Modelling the future impacts of climate and land-use change on suspended sediment transport in the River Thames (UK)
Modelling the future impacts of climate and land-use change on suspended sediment transport in the River Thames (UK)
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DOI：
10.1016/j.jhydrol.2016.09.010
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发表时间：
2016-11-01
影响因子：
6.4
通讯作者：
Whitehead, Paul G.
中科院分区：
文献类型：
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作者：
Bussi, Gianbattista;Dadson, Simon J.;Whitehead, Paul G.
气候变化和变异性对河流流量的影响已得到广泛研究。然而，这种变化对泥沙输运的影响却很少受到关注。这部分是因为模拟沉积物产生和迁移过程带来了更多的不确定性，但也是因为除了气候变化信号之外，土地覆被已经发生并预计将发生重大变化，对与沉积物有关的过程产生强烈影响。在这里，我们评估了一系列的气候变化和土地覆盖对泰晤士河流域（英国）的影响。我们首先计算系统对气候压力源（平均降水量，平均温度和极端降水量的增加）和土地覆盖压力源（耕地面积的变化）的响应。为此，我们使用印加水文和沉积物行为模型的集合。由此产生的系统响应，揭示了驱动因素之间的相互作用的性质，然后与源自UKCP 09评估（英国气候预测2009）的气候预测进行比较，以评估预测结果范围的可能性。结果表明，气候和土地覆盖对泥沙输运都有各自的控制作用。它们的影响因土地使用和预测的气候变化程度而异。在20305年A1 FI排放情景下，泰晤士河最低河段的悬浮泥沙产量预计将变化-4%（-16%至+13%，置信区间，p = 0.95），尽管这些数字可能会因极端降水量的增加而发生实质性变化，这可能会使悬浮泥沙产量再增加+10%。预计可耕地面积增加70%将使低地河段的产沙量增加约12%。预计减少50%将使产沙量减少约13%。(C)2016作者由爱思唯尔公司出版
The effects of climate change and variability on river flows have been widely studied. However the impacts of such changes on sediment transport have received comparatively little attention. In part this is because modelling sediment production and transport processes introduces additional uncertainty, but it also results from the fact that, alongside the climate change signal, there have been and are projected to be significant changes in land cover which strongly affect sediment-related processes. Here we assess the impact of a range of climatic variations and land covers on the River Thames catchment (UK). We first calculate a response of the system to climatic stressors (average precipitation, average temperature and increase in extreme precipitation) and land-cover stressors (change in the extent of arable land). To do this we use an ensemble of INCA hydrological and sediment behavioural models. The resulting system response, which reveals the nature of interactions between the driving factors, is then compared with climate projections originating from the UKCP09 assessment (UK Climate Projections 2009) to evaluate the likelihood of the range of projected outcomes. The results show that climate and land cover each exert an individual control on sediment transport. Their effects vary depending on the land use and on the level of projected climate change. The suspended sediment yield of the River Thames in its lowermost reach is expected to change by -4% (-16% to +13%, confidence interval, p = 0.95) under the A1FI emission scenario for the 20305, although these figures could be substantially altered by an increase in extreme precipitation, which could raise the suspended sediment yield up to an additional +10%. A 70% increase in the extension of the arable land is projected to increase sediment yield by around 12% in the lowland reaches. A 50% reduction is projected to decrease sediment yield by around 13%. (C) 2016 The Authors. Published by Elsevier B.V.