热带地理
熱帶地理
열대지리
TROPICAL GEOGRAPHY
2014年
2期
133-140
,共8页
崩岗侵蚀%三维激光扫描%侵蚀模数%点云数据%DEM
崩崗侵蝕%三維激光掃描%侵蝕模數%點雲數據%DEM
붕강침식%삼유격광소묘%침식모수%점운수거%DEM
collapsing hill and gully erosion%3D laser scanning%erosion modulus%point cloud data%DEM
崩岗复杂的地形及其动态发育过程是崩岗监测关注的重点和难点。三维激光扫描技术具有高精度、非接触性、穿透性、快速性等特点,能够突破传统监测手段的空间限制,有效获取崩岗地形的细部特征。在介绍基本原理和应用现状的基础上,利用Leica ScanStation 2三维激光扫描仪,对广东五华县莲塘岗崩岗进行连续3 a共6次实地监测。选择2011-06-03和2012-05-12两次监测结果,通过ArcGIS对数据进行处理分析。结果表明:莲塘岗崩岗体积侵蚀量为1007 m3/a,年侵蚀量为1380 t,侵蚀模数为269268 t/(km2·a),崩岗中下部位侵蚀强度高于上部。侵蚀最强烈地带出现在中下部海拔高度为111~116 m和116~121 m的崩积锥分布部位,侵蚀量分别为202和178 m3/a,崩积锥土体松散,极易在片流和股流作用下出现侵蚀,崩积锥快速侵蚀导致崩壁加高,使得崩岗呈现出越高越陡的态势。此外,在崩岗下部96~101 m和101~106 m两个区段的侵蚀作用也比较强烈,侵蚀量分别为151和157 m3/a,这一高程区为多条支沟汇合后的主沟道段,每年雨季水力侵蚀十分强烈,沟道侧蚀加宽和下切加深,进一步加速崩岗的重力侵蚀过程,致使莲塘岗崩岗仍处于快速侵蚀和崩壁加高变陡的壮年期阶段。三维激光扫描连续监测结果的对比分析,不但能够定量得到崩岗侵蚀量及地形的变动信息,还可进一步探究侵蚀泥沙的来源及其精细的空间分布特征,是崩岗监测较为理想的先进技术。
崩崗複雜的地形及其動態髮育過程是崩崗鑑測關註的重點和難點。三維激光掃描技術具有高精度、非接觸性、穿透性、快速性等特點,能夠突破傳統鑑測手段的空間限製,有效穫取崩崗地形的細部特徵。在介紹基本原理和應用現狀的基礎上,利用Leica ScanStation 2三維激光掃描儀,對廣東五華縣蓮塘崗崩崗進行連續3 a共6次實地鑑測。選擇2011-06-03和2012-05-12兩次鑑測結果,通過ArcGIS對數據進行處理分析。結果錶明:蓮塘崗崩崗體積侵蝕量為1007 m3/a,年侵蝕量為1380 t,侵蝕模數為269268 t/(km2·a),崩崗中下部位侵蝕彊度高于上部。侵蝕最彊烈地帶齣現在中下部海拔高度為111~116 m和116~121 m的崩積錐分佈部位,侵蝕量分彆為202和178 m3/a,崩積錐土體鬆散,極易在片流和股流作用下齣現侵蝕,崩積錐快速侵蝕導緻崩壁加高,使得崩崗呈現齣越高越陡的態勢。此外,在崩崗下部96~101 m和101~106 m兩箇區段的侵蝕作用也比較彊烈,侵蝕量分彆為151和157 m3/a,這一高程區為多條支溝彙閤後的主溝道段,每年雨季水力侵蝕十分彊烈,溝道側蝕加寬和下切加深,進一步加速崩崗的重力侵蝕過程,緻使蓮塘崗崩崗仍處于快速侵蝕和崩壁加高變陡的壯年期階段。三維激光掃描連續鑑測結果的對比分析,不但能夠定量得到崩崗侵蝕量及地形的變動信息,還可進一步探究侵蝕泥沙的來源及其精細的空間分佈特徵,是崩崗鑑測較為理想的先進技術。
붕강복잡적지형급기동태발육과정시붕강감측관주적중점화난점。삼유격광소묘기술구유고정도、비접촉성、천투성、쾌속성등특점,능구돌파전통감측수단적공간한제,유효획취붕강지형적세부특정。재개소기본원리화응용현상적기출상,이용Leica ScanStation 2삼유격광소묘의,대엄동오화현련당강붕강진행련속3 a공6차실지감측。선택2011-06-03화2012-05-12량차감측결과,통과ArcGIS대수거진행처리분석。결과표명:련당강붕강체적침식량위1007 m3/a,년침식량위1380 t,침식모수위269268 t/(km2·a),붕강중하부위침식강도고우상부。침식최강렬지대출현재중하부해발고도위111~116 m화116~121 m적붕적추분포부위,침식량분별위202화178 m3/a,붕적추토체송산,겁역재편류화고류작용하출현침식,붕적추쾌속침식도치붕벽가고,사득붕강정현출월고월두적태세。차외,재붕강하부96~101 m화101~106 m량개구단적침식작용야비교강렬,침식량분별위151화157 m3/a,저일고정구위다조지구회합후적주구도단,매년우계수력침식십분강렬,구도측식가관화하절가심,진일보가속붕강적중력침식과정,치사련당강붕강잉처우쾌속침식화붕벽가고변두적장년기계단。삼유격광소묘련속감측결과적대비분석,불단능구정량득도붕강침식량급지형적변동신식,환가진일보탐구침식니사적래원급기정세적공간분포특정,시붕강감측교위이상적선진기술。
The complex topography and dynamic erosion process are the key problems to be taken into consideration for collapsing hill and gully monitoring. 3D laser scanning is a very useful tool which is of high accuracy, non-contact, penetrating and rapidity. This paper has introduced the principles of 3D laser scanning technology and its application. By surveying Liantanggang collapsing hill and gully in the Wuhua County of Guangdong for 6 times during the last 3 years by 3D laser scanner (Leica ScanStation 2), the paper analyzes the data acquired on June 3rd, 2011 and May 12th, 2012 by ArcGIS. The results indicate that Liantanggang collapsing hill and gully erosion volume is 1 007 m3/a, i.e. 1 380 t/a, and the erosion modulus is 269 268 t/(km2·a). The erosion rate on the middle-lower zones of the collapsing hill and gully is higher than that of the upper, and the intense erosion zones appear at the elevation between 111~116 m and 116~121 m with the erosion volumes of 202 and 178 m3/a, respectively, where there are collapsing soils which are easily erodible by sheet wash and gully flow. The collapsing soil erosion makes the collapsing hill present such a form that the higher the elevation is, the steeper the headwall would be. The lower zones at the elevation between 96~101 m and 101~106 m also have an intense erosion with the erosion volumes of 151 and 157 m3/a, respectively. In those areas, the main gully with serveral tributary gullies, has intense lateral and down-cutting erosions during rainy season, that can trigger gravitational erosion to make the collapsing hill and gully keep in the mature phrase with a high erosion rate and steep headwall. 3D laser scanning can break through the space limits of traditional monitoring and so can effectively obtain topographic details of collapsing hill and gully. The comparative analyses of continuous monitoring data not only can obtain the information of the collapsing hill and gully erosion rate, but also the quantitative terrain changes, as well as a possible explanation for the erosion sediment sources from the collapsing hill and gully. 3D laser scanning may be a promising technology for collapsing hill and gully monitoring.