Seasonal and Inter-Annual Variability of Groundwater and Their Responses to Climate Change and Human Activities in Arid and Desert Areas: A Case Study in Yaoba Oasis, Northwest China

Abstract

Climate change and human activities have profound effects on the characteristics of groundwater in arid oases. Analyzing the change of groundwater level and quantifying the contributions of influencing factors are essential for mastering the groundwater dynamic variation and providing scientific guidance for the rational utilization and management of groundwater resources. In this study, the characteristics and causes of groundwater level in an arid oasis of Northwest China were explored using the Mann-Kendall trend test, Morlet wavelet analysis, and principal component analysis. Results showed that the groundwater level every year exhibited tremendous regular characteristics with the seasonal exploitation. Meanwhile, the inter-annual groundwater level dropped continuously from 1982 to 2018, with a cumulative decline depth that exceeded 12 m, thereby causing the cone of depression. In addition, the monthly groundwater level had an evident cyclical variation on the two time scales of 17-35 and 7-15 months, and the main periodicity of monthly level was 12 months. Analysis results of the climatic factors from 1954 to 2018 observed a significant warming trend in temperature, an indistinctive increase in rainfall, an inconspicuous decrease in evaporation, and an insignificant reduction in relative humidity. The human factors such as exploitation amount, irrigated area, and population quantity rose substantially since the development of the oasis in the 1970s. In accordance with the quantitative calculation, human activities were decisive factors on groundwater level reduction, accounting for 87.79%. However, climate change, including rainfall and evaporation, which contributed to 12.21%, still had the driving force to change the groundwater level in the study area. The groundwater level of Yaoba Oasis has been greatly diminished and the ecological environment has deteriorated further due to the combined effect of climate change and human activities.

Delineating the groundwater potential zones in Bangladesh

“…Temperature and humidity are two of the deciding phenomena for precipitation and are hence important for considering groundwater potential of a particular area. Increased surface temperature may have an impact the sub-surface water quantity ( Jakeman et al 2016;Salem et al 2017;Jannis et al 2021), whereas reduced humidity over a longer duration might result in extended periods of draughts, leading to over-extraction of groundwater and/or scarcity of it (Li et al 2020). Accordingly, higher weights were assigned to lower temperatures and higher humidity for this study.…”

Responses of two dominant desert plant species to the changes in groundwater depth in hinterland natural oasis, Tarim Basin

“…In these areas, desert riparian forests mainly consist of phreatophytes, Populus euphratica Oliv., and Tamarix ramosissima, which are primarily found in the floodplains of the catchments and are viewed as the lifeline of riparian zones (Han, Zhao, Feng, & Shi, 2015; Yu et al., 2021; Zhang, Zhou, Guan, et al, 2019) by providing critical habitats for various species and functioning as an "ecological shelter" against desertification (Ding et al., 2017). In desert riparian zones, groundwater is considered as a permanent and steady water source for native plant growth and reproduction due to the limited surface water flows and hyperarid climate conditions induced by severe drought events (Eamus et al., 2006; Evaristo & Mcdonnell, 2017; Li et al., 2020). Besides, in groundwater‐dependent arid ecosystems, plants could suffer from water stress when the groundwater depth is too deep, whereby soil water salinity could restrain plant growth when the water depth is too shallow (Maihemuti et al., 2021).…”

Detection of Groundwater Levels Trends Using Innovative Trend Analysis Method in Temperate Climatic Conditions

“…The method has been intensively used in the past decade to identify trends on extreme seasonal and annual value sets for climatic and hydrological parameters [39,40]. The ease of tracking trends by comparative analysis of data strings has led to the application of this method to identify solar radiation trends [41] and can be included in the analysis of trends of groundwater levels connected with different extreme hydroclimatic phenomena [42] or climatic changes [43]. These values of the ITA index are consistent with the slope trends identified for groundwater level for different classes.…”