青藏高原西部、南部和东北部边界地区天然水的水化学性质及其成因

特殊的地理和人文环境致使青藏高原天然水拥有独特的水化学性质并保存着较完整的原生状态,但随着人类活动强度的持续增大,可能导致当地水环境及水化学性质发生改变。通过对青藏高原存在人类活动的西部、南部和东北部边界地区进行水样采集、分析与测定,并探讨了当地天然水水化学性质的区域差异及其成因规律。结果表明:青藏高原不同边界地区天然水的物理性质、水化学性质和成因均存在差异,这些差异主要是地理环境、地质条件等综合作用的结果;水样pH的平均值为7.75,总溶解固体(TDS)的均值为171 mg/L,总硬度(TH)的均值为168 mg/L,总体来看水质较好,大部分能够满足国家和世界卫生组织(WHO)生活饮用水卫生标准,适宜饮用;水样中Ca²⁺和Mg²⁺为主要阳离子,HCO_3^-和SO_4^2-为主要的阴离子,主要由碳酸盐的风化和蒸发岩的溶解共同控制且碳酸盐岩风化的过程更为强烈;各边界地区天然水中的生物源物质均远低于国家和WHO标准,表明目前这些地区受人类活动的影响仍较小。

Hydrochemical characteristics and factors controlling of natural water in the western,southern, and northeastern border areas of the Qinghai-Tibet Plateau

The special geographic and human environment of the Qinghai-Tibet Plateau has created the unique hydrochemical characteristics of the region's natural water, which has been preserved in a completely natural state. However, as the intensity of human activities in the region continued to increase, the water environment and hydrochemical characteristics on the plateau have changed. In this study, we collected, analyzed, and measured water samples in the western, southern, and northeastern border areas of the Qinghai-Tibet Plateau, where human activities are ongoing, and the regional differences and factors controlling them were investigated. The key results were obtained as follows. (1) There were differences in the physical properties and hydrochemical characteristics, and their controlling factors in the different boundary areas of this plateau. These differences were mainly caused by the effects of the geographical environment and geological conditions. (2) The average pH of the water samples was 7.75, the average total dissolved solid (TDS) content was 171 mg/L, and the average hardness (TH) content was 168 mg/L. Overall, the water quality was good and suitable for drinking, with most samples meeting national and WHO drinking water standards. (3) The main cations were Ca ²⁺ and Mg ²⁺ in water samples, while HCO₃ ^- and SO₄ ^2- were the main anions. The chemical properties of water were mainly controlled by the weathering of carbonates and the dissolution of evaporative rocks, with the weathering of carbonate rocks being most influential. (4) The biological quality indicators of natural water in the border areas was far superior to national and WHO standards, which indicated that these areas were rarely affected by human activities.