The vadose zone serves as a connection and transformation link between the atmosphere, plants, soil, surface water and groundwater. It is considered to be an important component of the geosphere and has sensitive interactions with the hydrosphere, biosphere, and atmosphere, which greatly impacts the environment and human health. This study was conducted in the Achnatherum splendens grassland of the Qinghai Lake Basin, NE Qinghai–Tibet Plateau, China, and can provide references and guidance for research on the mechanisms governing the circulation and evolution of vadose-zone water in cold arid regions. Precipitation, dustfall, and vadose zone samples were collected to investigate transport in the vadose zone water using stable isotopes of hydrogen (δ²H) and oxygen (δ¹⁸O) as well as chloride as environmental tracers. The results showed that precipitation was the main source of chloride in the research area, accounting for 86.5% of total chloride deposition. The soil water in the vadose zone was mainly recharged by local precipitation. Strong evaporation occurred before the precipitation infiltrated and recharged soil water. The soil water, chloride content, and isotope values in the soil profile varied across different depths. The annual potential recharge from precipitation to the vadose zone soil water was 9.20 mm/yr, accounting for 2.17% of the local precipitation. The actual recharge from precipitation to groundwater was 26.29 mm/yr, accounting for 6.19% of the local precipitation. The infiltration recharge from preferential and piston flow accounted for 66.40% and 33.60% of the total infiltration recharge to groundwater, respectively, indicating that preferential flow was the main source of groundwater recharge in the studied grassland. The results of this study were compared with those of other relevant studies. The recharge mechanisms of the vadose zone soil water and groundwater varied between different regions and were controlled mainly by the spatiotemporal distribution of precipitation, topographic characteristics, and soil structure. These findings provide a reference and guidance for research on the circulation and evolution of vadose-zone water in the Qinghai Lake Basin and Qinghai–Tibet Plateau.

渗流带是大气，植物，土壤，地表水和地下水之间的连接和转化连接。它被认为是地球圈的重要组成部分，并且与水圈，生物圈和大气层之间存在敏感的相互作用，这极大地影响了环境和人类健康。该研究在青藏高原东北部青海湖盆地the草草地上进行，可为研究干旱干旱地区渗流带水循环与演化的机理提供参考和指导。沉淀，收集降尘，和渗流区的样品使用氢的稳定同位素（δ以调查在渗流区水运² H）和氧（δ ¹⁸O）以及氯化物作为环境示踪剂。结果表明，降水是研究区氯化物的主要来源，占氯化物总沉积量的86.5％。渗流带的土壤水分主要通过局部降水补给。在降水渗入和补给土壤水之前，发生了强烈的蒸发。土壤剖面中的土壤水分，氯化物含量和同位素值随深度的不同而变化。降水到渗流带土壤水的年潜在补给量为9.20毫米/年，占当地降水量的2.17％。降水到地下水的实际补给量为26.29毫米/年，占当地降水的6.19％。优先流和活塞流的入渗补给分别占66.40％和33。总入渗量中有60％补给了地下水，这表明优先流是被研究草地中地下水补给的主要来源。将该研究的结果与其他相关研究的结果进行比较。渗流带土壤水和地下水的补给机理在不同地区之间有所不同，并且主要受降水的时空分布，地形特征和土壤结构控制。这些发现为青海湖流域和青藏高原的渗流带水的循环和演化研究提供了参考和指导。渗流带土壤水和地下水的补给机理在不同地区之间有所不同，并且主要受降水的时空分布，地形特征和土壤结构控制。这些发现为青海湖流域和青藏高原的渗流带水的循环和演化研究提供了参考和指导。渗流带土壤水和地下水的补给机理在不同地区之间有所不同，并且主要受降水的时空分布，地形特征和土壤结构控制。这些发现为青海湖流域和青藏高原的渗流带水的循环和演化研究提供了参考和指导。