Impacts of the Belo Monte hydroelectric dam construction on pioneer vegetation formations along the Xingu River, Pará State, Brazil

There is an important pioneer vegetation formation along the Xingu River in the area where the Belo Monte hydroelectric dam is being constructed that is highly adapted to a seasonally fluctuating water levels. The aim of this study was to examine the habitat and flora of the pioneer formations in the Belo Monte area. The area was divided in three sections for study purposes (Reservoir, Low Flow, and Control) that were expected to experience different degrees of impact from the dam project. The calculations of habitat losses were based on satellite imagery classifications, and a total of 111 plots were established in the three areas for vegetation sampling. Habitat losses of the pioneer formations will total 89.7% when the project is fully functional. Forty-five of the 72 recorded species are restricted to single areas. Species richness and diversity were significantly lower in the control area. The completion of the Belo Monte reservoir will result in habitat reductions and will consequently reduce the richness and diversity of pioneer formations. Studies suggest monitoring the populations located in the reduced flow area to determine possible impacts resulting from changes in the regional hydrological cycle caused by the Xingu River dam.

Assessing the influence of dam construction on the spatial and temporal evolution of population density across the United States of America

Finding the optimum location for placing a dam on a river is usually a complicated process which generally forces thousands of people to flee their homes because they will be inundated during the filling of the dam. Dams could also attract people living in the surrounding area after their construction. The goal of this research is to check for dam attractiveness for people by comparing growth rates of population density in surrounding areas after dam construction to those associated with the period antecedent to the dam construction. To this aim, 1859 dams across the United States of America and high-resolution population distribution from 1790 to 2010 are examined. By grouping dams as a function of their main purpose, water supply dams are found to be, as expected, the most attractive dams for people, with the biggest growth in population density. Irrigation dams are next, followed by hydroelectricity, flood control, Navigation, and finally Recreation dams. Fishery dams and dams for other uses suffered a decrease in population in the years after their construction. The regions with the greatest population growth were found approximately 40-45 km from the dam and at distances greater than 90 km, whereas the regions with the greatest population decline or only a modest gain were located within 10-15 km of the dam.

Dam safety guide

A new Dam Safety Act (494/2009) came into force on 1st October 2009 and a Government Decree on Dam Safety (319/2010) on 5th May 2010. This Dam Safety Guide replaces the Dam Safety Code of Practice (Publication of the Ministry of Agriculture and Forestry 7/1997), removed from circulation on 1st October 2009. The Dam Safety Guide is not binding on the dam owner; the purpose is to complement and elucidate the relevant law and and decree through examples and descriptions. The Guide takes up questions concerning dam design, for instance hydrological dimensioning and technical safety requirements, dam construction and use, the dam break hazard analysis and the dam owner’s emergency action plan, maintenance, use, monitoring as well as the annual and periodic inspections. Dams are classified according to the hazard they pose into class 1, 2 or 3 dams. The classification is not needed, if, according to the dam safety authority, the dam poses no danger. The owner of a classified dam must prepare a monitoring programme, to be approved by decision of the dam safety authority. To establish the hazard caused by a dam, the owner of a class 1 dam must prepare an analysis of the dam hazard to humans and property as well as to the environment. The dam safety authority may also require a dam break hazard analysis for a dam other than class 1 dam if deemed necessary for classification. The owner of a class 1 dam must prepare a plan of measures in case of emergency or operational failure. The plan shall present the dam owner’s state of preparedness to act on their own initiative in the situations described above. In each case, the rescue authorities make a separate assessment for the need to prepare a plan as set out in the Rescue Act. The dam owner must provide the information specified in the Dam Safety Decree to be entered into the dam safety information system. The dam safety authority and the owner of the dam must keep up-to-date printouts in their own dam safety files from the information system for each dam as well as other important documents connected with dam safety to ensure that these are readily available in case of disturbance.

Impact of dams, dam removal and dam-related river engineering structures on sediment connectivity and channel morphology of the Fugnitz and the Kaja Rivers

In terms of changing flow and sediment regimes of rivers, dams are often regarded as the most dominant form of human impact on fluvial systems. Dams can decrease the flux of water and sediments leading to channel changes such as upstream aggradation and downstream degradation. The opposite effects occur when dams are removed. Channel degradation often requires further intervention in terms of river bed and bank protection works. The situation evolves more complex in river systems that are impacted by a series of dams due to feedback processes between the different system compartments. A number of studies have recently investigated geomorphic systems using connectivity approaches to improve the understanding of geomorphic system response to change. This paper presents a case study investigating the impact of dam construction, dam removal and dam-related river bed and bank protection measures on the sediment connectivity and channel morphology of the Fugnitz and the Kaja Rivers using a combination of DEM analyses, field surveys and landscape evolution modelling. For both river systems the results revealed low sediment connectivity accompanied by a fine river bed sediment facies in river sections upstream of active dams and of removed dams with protection measures. Contrarily, high sediment connectivity which was accompanied by a coarse river bed sediment facies was observed in river sections either located downstream of active dams or of removed dams with upstream protection. In terms of channel changes, significant channel degradation was examined at locations downstream of active dams and of removed dams. Channel bed and bank protection measures prevent erosion and channel slope recovery after dam removal. Landscape evolution modeling revealed a complex geomorphic response to dam construction and dam removal as sediment output rates and therefore geomorphic processes have been shown to act in a non-linear manner. These insights are deemed to have major implications for river management and conservation, as quality and state of riverine habitats are determined by channel morphology and river bed sediment composition.

The impact of sustainable construction and knowledge management on sustainability goals. A review of the venezuelan renewable energy sector

The recognition of the relevance of energy, especially of the renewable energies generated by the sun, water, wind, tides, modern biomass or thermal is growing significantly in the global society based on the possibility it has to improve societies′ quality of life, to support poverty reduction and sustainable development. Renewable energy, and mainly the energy generated by large hydropower generation projects that supply most of the renewable energy consumed by developing countries, requires many technical, legal, financial and social complex processes sustained by innovations and valuable knowledge. Besides these efforts, renewable energy requires a solid infrastructure to generate and distribute the energy resources needed to solve the basic needs of society. This demands a proper construction performance to deliver the energy projects planned according to specifications and respecting environmental and social concerns, which implies the observance of sustainable construction guidelines. But construction projects are complex and demanding and frequently face time and cost overruns that may cause negative impacts on the initial planning and thus on society. The renewable energy issue and the large renewable energy power generation and distribution projects are particularly significant for developing countries and for Latin America in particular, as this region concentrates an important hydropower potential and installed capacity. Using as references the performance of Venezuelan large hydropower generation projects and the Guri dam construction, this research evaluates the tight relationship existing between sustainable construction and knowledge management and their impact to achieve sustainability goals. The knowledge management processes are proposed as a basic strategy to allow learning from successes and failures obtained in previous projects and transform the enhancement opportunites into actions to improve the performance of the renewable energy power generation and distribution projects.

Effects of flooding of the River Paraná on the temporal activity of Anopheles (Nyssorhynchus) darlingi Root (Diptera: Culicidae), at the border state of Mato Grosso do Sul and São Paulo, Brazil

INTRODUCTION: Study of the temporal activity of malaria vectors during the implantation of a hydroelectric power station on the River Paraná, intended to generate electrical energy. The river separates the States of São Paulo and Mato Grosso do Sul, in Brazil. The objective was to verify whether alterations occurred in the wealth and diversity indices of Anopheles, following two successive floods, extended to the temporal activity and nycthemeral rhythm followed over a five year period. METHODS: Mosquito capture was performed monthly using the Human Attraction Technique and Shannon Traps. The first, executed for 24h, provided the nycthemeral rhythm and the second, lasting 15h, permitted the tracking of Anopheles during the two floods. RESULTS: The bimodal pattern of Anopheles darlingi defined before these floods was modified throughout the environment interventions. The same effect had repercussions on the populations of An albitarsis s.l., An triannulatus and An galvaoi. Activity prior to twilight was less affected by the environment alterations. CONCLUSIONS: The dam construction provoked changes in Anopheles temporal activity patterns, permitting classification of the area as an ecologically steady and unstable situation. Differences observed in Anopheles behavior due to the capture methods revealed the influence of solo and multiple attractiveness inside the populations studied.

Acompanhamento das Técnicas de Construção na Obra do Aproveitamento Hidroelétrico de Foz Tua

O presente trabalho foi desenvolvido na obra do Aproveitamento Hidroelétrico de Foz Tua onde a autora teve oportunidade de realizar o estágio curricular junto da equipa da Fiscalização no período de 2 de Fevereiro de 2015 a 31 de Julho de 2015. A elaboração do presente trabalho pretende transmitir conhecimentos adquiridos relacionados com a constituição de um Aproveitamento Hidroelétrico, os tipos de barragens existentes, monitorização e controlo da segurança da estrutura da Barragem, controlo de qualidade de betão e o processo construtivo de uma Barragem. A construção da Barragem do Aproveitamento Hidroelétrico de Foz Tua tem sido realizada através do método tradicional, que consiste na aplicação de betão convencional compactado por vibração interna. Ao longo deste processo, foram aplicadas diversas técnicas construtivas, nomeadamente: escavação, betonagem, refrigeração artificial, injeção de juntas e tratamento de fundações. Neste trabalho foram ainda analisados os cuidados de segurança necessários neste tipo de estruturas, tendo como base o Regulamento de Segurança de Barragens. Este regulamento define as regras a seguir durante a execução da barragem e a monotorização que deve ser efetuada à mesma, permitindo assim o controlo da segurança da estrutura na sua construção e vida útil. É necessário ainda existir um controlo da qualidade, produção e aplicação do betão na estrutura de modo a aumentar a segurança, qualidade e durabilidade da mesma.

Effects of flooding of the River Paraná on the temporal activity of Anopheles (Nyssorhynchus) darlingi Root (Diptera: Culicidae), at the border state of Mato Grosso do Sul and São Paulo, Brazil

INTRODUCTION: Study of the temporal activity of malaria vectors during the implantation of a hydroelectric power station on the River Paraná, intended to generate electrical energy. The river separates the States of São Paulo and Mato Grosso do Sul, in Brazil. The objective was to verify whether alterations occurred in the wealth and diversity indices of Anopheles, following two successive floods, extended to the temporal activity and nycthemeral rhythm followed over a five year period. METHODS: Mosquito capture was performed monthly using the Human Attraction Technique and Shannon Traps. The first, executed for 24h, provided the nycthemeral rhythm and the second, lasting 15h, permitted the tracking of Anopheles during the two floods. RESULTS: The bimodal pattern of Anopheles darlingi defined before these floods was modified throughout the environment interventions. The same effect had repercussions on the populations of An albitarsis s.l., An triannulatus and An galvaoi. Activity prior to twilight was less affected by the environment alterations. CONCLUSIONS: The dam construction provoked changes in Anopheles temporal activity patterns, permitting classification of the area as an ecologically steady and unstable situation. Differences observed in Anopheles behavior due to the capture methods revealed the influence of solo and multiple attractiveness inside the populations studied.

Potential schistosome-vector snails and associated trematodes in ricefields of Corrients province, Argentina: preliminary results

Considering the possibility of introduction of schistosomiasis mansoni into Argentina as a consequence of dam construction on the Rio De La Plata basin, preliminary studies have been carried out on agrosystems such as ricefields in Corrientes province with the following purposes: 1) to survey and estimate the relative abundance of planorbids and identify potential vector species; 2) to identify environmental factors capable of influencing Biomphalaria population dynamics; and 3) to find out snail-parasite associations and estimate snail infection rates in order to detect possible competitive interactions between larval stages of native trematodes that could be used in biological control of Schistosoma mansoni. Three potential schistosome vectors were detected in ricefields, namely Biomphalaria straminea, B. tenagophila and B. peregrina, although B. orbignyi, a species refractory to infection with S. mansoni, proved the most frequent and abundant. Positive correlations (P<0.05) were found between Biomphalaria abundance and some environmental parameters: conductivity, hardness, calcium, nitrites plus nitrates, ammonium and bicarbonates. Water temperature correlation was negative (P<0.05). No correlation (P>0.05) was found in total iron, phosphates (SRP), pH and soil granulometry. Echinocercariae developed from rediae and belonging to Petasiger sp., Paryphostomum sp., and other undetermined species were found.

Le Bassin de Ribeira Seca de Santiago, Cap Vert - une gestion basée sur l´approche GIRE The Reservoir of Ribiera Seca de Santiago, Cape Vert - Management Exploitation GIRE

Dans cet article, l´auteur caractérise l´eau et l´agriculture des îles du Cap Vert et analyse les défis de l´eau après la construction du barrage de Poilao dans la Vallée de Ribeira Seca, sur l´île de Santiago, en se servant de l´approche GIRE (Gestion Intégrée des Ressources en Eau). Au niveau de la législation, il s´avère nécessaire de proposer de nouvelles lois, décrets et règlements qui soient en accord avec notre réalité, en opposition à un important lot d´instruments juridiques inapplicables, obsolètes et de compréhension difficile. La construction du barrage de Poilão a produit des impacts environnementaux, socio-économiques et sur l´irrigation. Il s´agit de trouver un modèle de gestion qui s´adapte à la réalité du Cap Vert et de l´île de Santiago, regroupant tous les partenaires pour une gestion durable de la vallée de Ribeira Seca et qui puisse servir d´exemple aux futurs barrages à construire.

Effects of erosion and deposition on particle size distribution of deposited farmland soils on the chinese loess plateau

Particle size distribution (PSD) in the soil profile is strongly related to erosion, deposition, and physical and chemical processes. Water cycling and plant growth are also affected by PSD. Material sedimented upstream of the dam constructions formed large areas of deposited farmland (DF) soils on the Chinese Loess Plateau (CLP), which has been the site of the most severe soil erosion in the world. Two DFs without tillage on the CLP were chosen to study the combined effect of erosion and check dams on PSD. Eighty-eight layers (each 10 cm thick) of filled deposited farmland (FDF) soils and 22 layers of silting deposited farmland (SDF) soils of each studied soil profile were collected and 932 soil samples were investigated using laser granulometry. The particle sizes were stratified in both DFs based on soil properties and erosion resistance. The obtained results of clay and silt fractions showed similar horizontal distribution, indicating parallel characteristics of erosion and deposition processes. Fine sand represented the largest fraction, suggesting the preferential detachment of this fraction. The most erodible range of particle sizes was 0.25-0.5 mm, followed by 0.2-0.25 mm in the studied soil profiles. The correlation between particle size and soil water contents tended to increase with increasing water contents in FDF. Due to the abundant shallow groundwater, the relationship between particle size and soil water content in SDF was lost. Further studies on PSD in the DF area are needed to enhance the conservation management of soil and water resources in this region.

Patoturvallisuusopas

Uusi patoturvallisuuslaki (494/2009) tuli voimaan 1.10.2009 ja valtioneuvoston asetus patoturvallisuudesta (319/2010) 5.5.2010. Tämä patoturvallisuusopas korvaa patoturvallisuusohjeet (MMM:n julkaisuja 7/1997), jotka poistuivat käytöstä 1.10.2009. Patoturvallisuusoppaassa esitetty ei ole padon omistajaa sitovaa, vaan oppaan tarkoitus on täydentää ja selventää esimerkein ja selostuksin laissa ja asetuksessa esitettyä. Oppaassa käsitellään padon suunnittelua kuten hydrologista mitoitusta ja padon teknisiä turvallisuusvaatimuksia, padon rakentamista ja käyttöönottoa sekä vahingonvaaraselvitystä, padon omistajan turvallisuussuunnitelmaa sekä padon kunnossapitoa, käyttöä, tarkkailua, vuosi- ja määräaikaistarkastuksia. Padot luokitellaan vahingonvaaran perusteella luokkiin 1, 2 ja 3. Luokittelua ei tarvitse kuitenkaan tehdä, jos patoturvallisuusviranomainen katsoo, että padosta ei aiheudu vaaraa. Jokaiselle luokitellulle padolle on padon omistajan laadittava tarkkailuohjelma, jonka patoturvallisuusviranomainen hyväksyy päätöksellään. Padosta aiheutuvan vahingonvaaran selvittämiseksi 1-luokan padon omistajan on laadittava vahingonvaaraselvitys padosta ihmisille, omaisuudelle ja ympäristölle aihetuvasta vahingonvaarasta. Myös muusta kuin 1-luokan padosta voi patoturvallisuusviranomainen määrätä tehtäväksi vahingonvaaraselvityksen luokittelua varten. Padon omistajan on laadittava 1-luokan padolle turvallisuussuunnitelma onnettomuus- ja häiriötilanteiden varalle. Suunnitelmassa esitetään padon omistajan omatoiminen varautuminen em. tilanteiden varalle. Pelastusviranomainen arvioi tapauskohtaisesti pelastuslain mukaisen suunnitelman laatimistarpeen. Padon omistajan on toimitettava patoturvallisuusviranomaiselle tietojärjestelmään vietäväksi patoturvallisuusasetuksessa mainitut tiedot. Patoturvallisuusviranomaisen ja padon omistajan on säilytettävä kustakin luokitellusta padosta ajantasaiset tulosteet tietojärjestelmästä sekä muut padon turvallisuuden kannalta tärkeät asiakirjat patoturvallisuuskansiossa siten, että ne ovat mahdollisissa häiriötilanteissa nopeasti saatavilla.