Rural System's
Speech: Crescent Management: The Watershed Management Alternative (notes)
We are of the "glass half empty " school; we do not think that there have been major advances and improvements in the acceptance and demonstrated use of the research findings or the active use of the watershed concept in planning. There are some exceptional projects, but these do not deny the observation. Conventional watershed management promotion and practice have not worked (as judged by many criteria). An alternative is needed.
Why should we average and aggregate and group knowledge of land when we now have detailed data on every 10 x 10 meter tract of land in the tract? The North-facing slope is well known to be very different from the South-facing slope of a typical watershed. Why assume that they are the same throughout an area for runoff, percolation, evaporation, or transpiration?
The watershed-oriented effort gives us no advantages, limits some work (groundwater analyses and management), ads to some work (plant and animal species analyses), adds extraneous information to some work (e.g., wide-ranging wild animals or animals with very narrow ranges and most fossil fuel extraction analyses), and prevents us thinking about the unique spots of the Forest (the 10 x 10 GIS pixel each having 200 known factors stored) that are only very peripherally linked (or linkable) to costly-gotten information about the watershed.
We do need to improve watersheds but not constrain planning to thinking within the boundary-box. With ability to estimate conditions within any 10 x 10-meter land pixel in any watershed boundary, it seems silly to add or aggregate this information gathered and stored at such high costs. One word, "watershed, can have many meanings so the admonition to manage them can also have many meanings. We think there can be a big difference between a north- and south-facing slope of a watershed, and between conditions near the ridges and down in the valley. There are profound differences within each watershed. Each is unique for it is compused of unique entities. Averaging all of the factors, assuming that everything within a boundary is the same average value seem unwise.To aggregate is to lose data and the ability to transform it into ecologically or economically relevant values. We can keep data separate as long as possible within the computer, then use models to synthesize factors into key decision alternatives.
In RIEC (1995)2 we read that watershed analysis is essentially ecosystem analysis at the watershed scale. In The Trevey we propose that watershed analysis be limited to the analysis of the water budget within an area.
"Watershed " is any area of land that tends (at least in concept) to drain water falling on it (any form) to a common point or to a common reach
See Water Regions
See Trevey and Crescent Management
See watershed structure and function
See Rural System River Runners
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May 18, 2005