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GIS based Seismic Stability Zonation of Slope around Lanzhou City
Figure 5. Seismic stability zonation map of slopes around Lanzhou city (63.5% probability of exceedance in 50 years)
From above results we can see the slopes at south of Xigu district and Qilihe district have the highest landslide susceptibility in Lanzhou city. Many landslides occurred in this region in history [Wu et al., 1996], suggesting that the results are reasonable.
5 Conclusion
Based on the deterministic model for landslide evaluation, the distribution of safety factor of the slopes around Lanzhou city under three probability of exceedance were calculated using a pseudo-static analysis method of slope instability proposed by Koppula. GIS technology was used to support this work.
The results of seismic stability analysis of the slopes around Lanzhou city agree with the history landslide occurrence. The slopes at south of Xigu district and Qilihe district have the highest landslide susceptibility, which region should be defended preferentially.
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