Kåresdotter Elisie, Destouni Georgia, Ghajarnia Navid, Lammers Richard B, Kalantari Zahra
Department of Physical Geography and Bolin Centre for Climate Research Stockholm University Stockholm Sweden.
Earth Systems Research Center Institute for the Study of Earth, Oceans, and Space University of New Hampshire Durham NH USA.
Earths Future. 2022 Aug;10(8):e2022EF002848. doi: 10.1029/2022EF002848. Epub 2022 Aug 18.
Population growth is increasing the pressure on water resource availability. For useful assessment and planning for societal water availability impacts, it is imperative to disentangle the direct influences of human activities in the landscape from external climate-driven influences on water flows and their variation and change. In this study we used the water balance model, a gridded global hydrological model, to quantify and distinguish human-driven change components, modified by interventions such as dams, reservoirs, and water withdrawals for irrigation, industry, and households, from climate-driven change components on four key water balance variables in the terrestrial hydrological system (evapotranspiration, runoff, soil moisture, storage change). We also analyzed emergent effect patterns in and across different parts of the world, facilitating exploration of spatial variability and regional patterns on multiple spatial scales, from pixel to global, including previously uninvestigated parts of the world. Our results show that human activities drive changes in all hydrological variables, with different magnitudes and directions depending on geographical location. The differences between model scenarios with and without human activities were largest in regions with the highest population densities. In such regions, which also have relatively large numbers of dams for irrigation, water largely tends to be removed from storage and go to feed increased runoff and evapotranspiration fluxes. Our analysis considers a more complete set of hydrological variables than previous studies and can guide further research and management planning for future hydrological and water availability trends, including in relatively data-poor parts of the world.
人口增长对水资源的可利用性造成了越来越大的压力。为了对社会水资源可利用性影响进行有效的评估和规划，必须将人类活动对景观的直接影响与外部气候驱动对水流及其变化的影响区分开来。在本研究中，我们使用了水平衡模型（一种网格化全球水文模型）来量化和区分由水坝、水库以及灌溉、工业和家庭用水抽取等干预措施改变的人类驱动变化成分与陆地水文系统中四个关键水平衡变量（蒸发散、径流、土壤湿度、蓄水量变化）的气候驱动变化成分。我们还分析了世界各地不同区域内及区域间出现的效应模式，有助于探索从像素到全球的多个空间尺度上的空间变异性和区域模式，包括世界上此前未被研究的地区。我们的结果表明，人类活动驱动了所有水文变量的变化，其幅度和方向因地理位置而异。有人口活动和无人口活动的模型情景之间的差异在人口密度最高的地区最为显著。在这些地区，灌溉用坝数量也相对较多，水往往大量从蓄水量中被抽取，用于增加径流和蒸发散通量。与以往研究相比，我们的分析考虑了更完整的水文变量集，可为未来水文和水资源可利用性趋势的进一步研究及管理规划提供指导，包括在世界上数据相对匮乏的地区。
