是什么控制着河流搬运泥沙的能力（competence）与容量（capacity）？
What controls a river's competence and capacity to transport sediment?
搬运能力(competence)指河流能搬动的最大颗粒粒径，随流速的平方急剧增大；搬运容量(capacity)是单位时间内能携带的总泥沙量，与流量和坡度相关。洪水期流速骤增，二者都显著上升，塑造河床与三角洲。
Competence is the largest particle size a river can move and rises sharply with the square of flow velocity; capacity is the total sediment load it can carry per unit time, linked to discharge and slope. Both surge during floods, reshaping channels and deltas.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
丁曼《物理水文学》，Waveland Press，2015
Dingman, S.L., Physical Hydrology, Waveland Press, 2015
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL3903765W：Physical hydrology（首版 1
#河流搬运 #搬运能力 #搬运容量
长江三峡为什么能发出那么多电？
Why can the Three Gorges generate so much electricity?
三峡把长江巨大的水量和高落差的势能装进大坝，水流推动水轮机发电，是世界上最大的水力发电工程之一。
The dam captures the Yangtze's huge volume and head, spinning turbines—one of the world's largest hydropower projects.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
国际水电协会《2019年水电现状报告》
International Hydropower Association (2019), Hydropower Status Report
#三峡 #水电
什么是河口？
What is an estuary?
河流入海处淡水咸水交汇混合，泥沙淤积、养分丰富，是许多生物的育儿场。
Where a river meets the sea, fresh and salt water mix, making a nursery rich in life.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #河口
什么是牛轭湖？
What is an oxbow lake?
河流弯曲过度，洪水冲断颈部取直，被抛弃的旧河道围成新月形死水湖，即牛轭湖。
A river cuts off a tight meander during flood; the abandoned loop becomes a crescent oxbow lake.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #牛轭湖
什么是河漫滩？
What is a floodplain?
河漫滩是河流两侧洪水期才会淹到的平坦低地，沉积肥沃，宜农但也易涝。
A floodplain is the flat land beside a river flooded at high water; fertile but risky.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #河漫滩
河流为什么会改道？
Why do rivers change course?
洪水冲刷、泥沙淤积使河道摆动，或地壳抬升改变坡度，河流便会逐渐迁移或改道。
Floods and sediment build-up make channels shift, or crustal uplift changes the slope, so rivers gradually migrate or change course.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #河道
什么是地下河？
What is an underground river?
在喀斯特区地表水渗入溶洞，沿暗道流动形成地下河，常从泉眼重新涌出。
In karst, water flows through caves as underground rivers that re-emerge at springs.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #地下河
什么是溯源侵蚀？
What is headward erosion?
溯源侵蚀发生在谷头：水流集中在细沟、坡陡流急，加上源头下方渗流掏空支撑，陡壁不断崩落，谷头便朝分水岭后退、河谷延长。沟一旦抢到更大汇水面积，流量与能量齐升，后退自我放大，这是谷头比下游发展快的原因。边界在水与岩性：源头没水或遇抗蚀岩层即停止；若邻谷坡更陡、基准面更低，沟头反被截走——河流袭夺正是它重画水系分界的结果。
Headward erosion works at the head of a valley. There the water is squeezed into a small channel on a steep slope, so it cuts hard, and seepage at the head undercuts its support until the steep wall keeps collapsing; the valley head steps backward toward the divide and the valley lengthens. Once a gully gains a larger catchment, discharge and energy rise together and its own retreat feeds on itself, which is why heads advance faster than lower reaches. The limits are water and rock: a head with no flow, or one protected by resistant rock, stops retreating, and if a neighbouring valley has a steeper slope and a lower base level, that head is cut off instead - river capture is precisely headward erosion redrawing the water divide.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #溯源侵蚀
什么是河流阶地？
What is a river terrace?
河流阶地是被废弃的古谷底，河流下切后悬在洪水之上，成为阶梯状平台。形成要两步：先侧蚀堆积出宽阔谷底，再重新下切，老谷底便脱离泛滥。下切可来自构造抬升或基准面下降，也可来自气候与来沙变化让河流重调比降，所以阶地记的是水沙与基准面关系的改变，不等于地壳在抬。它也不再是河漫滩，判定要看下部河床砾石、上部漫滩细粒的二元结构。
A river terrace is an abandoned valley floor left hanging above the floodwater when the river cuts down, forming a step-like bench. It takes two stages: lateral erosion and deposition first make a wide floor, then renewed incision leaves it out of the flood. Cutting down may come from tectonic uplift or a fall in base level, but also from climate or sand-supply change that makes the river re-adjust its slope, so terraces record a shift in the balance between water, sediment and base level rather than proof that the crust is rising. They are no longer floodplains either, and identifying one means looking for the two-part structure of bed gravels below and overbank fines above.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #阶地
河流的源头一般在什么地方？
Where do rivers usually start?
多源于山地、冰川或湖泊，雨水积雪汇成小溪，逐渐汇聚成河，如长江源出青藏高原。
Often from mountains, glaciers or lakes; rain and snow become streams that join into a river, e.g. the Yangtze starts on the Qinghai-Tibet Plateau.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #河源
为什么河流会弯曲？
Why do rivers meander?
水流冲刷凹岸、淤积凸岸，河道逐渐弯成蛇形。
Water erodes one bank and deposits on the other, bending the channel.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#侵蚀 #沉积 #河道
蜿蜒的河流是如何形成牛轭湖的？
How do meandering rivers create oxbow lakes?
河流弯曲处外侧侵蚀、内侧堆积，使河弯越来越弯；洪水期水流可能冲断脖颈、取直河道，被遗弃的旧弯便封闭成新月形的牛轭湖。密西西比河平原多见此类地貌。
On a meandering river the outer bank erodes while the inner bank deposits, so bends grow tighter; during a flood the flow may cut across the neck and straighten the channel, leaving the abandoned loop sealed off as a crescent-shaped oxbow lake. The Mississippi Delta plain shows many such features.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
丁曼《物理水文学》，Waveland Press，2015
Dingman, S.L., Physical Hydrology, Waveland Press, 2015
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL3903765W：Physical hydrology（首版 1
#河曲 #牛轭湖 #裁弯取直
为什么河流入海口土地常很肥沃？
Why is land near river mouths often fertile?
河流是流域的搬运带，把上游侵蚀的细粒泥沙与养分带到下游。河口变宽变平、又遇静止咸水，流速骤降，海水电解质还把带电黏粒聚成絮团沉下，最细最富矿物的部分先停在这里，堆成深厚冲积层。关键是补给在循环：洪水定期漫滩摊回新沙，养分不会被种光。它也不是天生的：排水不畅会盐渍涝渍，上游筑坝截沙断了沙源后河口还会下沉、遭海水倒灌。
A river is the conveyor belt of its catchment, carrying the fine sediment and nutrients freed by erosion downstream. At the mouth the channel widens and flattens, the water meets relatively still salt water, and velocity drops sharply; electrolytes in the sea also clump the charged clay colloids into flakes that sink, so the finest and most mineral-rich fraction is the first to stop here, building a thick alluvial layer. What matters is that the supply keeps cycling: floods spill over the banks and lay fresh silt back on the surface, so the nutrients are never cropped out. This fertility is not a gift of the place either - poor drainage brings salinity and waterlogging, and once a dam upstream traps the sediment the mouth loses its supply, sinks, and takes in salt water.
难度 进阶 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #冲积平原
湖泊是什么？
What is a lake?
湖泊是陆地低洼处蓄积起来的静止水体，四周被陆地包围，不与海洋直接相连。
A lake is a body of still water in a land depression, surrounded by land.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #湖泊
瀑布是怎么形成的？
How do waterfalls form?
当河流流经软硬不同的岩层，软岩被冲刷快、硬岩留下，形成陡坎，水流跌落即成瀑布。
Where a river crosses layers of different hardness, soft rock erodes faster leaving a ledge, and water plunges over it as a waterfall.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #瀑布
三角洲是怎样形成的？
How does a delta form?
河流入海入湖时流速减慢，携带的泥沙沉积下来，久而久之形成扇形或三角形的平地。
Where a river meets the sea or lake its speed drops and deposits sediment, building a fan- or triangle-shaped plain over time.
难度 入门 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #三角洲
水是怎样循环的？
How does the water cycle work?
太阳晒热海洋和湖泊使水蒸发成云，降水落回地面，再汇成河流流回大海。
The sun evaporates water into clouds; rain falls and flows through rivers back to the sea.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #水循环
什么是地下水？
What is groundwater?
雨水雪水渗入地下，积存在岩石和沙土的空隙里，就是地下水，井和水泉都来自它。
Rain and snow soak into the ground and collect in spaces in rock and soil; that is groundwater, the source of wells and springs.
难度 入门 · 适合 小学低段(6-8)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#河流 #地下水