本文是与同组博士后Pertti的一篇合作论文。利用HydroGeoSphere模型模拟降雨径流过程，并重点描述了一种简单有效的参数率定方法以及地下水在产流过程中的影响。做模型参数率定的可以一观。

Journal of Hydrology, 2017, 547:664-677. DOI:10.1016/j.jhydrol.2017.02.023

全文Ala-aho et al. 2017. J Hydrology.pdf

Abstract:

Understandingthe role of groundwater for runoff generation in headwater catchments is achallenge in hydrology, particularly so in data-scarce areas. Fully-integrated surface-subsurface modelling has shown potential in increasing processunderstanding for runoff generation, but high data requirements and difficultiesin model calibration are typically assumed to preclude their use incatchment-scale studies. We used a fully integrated surface-subsurfacehydrological simulator to enhance groundwater-related pro- cess understandingin a headwater catchment with a rich background in empirical data. To set upthe model we used minimal data that could be reasonably expected to exist forany experimental catchment. A novel aspect of our approach was in using simplifiedmodel parameterisation and including parameters from all model domains(surface, subsurface, evapotranspiration) in automated model calibration.Calibration aimed not only to improve model fit, but also to test theinformation content of the observations (streamflow, remotely sensedevapotranspiration, median groundwater level) used in calibration objectivefunctions. We identified sensitive parameters in all model domains (subsurface,surface, evapotranspiration), demonstrating that model calibration should beinclusive of parameters from these different model domains. Incorporatinggroundwater data in calibration objectives improved the model fit forgroundwater levels, but simulations did not reproduce well the remotely sensedevapotranspiration time series even after calibration. Spatially explicit modeloutput improved our understanding of how groundwater functions in maintainingstreamflow generation primarily via saturation excess overland flow. Steadygroundwater inputs created saturated conditions in the valley bottom riparianpeatlands, leading to overland flow even during dry periods. Groundwater on thehillslopes was more dynamic in its response to rainfall, acting to expand thesaturated area extent and thereby promoting saturation excess overland flowduring rainstorms. Our work shows the potential of using integrated surface-subsurface modelling alongside with rigorous model calibration to betterunderstand and visualise the role of groundwater in runoff generation even withlimited datasets.