Mining is of major economic, environmental and societal consequence, yet knowledge and understanding of its global footprint is still limited. Here, we produce a global mining land use dataset via remote sensing analysis of high-resolution, publicly available satellite imagery. The dataset comprises 74,548 polygons, covering ~66,000 km² of features like waste rock dumps, pits, water ponds, tailings dams, heap leach pads and processing/milling infrastructure. Our polygons finely contour the edges of mine features and do not include the space between them. This distinguishes our dataset from others that employ broader definitions of mining lands. Hence, despite our database being the largest to date by number of polygons, comparisons show relatively lower global land use. Our database is made freely available to support future studies of global mining impacts. A series of spatial analyses are also presented that highlight global mine distribution patterns and broader environmental risks.

Alluvial sedimentary records in the North China Plain are essential in expanding flood history and understanding hazard patterns in the Yellow River basin where inundation risk exists and would probably increase under future global change. A detailed study of the Longwangmiao profile in the lower Yellow River floodplain reveals ancient flooding records over the late Holocene. Slackwater deposits are distinguished by typical sedimentary features and share similarities with those in the upper and middle Yellow River. This indicates that the traditional method can still be applied for paleoflood research beyond the gorge. However, unlike confined bedrock gorges, multiphase flood deposits of slackwater and overbank deposits represent different stages of flood events. These sedimentary assemblages recorded six flooding periods, further confirmed by the analysis of grain size and geochemistry. The profile was broadly subdivided into two flood-poor phases (3.7–6.7 ka, 0.8–1.7 ka) and three flood-rich phases (before 6.7 ka, 1.7–3.7 ka, after 0.8 ka) based on the dating results. Compared with the existing related research in the nearby area, the synchronous deposition cycles of floods and inter-floods are mainly controlled by the hydrodynamic conditions of the old Yellow River course. This study provides an analogue of paleoflood research in the lower Yellow River and similar alluvial plains. It explores the potential of interlinking paleoflood records in the whole Yellow River basin.

The Maoniuping Rare Earth Elements (REE) deposit, the second largest light REE deposit in the world, has been mined for decades, with serious impacts on the surrounding environment. However, the impact of mining on heavy metals in the downstream area (Nanhe River Basin) has not been systematically documented. To address this issue, this study explored the extent, transport, and accumulation of heavy metal contamination in the Nanhe River Basin through field surveys (2946 topsoil samples and four vertical soil sections) and regional geographic attributes (e.g., mining area, river, and elevation) combined with a variety of methods such as statistics, geostatistics, spatial analysis, geo-accumulation index, and potential ecological risk index. The results showed that soils in the Nanhe River Basin presented different degrees of heavy metal pollution, with Pb and Cd being the most abundant, and the soils as a whole showed moderate-heavy ecological risks. The spatial distribution and correlation of heavy metals exhibited similar distribution patterns and sources. Further analyses revealed that mining of REE in Maoniuping was the main source of heavy metal pollution in the Nanhe River Basin, with heavy metals entering the soil through runoffs. At the same time, mining activities led to the migration of heavy metals in different directions in the Nanhe watershed, i.e., about 1.3 km horizontally, 16 km longitudinally, and more than 1 m vertically. In addition, about 38.1 km² of the watershed is contaminated by mine wastes, which is 6.6 times the size of the mining area. In order to mitigate the threat of heavy metals, the local government has implemented water diversion projects and crop conversion in the Nanhe River Basin. This study provides a reference for research on the environmental problems caused by the exploitation of REE mines and other mineral resources.