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Abstract Like many urban rivers, the Pearl River in China is contaminated with microplastics. Compared with marine environments, microplastic pollution in freshwater is less understood, especially in urban rivers. In the present study, the abundance and distribution of microplastics in water from the Pearl River was investigated, including the estuary and the urban section along Guangzhou. The average abundance of microplastics was 19,860 items/m3 and 8902 items/m3 in the urban section and estuary, respectively. Wastewater effluents from cities might be a main source of microplastics in the Pearl River, and the urban tributaries might act as retention systems for microplastics. Among these microplastics, over 80% of them were less than 0.5 mm. The main shapes of microplastics were film, fragment, and fiber, mostly blue or transparent. Moreover, the most common polymer types of these microplastics were polyamide (26.2%) and cellophane (23.1%). This study reveals the contamination and characteristics of microplastics in the Pearl River, and provides important data for further research on microplastics in freshwater ecosystems. Graphical abstract Image 1 Highlights • First comparison of microplastics between estuary and urban section of the Pearl River. • Films were the main shape in the Pearl River. • PA and cellophane were the dominant polymer types in the Pearl River. • Waste water effluents from urban city might be a main source of microplastics. [ABSTRACT FROM AUTHOR]

The effectiveness of conservation in Antarctica is of critical global concern. Yet information on the impacts of increasing human activities in the region has been limited to date. Improved knowledge is critical for understanding the effectiveness of conservation, and evaluating how increasing human activity may influence the future of the continent. With no permanent human presence in Antarctica, personnel temporarily stationed at research bases provide a unique source of local and experiential knowledge on human activity and local changes in environment. In this paper, we report on the use of focus groups and participatory mapping activities with personnel at Scott Base, Ross Island, to explore perceptions of how Antarctica is used and valued. We found that all base personnel were concerned that increasing human activity would increase negative human impact at sites designated as Antarctic Specially Protected Areas. However, a quarter of participants also saw benefits to increasing human activity, including the potential to enhance advocacy for the future of the continent and increase support for environmental protection. Notably, base personnel perceived Antarctic Specially Protected Areas as being valued differently to the values identified in management documents, calling into question the clarity around ASPA designation and how well the protected area network in Antarctica is understood. Such information can be integrated with data from the natural sciences to develop a more complete picture of human impact on the continent, and can be used to evaluate the effectiveness of conservation management in Antarctica. [ABSTRACT FROM AUTHOR]

Human perception refers to people's psychological feelings about a place. Understanding residents' perception and their activities is important for promoting people-oriented urban construction. Recently, with the development of machine learning, researchers used this technology to study human perception from the open-source street view images. However, the perception measurement is limited, caused by the inadequate feature extraction. Besides, human perceptions and their activities are separately studied, which hinders the process of revealing the relationship between human and environment. Hence, a human perception model was firstly proposed, where a Transformer network was introduced to extract more discriminative semantic features and visual elements were integrated to enhance the feature representations. Experiments showed that the average deviation of perceptual scores was controlled within 1.6 points, and its performance was improved by around 1%–18% in mean square error (MSE), root mean square error (RMSE) and mean absolute error (MAE) compared with the existing best results. Secondly, the collaborative study of environmental perception and residents' activities was carried out in the case area. Specifically, the perceptual measures of environment were implemented based on the street view video data. Meanwhile, the activities of residents were recognized by SlowFast network and quantified by a new informatics-based diversity indicator (Active Index). This study finally obtained their spatial distribution map, and showed that the perceptual dimensions lively , boring , safe , and depressing are correlated with information quantity of activities. The paper provides a novel method to understand better the urban environment and the distribution of residents' activities to facilitate urban planning. • A human perception model with better performance was proposed. • An informatics-based diversity indicator Active Index was designed. • Street view videos were used for the case study of human-urban environment. [ABSTRACT FROM AUTHOR]

Climate change often leads to the vulnerability of vegetation cover, while the impact of human activities on vegetation cover is undoubtedly more complex in this context, especially in Ethiopia. This paper analyzed the spatiotemporal dynamics of vegetation growth in Ethiopia from 2003 to 2018 by the enhanced vegetation index (EVI) based on different time scales and explored the coefficient of variation and driving factors of the fractional vegetation coverage (FVC). The results indicated that the EVI mainly presents a "double peak" pattern, with large spatiotemporal differences between quarters and months in Ethiopia. The FVC increased by 0.0005 per year, but vegetation showed a browning trend after 2013. The FVC degraded area accounted for 43.9% of the total area, of which the significantly degraded area accounted for 7.51% due to human activities, mainly in northern, central, and southern Ethiopia. The effects of precipitation and maximum temperature on vegetation differed on time scales. Spatially, the vegetation on the northwest side of the Main Ethiopian Rift Valley (MERV) was dominated by a combination of maximum temperature and precipitation, while vegetation on the southeast side of MERV was mainly influenced by precipitation. However, the spatial overlay analysis with degraded and healthy vegetation zones revealed that human activities were the key driver of vegetation cover change rather than climate change. This study provides support for further development of vegetation health conservation policies in Ethiopia and monitoring of vegetation dynamics in other countries around the world. • The annual EVI values show a "double peak" pattern in Ethiopia. • The dominant climatic factors on the southeast and northwest sides of MERV differ. • Ethiopia's FVC showed an overall growth trend with an annual growth rate of 0.05%. • Human activities dominate the dynamic evolution of vegetation in Ethiopia. [ABSTRACT FROM AUTHOR]

Abstract: This paper addresses the recent (1970s–1990s) processes of river mouth bar formation, riverbed aggradation and distributary migration in the Huanghe River mouth area, in the light of station-based monitoring, field measurements and remote sensing interpretation. The results show that the morphological changes of the river mouth bar have been closely associated with the largely reduced fluvial discharge and sediment load. Landform development such as bar progradation occurred in two phases, i.e. before and after 1989, which correspond to faster and lower bar growth rates, respectively. Fast riverbed aggradation in the mouth channel was strongly related to river mouth bar progradation. During 1976–1996, about 2.8% of the total sediment loads were deposited in the river channel on the upper to middle delta. Therefore, the river water level rose by a few meters from 1984 to 1996. The frequent distributary channel migration, which switched the radial channel pattern into the SE-directed pattern in the mid-1980s, was linked with mouth bar formation. Marine conditions also constrain seaward bar progradation. Furthermore, the history of river mouth bar formation reflects human impacts, such as dredging and dyking in order to stabilize the coastal area. [Copyright &y& Elsevier]

• The rainfall-runoff relationship has changed under climate change and human activities in the TRH region. • The impacts climate indicators of rainfall-runoff ratio in the sub-basins of TRH region were different. • The contribution rates of human activity in the YRB were a little higher than that in the YARB. Identifying the impact of climate change and human activities on rainfall-runoff relationship in the Three-River Headwaters (TRH) region is essential for water source conservation, ecological security, and biodiversity maintenance of China and East Asia. In this paper, the runoff-rainfall ratio was used as the index of rainfall-runoff relationship. Different methods were employed to identify the impact indicators and quantitative assessment of rainfall-runoff relationship from 1957 to 2016. The results are the following: (1) the rainfall-runoff relationship has changed in the source regions of Yangtze River basin (YARB) and Yellow River (YRB), and runoff-rainfall ratio has increased by 2.9% and decreased by 3.2%, respectively; (2) the main climate indicators of runoff-rainfall ratio were rainfall, potential evaporation and sunshine hours in the YARB, and rainfall, potential evaporation and temperature in the YRB; (3) the contribution rates of human activity in the YRB were a little higher than that in the YARB, and the contribution rates of climate change and human activity were 90.9% and 9.1% in the YARB and 42.9% and 57.1% in the YRB. The results can provide invaluable information for managing water resources and taking ecological protection measures. [ABSTRACT FROM AUTHOR]