Historic drought puts the brakes on earthflows in Northern California
Historic drought puts the brakes on earthflows in Northern California
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DOI：
10.1002/2016gl068378
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发表时间：
2016-06-16
影响因子：
5.2
通讯作者：
Guillod, B. P.
中科院分区：
文献类型：
--
作者：
Bennett, G. L.;Roering, J. J.;Guillod, B. P.
加州持续的、史无前例的干旱对该州的资源产生了深远的影响。在这里，我们评估了它对北加州 98 起深层、缓慢移动的山体滑坡的影响。我们使用航空照片分析、卫星干涉测量和卫星像素跟踪来测量 1944 年至 2015 年期间的土流速度，并将这些趋势与帕尔默干旱严重度指数（控制滑坡运动的土壤湿度和孔隙压力的代表）进行比较。我们发现，土流速度在 2012-2015 年干旱期间达到了历史最低点，但土流速度在世纪之交开始减速，以应对长期的水分不足。我们的分析表明，土流对气候强迫的敏感性与深度有关，较厚的土流反映了长期气候趋势，而较薄的土流则表现出较少的系统性速度变化。这些发现对于将滑坡运动与气候变化以及该地区沉积物输送联系起来的机械-水文相互作用具有重要意义。
California's ongoing, unprecedented drought is having profound impacts on the state's resources. Here we assess its impact on 98 deep-seated, slow-moving landslides in Northern California. We used aerial photograph analysis, satellite interferometry, and satellite pixel tracking to measure earthflow velocities spanning 1944-2015 and compared these trends with the Palmer Drought Severity Index, a proxy for soil moisture and pore pressure that governs landslide motion. We find that earthflow velocities reached a historical low in the 2012-2015 drought, but that their deceleration began at the turn of the century in response to a longer-term moisture deficit. Our analysis implies depth-dependent sensitivity of earthflows to climate forcing, with thicker earthflows reflecting longer-term climate trends and thinner earthflows exhibiting less systematic velocity variations. These findings have implications for mechanical-hydrologic interactions that link landslide movement with climate change as well as sediment delivery in the region.