A clear concept of the recharge pathways for surface flow in mountain rivers is important for understanding the effects of climate change on streamflow in mountain block hydrology. In a mountain river in Alberta, Canada, three subsurface end-member sources were identified using silica, sulfate, and the isotopic composition of sulfate: interflow (water that has not undergone significant rock-water interaction), and groundwater derived from two types of hydrogeologic units (carbonate and siliciclastic fractured rock aquifers).

A three end-member mixing model was used to determine their relative contributions to river discharge and infer relative groundwater ages using silica dissolution kinetics and tritium.

In the three years of sampling, proportional contributions from subsurface end-members varied up to 25% within a given year while mean contributions between years varied as much as 19%. Interflow is the dominant source for the majority of the study period, contributing ~50% of river discharge during spring melt and 40–60% over the rest of the season. Siliciclastic and carbonate aquifer contributions varied interannually and seasonally. Although carbonate rocks comprise the majority of the watershed area, siliciclastic rocks contribute nearly equally to annual streamflow (~30% each), suggesting that siliciclastic aquifers transmit more water.

Silica- and tritium-based ages suggest residence times on the order of <5–10 years. The combination of short residence times and significant variability in streamflow provenance suggest streamflow in this river will be rapidly affected by climatic change.

山区河流地表水流补给路径的清晰概念对于理解气候变化对山区水文流量的影响很重要。在加拿大阿尔伯塔省的一条山区河流中，使用二氧化硅、硫酸盐和硫酸盐的同位素组成确定了三个地下端元源：互流（未经历显着岩水相互作用的水）和来自两种类型的地下水水文地质单元（碳酸盐和硅质碎屑岩含水层）。

三端元混合模型用于确定它们对河流流量的相对贡献，并使用二氧化硅溶解动力学和氚推断相对地下水年龄。

在采样的三年中，来自地下终端成员的比例贡献在给定年份内变化高达 25%，而年份之间的平均贡献变化高达 19%。互流是研究期间大部分时间的主要来源，在春季融化期间贡献了约 50% 的河流流量，在其余季节贡献了 40-60%。硅质碎屑和碳酸盐含水层的贡献因年际和季节性而异。虽然碳酸盐岩占流域面积的大部分，但硅质碎屑岩对年流量的贡献几乎相等（每个约 30%），表明硅质碎屑含水层传输更多的水。

基于二氧化硅和氚的年龄表明停留时间<5-10 年。短暂的停留时间和水流来源的显着变化相结合，表明这条河流中的水流将迅速受到气候变化的影响。