USING MEASURED DATA AND EXPERT OPINION IN A MULTIPLE OBJECTIVE DECISION SUPPORT SYSTEM FOR SEMIARID RANGELANDS

Abstract

A Decision Support System (DSS) can be used to structure information in a way that leads to improveddecision making for natural resources. The decisions will only be as good as the information on which they are based. Asthe applications of a DSS are outpacing the available databases and simulation models, there is an increasing reliance onexpert opinion for information on resource management systems. As a result, the effect of information source on theoutcome from the DSS is an important issue. This article compares the outcomes from a prototype DSS (P-DSS) developedby the USDA-ARS Southwest Watershed Research Center in Tucson, Arizona, when measured data and expert opinion areused to quantify eight decision criteria in the evaluation of four management systems (yearlong and rotation grazing,each with mesquite trees (Prosopis velutina Woot.) retained or removed) for semiarid rangelands. The decision criteriaare sediment yield, channel erosion, runoff rate and quantity, rangeland condition, aboveground net production, andwildlife habitat for quail and javelina, although the analysis is not restricted to these criteria. When measured data areused to quantify the decision criteria, rotation grazing with mesquite removed is the preferred management system,whereas yearlong grazing is the preferred system when expert opinion is used. The experts also directly ranked the fourmanagement systems. The difference between the experts ranking and the P-DSS results based on expert inputs is aconcern for future use of decision support system technology, particularly when information sources are blended.