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While we have rivers on our minds see this Ecology & Society special feature article Compromised Rivers: Understanding Historical Human Impacts on Rivers in the Context of Restoration.
Abstract
A river that preserves a simplified and attractive form may nevertheless have lost function. Loss of function in these rivers can occur because hydrologic and geomorphic processes no longer create and maintain the habitat and natural disturbance regimes necessary for ecosystem integrity. Recognition of compromised river function is particularly important in the context of river restoration, in which the public perception of a river’s condition often drives the decision to undertake restoration as well as the decision about what type of restoration should be attempted. Determining the degree to which a river has been altered from its reference condition requires a knowledge of historical land use and the associated effects on rivers. Rivers of the Front Range of the Colorado Rocky Mountains in the United States are used to illustrate how historical land uses such as beaver trapping, placer mining, tie drives, flow regulation, and the construction of transportation corridors continue to affect contemporary river characteristics. Ignorance of regional land use and river history can lead to restoration that sets unrealistic goals because it is based on incorrect assumptions about a river’s reference condition or about the influence of persistent land-use effects.Flow regulation and the construction of transportation corridors are intimately related to the NOLA problem but there have been a large number of articles about the environmental consequences of these alterations that haven't been the focus of politicians and the press. Those thinking about the environmental issues have kept their heads down a bit. There have been rumblings about blaming environmental restrictions for some of the destruction. There is a basic conflict between human desires and ecosystem integrity for the whole river and delta system.
The same is true on a smaller scale for many rivers but some of those human desires might be more amenable to change if the issues are well understood. Perhaps it can be seen as more sophisticated aesthetics?
An emphasis on appearance only can be misleading when the general public’s conception of river health is based on a tidy appearance rather than on an understanding of ongoing river functions, such as floods that maintain the grain-size distribution of pool and riffle bedforms. A segment of river can meet many people’s expectations of a healthy river if the water is clear and the stream banks are not rapidly eroding. However, the function of such a healthy-looking river can be highly compromised if flow and sediment are no longer moving downstream so that the habitats needed for diverse aquatic and riparian communities are not being maintained. This dichotomy between appearance, or form, and function gives rise to the concept of a compromised river. A compromised river is one that preserves a simplified albeit attractive form but has lost function because the hydrologic and geomorphic processes no longer create and maintain the habitat and natural disturbance regime necessary to ecosystem integrity.I'm a bumpkin used to living near a more or less natural river but the last thing I would find attractive is a tidy appearance. Rivers are supposed to be ever changing object lessons in water and force. They can uproot trees and tear down mountains. Heap big medicine! Terrible beauty.
The concept of an attractively tidy but less functional river is particularly important in the context of river restoration. That is because the public perception of a river’s condition often drives the decision to undertake the restoration as well as the decision about what type of restoration is needed. If a river appears relatively attractive and healthy, the history of land use and the river responses that have directly influenced its current condition are unlikely to be explored. The net effect of most land use is to reduce the complexity and diversity of river form and function. At some point, these reductions cross a threshold, and the river is perceived as compromised and in need of restoration. This threshold can be very high. An alteration of the flow regime, a disconnection of the stream channel from the adjacent floodplain and hyporheic zone, a reduction of aquatic and riparian habitat diversity, and a loss of macroinvertebrate, fish, and riparian vegetation diversity can all be severe before the general public perceives that a river has lost function. Conversely, a river that is considered unattractive is more likely to be considered compromised and in need of restoration even if its appearance reflects the expected response to climatic and geologic conditions within the drainage basin. Braided rivers, or rivers along which large floods periodically reconfigure the channel and valley bottom, are more likely to be perceived as needing restoration even if their form and function have not been compromised relative to a reference condition.See, this is just wrong. But true. Our society has lost any sense of natural beauty and now considers broken rivers attractive and unbroken rivers as needing restoration. Not that a river can't be both broken and unattractive or unbroken and attractive. I think we are capable of a more sophisticated aesthetic but it must be taught to an urban society lacking personal experience with nature except for brief and controlled encounters or ersatz simulations. It's something like our current lack of sophistication, I think, about feminine beauty. Many of us have difficulty seeing things that are strong, wild, dangerous and fecund as beautiful. I'm not one of them, but I understand that it is a sincere lack and perhaps can be changed by information.
Update:
See Rivers: Trophy Wives or Wild Women?, at New West Magazine - The Voice of the Rocky Mountains, where Jon Christensen's blog post (see the original at The Uneasy Chair) that extends these thoughts was picked up. Money comment about the post:
By Courtney Lowery, 9-28-05
This is a terrific analogy Jon. I consider myself to be a messy, complicated, but perfectly functioning river.
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For example, what may seem like unsightly debris in a river is actually prime spawning habitat.The same can be said of my love handles -- they are protecting my ovaries afterall.