Synthesizing knowledge to provide a holistic understanding of water quality in the glaciated Rio Santa, Peru

Here we present an interdisciplinary approach to providing a holistic understanding of an environmental challenge by synthesizing existing published studies and data about water quality in a glaciated Peruvian river basin, the Rio Santa. In mountain regions such as the Cordillera Blanca, connecting the impacts of a changing cryosphere with downstream environmental challenges such as water quality is crucially important for water resource management. Poor water quality negatively impacts human health and ecosystems, yet longitudinal, uninterrupted data to assess trends across time and space is rarely available. We focus on the Rio Santa as a proof of concept for our approach, where water security is already a significant challenge, and one that will become more acute under future climate change, glacier retreat, water and land use change, and water governance.

Research on environmental issues that require in-situ data, such as water quality, is usually fragmented, short-term, and focused on specific aspects or locations, making it difficult to establish a wider, holistic perspective in data-scarce regions. Our approach utilises published data to build a more comprehensive understanding of water quality over a greater temporal and spatial scale than individual studies can provide. Data and knowledge about environmental problems are generated by various research projects over time, but these projects are often unconnected and exist in disciplinary silos. By synthesizing data from existing published research, and seeking to include both quantitative and qualitative data where available, we can aim to create a broader understanding of water quality for a catchment or region, and provide different types of insights, context and knowledge.

We compiled water quality data for the Rio Santa basin from the past two decades, focusing on published variables, such as pH and heavy metal content. We then developed methods to integrate these datasets, providing a more comprehensive understanding of water quality for this catchment. Learnings from this research allow us to expand our understanding from individual studies to build an interdisciplinary and holistic view of water quality across the basin over time. The work also helps to provide a knowledge base for current and future research projects to increase the applicability of data and results, maximising impact and meaning.