Streamflow Simulation Based on Multi-layer Soil Moisture Data Assimilation in a Small Catchment
Soil moisture status plays a critical role in the hydrologic cycle and has a significant impact on the accuracy of streamflow forecasting.In this paper,the role of assimilating soil moisture data is investigated and the Shale Hills catchment in central Pennsylvania,USA,is used as the study area.Firstly,the daily streamflow process in the study ar-ea from 2008 to 2012 is simulated by using the Xin'anjiang model.Meanwhile,an assimilation model based on the ensem-ble Kalman filter algorithm,and an unassimilated open-loop experiment was set up to study the effect of multi-layer soil moisture data assimilation on streamflow simulation.The simulation results show that the Xin'anjiang model has good ap-plicability in this catchment.Compared with the open-loop,the relative error of streamflow is reduced by 5.2%,the Nash coefficient is increased from 0.62 to 0.66,and the root mean square error of soil moisture content decreased from 16.4 mm to 3.0 mm after assimilating multi-layer soil moisture in the model.The assimilation of soil moisture content of the lower layer has a more obvious effect on streamflow simulation than that of the upper layer,but adding the upper lay-er of measured soil moisture content can reduce the uncertainty of the lower layer.Assimilating multi-layer soil moisture can improve the accuracy of streamflow simulation to a certain extent,and also can effectively improve the simulation re-sults of soil moisture.
万方数据
维普
