5．12汶川地震对都汶公路(G213)沿线土地破坏及损失评价

Land Destruction by 5.12 Wenchuan Earthquake along Dujiangyan-Wenchuan Highway and Its Loss Evaluation

5.12汶川地震及其次生山地灾害对灾区的土地资源造成了严重破坏,损失巨大。以重灾区都汶公路沿线为研究对象,通过野外实际调查,利用遥感影像解译和土地利用资料,探讨了地震引起的崩塌、滑坡等次生山地灾害对土地利用的破坏方式和特征,次生山地灾害以移动破坏、淤埋破坏和拉裂破坏3种形式破坏土地资源,并对土地利用损失进行了评估。结果表明:①各种土地利用类型中,淤埋破坏是最主要的破坏形式,占总破坏面积的77.23%,移动破坏面积占总破坏面积的22.77%;②林地和草地破坏呈现出在缓坡地带和陡坡地带破坏比例高,在中间地带破坏比例低的规律,旱地破坏具有随着坡度的增大而加剧的趋势;③研究区内各类土地利用类型总损失价值达76 577.26万元,其中林地损失量最大,占总损失价值的87.18%,是地震引起崩塌、滑坡灾害损失的主要对象。

The land resource of seismic disastrous area was seriously damaged by 5.12 Wenchuan Earthquake, which induced geo-hazards, including collapse, landslide, debris flow, ground cranny, geoazard dam lake and so on. This paper discusses the damage patterns and characteristics of different landuse types in the areas along Dujiangyan-Wenchuan Highway and evaluates their losses based on field investigation and remote sensing image analysis. This work demonstrates that geo-hazards have demolished land resources by movement damage, buried damage and land surface cranny. The results show that： （1） 22.77 % and 77.23% land resources damage was induced respectively by movement damage and buried damaged, and land surface cranny exacerbated land resources damage. （2） The damage percent of woodland and grassland was high in the gentle and steep slope and low in the mid slope. The damage percent of dry farmland increased with the farmland slope gradient rising. （3） The total loss value of the study area was 765.77 million Yuan, and that of the woodland accounted for 87.18% of the total loss value.