This study examines permafrost thermal regimes and hydrological responses to climate change in the Navarro Valley, Chile's Dry Central Andes, using a decade of ground temperature data (2013-2022) from two rock glaciers-RG1 (3805 m) and RG2 (4047 m)-alongside short-term meltwater conductivity records, meteorological data, and long-term streamflow records. We assess permafrost stability and climatic sensitivity by analyzing thermal offset data (2017-2022) and ground temperature trends. Both sites show sustained warming, but RG1 exhibits accelerated warming (+ 2.84 degrees C/decade), frequent freeze-thaw cycles, and extended thaw periods, indicating a transitional regime. In contrast, RG2 shows fewer freeze-thaw cycles and greater thermal buffering, consistent with cold permafrost. The statistical model overestimated thaw dynamics at RG2, highlighting the importance of field-based data for accurate classification. Hydrological signals at RG1-including cold, mineralized meltwater and rapid ground surface temperature stream coupling-are attributed to thawing and deeper flowpaths. Conductivity data (2014-2015) reveal solute pulses consistent with early melt events and debris interaction. Meanwhile, long-term streamflow trends indicate declining discharge. These findings suggest feedback between permafrost loss and water availability. This study underscores the divergent evolution of adjacent rock glaciers under warming by integrating thermal, hydrological, and climatic data. RG1 shows signs of degradation, while RG2 may act as a temporary refuge. Continued monitoring is essential for managing water security in vulnerable mountain regions like the Dry Andes.Graphical AbstractThis graphical abstract visually summarizes a ten-year monitoring effort of mountain permafrost and glacier hydrology in the Navarro Valley, Dry Andes (32 degrees S), with implications for water security under climate change. The left panel situates the study area within the upper Aconcagua Basin, identifying two instrumented sites within the Tres Gemelos rock glacier complex-RG1 (3805 m) and RG2 (4047 m)-and an automatic weather station. These sites were selected for continuous monitoring of ground temperature and streamflow to assess permafrost behavior in a water-stressed mountain catchment. Moving to the center, the image presents an integrated monitoring framework that links temperature-depth profiles, surface-subsurface thermal dynamics, and discharge records. Key indicators such as freeze-thaw cycle counts and thawed-day metrics are used to classify thermal regimes and detect warming trends. The upper-right panel features a conceptual model that connects permafrost degradation to hydrological responses: RG1, characterized as transitional, shows signs of enhanced shallow flow and seasonal meltwater pulses, while RG2 retains cold, thermally buffered conditions that support greater storage stability. These contrasts are further illustrated by temperature trend graphs, which reveal faster warming at RG1 (+ 2.84 degrees C/decade) compared to RG2 (+ 1.92 degrees C/decade), as well as increased thaw metrics. Below, a long-term streamflow graph (1970-2023) documents declining discharge, visually supported by a field photo of a dry riverbed. The bottom panel summarizes the study's key finding: RG1 and RG2 are evolving along divergent thermal and hydrological trajectories, underscoring the need for high-resolution monitoring to guide water resource planning in an era of warming and drought.

It is very important to analyze the change of the active layer and the permafrost thermal regime for Qinghai-Tibet Plateau. Formerly, there is only few data of monitoring to analyze the response of the active layer and the permafrost to climate change in Qinghai-Tibet Plateau. The monitoring data of the permafrost thermal regime with seven sites from 1995 to 2000 make it possible to analyze this response relationship. The monitoring data is used to analyze the recent change in the thickness of active layer, the subsurface temperature, the near permafrost surface temperature, and the permafrost temperature at the depth of 6 or 8 m. The results show that their changes have a better accordance with air temperature change. The climate change has an impact on the change of the active layer and the thermal regime of the permafrost. The change of the active layer and the thermal regime of the permafrost can indirectly explain some features of climate change. (C) 2004 Elsevier B.V All rights reserved.