FLOOD OPERATION OF VAAL DAM IN THE VAAL ORANGE 在瓦尔橙色的瓦尔河防洪大坝运行

1、FLOOD MANAGEMENT,By: Joyce Mathole Directorate: Hydrological Service Department of Water Affairs and Forestry,FLOOD MANAGEMENT OPERATION IN THE VAAL / ORANGE RIVER SYSTEM,Management of both minor and major floods in the Vaal / Orange River System is done by the Directorate Hydrological Service of th

2、e Department of Water Affairs and Forestry. The “Flood Room” in Pretoria serves as an information centre to collect, process and distribute rainfall, stage and flow data Normal operation of the individual dams in the system is the responsibility of the Departmental Regional Offices,The main objectiv

3、es of flood management in order of priority are:-,To ensure the safety of the structures. To minimise the damages. To ensure that the dams are 100% full at the end of each flood.,Vaal Dam,Located in the Vaal River 65 km upstream of the town Vereeniging,Equipped with 60 crest gates Discharge of one g

4、ate at FSL: 105 m3/s Capacity of dam: 2 603 mil m3 Catchment area of dam: 38 505 km2,Vaal / Orange River System,Vaal/ Orange System covers about 49% the size of the RSA, excluding Lesotho,Vaal and Bloemhof Dams are the only dams equipped with spillway gates - some control possible,Data for the NWSRF

5、S,Rainfall Data (South African Weather Service) Real Time Flow stations (DWAF),SAWS: Satellite Data,Radar Data,Rain Gauge Data,Spatial interpolation and mapping of rainfall,Real time data collection points in the Vaal / Orange River System,52 gauging stations collecting near real time flow and / or

6、rainfall data - available on the Hydrology real time web site,Liebenbergsvlei River at Frederiksdal,Uses of Data,Rainfall data: Input to Rainfall/Runoff models (Kovacs/Sacramento) Real Time Flow Data: Input to routing model (Muskingum) Weather forecast: Information for dam operation Above Info: Floo

7、d Management,Routing times in Vaal / Orange System (days),Flood warnings can provide time for people to take action to protect their property as well as allowing emergency services to prepare and plan for evacuations and other emergency actions,Overview of the 1988 major flood in the Vaal / Orange River System,Spitskop Dam in t