Subsurface stormflow is a dominant runoff mechanism in steep humid mountainous areas.An insite measurement of subsurface stormflow suggests that the bedrock surface plays an important role in the runoff generation and routing process,which was rarely adopted in hydrological modelling studies.To improve the runoff simulation performance,the bedrock surface topographic index is introduced,and a modified TOPMODEL based on the bedrock surface topographic index is developed to simulate the runoff.The modified TOPMODEL is applied to the Huangbengliu(HBL),a steep watershed in Gongga Mountain,and proved to be more appropriate for the HBL watershed,especially for peak simulation.The Nash-Sutcliffe model efficiency(NSE)is improved from 0.24 to 0.58 in the calibration period and from 0.40 to 0.62 in the verification period.The result of this study can advance the understanding of the mechanism of flash floods and contribute flood control and disaster prevention in the HBL watershed and similar areas.
QIU An-niZHANG Yan-junWANG Gen-xuCUI Jun-fangSONG Yuan-xinSUN Xiang-yangCHEN Li
The Limpopo River basin (LRB) is known for its vulnerability to floods, high rates of evapotranspiration, and droughts that cause significant losses to the local community. The present study aimed to perform simulations of flood events occurring in two Mozambican sub-basins of LRB, namely Chókwè and Xai-Xai from 2000 to 2015 with TOPography-based hydrological MODEL (TOPMODEL) and satellite remote sensing data. As input in TOPMODEL, data from two high-resolution global satellite-based precipitation products: Climate Prediction Center MORPHing technique (CMORPH) and Integrated Multi-Satellite Retrievals for the Global Precipitation Mission (GPM) algorithm (IMERG), 8-day MOD16 evapotranspiration product and surface runoff data estimated by Global Land Data Assimilation System (GLDAS) were used. The sensitivity tests of TOPMODEL parameters were applied using the Monte Carlo simulation. Calibration and validation of the model were performed by the Shuffled Complex Evolution (SCE-UA) method and were evaluated with the Kling-Gupta Efficiency (KGE) index. The results indicated that simulations with the GPM-IMERG (KGE: 0.59 and 0.65) tended to underestimate the stream flows, while with the CMORPH product the performance was much better (KGE: 0.66 and 0.77) in both sub-basins. Thus, TOPMODEL can help to develop flood monitoring systems from satellite remotely sensed data in similar regions of Mozambique.
Tomásio Eduardo JanuárioAugusto José Pereira FilhoMarcos Figueiredo Salviano
