《Journal of Hydrologic Engineering 》杂志刊登

“人工水库规模和土地利用/土地覆盖模式对可能最大降水和洪水的影响：以美国河流上的Folsom坝为例”

作  者：Wondmagegn Yigzaw, Faisal Hossain, Alfred Kalyanapu

刊  物：《Journal of Hydrologic Engineering》，第18卷第9期（2013年9月），1180–1190页

关键词：Montedoglio坝，溢洪道垮塌，数据收集，模拟

摘  要： 大坝的设计通常需要考虑洪水频率分析的历史数据。由于设计中无法预见的自然因素、洪水频率发生潜在的转变，因此该方法具有一定的局限性。例如，因水库、周边土地利用及土地覆盖(LULC)产生的强大大气反馈，未来极端洪水可能发生变化。由可能最大降水(PMP)和流域的水文特征得到的可能最大洪水(PMF)可作为大坝水力特性的关键设计参数。鉴于降雨-径流过程的非线性，需要回答的一个关键问题是：水库规模和/或土地利用及土地覆盖模式如何改变极端洪水模式，特别是通过可能最大降水得到的可能最大洪水？本研究以美国的一个大型人工水库（即Folsom坝）所在的流域作为代表，应用分布式可变入渗能力模式(VIC)模型模拟可能最大洪水，可能最大洪水受不同的土地利用/土地覆盖模式模拟得到的大气反馈的影响。利用区域大气模拟系统(RAMS)模拟得到的大气反馈可作为可能最大降水。区域大气模拟系统得到的可能最大降水通过可变入渗能力模式模型模拟可能最大洪水。建坝前和当前的可能最大洪水的比较表明，可能最大洪水对应的洪峰流量可降低约105m³/s，而当前不考虑灌溉的可能最大洪水表明灌溉会使可能最大洪水增加125m³/s。另一方面，水库的规模对可能最大降水没有影响，因此对可能最大洪水也没有影响。下游堤防设计为与大坝溢洪道泄洪能力相适应，如案例所述，可能影响到下游洪水风险，洪水管理需与之相适应。现代大坝设计和运行应当综合大气-水文模型来估算因大坝导致的主动潜在的极端降水变化。

Impact of Artificial Reservoir Size and Land Use/Land Cover Patterns on Probable Maximum Precipitation and Flood:

Case of Folsom Dam on the American River

Authors: Wondmagegn Yigzaw, Faisal Hossain, Alfred Kalyanapu

Journal: Journal of Hydrologic Engineering , Volume 18, Issue 9 (September 2013) , 1180–1190  

Key words: Montedoglio dam, spillway collapse, data collection, simulation

Abstract: The design of the dams usually considers available historical data for analysis of the flood frequency. The limitation of this approach is the potential shift in flood frequency due to physically plausible factors that cannot be foreseen during design. For example, future flood extremes may change, among other factors, due to strong local atmospheric feedbacks from the reservoir and surrounding land use and land cover (LULC). Probable maximum flood (PMF), which is the key design parameter for hydraulic features of a dam, is estimated from probable maximum precipitation (PMP) and the hydrology of the watershed. Given the nonlinearity of the rainfall-runoff process, a key question that needs to be answered is how do reservoir size and/or LULC modify extreme flood patterns, specifically probable maximum flood via climatic modification of PMP? Using the American River Watershed (ARW) as a representative example of an impounded watershed with a large artificial reservoir (i.e., Folsom Dam), this study applied the distributed variable infiltration capacity (VIC) model to simulate the PMF from the atmospheric feedbacks simulated for various LULC scenarios (preamp, current scenario, no irrigation, and reservoir-double). The atmospheric feedbacks were simulated numerically as PMP using the regional atmospheric modeling system (RAMS). The RAMS-generated PMP scenarios were propagated through the VIC model to simulate the PMFs. Comparison of PMF results for preamp and current scenario conditions showed that PMF peak flow can decrease by about 105m3/s , while comparison of current scenario with no irrigation PMF results showed that irrigation development has increased the PMF by 125m3/s . On the other hand, the reservoir size had virtually no detectable impact on PMP and consequently on PMF results. Where downstream levee capacity is already under designed to handle a dam’s spillway capacity, such as for the case study, such increases indicate a likely impact on downstream flood risk to which any flood management protocol must adapt. The premise that modern dam design and operations should consider an integrated atmospheric-hydrologic modeling approach for estimating proactively potential extreme precipitation variation due to dam-driven LULC change is well-supported by this case study.

原文链接：http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29HE.1943-5584.0000722