Characteristics of Groundwater and Vegetation Responses in Nonperennial River Areas—A Case Study of Intermittent Rivers

ABSTRACT Intermittent rivers constitute the main water supply source for ecosystems in arid areas. It is very important to explore the ecological responses in intermittent river areas by quantitatively analyzing the interactions among surface water, groundwater, and the vegetation continuum without disturbing the regional water balance. This study focused on intermittent rivers to explore the characteristics of groundwater level fluctuations and vegetation responses via a combination of comprehensive observations, model constructions, and remote sensing analyses. The main conclusions are as follows: fluctuations in the groundwater level were influenced by the spreading recharge and delay response effects in the intermittent groundwater recharge process due to the limited groundwater flow velocity and alternating runoff and no‐flow periods. The groundwater level still increased after intermittent groundwater recharge. In addition, the groundwater level in the riparian zone gradually reached the necessary conditions for vegetation growth due to multistage groundwater recharge, and relatively stable vegetation communities formed in local areas. The groundwater level gradually decreased during the no‐flow period. However, the effects of groundwater level fluctuations on vegetation decline were limited in certain periods because of the self‐regulation strategy and drought adaptability of plants under different water environment conditions during the river no‐flow period. In addition, vegetation coverage decreased as no‐flow processes continued. Therefore, improving water resource utilization efficiency in intermittent river areas via planned water conveyance is beneficial.