Numerical modeling of groundwater‐driven stream network evolution in low‐relief post‐glacial landscapes
Numerical modeling of groundwater‐driven stream network evolution in low‐relief post‐glacial landscapes
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冰川后低洼地貌中地下水驱动的河流网络演化的数值模拟
DOI：
10.1002/esp.5278
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发表时间：
2021
影响因子：
3.3
通讯作者：
Druhan, Jennifer L.
中科院分区：
文献类型：
--
作者：
Cullen, Cecilia;Anders, Alison M.;Lai, Jingtao;Druhan, Jennifer L.
在美国中部低地的低起伏冰后期景观中，尽管低坡度和大部分陆地表面被封闭的洼地占据，但河流网络在冰川消退后形成并扩大。低起伏地形允许微妙的地表水分水岭，并增加了地下水分水岭与地表水分水岭不一致的可能性。我们研究如何通过微妙的地表水划分地下水转移促进渠道网络的扩展使用的数字模型建立在Landlab平台上。我们的模型模拟地表和地下水路由和河流侵蚀。我们考虑了两种地表水路由的端元情景，一种是封闭洼地中的地表水被迫连接到流域出口（路由），另一种是封闭洼地中的地表水因蒸散而损失（无路由）。地下水模拟为承压含水层内的完全饱和流。地下水在地貌侵蚀到一定深度时以地表水的形式出现。我们保持总水通量不变，并改变了作为地下水与降水引入的水的比例。给定相同的地下水份额，路由情况下的通道增长明显快于无路由情况。在有路由和无路由的情况下，当总水量的约30%作为地下水进入系统时，渠道扩展最快。地下水的贡献也产生独特的形态，包括地下水渗漏下面的陡峭的通道剖面。地下水水头梯度随地形而变化，地下水补给渠道的增长速度可能比地表水集水区较大的渠道更快。我们的结论是，在低海拔冰川后地区的通道网络的增长率是敏感的地下水的贡献。更广泛地说，我们的研究结果表明，景观演变模型可能会受益于更详细的水文过程的代表性。
In the low‐relief post‐glacial landscapes of the Central Lowlands of the United States, fluvial networks formed and expanded following deglaciation despite the low slopes and large fraction of the land surface occupied by closed depressions. Low relief topography allows for subtle surface water divides and increases the likelihood that groundwater divides do not coincide with surface water divides. We investigate how groundwater transfer across subtle surface water divides facilitates channel network expansion using a numerical model built on the Landlab platform. Our model simulates surface and subsurface water routing and fluvial erosion. We consider two end‐member scenarios for surface water routing, one in which surface water in closed depressions is forced to connect to basin outlets (routing) and one in which surface water in closed depressions is lost to evapotranspiration (no routing). Groundwater is modeled as fully saturated flow within a confined aquifer. Groundwater emerges as surface water where the landscape has eroded to a specified depth. We held the total water flux constant and varied the fraction of water introduced as groundwater versus precipitation. Channel growth is significantly faster in routing cases than no‐routing cases given identical groundwater fractions. In both routing and no‐routing cases, channel expansion is fastest when ~30% of the total water enters the system as groundwater. Groundwater contributions also produce distinctive morphology including steepened channel profiles below groundwater seeps. Groundwater head gradients evolve with topography and groundwater‐fed channels can grow more quickly than channels with larger surface water catchments. We conclude that rates of channel network growth in low‐relief post‐glacial areas are sensitive to groundwater contributions. More broadly, our findings suggest that landscape evolution models may benefit from more detailed representation of hydrologic processes.
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低地地区溪流与地下水系统界面的动态，参考溪流网演化
影响因子：
6.4
作者：
J. J. Vries
通讯作者：
J. J. Vries
GroundwaterDupuitPercolator：用于地下水流的 Landlab 组件
影响因子：
--
作者：
Litwin, David;Tucker, Gregory;Barnhart, Katherine;Harman, Ciaran
通讯作者：
Harman, Ciaran
DOI：
10.5194/esurf-8-431-2020
发表时间：
2020-06
期刊：
--
影响因子：
--
作者：
Richard Barnes;K. Callaghan;A. Wickert
通讯作者：
Richard Barnes;K. Callaghan;A. Wickert
无人居住的荒地：十九世纪美国伊利诺伊州大草原城的改造
影响因子：
1
作者：
M. Urban
通讯作者：
M. Urban
流域演化模型对径流产生性质和初始条件的敏感性
DOI：
--
发表时间：
1992
期刊：
影响因子：
--
作者：
E. Ijjász;R. Bras;G. Moglen
通讯作者：
G. Moglen