Abstract

Identifying a good site for groundwater exploitation in arid areas with scarce hydrogeological data is a challenging task. In this study, west of the Tibet Autonomous Region located at the peak of the world ridge that belongs to the extreme water-scarce poverty zone is used as the study area. This study is the first to determine the formation and controlling factors affecting the groundwater resources in Ali area via comprehensive geophysical and geochemical prospecting. The meteorological and hydrological characteristics of the study area are analysed, and the source and characteristics of water vapour in the study area are determined. Although the Indian peninsula and the Arabian Sea water vapour transmission paths exist, only small amounts of water vapour enter the area because of the distance limit and alpine barrier, which is the main reason for the drought in the study area. An overall conclusion of the hydrogeological condition and groundwater resources in Ali area is drawn on the basis of geophysical surveying, hydrogeological drilling, and water chemical analysis. The distribution of water resources in the Quaternary Aquifer, which is controlled by water vapour transport, aquifer-forming deposits, river distribution, and temperature, is not well-proportioned. The aquifer potentiality reduces from the southern to the northern direction in sequence. Thus, the great mass of midlands and the northern region belong to drought zones. Groundwater salinity, which is affected by drought, is higher than surface water salinity and obviously increases in constituent concentrations. The findings promote the understanding and utilisation of water resources in the study area.

Research highlights

• The study area located at the peak of the world ridge that belongs to the extreme water-scarce poverty zone.

• This study is the first to determine the formation and controlling factors affecting the groundwater resources in Ali area via comprehensive geophysical and geochemical prospecting.

• The distribution of water resources in the Quaternary Aquifer of Ali area, which is controlled by water vapour transport, aquifer-forming deposits, river distribution, and temperature, is not well-proportioned.

• The water vapour originating from the Indian Peninsula and the Arabian Sea is blocked by high mountains, thereby minimising the amount of water vapour that can enter Ali and inducing less precipitation, which is the main reason for the drought in the study area.