The rebuilding and resuming of SD model of the eco-environment in the agriculture and animal husbandry interlock zone along the Great Wal

The rebuilding of SD model and resuming of the eco-environment in the agricdture and animal husbandry in．terlock zone along the Great W all were established by a system dynamic theory，and a simulating study for three typical managem ent patterns，a intensified management，steady development and traditional managem ent，in the region WaS made by the SD mod e1．The results show that the intensified management pattern is the best approach tO harness the eco-envl-ronment in the region，it can balance the development of agriculture，forestry and animal husbandry，reduce the soil erosion by 76．1％ ，return a good circle of eco。environment in the region、