Numerical Simulation and Evaluation of a New Hydrological Model Coupled with GRAPES

• Published in: Acta meteorologica Sinica Vol. 26; no. 5; pp. 653 - 663
• Main Author: 郑子彦 张万昌 徐精文 赵琳娜 陈静 严中伟
• Format: Journal Article
• Language: English
• Published: Heidelberg The Chinese Meteorological Society 01.10.2012; Key Laboratory of Regional Climate-Environment Research for East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029; University of the Chinese Academy of Sciences, Beijing 100049%Center for Earth Observation and Digital Earth, Chinese Academy of Sciences, Beijing 100094%College of Resources and Environment, Sichuan Agricultural University, Yaan 6250145%National Meteorological Center, China Meteorological Administration, Beijing 100081%Key Laboratory of Regional Climate-Environment Research for East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Atmospheric Sciences; Earth and Environmental Science; Earth Sciences; Geophysics and Environmental Physics; GRAPES; Meteorology; TOPMODEL; 径流计算; 数值模拟; 水量平衡模型; 流域水文模型; 耦合; 评价; coupled model; XXT; GRAPES
• ISSN: 0894-0525; 2191-4788
• DOI: 10.1007/s13351-012-0509-1

Hydrological processes exert enormous influences on the land surface water and energy balance, and have a close relationship with human society. We have developed a new hydrological runoff parameteriza- tion called XXT to improve the performance of a coupled land surface-atmosphere modeling system. The XXT parameterization, which is based upon the Xinanjiang hydrological model and TOPMODEL, includes an optimized function of runoff calculation with a new soil moisture storage capacity distribution curve （SMSCC）. We then couple XXT with the Global/RegionM Assimilation Prediction System （GRAPES） and compare it to GRAPES coupled with a simple water balance model （SWB）. For the model evaluation and comparison, we perform 72-h online simulations using GRAPES-XXT and GRAPES-SWB during two torrential events in August 2007 and July 2008, respectively. The results show that GRAPES can reproduce the rainfall distribution and intensity fairly well in both cases. Differences in the representation of feedback processes between surface hydrology and the atmosphere result in differences in the distributions and amounts of precipitation simulated by GRAPES-XXT and GRAPES-SWB. The runoff simulations are greatly improved by the use of XXT in place of SWB, particularly with respect to the distribution and amount of runoff. The average runoff depth is nearly doubled in the rainbelt area, and unreasonable runoff distributions simulated by GRAPES-SWB are made more realistic by the introduction of XXT. Differences in surface soil moisture between GRAPES-XXT and GRAPES-SWB show that the XXT model changes infiltration and increases surface runoff. We also evaluate river flood discharge in the Yishu River basin. The peak values of flood discharge calculated from the output of GRAPES-XXT agree more closely with observations than those calculated from the output of GRAPES-SWB.