Case 1: Floods in the Río Cabra Basin
This system was designed in response to floods that occurred in September 2004, which affected 25 communities, claimed 12 lives, completely destroyed 6 houses, partially damaged 700 homes and affected some 3,000 persons in the communities of Prados del Este, El Pantanal, Nueva Esperanza Arriba, Nueva Esperanza Abajo, Montería, Palo Alto, Tocumen and many other small towns along the Río Cabra.
The main purpose of the Rio Cabra EWS is to provide the residents of affected communities a tool to react quickly when confronted with imminent floods, in order to protect life and property with the fewest casualties possible. To accomplish that, it is necessary to train people to learn and understand the contingency plans being devised by the authorities and know how the EWS operates. They must know the warning and evacuation protocols for threatened areas in the event of phenomena identified by the Office of Early Warning and Climate Forecasting of the Hydrology and Meteorology Branch of ETESA. At the same time, it is important for the residents to be well acquainted with the surroundings where they carry out their daily chores.
The River Cabra Basin is extremely small. Therefore, the implementation of the Early Warning System in that river was a challenge for the technical personnel and the experts who developed it. The operating principles of the system have been established and, it is hoped, this experience can be replicated in neighboring basins and in other small basins in Panama’s interior where there is vey little time to identify the meteorological event, gather the data from the hydrologic-meteorological stations, do the calculations, inform the National Civil Protection System (SINAPROC), and disseminate the warning to the population.
To do this, the data showing the levels that the river will reach upstream was used to make adjustments to the hydraulic models that estimate the levels the river will reach in areas with human settlements. Plus, meteorological information, an important component, was added and, for that purpose, plans to transform conventional meteorological stations close to meteorological stations with automatic satellite transmission are being strengthened in corridors where the movement of storms has been observed. In addition, new satellite hydrometeorological stations will be installed to cover the whole research area. This will make it possible to gather measuring data before the storm enters the basin where the EWS has been implemented.
To implement this EWS, a meteorological station with satellite capability was installed at the highest point in the basin, a hydrological and meteorological station with satellite transmission was installed at the mid-point of the basin, and a series of rulers or water-level gauges were also installed to measure the depth of the river at different points along its course. Once the data was compiled, mathematical models were adjusted to estimate possible flood levels, time of occurrence and what areas could be affected.
In order to implement this EWS, the following technological tools have been used:
- Satellite images
- ACP Radar (Panama Canal Authority)
- Satellite images of the RAMSDIS system (water precipitation estimates)
- CAFFG Flash Floods Satellite System
- Data transmissions from meteorological and hydrological stations.
- Readings of the rulers in the river.
- Two-way radios SINAPROC-ETESA
- Thunderstorms Detection System.
- Hourly information from the Civil Aeronautics Authority (METARES and SPECI)
The operation of the EWS requires that:
- Meteorological personnel watch the development of bad weather. Share and analyze information with PCA staff and SINAPROC volunteers to determine magnitude.
- Meteorologists and Hydrologic analysts monitor stations’ measurements.
- A special probability flood forecast be prepared and sent to SINAPROC.
- The warning protocol be activated (SINAPROC). The meteorological and hydrological watch continues.
- The SINAPROC Emergency Operations Center participates in disseminating warnings to the population.
- Preparation of reports and lessons learned. Improvement of the EWS.
As a basic premise, the proponents of this EWS have devised the following equation to determine its hydrological viability:
Tc > Ta = t1 + t2 + t3
Tc = Time of concentration on the basin
Ta= total time required to issue warning
t1 = time needed to record and transmit data
t2 = time needed for evaluation and to make calculations
t3 = time required to react
This EWS has the following characteristics:
- It was designed by a private firm and it is being operated jointly with the National Civil Protection System.
- It is a centralized EWS.
- Different state entities participate in its operation (National Environment Authority, ANAM; Civil Aeronautics Authority, AAC; Panama Canal Authority, ACP; the National Civil Protection System, SINAPROC; the Ministry of Agriculture and Livestock, MIDA; the Government Security Office and the state-owned Electric Transmission Company, ETESA, among others. There is also coordination with the National Weather Service of the United States of America.
- It has been designed using existing technology that has been developed and tested in different areas.
- This experience can be applied in other areas with similar problems.
Presenter
• Luz Graciela de Calzadilla
Documents
• Animation and Simulations
• Simulation Hec RAS (Video)
• Simulation Hec Geo RAS (Video)
• LG Early Warning System Presentation
• Cabra EWS Review
Cases
• Case 1: Floods in the Río Cabra Basin
• Case 2: Susquehanna River (Pennsylvania) and San Antonio River (Texas)
• Case 3: An Early Warning System
