scholarly journals Hydrochemical Characteristics and Cause Analysis of Natural Water in the Southeast of Qinghai-Tibet Plateau

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3345
Author(s):  
Zongjun Gao ◽  
Hui Tong ◽  
Qiao Su ◽  
Jiutan Liu ◽  
Fasheng Gao ◽  
...  

This study investigated the hydrochemical characteristics and formation mechanism of natural water in the southeastern Qinghai-Tibet Plateau. To this end, 19 groundwater samples were collected, tested, and analyzed using various methods, such as mathematical statistics, a Piper diagram, correlation analysis, Gibbs plots, and an ion ratio analysis. The results show that the dominant anions are HCO3− and SO42−, and the dominant cations are Ca2+ and Mg2+, which accounted for 98.50% and 85.94% of the total amount of anions and cations, respectively. The samples were weakly alkaline water, where the TDS (total dissolved solids) ranged from 28.00 mg/L to 242.00 mg/L, with an average value of 129.10 mg/L. The hydrochemical types were mainly Ca·Mg-HCO3·SO4—accounting for 42.10%. The hydrochemical evolution process was found to be mainly controlled by the weathering and dissolution of carbonate and silicate rocks. The main sources of Na+ and K+ are rock salt and silicate rocks, and those of Ca2+, Mg2+, HCO3−, and SO42− are from the dissolution of dolomite, calcite, gypsum, and other calcium and magnesium bearing minerals. In addition, atmospheric precipitation serves as a replenishment source of natural water in the region, and the recharge is affected by evaporation.

2018 ◽  
Vol 626 ◽  
pp. 366-376 ◽  
Author(s):  
Weihua Wang ◽  
Tonghua Wu ◽  
Lin Zhao ◽  
Ren Li ◽  
Changwei Xie ◽  
...  

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2269
Author(s):  
Jinlong Li ◽  
Wei Wang ◽  
Dahao Wang ◽  
Jiaqi Li ◽  
Jie Dong

Thermokarst lakes are a ubiquitous landscape feature that impact the thermal state, hydrological process, ecological environment, and engineering stability of the permafrost. This study established the hydrochemistry and stable isotope (δ18O and δD) variations of lake water and groundwater in a typical basin located in the central Qinghai–Tibet Plateau (QTP) of China. The results showed that most water samples could be classified as slightly alkaline, with high levels of salinity and hardness, while the dominant water types were HCO3-CO3 and Cl types. Natural hydrochemical processes, such as mineral dissolution, cation exchange, and groundwater evaporation, had strong impacts on the groundwater chemistry in this region. Dissolution of halite and carbonate minerals causes the major reactions controlling water chemistry in this basin. Additionally, the calculation of the saturation index (SI) values suggested that aragonite, calcite, and dolomite are saturated, while halite is not. Based on the analysis of the stable isotope characteristics, atmospheric precipitation, groundwater, and meltwater from the permafrost are the major sources of thermokarst lakes. Moreover, the evaporation-to-inflow ratio (E/I) indicated that all of the lakes continuously expanded and rapidly developed. Overall, groundwater is an crucial source of lake recharge and its hydrochemical characteristics also have a certain impact on lake water quality.


Author(s):  
Yao Wen ◽  
Jiahao Qiu ◽  
Si Cheng ◽  
Changchang Xu ◽  
Xiaojiang Gao

Identification of geochemical characters and the influence of river and seawater on coastal areas are of significant impact on water resources management in coastal areas globally. Thus, it requires careful investigation of the hydrochemical evolution mechanisms and assessment of the quality of shallow groundwater. The study specifically focused on the estuarine coastal zone of Qidong, China, a city located on the Yangtze estuary. Thirty shallow groundwater samples and five surface water samples were collected during a field investigation, and 25 water quality indexes were analyzed. Methods including mathematical statistics, Gibbs figure, Piper diagram, and ionic rations were used to analyze the hydrochemical characteristics and evolution mechanisms. The spatial distribution of key parameters was assessed using a GIS-based spatial gridding technique. Results showed that the shallow groundwater in this estuarine coastal zone is weakly alkaline. The major hydrochemical parameters, including total dissolved solids (TDS), Na+ and Cl−, Mg2+, and SO42−, displayed similar spatial distributions; the distributions of Ca2+ and Mg2+ were irregular; the distributions of SO42− and HCO3− shared a similar trend, increasing gradually from the southern to northern regions of the study zone; and the values of NO3− and NH4+ were generally low in the study area. The hydrochemistry of the groundwater consists of HCO3-CaMg type and HCO3-Na, with HCO3·Cl-Na type and Cl-Na being the dominant constituents toward the coastal strip. The coastal aquifers are subjected to the ongoing influence of seawater intrusion, ion exchange processes, freshwater infiltration, and mineral (carbonate and silicate) dissolution, which impact groundwater evolution. Most of the groundwater samples are unsuitable for drinking purposes, but more than 90% of samples have irrigation suitability, based on the WHO standards and the classifications of sodium absorption ratio (SAR), soluble-sodium percentage (SSP).


2021 ◽  
Vol 166 ◽  
pp. 104093
Author(s):  
Fei Peng ◽  
Wenjuan Zhang ◽  
Chimin Lai ◽  
Chengyang Li ◽  
Quangang You ◽  
...  

Author(s):  
Deyan Ge ◽  
Anderson Feijó ◽  
Zhixin Wen ◽  
Alexei V Abramov ◽  
Liang Lu ◽  
...  

Abstract For organisms to survive and prosper in a harsh environment, particularly under rapid climate change, poses tremendous challenges. Recent studies have highlighted the continued loss of megafauna in terrestrial ecosystems and the subsequent surge of small mammals, such as rodents, bats, lagomorphs, and insectivores. However, the ecological partitioning of these animals will likely lead to large variation in their responses to environmental change. In the present study, we investigated the evolutionary history and genetic adaptations of white-bellied rats (Niviventer Marshall, 1976), which are widespread in the natural terrestrial ecosystems in Asia but also known as important zoonotic pathogen vectors and transmitters. The southeastern Qinghai-Tibet Plateau (QHTP) was inferred as the origin center of this genus, with parallel diversification in temperate and tropical niches. Demographic history analyses from mitochondrial and nuclear sequences of Niviventer demonstrated population size increases and range expansion for species in Southeast Asia, and habitat generalists elsewhere. Unexpectedly, population increases were seen in N. eha, which inhabits the highest elevation among Niviventer species. Genome scans of nuclear exons revealed that among the congeneric species, N. eha has the largest number of positively selected genes. Protein functions of these genes are mainly related to olfaction, taste and tumor suppression. Extensive genetic modification presents a major strategy in response to global changes in these alpine species.


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