合成孔径雷达(SAR)具有全天时、全天候成像能力和图像立体感强的优势,在汶川大地震灾情监测与评估中发挥了不可替代的作用.利用多源多时相高分辨率雷达遥感数据,对汶川地震灾区各城镇和次生灾害进行了快速、系统、连续的监测,并根据雷达图像特征对房屋损毁情况、滑坡和堰塞湖的分布与规模等进行了快速定量评估,建立了相应的解译标志.监测成果及报告呈送了国家各有关部门和救援队伍,为抢险救灾及灾后重建工作提供了详实、可靠的科学依据.

Synthetic ApertureRadar(SAR)has significantadvantages in disaster monitoring thatare allweather, inde-pendentof illumination mi aging capabilities and strong stereoscopic sense. SAR technology played irreplaceable role in rapid response toWenchuanEarthquakemonitoring and damage assessment. Wenchuan Earthquake generated numerous of landslides, landslide lakes and dams, aswellasdebris flows. Theirquantity, scale and dmi ension brake historic records.Landslides buried towns and villages, blocked up river channelswhich inundated villages and heavily destroyed the road networks andmade the rescuework extremely difficult. The hardship ofrescue effortswasbeyond of human miagination in Wenchuan Earthquake.With high resolution SAR mi ageswe detecte a greatdealof landslides and landslide lakes. Those giant catastrophic landslides reach very large size and scale. One of the largest landslideswe detecte has total area of 7km 2 and fly distance of 4km. They fly from one side of the riverbank to the opposite bank. It ishard to explain theirbe-havior and scalewith ordinary conceptof landslide. Moving such amountofmaterialneeds tremendous energy. DoesWen-chuan Earthquake provide such amountof energy Why doesWenchuan Earthquake generate somany seismic secondary disasters Certainly geosciences community needs further research to solve this puzzle.Themicrowave remote sensing division in Institute ofRemote Sensing Applicationsmade 7 reports on Tangjiashan landslide and Landslide Lake,Beichuan countywithmulti-temporalSAR mi ages,7 reports on other landslides and land-slide lakes,1 reporton building damage assessment for several counties,includingAnchang town, HuagaiTown, Mianzu City and LuojiangCity. All the reportswere delivered to central and localgovernment, ministries and rescue teams. This paper summaries thework thathas been done forWenchuan Earthquake.This paperpresents the SAR miage interpretation on building damage assessment,landslide and landslide lakemoni-toring, especially their characteristics on SAR mi ages.The damaged building normally has no clear texture or shadow in contrastwith buildings in good conditions. Owing to the good stereoscopic sense ofSAR mi ages,we can identify the back scar, debris deposit, fly trace and measure the total area and the flying distance of a landslide. With continuously acquiredmulti-temporal SAR mi ages, including Terra SAR-X and COSMO-SkyMed satellite SAR mi ages,we can track the development of a landslide lake such asTangjiashan LandslideLake.Aswater level rising,the small towns such as Xuan Ping, Zhicheng and village ShengKenziare inundated. TheXuan PingTown is finally totalunderwater.Many roads along the Jian Riverare inundated aswel.l The tail of Tangjiashan Landslide Lake extends toward upstream gradually, andwidens the riverchannelobviously.All the information extracted and evaluation delivered from SAR miagesmade greatcontri-bution to the decisionmaking and rescue action.