A paradigm shift in stormflow predictions for active tectonic regions with large-magnitude storms: generalisation of catchment observations by hydraulic sensitivity analysis and insight into soil-layer evolution
A paradigm shift in stormflow predictions for active tectonic regions with large-magnitude storms: generalisation of catchment observations by hydraulic sensitivity analysis and insight into soil-layer evolution
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DOI：
10.5194/hess-17-4453-2013
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发表时间：
2013-11
影响因子：
6.3
通讯作者：
M. Tani
中科院分区：
文献类型：
--
作者：
M. Tani
在大型风暴活动的构造区，如果不利用观测资料进行参数标定，就很难用集水区的分布式径流模型来预测暴雨响应。这篇论文是解决这一问题的一种尝试。对观测研究的回顾表明，暴雨的产生机制是不均匀的和复杂的，但在暴雨贡献面积因雨量充足而空间不变的情况下，暴雨的响应简单地用一个带排水孔的单一水箱来模拟。这些结果表明，这种快速的流入/流出流波形传输来自于准稳态下水力连续体的形成。通过对坡面土层的灵敏度分析，从理论上考察了产生连续体的一般条件。利用Richards方程建立了一个新的相似框架，用于描述波形传输对地形和土壤性质的敏感性。敏感性分析表明，饱和-过剩坡面流一般产生于没有大孔隙效应的土层中，而在大孔隙效应产生的排水能力较大的土层中，饱和-过剩坡面流主要来自垂直非饱和水流，而不是下坡水流。两者对于快速传输都是可能的，但对土层演变过程的讨论表明，由于排水能力大，对陆面水流的抑制起到了关键作用，因为可能需要限制土层内的水流，以抵御地理区域的强烈侵蚀力。其漫长的演变历史可能会在简单的暴雨响应和复杂的集水区特性之间起到调节作用。因此，通过比较水文学对这一演变过程的洞察和对集水区特性相关性的直观评估，可以用分布式径流模型来预测暴雨径流响应。
In active tectonic regions with large-magnitude storms, it is still difficult to predict stormflow responses by distributed runoff models from the catchment proper- ties without a parameter calibration using observational data. This paper represents an attempt to address the problem. A review of observational studies showed that the storm- flow generation mechanism was heterogeneous and com- plex, but stormflow responses there were simply simulated by a single tank with a drainage hole when the stormflow- contribution area was spatially invariable due to the suffi- cient amount of rainfall supply. These results suggested such a quick inflow/outflow waveform transmission was derived from the creation of a hydraulic continuum under a quasi- steady state. General conditions necessary for the continuum creation were theoretically examined by a sensitivity analy- sis for a sloping soil layer. A new similarity framework using the Richards equation was developed for specifying the sen- sitivities of waveform transmission to topographic and soil properties. The sensitivity analysis showed that saturation- excess overland flow was generally produced from a soil layer without any macropore effect, whereas the transmis- sion was derived mainly from the vertical unsaturated flow instead of the downslope flow in a soil layer with a large drainage capacity originated from the macropore effect. Both were possible for the quick transmission, but a discussion on the soil-layer evolution process suggested that an inhibition of the overland flow due to a large drainage capacity played a key role, because a confinement of the water flow within the soil layer might be needed for the evolution against strong erosional forces in the geographical regions. The long history of its evolution may mediate a relationship between simple stormflow responses and complex catchment properties. As a result, an insight into this evolution process and an induc- tive evaluation of the dependences on catchment properties by comparative hydrology are highly encouraged to predict stormflow responses by distributed runoff models.