Mapping the Consequences of American Urbanization and Stream Burial

Ad:


Share:

Scientists in the Department of Natural Sciences at the University of Michigan­, Dearborn have studied stream burial in American cities. Urban development is often undergone so quickly that the environment is not valued for more than its aesthetic value, so streams are “buried”, to enable construction on the floodplain and maximize the area on which the city can expand. Stream burial means that streams are forced through underground concrete canals and separated from their network of channels. This study is an interdisciplinary effort in urban geography and fluvial geomorphology. By using maps from different periods in history, historical documents, and GIS and LiDAR to evaluate stream networks, it seeks to map buried streams. The study finds that much of the area of urban America ­ particularly in the Great Lakes region (8.3% of urban area), the Arizona Sun Corridor (7.1%), and Northern California (10.9%) but elsewhere all over the United States (6.2% total) ­ are “urban stream deserts” in which a city is “riverless… due to the effects of human development and population growth”. However, it should be noted that an urban stream desert does not always result from a history of stream burial, and urban areas in the Arizona Sun Corridor may have never had streams.

Map and summary table of Urban stream deserts (UrbSDs) within the Great Lakes Megaregion. The inset table summarizes the ten largest UrbSD Urban Areas (UAs). From: Napieralski and Carvalhaes, 2016.

Map and summary table of Urban stream deserts (UrbSDs) within the Great Lakes Megaregion. The inset table summarizes the ten largest UrbSD Urban Areas (UAs). From: Napieralski and Carvalhaes, 2016.

When some streams in a network are buried and the services of the floodplain are removed, the remaining streams must accommodate a much greater percentage of the volume of water and extensive, manmade, often concrete drainage systems must be constructed underground. The urban stream deserts usually correspond to the core of the city where the ground is least permeable and population density is highest. This is only one example of the history of nature being tamed and manipulated to suit human needs. Likewise, it is only one case in which the existing environmental system and the services it provided are missed. By mapping urban stream deserts, this study “identif[ies] priority areas to improve stream management practices”, provides the first step to the recovery of streams (a map of the history), and provides local communities information that can help them better understand their city and appreciate natural spaces in urban environments.

For more on this work, check out Applied Geography 67, the February 2016 edition:

Napieralski, J. and T. Carvalhaes. 2016. Urban stream deserts: Mapping a legacy of urbanization in the United States. Applied Geography 67: 129­139.