气候变化领域集成服务门户(CCPortal): Groundwater influence on soil moisture memory and land-atmosphere fluxes in the Iberian Peninsula

CCPortal

DOI	10.5194/hess-23-4909-2019
	Groundwater influence on soil moisture memory and land-atmosphere fluxes in the Iberian Peninsula
	Martínez-De La Torre A.; Miguez-Macho G.
发表日期	2019
ISSN	1027-5606
起始页码	4909
结束页码	4932
卷号	23 期号:12
英文摘要	Groundwater plays an important role in the terrestrial water cycle, interacting with the land surface via vertical fluxes through the water table and distributing water resources spatially via gravity-driven lateral transport. It is therefore essential to have a correct representation of groundwater processes in land surface models, as land-atmosphere coupling is a key factor in climate research. Here we use the LEAFHYDRO land surface and groundwater model to study the groundwater influence on soil moisture distribution and memory, and evapotranspiration (ET) fluxes in the Iberian Peninsula over a 10-year period. We validate our results with time series of observed water table depth from 623 stations covering different regions of the Iberian Peninsula, showing that the model produces a realistic water table, shallower in valleys and deeper under hilltops. We find patterns of shallow water table and strong groundwater-land surface coupling over extended interior semi-arid regions and river valleys. We show a strong seasonal and interannual persistence of the water table, which induces bimodal memory in the soil moisture fields; soil moisture "remembers" past wet conditions, buffering drought effects, and also past dry conditions, causing a delay in drought recovery. The effects on land-atmosphere fluxes are found to be significant: on average over the region, ET is 17.4 % higher when compared with a baseline simulation with LEAFHYDRO's groundwater scheme deactivated. The maximum ET increase occurs in summer (34.9 %; 0.54 mm d-1). The ET enhancement is larger over the drier southern basins, where ET is water limited (e.g. the Guadalquivir basin and the Mediterranean Segura basin), than in the northern Miño/Minho basin, where ET is more energy limited than water limited. In terms of river flow, we show how dry season baseflow is sustained by groundwater originating from accumulated recharge during the wet season, improving significantly on a free-drain approach, where baseflow comes from water draining through the top soil, resulting in rivers drying out in summer. Convective precipitation enhancement through local moisture recycling over the semi-arid interior regions and summer cooling are potential implications of these groundwater effects on climate over the Iberian Peninsula. Fully coupled land surface and climate model simulations are needed to elucidate this question. © Author(s) 2019. This work is distributed under the Creative Commons Attribution 4.0 License.
语种	英语
scopus关键词	Climate models; Drought; Groundwater resources; Rivers; Soil moisture; Surface measurement; Climate model simulations; Convective precipitation; Groundwater modeling; Groundwater process; Land surface models; Land-atmosphere couplings; Shallow water tables; Soil moisture distribution; Recharging (underground waters); air-soil interaction; climate modeling; evapotranspiration; seasonal variation; semiarid region; shallow water; soil moisture; water table; Andalucia; Guadalquivir Basin; Iberian Peninsula; Segura River; Spain
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/159553
作者单位	Martínez-De La Torre, A., Nonlinear Physics Group, Faculty of Physics, Universidade de Santiago de Compostela, Santiago de Compostela, Spain, Centre for Ecology and Hydrology, Wallingford, United Kingdom; Miguez-Macho, G., Nonlinear Physics Group, Faculty of Physics, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
推荐引用方式 GB/T 7714	Martínez-De La Torre A.,Miguez-Macho G.. Groundwater influence on soil moisture memory and land-atmosphere fluxes in the Iberian Peninsula[J],2019,23(12).
APA	Martínez-De La Torre A.,&Miguez-Macho G..(2019).Groundwater influence on soil moisture memory and land-atmosphere fluxes in the Iberian Peninsula.Hydrology and Earth System Sciences,23(12).
MLA	Martínez-De La Torre A.,et al."Groundwater influence on soil moisture memory and land-atmosphere fluxes in the Iberian Peninsula".Hydrology and Earth System Sciences 23.12(2019).