Spatio-Temporal Exploration of Sheep Grazing Operations in the California Mojave Desert

Publication Date


Committee Chair

Karen K. Kemp, Ph.D.

Committee Members

Jill S. Heaton, Ph.D.
Rick Rossi, Ph.D.
Glenn Hyman, Ph.D.


This report describes the visualization, tracking and habitat modeling of sheep grazing operations in the California Mojave Desert. It is being designed and implemented for the Desert Tortoise Project (DTP) at the Redlands Institute, an applied research group within the University of Redlands. Grazing is a potential threat to desert tortoise (Gopherus agassizii) habitat, and the client is interested in understanding where grazing occurs within allotment boundaries and the factors that determine the spatio-temporal occurrence of grazing operations. Grazing is administered within the Mojave Desert by the Bureau of Land Management (BLM).

Tracking themes that show the patterns of movement of sheep bands within allotments were generated based on records of actual use submitted by sheep operators to the BLM. Use area boundary changes between 1990 and 2001 show the impact of listing of the desert tortoise as a threatened species on grazing operations. The professional judgment that the range personnel employ in managing grazing operations and the various administrative factors that constrain the occurrence of grazing were documented as use cases and developed into propositions. A knowledge base was then designed using NetWeaver, an object oriented, modular system based on fuzzy logic, to model habitat suitability for grazing operations. The knowledge base has been designed such that it can be evaluated based on user defined values. The outputs can be cross checked against outputs from the tracking application.

Full text is available at the University of Redlands


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