iuwm in teresina - world bank · lake oleiros needs every year water pumped from the river in order...
TRANSCRIPT
TERESINA AND THE RIVERS
• In the confluence of Parnaíba and Poty rivers is “Lagoas do Norte” neighbourhoods. It has 13 km2 and a dike protecting the area against the floods from the major rivers.
• The Parnaiba River which receives Poty has 300,000 km2.
• The region in Dry tropical climate with annual total rainfall around 700 mm which falls from January to May.
KEY ISSUES
• In the beginning the main issue was Floods, but it could not be solved alone;
• The solution for floods with existing lakes requires: sanitation of the area, waste management, urban drainage (Urban Waters) and improvement of the lakes, resettlement, transport and social improvement;
• It come to be an IUWM project
SYSTEM OF LAGOONS
• Many lagoons interconnected • The origin of the lagoons is from former flood
plains of both rivers. • Some of the lagoons dry during dry months • The flow output from the area is by a pump
stations
Pumpstation
• Objetives were to hold the lagoons;• Keep water all year long • Urbanization of the border of the lagoons • Avoid sewage, waste management • Ressetlment of the population inside of
management levels • Recreation, museum among others• Social support
MODEL CONFIGURATION
• Rainfall -runoff simulation for the catchments and hydrodynamic flow through reservoirs and pump station
• Simulation of scenarios of flood to define the upper limits lake flood and definition of the parks and surroundings
• Long term simulation in order to keep water in the lakes.
SIMULATIONS SCENARIOS
• Flood levels design for 25 years flood. From that level was define the lake limits
• Verification for 50 years floods. The objetive of the the verification is that the water does not enter the houses.
• This allow the design of interconnection of the lakes and the pump station capacity.
• The simulation had to be done by a few days because of the initial conditions.
FLOODS• Simulation with rainfall of the
period of 1913 –2010;• It simulated the level duration
curves for each lagoon;• The results shows that the large
lake Oleiros needs every year water pumped from the River in order to keep water during dry period;
• It also requires some improvement of the connections among the lakes.
DRY PERIOD
FIRST PHASE before
after
COMMENTS
• The flood solution was low cost because the were a large volume for detention;
• The costs were low because the needs were the increase capacity of pump stations and improve the connection among lakes;
• The lakes could not be uses if the projects would developed the sanitation waste management solutions
• The use of the spaces for school, museum and others use were important together with the participation of the communities
