地貌学_8_水系

1、第九节第九节 河流地貌的发育河流地貌的发育一、水系的形式一、水系的形式水系是指一条干流及其所属各级支流共同组成的河流系水系是指一条干流及其所属各级支流共同组成的河流系统，在空间上呈网络状。如中国的七大江河、水系：统，在空间上呈网络状。如中国的七大江河、水系： 长江水系长江水系 黄河水系黄河水系 珠江水系珠江水系 松松-辽水系辽水系 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长江流域（水系）长江流域（水系）黄河流域（水系）黄河流域（水系）珠江流域（水系）珠江流域（水系）松花江松花江- -辽河流域（水系）辽河流域（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）水系是构成流域的骨架（如树叶和叶脉的关系）。水系是构成流域的骨架（如树叶和叶脉的关系）。：源头最小的河流开始算起；：源头最小的河流开始算起；：将纳入干流的河流称为一级支流：将纳入干流的河流称为一级支流 分支法的缺点：同一级别支流大小悬殊。分支法的缺点：同一级别支流大小悬殊。水系的形态分类：水系的形态分类：影响因素影响因素 地质：岩性、构造形态和构造运动；地质：岩性、构造形态和构造运动； 地貌地貌按照平面形状分：按照平面形状分：（一）（一）（陕西泾河流域）（陕西泾河流域）水系分支不规则，主支流之间以近水系分支不规则，主支流之间以近。 地形：平坦，如平原区；地形：平

3、坦，如平原区； 岩性：均一，产状水平，如黄土高原；岩性：均一，产状水平，如黄土高原； 构造运动：大面积缓慢抬升，无断块活动。构造运动：大面积缓慢抬升，无断块活动。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）（澜沧江及支流）（澜沧江及支流）支流和主干均作支流和主干均作或汇合。或汇合。 褶皱区；褶皱区； 单斜山区；单斜山区； 两组节理直交的结晶岩区（压、张应力往往垂直相交）。两组节理直交的结晶岩区（压、张应力往往垂直相交）。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）（梳状水系，如淮河流域）（梳状水系，如淮河流域）各级河流大体相互平行。各级河流大体相互平行。 发育在有一定坡度，向某一方向倾斜的地形上，如掀斜发育在有一定坡度，向某一方向倾斜的地形上，如掀斜构造上升区；构造上升区； 单斜岩层区的顺岩层倾斜的斜坡；单斜岩层区的顺岩层倾斜的斜坡； 大片倾斜的泛滥平原上，如黄泛区入淮河的各级支流。大片倾斜的泛滥平原上，如黄泛区入淮河的各级支流。（四）（四）（长白山天池）（长白山天池）以高地为中心，河流呈放射状向四周外流，常见于穹窿山地以高地为中心，河流呈放射状向四周外流，常见于穹窿山地和火山锥地区。和火山锥地区。

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）如果穹窿中部被侵蚀，呈现多列同心圆排列的

7、单斜山和单斜如果穹窿中部被侵蚀，呈现多列同心圆排列的单斜山和单斜谷，则沿软弱岩层发育的许多单斜谷水系，就呈现多列同心谷，则沿软弱岩层发育的许多单斜谷水系，就呈现多列同心圆的环状水系。这时放射状支流常注入环形干流中。圆的环状水系。这时放射状支流常注入环形干流中。（六）（六）（塔里木盆地四周）（塔里木盆地四周）从四周山地流出的河流向盆地汇聚，冰雪消融水，干旱蒸从四周山地流出的河流向盆地汇聚，冰雪消融水，干旱蒸发，断流，到达之处为绿洲。发，断流，到达之处为绿洲。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. 向心状水系向心状水系（Centripetal drainage pattern）（七）（七）（辫状水系）（辫状水系）发育在三角洲、冲积扇、山前倾斜平原，及水流小而河谷很发育在三角洲、冲积扇、山前倾斜平原，及水流小而河谷很宽的河谷区（构造下沉或长期稳定的河谷）宽的河谷区（构造下沉或长期稳定的河谷）（八）倒钩状水系（八）倒钩状水系（典型的如拉萨河以钝角汇入雅鲁藏布江典型的如拉萨河以钝角汇入雅鲁藏布江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 火星上的河网火星上的河网水系的平面形态可以提供很多关于地表地貌、构造和岩性水系的平面形态可