroinvertebrate beta diversity weighted by incidence and abundance data in a subtropical river system with a distinct urbanization gradient. We also investigated how total beta diversity patterns stem from replacement versus richness difference among sites. Our results showed that taxonomic and phylogenetic beta diversities weighted by incidence data were primarily driven by replacement of taxa, whereas the richness difference contributed more to multiple facets of beta diversity based on abundance data. Furthermore, multiple facets of beta diversity decreased with urbanization for both incidence-weighted and abundance-weighted data, but the former showed more substantial decreases. Both replacement and richness difference components contributed roughly equally to the decline of incidence-weighted beta diversity. In contrast, the losses of abundanceweighted beta diversity were mainly associated with replacement of taxa. Variation partitioning results revealed that all beta diversity measures based on incidence data were governed primarily by local and land-use variables, whereas spatial variables were more relevant in driving beta diversity weighted by abundance data. Overall, by comparing different facets and components of beta diversity weighted by incidence versus abundance data, we suggest that incidence-weighted data may be more sensitive in portraying the impacts of urbanization on macroinvertebrate diversity. This likely resulted from the fact that incidence-weighted data shows the importance of rare taxa in shaping homogenization induced by urbanization.Peer reviewe

Different responses of incidence-weighted and abundance-weighted multiple facets of macroinvertebrate beta diversity to urbanization in a subtropical river system

Urbanization is one of the major drivers of biotic homogenization (i.e., decrease in beta diversity) in freshwater systems. However, only a few studies have simultaneously examined how urbanization affects multiple facets (i. e., taxonomic, functional and phylogenetic) of beta diversity and its underlying ecological drivers in urban river macroinvertebrates. Here, we distinguished the patterns and ecological mechanisms of multiple facets of macroinvertebrate beta diversity weighted by incidence and abundance data in a subtropical river system with a distinct urbanization gradient. We also investigated how total beta diversity patterns stem from replacement versus richness difference among sites. Our results showed that taxonomic and phylogenetic beta diversities weighted by incidence data were primarily driven by replacement of taxa, whereas the richness difference contributed more to multiple facets of beta diversity based on abundance data. Furthermore, multiple facets of beta diversity decreased with urbanization for both incidence-weighted and abundance-weighted data, but the former showed more substantial decreases. Both replacement and richness difference components contributed roughly equally to the decline of incidence-weighted beta diversity. In contrast, the losses of abundanceweighted beta diversity were mainly associated with replacement of taxa. Variation partitioning results revealed that all beta diversity measures based on incidence data were governed primarily by local and land-use variables, whereas spatial variables were more relevant in driving beta diversity weighted by abundance data. Overall, by comparing different facets and components of beta diversity weighted by incidence versus abundance data, we suggest that incidence-weighted data may be more sensitive in portraying the impacts of urbanization on macroinvertebrate diversity. This likely resulted from the fact that incidence-weighted data shows the importance of rare taxa in shaping homogenization induced by urbanization.Peer reviewe

Coal based carbon dots: recent advances in synthesis, properties, and applications

Carbon dots are zero-dimensional carbon nanomaterials with quantum confinement effects and edge effects, which have aroused great interests in many disciplines such as energy, chemistry, materials, and environmental applications. They can be prepared by chemical oxidation, electrochemical synthesis, hydrothermal preparation, arc discharge, microwave synthesis, template method, and many other methods. However, the raw materials' high cost, the complexity and environmental-unfriendly fabrication process limit their large-scale production and commercialization. Herein, we review the latest developments of coal-based carbon dots about selecting coal-derived energy resources (bituminous coal, anthracite, lignite, coal tar, coke, etc.) the developments of synthesis processes, surface modification, and doping of carbon dots. The coal-based carbon dots exhibit the advantages of unique fluorescence, efficient catalysis, excellent water solubility, low toxicity, inexpensive, good biocompatibility, and other advantages, which hold the potentiality for a wide range of applications such as environmental pollutants sensing, catalyst preparation, chemical analysis, energy storage, and medical imaging technology. This review aims to provide a guidance of finding abundant and cost-effective precursors, green, simple and sustainable production processes to prepare coal-based carbon dots, and make further efforts to exploit the application of carbon dots in broader fields

Estimation of surface soil moisture by a multi-elevation UAV-based ground penetrating radar

The measurement of soil moisture is important for a wide range of applications, including ecosystem conservation and agricultural management. However, most traditional measurement methods, e.g., time-domain reflectometry (TDR), are unsuitable for mapping field scale variability. In this study, we propose a method that uses an unmanned aerial vehicle (UAV) to support a ground penetrating radar (GPR) system for spatial scanning investigation at different elevations above ground level. This method measures the surface reflectivity to estimate the soil moisture, exploiting the linear relationship between the ratio of the reflected and the direct wave amplitudes along with the reciprocal of GPR antenna height. This relationship is deduced in this study based on the point source assumptions of a transmitter antenna and ground reflections, which is confirmed by numerical simulation results using the gprMax software. Unlike previous air-launched GPR methods, the UAV-GPR method presented here removes the limitations of a steady transmitter power and a fixed GPR survey height and the need for calibration of antenna transfer functions and geophysical inversion calculations, and thus is simpler and more convenient for field applications. We test the method at field sites within the riparian zone and a river-island grassland adjacent to the Yangtze River. The results from the field study illustrate comparable measured soil moisture to those obtained invasively using TDR. The root mean square error (RMSE) of surface reflectivity and soil moisture values between UAV-GPR with 8 antenna height investigations and TDR in the grassland are 0.03 and 0.05 cm3/cm3, respectively