Take a photo of the river! Assessing the feasibility of using Google Street View images as source materials for assessing river hydromorphology

Recently developed documentation technologies in the science of aquatic ecosystems can provide a large volume of new data. Some sets of documentary data, although developed for a different purpose, can be used to increase the effectiveness of water management and possibly help to better protect riverscapes. Such a source of data is riverscape photos can be used to assess the state of the river environment. In our article, we attempted to assess the hydromorphological condition of rivers based on available riverscape photos in Google Street View (GSV). In accordance with the River Habitat Survey protocol, one of the classic methods of assessing the hydromorphological condition implemented worldwide, we assessed the parameters of the hydromorphological condition of 60 stretches of selected Polish rivers located in different regions of the country, having specific and different physiographic features (slope, flow velocity, discharge, degree of modification). Then, based on available multimedia materials (GSV photos), we independently assessed the same parameters affecting the class of the hydromorphological condition of rivers and performed a comparative statistical analysis. No statistically significant difference between the assessment of the hydromorphological river status using the standard RHS field protocol and the assessment using GSV (p values of the Wilcoxon Signed-Rank Test 0.19 – 0.98). Although the results require further verification on larger data sets, we see significant potential for using GSV in supplementing field methods of river hydromorphology assessment with this data. We postulate that in the absence of field analyses and with the availability of GSV materials or other photographic materials from rivers (e.g., citizen science), a reliable assessment of the hydromorphological state of rivers can still be made.