Chia-Chi Huang

and 1 more

The complex interaction of climate change and human activities has led to significant changes in hydrological patterns, thus affecting the catchment hydrological processes around the world. This has resulted in increased water resource problems and conflicts between social development and environmental sustainability. Moreover, the groundwater resource is less concerned than others due to the challenges posed by groundwater and aquifer monitoring. Recession analysis is typically used to explore the groundwater-streamflow relationship with easily accessible streamflow data. The environmental impacts can be considered as a variable into the recession analysis to assess the changes in dynamic groundwater storage and storage-discharge relationships. Seventeen gauge stations in Southern Taiwan were selected as a case study to elucidate the spatial and temporal results under a comprehensive impact. In addition, the quantified environmental impacts and changes in vegetation coverage were compared to assess whether these changes were consistent and their effect on the catchment drainage processes. The results showed that the regional differences in low-flow recession characteristics and the dynamic storage indicated the local differences in the aquifer properties. Decreasing dynamic storage and increasing storage-discharge sensitivities in most catchments indicated a consistent change with quantified environmental impacts. This demonstrated that the environmental change led to more groundwater loss and a lower streamflow with a reduced flow variation. This study attempted to explore the storage-discharge dynamics caused by the overall environmental impact, and the quantified impact can help us to realize whether the groundwater storage and the susceptibility to baseflow increase or decrease in the catchment drainage behaviors. This provides a simple way to explain comprehensive effect on storage-discharge processes under the environmental co-evolution.