地貌學(xué)_8_水系

1、第九節(jié)第九節(jié) 河流地貌的發(fā)育河流地貌的發(fā)育一、水系的形式一、水系的形式水系是指一條干流及其所屬各級支流共同組成的河流系水系是指一條干流及其所屬各級支流共同組成的河流系統(tǒng)，在空間上呈網(wǎng)絡(luò)狀。如中國的七大江河、水系：統(tǒng)，在空間上呈網(wǎng)絡(luò)狀。如中國的七大江河、水系： 長江水系長江水系 黃河水系黃河水系 珠江水系珠江水系 松松-遼水系遼水系 海河水系海河水系 淮河水系淮河水系 太湖水系等太湖水系等長江流域（水系）長江流域（水系）黃河流域（水系）黃河流域（水系）珠江流域（水系）珠江流域（水系）松花江松花江- -遼河流域（水系）遼河流域（水系）海河流域（水系）海河流域（水系）淮河流域（水系）淮河流域（水系）

2、太湖流域（水系）太湖流域（水系）水系是構(gòu)成流域的骨架（如樹葉和葉脈的關(guān)系）。水系是構(gòu)成流域的骨架（如樹葉和葉脈的關(guān)系）。：源頭最小的河流開始算起；：源頭最小的河流開始算起；：將納入干流的河流稱為一級支流：將納入干流的河流稱為一級支流 分支法的缺點：同一級別支流大小懸殊。分支法的缺點：同一級別支流大小懸殊。水系的形態(tài)分類：水系的形態(tài)分類：影響因素影響因素 地質(zhì)：巖性、構(gòu)造形態(tài)和構(gòu)造運動；地質(zhì)：巖性、構(gòu)造形態(tài)和構(gòu)造運動； 地貌地貌按照平面形狀分：按照平面形狀分：（一）（一）（陜西涇河流域）（陜西涇河流域）水系分支不規(guī)則，主支流之間以近水系分支不規(guī)則，主支流之間以近。 地形：平坦，如平原區(qū)；地形：平

3、坦，如平原區(qū)； 巖性：均一，產(chǎn)狀水平，如黃土高原；巖性：均一，產(chǎn)狀水平，如黃土高原； 構(gòu)造運動：大面積緩慢抬升，無斷塊活動。構(gòu)造運動：大面積緩慢抬升，無斷塊活動。The dendritic pattern is the most common drainage pattern. The diagram to the left shows a classic example. The photo to the right (taken from the space shuttle) is from the country of Yemen. Source: TextSource: NASA ph

4、oto 41G-36-036（二）（二）（瀾滄江及支流）（瀾滄江及支流）支流和主干均作支流和主干均作或匯合?；騾R合。 褶皺區(qū)；褶皺區(qū)； 單斜山區(qū)；單斜山區(qū)； 兩組節(jié)理直交的結(jié)晶巖區(qū)（壓、張應(yīng)力往往垂直相交）。兩組節(jié)理直交的結(jié)晶巖區(qū)（壓、張應(yīng)力往往垂直相交）。Trellis patterns are common in the eastern US Appalachians and Oklahomas Quachita Mountains where underlying terrain is heavily folded. Trellis drainage pattern in Appalac

5、hians near Norris, TN（三）（三）（梳狀水系，如淮河流域）（梳狀水系，如淮河流域）各級河流大體相互平行。各級河流大體相互平行。 發(fā)育在有一定坡度，向某一方向傾斜的地形上，如掀斜發(fā)育在有一定坡度，向某一方向傾斜的地形上，如掀斜構(gòu)造上升區(qū)；構(gòu)造上升區(qū)； 單斜巖層區(qū)的順巖層傾斜的斜坡；單斜巖層區(qū)的順巖層傾斜的斜坡； 大片傾斜的泛濫平原上，如黃泛區(qū)入淮河的各級支流。大片傾斜的泛濫平原上，如黃泛區(qū)入淮河的各級支流。（四）（四）（長白山天池）（長白山天池）以高地為中心，河流呈放射狀向四周外流，常見于穹窿山地以高地為中心，河流呈放射狀向四周外流，常見于穹窿山地和火山錐地區(qū)。和火山錐地區(qū)。

6、Source: Microsoft TerraserverThis aerial photo of Mount Ranier shows glaciers and glacial streams emanating from the peak in a radial drainage pattern. Source: Text Radial patterns are typically found on volcanic mountains such as Mount Egmont or Mount Ranier.（五）（五）（牡丹江流域）（牡丹江流域）如果穹窿中部被侵蝕，呈現(xiàn)多列同心圓排列的

7、單斜山和單斜如果穹窿中部被侵蝕，呈現(xiàn)多列同心圓排列的單斜山和單斜谷，則沿軟弱巖層發(fā)育的許多單斜谷水系，就呈現(xiàn)多列同心谷，則沿軟弱巖層發(fā)育的許多單斜谷水系，就呈現(xiàn)多列同心圓的環(huán)狀水系。這時放射狀支流常注入環(huán)形干流中。圓的環(huán)狀水系。這時放射狀支流常注入環(huán)形干流中。（六）（六）（塔里木盆地四周）（塔里木盆地四周）從四周山地流出的河流向盆地匯聚，冰雪消融水，干旱蒸從四周山地流出的河流向盆地匯聚，冰雪消融水，干旱蒸發(fā)，斷流，到達(dá)之處為綠洲。發(fā)，斷流，到達(dá)之處為綠洲。Centripetal drainage pattern from the Gulf of Carpentaria, Australia,

8、This satellite image depicts a centripetal pattern of ephemeral streams draining into northern Saudi Arabias Wadi-as-Sirhan. Centripetal patterns are the opposite of radial patterns. They are composed of streams converging in a basin. The basin to the left is the ocean while the basin to the right i

9、s a desert bajada. 向心狀水系向心狀水系（Centripetal drainage pattern）（七）（七）（辮狀水系）（辮狀水系）發(fā)育在三角洲、沖積扇、山前傾斜平原，及水流小而河谷很發(fā)育在三角洲、沖積扇、山前傾斜平原，及水流小而河谷很寬的河谷區(qū)（構(gòu)造下沉或長期穩(wěn)定的河谷）寬的河谷區(qū)（構(gòu)造下沉或長期穩(wěn)定的河谷）（八）倒鉤狀水系（八）倒鉤狀水系（典型的如拉薩河以鈍角匯入雅魯藏布江典型的如拉薩河以鈍角匯入雅魯藏布江Special Report: June 20, 2000 Evidence of Water on Mars NASA has discovered eviden

10、ce of water on the Red Planets surface. The finding, made by the Mars Global Surveyor spacecraft, The discovery involves evidence of seasonal deposits that could be associated with springs on the planets surface. The discovery, if confirmed, of a primary goal in NASAs program to explore Mars. NASAs

11、ambitious plans for Mars focus on gaining an understanding of the potential for either past or present life on the planet. The program also aims to improve sciences understanding of Mars climate and its resources. Key to all three themes is water: Where and when it may have flowed in the past, where

12、 it might lurk today and in which forms and what quantities. Water most likely flowed in the distant past on Mars, carving channels and other features clearly visible on its surface. But other than in the form of clouds and ice, liquid water cannot exist on the planets surface today, thanks to the t

13、hinness of its atmosphere. Scientists have hypothesized that vast stores of water could still persist beneath the surface of Mars. The images that contributed to scientists conclusion that water has flowed across portions of the planets （Mars）surface relatively recently.Sedimentary rock layers like

14、these in Marss Holden Crater suggest that the Red Planet was once home to ancient lakes Nirgal Vallis, south of the eastern part of Valles Marineris, superficially resembles a river-cut valley on Earth Martian gullies in Newton Crater. Scientists hypothesize that liquid water burst out from underground, eroded the gullies, and pooled at the bottom of this crater as it froze and evaporated. If so, life-sustaining ice and water might exist even today below the Martian surface - water that could potentially support a human mission to Mars 火星上的河網(wǎng)火星上的河網(wǎng)水系的平面形態(tài)可以提供很多關(guān)于地表地貌、構(gòu)造和巖性水系的平面形態(tài)可