National Consultation with TNMC 3 May 2005, Bangkok WUP-FIN Phase II – Model development

2 Nam Songram watershed area Area: km2 Elevation: min 135 m amsl max 675 m amsl

3 Tools 2D distributed hydrological model coupled with a 1D hydrodynamic river, reservoir and lake model Physical model of the application area that takes into account variability in elevations, soil properties, vegetation, land use etc. Run through a GIS-type graphical user interface 1D lumped hydrological model HBV 3D hydrodynamic model

4 Nam Songkhram application areas

5 VMod model structure Flow from grid boxes obove overflow interflow kerros 2 kerros 1 Pintakerros Evapotranspiration ground water flow Flow to river Soil layer 2 Soil Layer 1 Surface layer Wilting point Field capacity Maximum capacity Precipitation One grid box computationModel grid & flow network

6 Data Digital elevation map for the land area with 50 m resolution from old topographical maps and new SRTM elevation model with 90 m resolution (MRC) Hydrographic atlas for Mekong mainstream, bathymetry of the river (MRC) The older (1997) and new (year 2002) land use data (MRC). Soil types (MRC) Location of river networks (MRC) Precipitation from 16 stations at or near the watershed (MRC)

7 Data Temperature (daily minimum and maximum temperatures) from one station at the watershed and a few further away (MRC) Evaporation from three stations at or near the watershed and a few further away (MRC) Discharge and water level observations form two points on the watershed: Ban Tha Kok Daeng and Nam Oon dam Discharge and water levels from the Mekong mainstream river Nakhon Phanom measured water levels and discharges Discharge from DSF to 3D model upper boundary condition in Mekong mainstream

8 Elevation km2 heights min 135m max 675 m

9 Landuse/Irrigated area 89% of landuse agriculture irrigated 3280 km 2 (25% of catchment)

10 Soils ~40 % acrisol ~40 % plinthic acrisol low water retention and conductivity

11 Weather data 16 precipitation stations Temperature data from at least one station Evaporation, few stations

12 Modelling 1km model grid (resolution can be increased) flow network computed from DEM 16 landuse classes 10 soil classes irrigation and rice agricultural practice not yet taken into accont

13 Model user interface

14 Computed flow at Ban Tha Kok Daeng compared to measured data Preliminary flow computation with VMod

15 3D hydrodynamic and WQ application 3D hydrodynamic model coupled with a water quality model 3D hydrodynamics flood arrival time, duration and depth in different locations of the modelled area, other flood characteristics Water quality: sediment concentration, net- sedimentation, oxygen, etc Run through a GIS-type graphical user interface

16 Input data for the 3D model River and floodplain topography Hydrographic atlas data river cross-sections for Nam Songkhram digital elevation map (DEM) for floodplain Boundary conditions Upstream discharge and water level in Mekong Upstream dishcarge in Nam Songkhram Downstream rating curve (in Mekong) Landuse Wind (Precipitation)

17 Digital elevation model and model area

18 3D view on the wetlands

19 Inundation on Sept 2000

20 3D model grid for NSK model

21 3D model grid for NSK hydrodynamic model

22 Model animation window

23 Output Tool to understand the hydrology of the Nam Songkhram watershed Scenarios Landuse Climate change Irrigation development Reservoir development Floodplain dynamics with the 3D model application Interaction between Nam Songkhram and Mekong

24 Requested data Socio-Economic data Statistical or spatial district/commune level data (preferably from many years to see trends) on primary &secondary occupations, particularly on fish- related livelihoods population, including rural/urban population &migration poverty. + info on other reports related to above mentioned issues.

25 Requested data Hydrological, hydrodynamic and water quality model data: Cross section data for Nam Songkhram and other tributaries including areas from both banks and floodplain: survey by DEDP in 1993 or 1994 Water level and discharge data and rating curves from the Nam Songkhram basin: Nam Songkhram at Ban Chai Buri and Ban Tha Huai Lua Nam Oon at Ban Phok Yai, Pannanikom and Bang Nong Bua Nam Yam at Akat Amnuai and Ban Khon Sai Huai Khong at Ban Tha Sri Chomchun Huai Hi at Ban Nong Yang Nam Mao at Ban Kham Hai Water level at stations measured by NEDECO in with temporary gauges. Irrigation data: irrigation practices, location of pumping stations, discharge of pumping in each station, project area and location, etc. Ground water levels from as many wells as available Detailed data (height, storage capacity, bridge dimensions etc.) from existing control structures (dams, weirs, dikes, bridges, road embankments, gates) in the basin.

26 Expected inputs from the MRCS modelling team and Thai partners Collection and basic processing of existing data Active participation in training, field measurements and modeling activities Scenario modeling Participation in field measurement data and modeling results processing Participation in reporting and publication of results Project resources for any specific local application are quite limited. Because of this, applications must get strong local support in form of work force and data collection.

27 More information: Content of the project’s two phases Personnel & contact details Documents downloadable Training portfolio: presentations, documents, exercises

MRCS/WUP-FIN