Climate Change Impact on the Evolution of the Saline Lakes of the Soan-Sakaser Valley (Central Salt Range; Pakistan): Evidences from Hydrochemistry and Water (δD, δ18O) and Chlorine (δ37Cl) Stable Isotopes
Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt lake Resources, Qinghai Institute of Salt lakes, Chinese Academy of Science, Xining 810008, China
Qinghai Provincial Key Laboratory of Geology and Environment of Salt lakes, Xining 810008, China
University of Chinese Academy of Science, Beijing 100049, China
GFZ German Research Centre for Geosciences, 14473 Potsdam, Germany
Geotop-Earth and Atmosphere Sciences Department, UQAM, Case postale 888, Succursale Centre-Ville, Montreal, H3C 3P8, QC, Canada
Authors to whom correspondence should be addressed.
Water 2019, 11(5), 912; https://doi.org/10.3390/w11050912
Received: 27 February 2019 / Revised: 30 March 2019 / Accepted: 26 April 2019 / Published: 1 May 2019
(This article belongs to the Section Aquatic Systems—Quality and Contamination)
The surfaces of saline lakes are shrinking at a threatening rate worldwide. Likewise, the Uchhali complex (formed by three saltwater lakes located in the Salt Range, Pakistan) that serves as a major regional source of water for humans and as a habitat for water birds must be monitored. With this objective in mind, we conducted a study coupling hydrochemistry and stable isotope compositions (δ37Cl, δ18O and δD) in order to characterize its hydrochemical properties and the main processes controlling them. Results showed that the Uchhali complex salinity has dramatically increased compared to other similar lakes in the world. While the Uchhali (UL) and Khabbeki (KL) lakes present a sodium-chloride hydrofacies, the Jahlar (JL) is of a sodium-bicarbonate type. Hydrochemistry parameters indicate that the weathering of surrounding rocks is the major vector for the increase of total dissolved solids in the water. On the other hand, the observed enrichment in heavy isotopes of the water stable isotope compositions implies that the different lakes are undergoing a long history of intense evaporation. The study of the corresponding δ37Cl isotope compositions supports the conclusion that evaporation, along with weathering, are the main driving processes. Besides climate effects that result in the decrease of annual precipitation and the increase of evaporation, water consumption for domestic purposes (household and agriculture) aggravates the rise of the lakes’ salinity.