Response of phreatophytes to short‐term groundwater pumping in a semiarid region: Field experiments and numerical simulations

Abstract

Balancing the water demand between human usage and ecosystems remains a challenge in water‐limited regions where one of the main groundwater uses is short‐term pumping. A 23‐day pumping test was performed in a semiarid site of north‐west China to test the hypothesis that native phreatophytes can tolerate short‐term pumping. The monitoring indicated that sap flow velocity of groundwater‐dependent willow trees began to decrease on Day 4 after pumping and almost fully recovered on Day 9 after the cessation of pumping. Numerical simulations using HYDRUS‐1D were conducted for the period of 1954–2013 to assess the response of phreatophytes to groundwater withdrawal under various climatic conditions. The modelling results reveal that phreatophytes can recover from the stress induced by groundwater pumping because they can adapt to short periods of water stress using physiological and morphological traits and the degree of water stress depends on the amount and/or frequency of rainfall during and after pumping. Therefore, pulsed pumping, under particular climatic conditions, could be used to reduce negative impacts of groundwater extraction on phreatophytes, while still providing groundwater for socio‐economic activities in semiarid zones.

Non-renewable groundwater use and groundwater depletion: a review

“…Shafroth et al 2000). Apart from the direct individual effects on evaporation and therefore productivity of phreatophytes (Yin et al 2018), the lowering of water tables also affects the competitive advantages of rare species that have been adapted to shallow water tables and oxygenpoor soils (Runhaar et al 1997, Elmore et al 2006. For instance, Runhaar et al (1997) provide strong relationships between the relative abundance of hydrophytes and xerophytes and mean spring water table depth.…”

Large-scale sensitivities of groundwater and surface water to groundwater withdrawal

“…Groundwater that is pumped comes either out of storage, from reduced groundwater discharge, or from reduction of evaporation fed from below by groundwater through capillary rise and/or phreatophytes (Theis, 1940;Alley et al, 1999;Bredehoeft, 2002;Konikow and Leake, 2014). Thus, extensive groundwater pumping not only leads to groundwater depletion (Wada et al, 2010), but also to a reduction in streamflow (Wada et al, 2013;Mukherjee et al, 2019;De Graaf et al, 2019;Jasechko et al, 2021) and desiccation of wetlands and groundwater-dependent terrestrial ecosystems (Runhaar et al, 1997;Shafroth et al, 2000;Elmore et al, 2006;Yin et al, 2018). However, the effect of groundwater pumping on groundwater depletion and surface water depletion heavily depends on the nature of the interaction between groundwater and surface water.…”

Large-scale sensitivities of groundwater and surface water to groundwater withdrawal

“…Groundwater that is pumped comes either out of storage, from reduced groundwater discharge or from reduction of surface evaporation fed from below by groundwater through capillary rise and/or phreatophytes (Theis, 1940;Alley et al 1999;Bredehoeft, 2002); Konikow and Leake, 2014). Thus, extensive groundwater pumping not only leads to groundwater depletion (Wada et al, 2010) but also to a reduction in streamflow (Wada et al, 2013;Mukherjee et al, 2019;De Graaf et al, 2019) and desiccation of wetlands and groundwater dependent terrestrial ecosystems (Runhaar et al 1997;Shafroth et al, 2000;Elmore et al 2006;Yin et al 2018). However, the effect of groundwater pumping on groundwater depletion and surface water depletion heavily depends on the nature of the interaction between groundwater and surface water.…”