FLOODS IN COIMBRA – CAN SOMEONE BE RESPONSIBLE FOR WHAT HAPPENED?

This year, rain started late in Portugal. Aguieira dam, located 25 km upstream Coimbra (Figure 1) is the main responsible for the Mondego river regulation, the largest in Portugal that is entirely Portuguese. After its construction, floods in Coimbra and in the fields downstream Coimbra are not so often comparing with the old times. However, on 11th January, Aguieira dam had to release water through its spillways (Figure 2). Accordingly to EDP (Portuguese electric company, owner of Aguieira dam), the flow that reached Aguieira was 1200 m3/s and dam used 400 m3/s to produce energy and release more 400 m3/s through its spillways. According to newspaper the flow verified in Coimbra dam (Figure 3) in 11st January was 1470 m3/s and water level increased more than 1 m causing again floods in Coimbra “Parque Verde” (Figure 4) and in fields downstream Coimbra.

Figure1_Quicsblog'

Figure 1 – Localization of Mondego river, Agueira dam, Coimbra and Figueira da Foz

Fig2    Fig3

Figure 2 – Aguieira dam spillways discharge               Figure 3 – Coimbra dam

https://www.youtube.com/watch?v=LzI_auovBb4 ; https://www.youtube.com/watch?v=ENmD9fKwkpw

Fg4a

Fig4b Fig4e Fig4d Fig4c

Figure 4 – Coimbra “Parque Verde” floods (https://www.youtube.com/watch?v=1jIxtf467jk ;  https://www.youtube.com/watch?v=yf1TrXk6-00)

It was the highest water level since “Parque Verde do Mondego” exists and several losses in its monuments, bars and restaurants occurred caused by sediments and water in electrical equipment (thousands of Euros off losses) as well as in the fields downstream. Last floods caused by Mondego river were on 27th January 2001 for the discharge of 1910.7 m3/s and in 1948, when, without Aguieira and Coimbra dam, the natural discharge was estimated as 4000 m3/s. TNevertheless, the major losses were caused by 2001 floods in spite of being caused with half water discharge of 1948 floods.
Some try to responsible nature and climate changes, other EDP since it looks always for the most profit generating hydropower. Is that correct?
Nature cannot be responsible! We just have to appreciate it, sometimes try to understand and never hurt it. Leading with floods, 3 causes are always present: 1- river side occupation; 2- lack of maintenance related with accretion and 3- failed in operating hydraulic structures or in plans to preview losses or even disrespect with available studies.
Several studies shows that under level 21 m, all could be flooded occasionally, thus constructions under this level should be provisional or plans to minimize losses should be done and activated when needed. Human floods culture was lost when the river become regulated by the dams, any problem that causes floods should not be endorsed exclusively to one responsable.
In addition, some Mondego tributaries are not regulated, dams construction could be important to regulate flow in those tributaries. Accreation/Erosion of river bed should be monitorized and maintained. Structures to protect areas such as gates, provisional structures constructed with sediments bag, boxes and stop overs, rubber to isolate and avoiding equipment areas flooded should be provided.

Hopefully Quics will visit Coimbra and Parque Verde in 2017.

Rita F. Carvalho

FLOODS IN COIMBRA – CAN SOMEONE BE RESPONSIBLE FOR WHAT HAPPENED?

Statistical Parameter Optimization Tool

This paper from the Giessen group may be of interest to those working in modelling – it’s  on an open source and open access software package for model uncertainty estimation, calibration, parameterization etc.

Houska, T., Kraft, P., Chamorro-Chavez, A. and Breuer, L.: SPOTting Model Parameters Using a Ready-Made Python Package, PLoS ONE, 10(12), e0145180, doi:10.1371/journal.pone.0145180, 2015. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0145180

You might also be interested in the latest updates of the tool:

Please note that the development of SPOTPY was transferred to GitHub (https://github.com/thouska/spotpy). Please report any bugs or ideas on this website. Furthermore, you are warmly invited to contribute to the development. The latest stable version can be found at https://pypi.python.org/pypi/spotpy. The SVN-Server is no longer maintained.

Happy parameter spotting.

Tobias, Philipp, Alejandro and Lutz

Statistical Parameter Optimization Tool

Brazilian biggest environmental disaster

 

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Location of Mariana city, state of Minas Gerais, Brazil. (Image via Wikipedia/Raphael Lorenzeto de Abreu)

16h20, 5th of November of 2015: This is the exactly time of the burst of a tailing-pond dam at an iron ore mine owned by Samarco (a joint venture between Vale SA and BHP Billiton) in the state of Minas Gerais (MG), Brazil.

The volume of 62 million cubic meters of mineral sludge took 40 minutes to reach the location of Bento Rodrigues, a subdistrict of Mariana-MG, destroying 82% of the buildings in the location and killing 17 people (and 2 are still missing). Seven other villages and districts that are located nearby were hit with minor damage.

Flooding_after_Bento_Rodrigues_dam_breach
Flooding after Bento Rodrigues dam break. (Image via NASA)

Few hours later, the mud reached the Rio Doce River, which basin has a drainage area of about 86.715 square kilometers, flowing down about 600 kilometers until reaches the Atlantic Ocean spreading for around 168 square kilometers.

Atlantic ocean
Plume reaching the Atlantic Ocean. (Credit photo: Ricardo Moraes/Reuters)
fish rio doce river
Impact of Samarco’s mud on river fauna. (Credit photo: Leonardo Mercon/Últimos Refúgios)

The total of 1.5 thousands hectares of vegetation was devastated, at least 11 tons of dead fish were removed from the Rio Doce River and 35 cities were affected by the cut off of water supply, leaving around 400 000 people with no drinking water for a week.

An independent group of scientists GIAIA released the first results of water quality analysis presenting levels of manganese, arsenic, lead, iron and aluminium higher than the limit established by the National Environmental Council – CONAMA (in portuguese, Conselho Nacional de Meio Ambiente).

The accident was described as the biggest environmental disaster in Brazil’s history by the Brazil president Dilma Rousseff during the COP21 (France, 2015).

 

Brazilian biggest environmental disaster