Groundwater sources, flow patterns, and hydrochemistry of the Central Yinchuan Plain, China

Abstract

Groundwater in the Yinchuan Plain (China) is a critical domestic resource that is also used for agricultural irrigation and to maintain ecological environments, among other purposes. Recent research has shown that ineffective planning of water resources, along with large-scale groundwater pumping (mining) has led to ecological problems. To further analyze the characteristics of the regional groundwater flow patterns, and guide the development and utilization of water resources, potentiometric, hydrochemical, and isotopic data were collected along a 60-km transect that crosses the middle Yinchuan Plain. The data were used to develop a two-dimensional conceptual model of the sources, flow patterns, and geochemical evolution of groundwater from the Helan Mountains in the west across the Yellow River in the east. An important component of the model is that in the process of groundwater flow from west to east, the flow direction changes due to the influence of a thick fine-grained sandy-clay unit and long-term groundwater pumping. Local lakes and the shallow groundwater system are recharged by water from the Yellow River. Geochemically, water within the proluvial deposits exhibits relatively low concentrations of total dissolved solids. Further east, the water gradually becomes brackish. The geochemical composition of the shallow groundwater beneath the fluviolacustrine plain west of the Yellow River is also controlled by evaporation, precipitation and cation exchange processes. In other areas, groundwater chemistry is mainly controlled by water-rock interactions and cation exchange. This study enhances understanding of groundwater flow in the region, and provides information critical to water resources development and management.

Deep Groundwater Flow Patterns Induced by Mine Water Injection Activity

“…The deep groundwater regime within the large hydrogeological basin is controlled both by geology and topography [ 46 ]. Studying its flow patterns proved to be the ideal method for understanding the groundwater flow process, paths, direction, system, circulation and geochemical evolution [ 47 ]. The large-scale sedimentary Ordos Basin was developing with the nested groundwater flow systems, such as the regional, intermediate, and local-scale groundwater systems or subsystems [ 48 ].…”

The Vulnerability of Shallow Groundwater on a Small Tropical Indonesian Island

“…These chemical changes cause typical changes in shallow groundwater in the study area. The mixing of ions results in ion exchange, which can be described by the relationship between concentrations, i.e., (Ca 2+ + Mg 2+ )−(SO 4 2− + HCO 3 − ) and (Na + + K + )−Cl − (Li et al, 2021), as well as chloro-alkaline indices (CAI) (Tiwari et al, 2019). The results of calculations using data from Tables 1 and 2 indicate that, regardless of when they were collected, all water samples from the dug wells had negative concentration relationship values with positive CAI.…”

“…The results of calculations using data from Tables 1 and 2 indicate that, regardless of when they were collected, all water samples from the dug wells had negative concentration relationship values with positive CAI. This suggests the withdrawal of Na + + K + ions and the release of Ca 2+ and Mg 2+ ions in the water samples from the dug wells; this process is referred to as reverse ion exchange (Li et al, 2021;Tiwari et al, 2019).…”

“…Before June 2021, the groundwater chemistry of the dug wells on Pari Island was controlled by rock weathering processes; subsequently, between June and November, this chemistry was controlled by the processes of evaporation or crystallization (Li et al, 2021;Tiwari et al, 2019). There is a positive relationship between EC and TDS, in which an increase in TDS concentration will result in further increases in EC value (Rebello et al, 2020;Rusydi, 2018).…”

Hydrochemical Characteristics and the Relationship between Surface and Groundwater in a Typical ‘Mountain–Oasis’ Ecosystem in Central Asia

“…Therefore, hydrochemical information for various water bodies can reflect the basic characteristics of inland river basins, which is of great significance for maintaining regional water security, the rational utilization of water resources and sustainable development [11]. In the past several decades, hydrochemical information on inland river systems in Central Asia [11][12][13], North Africa [14] and arid inland areas of China [15][16][17][18] has been fully recorded and analyzed. The projection of temporal and spatial distribution characteristics of river water chemistry provides unique insights into the protection of the ecological environment, the rational utilization of water resources and the hydrological function of inland river basins.…”