热带地理
熱帶地理
열대지리
TROPICAL GEOGRAPHY
2014年
3期
344-350
,共7页
舒成强%何政伟%张斌%蒋良群%罗明良%林叶彬
舒成彊%何政偉%張斌%蔣良群%囉明良%林葉彬
서성강%하정위%장빈%장량군%라명량%림협빈
元谋%土桥%干热河谷%潜蚀地貌%冲沟
元謀%土橋%榦熱河穀%潛蝕地貌%遲溝
원모%토교%간열하곡%잠식지모%충구
Yuanmou%soil bridge%Dry-hot Valley%erosional landforms%gully
元谋干热河谷区的土桥地貌是当地常见的一种潜蚀地貌,是区域地貌的重要组成部分。元谋土桥是造成当地水土流失的重要原因之一,研究其形态特征及演化过程对于认识区域地貌演化及生态地质环境的治理具有重要的现实意义。2009-2013年,通过多次对土桥形态特征、分布区域的地形地貌的现场测定,对土层进行了分析。结果表明:1)元谋土桥大部分分布于冲沟中上游的沟底,少部分分布于冲沟边缘的峭壁下,有连续出现,也有单独出现;2)土桥发育的土层具有层间差异性,即桥洞所在土层较其顶部土层抗崩解性弱,易受侵蚀;3)地层构造节理及冲沟坡度的变化等因素对土桥的形成具有一定的影响作用;4)元谋土桥的形态、结构与一般天生桥或人工桥梁具有相同的桥体结构,形态规模一般都不大;5)演化过程遵循一般事物的发展规律,分为萌芽期、年轻期、成熟期、消亡期4个阶段;6)元谋土桥与陷穴、冲沟等地貌具有一定的耦合关系。
元謀榦熱河穀區的土橋地貌是噹地常見的一種潛蝕地貌,是區域地貌的重要組成部分。元謀土橋是造成噹地水土流失的重要原因之一,研究其形態特徵及縯化過程對于認識區域地貌縯化及生態地質環境的治理具有重要的現實意義。2009-2013年,通過多次對土橋形態特徵、分佈區域的地形地貌的現場測定,對土層進行瞭分析。結果錶明:1)元謀土橋大部分分佈于遲溝中上遊的溝底,少部分分佈于遲溝邊緣的峭壁下,有連續齣現,也有單獨齣現;2)土橋髮育的土層具有層間差異性,即橋洞所在土層較其頂部土層抗崩解性弱,易受侵蝕;3)地層構造節理及遲溝坡度的變化等因素對土橋的形成具有一定的影響作用;4)元謀土橋的形態、結構與一般天生橋或人工橋樑具有相同的橋體結構,形態規模一般都不大;5)縯化過程遵循一般事物的髮展規律,分為萌芽期、年輕期、成熟期、消亡期4箇階段;6)元謀土橋與陷穴、遲溝等地貌具有一定的耦閤關繫。
원모간열하곡구적토교지모시당지상견적일충잠식지모,시구역지모적중요조성부분。원모토교시조성당지수토류실적중요원인지일,연구기형태특정급연화과정대우인식구역지모연화급생태지질배경적치리구유중요적현실의의。2009-2013년,통과다차대토교형태특정、분포구역적지형지모적현장측정,대토층진행료분석。결과표명:1)원모토교대부분분포우충구중상유적구저,소부분분포우충구변연적초벽하,유련속출현,야유단독출현;2)토교발육적토층구유층간차이성,즉교동소재토층교기정부토층항붕해성약,역수침식;3)지층구조절리급충구파도적변화등인소대토교적형성구유일정적영향작용;4)원모토교적형태、결구여일반천생교혹인공교량구유상동적교체결구,형태규모일반도불대;5)연화과정준순일반사물적발전규률,분위맹아기、년경기、성숙기、소망기4개계단;6)원모토교여함혈、충구등지모구유일정적우합관계。
Soil bridge isone of thecommon erosional landforms in Yuanmou Dry-hot Valley. It is alsoan importantreasoncausinglocalwaterand soilloss,studyingthemorphologicalcharacteristics and evolution process of soil bridgewouldhave important practical significanceforbetterunderstandingof the evolution of regional landforms andmanagement of localeco-geological environment.From 2009 to 2013the authors made field investigationsonthe morphological characteristics,microtopography of the soil bridge, the soil bridge position, and the shape of the longitudinal profile of the gully. And thepropertiesof soil layerswere analyzed. The resultsshowed: 1) Soil bridge mainly developedatthe bottomin upper and middle reachesof the gully,less at the bottom of cliffat the edge of gully. Somesoil bridgesoccurred continuously and some lonely. 2) Therewas differenceamongsoil layers ofthebridge,the resistance of thesoil layer of bridge holeagainstdisintegration and erosionwas weakerthanthat ofthe top layer ofthebridge. 3) Therewas some influence of structure joints and gully slope on the formation of soil bridge. 4) The shape and structure of soil bridgeweresimilar to those ofthe naturalbridge or the artificial bridge. The scaleof soil bridge was generally little. Theshapeofthebridge hole was mainlysimilarto triangle andsometimes to arc. The top of the hole mainly developed along the vertical joint and collapsewasmorefrequentlyobserved. The influencing factors of thesoil bridgedevelopmentweremainly the climate environment, the tectonic setting, the formation joint and the slope of gully, etc. 5) Theevolution processof soil bridgefollowed the general law of thing development, whichcould bedivided into four stages:germination stage, young stage, mature stage and withered stage. 6) Therewascertaincoupling relationship between soil bridge and sink hole and gully in Yuanmou.