Effect of baseline snowpack assumptions in the HySIM model in predicting future hydrological behaviour of a Himalayan catchment
Effect of baseline snowpack assumptions in the HySIM model in predicting future hydrological behaviour of a Himalayan catchment
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DOI：
10.2166/nh.2018.069
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发表时间：
2018-11
影响因子：
2.7
通讯作者：
R. Remesan;Sazeda Begam;I. Holman
中科院分区：
文献类型：
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作者：
R. Remesan;Sazeda Begam;I. Holman
冰川和积雪通过改变流量和时间来影响径流。如果没有关于基准冰雪数量、性质和行为的可靠数据，为气候影响评估初始化水文模型是具有挑战性的。根据观测流量数据(2000-2008年)，对两个不同的HySIM模型进行了校准和验证，假设高海拔次集水区的基准永久积雪储备的积雪要么受到限制(融雪仅限于季节性积雪)，要么不受限制(融雪仅限于能量有限)。然后，我们在情景中立的框架内应用这两个模型来开发对未来年温度和降水量变化的水文响应的影响响应面。两个模型具有相似的基准模型性能(校正NSE为0.69-0.70，验证NSE为0.64-0.66)，但在日流量低(Q10)和高(Q90)时，影响响应面在模型对气候变化的响应的大小和方向上有所不同。文中还讨论了历史数据的不足对评估气候变化影响和相关水文临界点时间的影响。
Glaciers and snowpacks influence streamflow by altering the volume and timing of discharge. Without reliable data on baseline snow and ice volumes, properties and behaviour, initializing hydrological models for climate impact assessment is challenging. Two contrasting HySIM model builds were calibrated and validated against observed discharge data (2000–2008) assuming that snowmelt of the baseline permanent snowpack reserves in the high-elevation sub-catchment are either constrained (snowmelt is limited to the seasonal snow accumulation) or unconstrained (snowmelt is only energy-limited). We then applied both models within a scenario-neutral framework to develop impact response surface of hydrological response to future changes in annual temperature and precipitation. Both models had similar baseline model performance (NSE of 0.69–0.70 in calibration and 0.64–0.66 in validation), but the impact response surfaces differ in the magnitude and (for some combinations) direction of model response to climate change at low (Q10) and high (Q90) daily flows. The implications of historical data inadequacies in snowpack characterization for assessing the impacts of climate change and the associated timing of hydrological tipping points are discussed.