Submitted to: American Water Resources Association Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/17/1998
Publication Date: N/A
Technical Abstract: Multiple objective decision methodology is used to evaluate watershed or ecosystem management with respect to environmental criteria. A structure for determining Rangeland Health is presented and the methodology is applied to 4 small semi-arid watersheds within the Santa Rita Experimental Range in southeastern Arizona. The individual attributes of the Rangeland Health rating system were developed by the Natural Resource Conservation Service from recommendations made by the National Research Council. Rangeland Health is the result of summing the results from 3 functional categories: watershed function and soil stability, nutrient cycling and energy flow, and recovery mechanisms. There are 17 individual attributes, allocated to one or more of these categories, that are weighed independently of each other. A simple algorithm based on linear and dynamic programming is implemented in a computer spreadsheet. This allows for quick computation of the ratings from most optimistic to most pessimistic. The overall Rangeland Health rating is computed without the need to specify explicit weights. This approach is useful for examining land areas from numerous decision making viewpoints. Surface runoff, sediment yield, and plant species density, frequency and canopy cover data collected over a 23 year period are used to provide a quantitative measure to evaluate the relevancy of the qualitative assessment process.