Study identifies gaps in monitoring of streams

A new study from Penn. State found gaps in data on streams around the world, highlighting potential priorities for the future installation of monitoring tools.

The research looked at where stream gauges were placed and whether they overrepresent certain types of waterways. It focused on stream gauges included in two popular datasets: the Global Streamflow Indices and Metadata Archive.

To assess whether certain types of waterways were overrepresented in these global gauging networks, scientists combined data on the placement of over 32,000 gauges in the datasets with information on the characteristics of streams and their surrounding landscapes.

“We find that gauges are located disproportionally in large, perennial rivers draining more human-occupied watersheds,” the authors write in their paper, which was published in Nature Sustainability. “Gauges are sparsely distributed in protected areas and rivers characterized by non-perennial flow regimes, both of which are critical to freshwater conservation and water security concerns.”

“As we respond to climate change and work toward conservation, it’s important to recognize that the information we have from stream gauges is not completely representative,” says Corey A. Krabbenhoft, the study’s senior author.

The datasets used did not include every stream gauge in the world: Gauges in regions that have not shared data publicly were missing, along with data from streams that were monitored independently by organizations that did not integrate findings into public databases.

Still, the number of stream gauges covered in the study is large, and comparable to the extent of datasets typically used in analyzes of global hydrology research, Krabbenhoft notes. Identifying biases in the placement of these gauges is vital as information from such datasets underpins important knowledge regarding the world’s freshwater resources.

She offers the case of non-perennial rivers as an example of why it’s important to call attention to gaps in stream gauge data.

“One disparity we see is in the monitoring of non-perennial rivers, which periodically dry up and stop flowing,” she says. “We need more data on these types of streams. There are plenty of places across the world where we expect the number of streams that periodically go dry to increase in the future, and in some cases these streams are part of larger river networks people rely on for their drinking water.”

The research was a product of the Dry Rivers Research Coordination Network, which was supported by funding from the U.S. National Science Foundation to Daniel C. Allen, PhD, at Penn State.