State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, P.R. China.
Department of Earth Sciences, University of California, Riverside, CA, 92521, USA.
Nat Commun. 2020 Nov 26;11(1):6012. doi: 10.1038/s41467-020-19744-3.
Humans are primary agents of geomorphic change, and rates of anthropogenic landscape change likely far exceed the pace of change expected from natural geologic processes. Nevertheless, our understanding of the impact of humans on the natural landscape is limited by difficulties in accurately comparing past and present rates of change across wide spatial and temporal scales. Here, we present a compilation of >4000 rates of alluvial sediment accumulation that provide an indirect record of North American erosion, mass transfer and sediment storage from the late Pleistocene to the present day. Continent-wide rates of alluvium accumulation were broadly stable for ~40,000 years, but increased 10-fold during the rapid expansion of agriculture and river system modification associated with European colonization. Interpreted in terms of mass transfer, humans have moved as much sediment in North America in the past century as natural processes can transfer in 700-3000 years.
人类是地貌变化的主要因素，人为景观变化的速度可能远远超过自然地质过程预期的变化速度。然而，由于难以在广泛的时空尺度上准确比较过去和现在的变化速率，我们对人类对自然景观的影响的理解受到限制。在这里，我们提供了超过 4000 个冲积物堆积速率的汇编，这些速率为从更新世晚期到现在的北美侵蚀、物质转移和沉积物储存提供了间接记录。在大约 40000 年的时间里，大陆范围内的冲积物堆积速率基本稳定，但在与欧洲殖民化相关的农业和河流系统改造的快速扩张期间，增加了 10 倍。根据物质转移来解释，人类在过去一个世纪中在北美洲搬运的沉积物与自然过程在 700-3000 年内可以转移的沉积物一样多。
