The Importance of Interflow to Groundwater Recharge in a Snowmelt‐Dominated Headwater Basin

Abstract

Understanding the sensitivity of groundwater generation to climate in a mountain system is complicated by the tight coupling of snow dynamics to vegetation and topography. To address these feedbacks, we combine light detection and ranging (LiDAR)‐derived snow observations with an integrated hydrologic model to quantify spatially and temporally distributed water fluxes across varying climate conditions in a Colorado River headwater basin. Results indicate that annual groundwater flow is an important and stable source of stream water. However, interflow decreases during drought as a function increased plant water use and the relative fraction of groundwater to streams increases. Seasonal snowmelt and vegetation water use regulate small recharge rates in the lower portions of the basin, but snowmelt transported via interflow from high mountain ridges toward convergent topographic zones defines preferential recharge in the upper subalpine. Recharge in this zone appears decoupled from annual climate variability and resilient to drought.

Importance of snowmelt contribution to seasonal runoff and summer low flows in Czechia

“…Our results showed that less snow led to a lower snowmelt contribution to total runoff and to lower spring groundwater recharge with larger differences for catchments with higher S f . These results correspond to other studies (Carroll et al, 2019;Cochand et al, 2019;Meriö et al, 2019). However, it does not necessarily mean that summer baseflow and potentially low flows are lower as well, since both the baseflow and low flows are more influenced by other water balance components, such as precipitation and evapotranspiration during spring and summer (Floriancic et al, 2019;Jenicek et al, 2016).…”

“…For the groundwater recharge, the topography is important, as the water is transported from steep terrain surrounding mountain ridges to lower elevations (Carroll et al, 2019). Therefore, higher elevations are important for catchment storage (Floriancic et al, 2018;Hood and Hayashi, 2015;Staudinger et al, 2017) as well as for stabilizing the streamflow at lower elevations especially during drought periods (Carroll et al, 2019;Cochand et al, 2019). Higher snowpack disproportionally feeds groundwater leading to more streamflow (Barnhart et al, 2016).…”

Differential C-Q Analysis: A New Approach to Inferring Lateral Transport and Hydrologic Transients Within Multiple Reaches of a Mountainous Headwater Catchment

“…The steep slopes, high relief and convergent topographic features of EBC can result in an uninterrupted supply of certain solutes such as P and SO 4 . Carroll et al (2019) also noted that recharge in the Copper Creek sub-catchment appears to be decoupled from annual climate variability, resulting in a steady supply of certain solutes.…”

Mountain‐Block Recharge: A Review of Current Understanding

“…This suggests a mountain aquifer permeability threshold below which absolute MBR rates may be insensitive to warming and associated declines in precipitation available for infiltration. Other studies have found that recharge to mountain aquifers composed of fractured crystalline rock (i.e., lower K) commonly may be permeability limited rather than precipitation limited (Carroll et al, ; Flint et al, ; Manning & Solomon, ). Furthermore, Manning () concluded that the absolute MBR rate from the crystalline‐rock Sangre de Cristo Mountains, New Mexico, USA, probably decreased little from the cooler, wetter Pleistocene to warmer, drier Holocene epochs based on NGTs and radiocarbon ages from wells in the adjacent Española Basin.…”