Dr. Fei Yuan , Prof. Zhongbo Yu, Dr. Chuanguo Yang, Dr. Xiaoli Yang & Ms. Luyan Gong

1. The 5th International Symposium on IWRM The 3rd International Symposium on Methodology in Hydrology Nanjing, Nov. 20-21, 2010 Application of a coupled land-surface-hydrologic model system Noah/LSM/HMSin the Poyang Lake Region Dr. Fei Yuan, Prof. Zhongbo Yu, Dr. Chuanguo Yang, Dr. Xiaoli Yang & Ms. Luyan Gong State Key Laboratory of Hydrology-Water Resouces and Hydraulic Engineering, Hohai University, Nanjing, China Email: fyuan@hhu.edu.cn Phone: +86-25-83787488 Prof. Harald Kunstmann, Dr. Benjamin Fersch & Dr. Sven Wagner IMK-IFU, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, Germany

2. Objective LSX-HMS Noah-LSM-HMS Case study in the Poyang Lake region Discussion Outline

3. Include more detailed hydrologic process parameterization scheme in land-surface models so as to improve meteorological simulations. Apply this new model system for interactive mesoscale meteorology-hydrology simulations. Objective

4. Atmospheric component -- Observed meteorology -- GCMs / RCMs Land-surface component -- LSX in GENESIS GCM -- Atmosphere-land-surface- hydrology coupling interface -- 6 soil layers (0~4.25m) -- 12 vegetation classes -- Spatial resolution: ~1.9° Hydrologic component -- HMS -- hydrologic process such as interactions among unsaturated soil water, groundwater, rivers and lakes -- Spatial resolution: ~ 20 km LSX-HMS Zhongbo Yu (2006, Journal of Hydrology) Sketch of LSX-HMS Downscaling method

5. Channel flow The Muskingum-Cunge method (Cunge, 1969; Bedient and Huber, 1988) was implemented for channel-flow routing through the DEM thrived channel networks. The extended finite difference form of the governing equation can be written: where Qx is the inflow to a given stream grid cell; Qx+1 is the outflow from a given stream grid cell; k is a travel time parameter; and ε is a weighing factor. Channel flow LSX-HMS

6. The following second-order partial differential equation is used to describe ground-water flow in an aquifer (Prickett and Lonnquist, 1971; Domenico and Schwartz, 1990; Z. Yu, 1997): where T is transmissivity; h is hydraulic head, S is storativity; t is time; and Qnet is net ground-water withdrawal rate. Groundwater Hydrology LSX-HMS

7. Channel-Groundwater Interaction A layer of low permeable material in the stream-bed is assumed to separate water in the channel from the ground-water system at each stream cell. The inflow/outflow is a function of the hydraulic head difference between the ground water and river stage. It is calculated by Darcy’s Law as follows. where Cd is the hydraulic conductance; hi,jis the hydraulic head of the ground water; Bi,jis the elevation of stream-bed; and di,jis the water depth in the channel. LSX-HMS

8. LSX-HMS Spatial resolution: LSX:1.9°×1.9°HMS:10×10 km2 or 20×20 km2 Time interval: LSX:30 min HMS: 1 day Meteorology: NCEP reanalysis data (1.9°×1.9°, 6 h) Higgins precipitation data (2.5 °×2°, 1 h)

9. Monthly hydrographs at the Cuntan station on the Yangtze main stream Monthly hydrographs at the Maotai station in the Chishui watershed Daily hydrographs at the Maotai station in the Chishui watershed Reason 1: spatial variability of infiltration capacity is not considered in infiltration excess surface runoff calculation. LSX-HMS Reason 2: the spatial resolution of LSX grid cells and input precipitation data are coarse. LSX grid cell: 1.9° Higgins precipitation data: 2.0°×2.5°

10. Noah-LSM-HMS

11. Schematic overview of Noah-LSM-HMS Atmospheric component -- Observed meteorology or WRF -- Spatial scale: ~ 20 km Land-surface component -- Noah-LSM in WRF -- Land-surface process simulation and calculate surface runoff, infiltration and evaporation for HMS -- Spatial scale: ~ 20 km Hydrologic component -- HMS -- Detailed hydrologic process simulation such as interactions among unsaturated soil water, groundwater, rivers and lakes -- Spatial scale: ~ 20 km Noah-LSM-HMS No downscaling from Noah-LSM to HMS

12. Case study in the Poyang Lake region Haihe River basin Poyang Lake basin Location of the Haihe River basin and Poyang Lake basin

13. Yangtze River Rao River Five main rivers flowing Into the Poyang lake: Xiushui River • Ganjiang River (81600 km2) • Xiushui River (14800 km2) • Xinjiang River (15941 km2) • Rao River (15000 km2) • Fuhe River (15811 km2) Xinjiang River Ganjiang River Yangtze River exchanges water with the Poyang lake. Fuhe River Streamflow stations (21) Meteorological stations (26) Rain gages (68) Map of Poyang Lake basin

14. Case study in the Poyang Lake region Waizhou streamflow station at the Ganjiang River Hydrographs at Waizhou station in the calibration years1978~1983 Nash = 0.751 Bias = 8.0 % Hydrographs at Waizhou station in the validation years1984~1987 Nash = 0.528 Bias = 9.8 %

15. Hydrographs at Lijiadu station in the calibration years1978~1983 Nash = 0.567 Bias = 16.0 % Hydrographs at Lijiadu station in the validation years1984~1987 Lijiadu streamflow station at the Fuhe River Nash = 0.428 Bias = 18.6 % Case study in the Poyang Lake region

16. Hydrographs at Meigang station in the calibration years1978~1983 Nash = 0.588 Bias = 7.6 % Hydrographs at Meigang station in the validation years1984~1987 Meigang streamflow station at the Xinjiang River Nash = 0.588 Bias = 11.3 % Case study in the Poyang Lake region

17. Hydrographs at Hushan station in the calibration years1978~1983 Nash = 0.530 Bias = 23.0 % Hydrographs at Hushan station in the validation years1984~1987 Hushan streamflow station at the Raohe River Nash = 0.415 Bias = 25.0 % Case study in the Poyang Lake region

18. Wanjiapu streamflow station at the Xiuhe River Hydrographs at Wanjiapu station in the calibration years1978~1983 Nash = 0.506 Bias = -7.6 % Hydrographs at Wanjiapu station in the validation years1984~1987 Nash = 0.302 Bias = -17.8 % Case study in the Poyang Lake region

19. Mean annual precipitation (mm/a) Mean annual evapotranspiration (mm/a) Mean annual surface runoff (mm/a) Mean annual soil infiltration (mm/d) Case study in the Poyang Lake region

20. Mean annual soil moisture (relative to saturation) Groundwater table (elevation above sea level, m) River Vadose zone (mm/d) River Aquifer (mm/d) Case study in the Poyang Lake region

21. Further model validation using more observed data NDVI < 0 Yes No CLASS 0 CH1 < 11 Water body identification from AVHRR images Yes No • AVHRR images • Period: 1982~1987 • Spatial resolution: • 1.1 or 4.4 km CLASS 1 (Water body) CLASS 2 Decision tree for water body identification from AVHRR images Discussion • Soil moisture • Groundwater table • Lake area

22. Discussion Jan. 6 1837km2 Feb. 12 1627km2 Mar. 31 2077km2 Apr. 6 2249km2 Jun. 3 1835km2 May 24 1822km2 Jul. 29 2795km2 Aug. 7 2807km2 Sep. 22 1864 km2 Oct. 12 1474km2 Nov. 9 1377km2 Dec. 8 2101km2 Poyang Lake Area in 1986 based on AVHRR remotely-sensed image

23. Next steps • Hydrologic simulations with the integration of the remotely-sensed precipitation data(TRMM, Tropical Rainfall Measuring Mission) • Coupling of Noah/LSM/HMS with WRF • Joint Climate Change & Land Use Change Feedback Analysis

24. Thanks for your attention!