Spain: Presentations at CICES highlight erosion control work in a variety of Iberoamerican countries

In my previous post, I summarized some of the introductory presentations at CICES, the IECA Iberoamerican Chapter’s October 2012 conference in Granada, Spain.  In this post, I’ll focus on a few of the subsequent presentations that dealt with erosion and sedimentation issues in Spain and Latin America.  These were not necessarily the “best” presentations (although they were good to excellent) but I wanted to include examples from several different countries in order to give you readers a better idea of the wide geographical range of professionals working on erosion and sedimentation issues in Spanish and Portuguese speaking countries.  At least 17 countries were represented at the conference.

Olive groves are found in great abundance in the Andalucía region of southern Spain.  We had several presentations about erosion problems associated with olive cultivation.   One was titled “Initiative against erosion through integrated restoration in watersheds dominated by steeply-sloping olive groves in Andalucía” (my English translation).  The authors included some spectacular photos of catastrophic erosion in olive groves.  The principal author, Federico Julián Fuentes, noted that this problem has accelerated since the mechanization of Spanish agriculture took off in the 1960s.  He pointed out that social, economic, legal, administrative, and technical factors are obstacles in the restoration of affected watersheds.  He spoke of the need for a pilot project which would include not only technical studies but also incorporate an action plan supported by the participation, collaboration, and consensus of public administrators, affected farmers, environmentalists, and civic organizations.

Left: Small rivulets start to develop between lines of olive trees planted on a slope. Right: The rivulets naturally evolve into large gullies with time. 

photos from presentation by Federico Julián Fuentes

 

There were a number of presentations from Argentina.  “Riparian infrastructure for urban restoration in the city of Tartagal, Province of Salta, Argentina” (presented by Gustavo Arce) focused on traditional structural measures to control slope failures adjacent to a deeply incised river channel in a densely populated urban area.  Throughout its history, the Tartagal River has suffered from floods which undercut steep hillsides causing homes to collapse.  To address this problem, engineers from INMAC, a Buenos Aires-based consulting firm specializing in erosion and sediment control, used geotechnical approaches such as retaining walls (gabions and reinforced concrete) to channelize the river.  My first impression was that their approach was perhaps a bit heavy on large-scale structural controls.  However, in a crowded urban setting, I wonder if this is perhaps a more practical option than an environmentally-friendly and aesthetically-pleasing design relying on bioengineering.   

Photos at the beginning of construction (top left) and following completion (bottom right) show how the steep unstable slope on the top left was moderated and terraced above the new retaining walls. 

photos from presentation by Gustavo Arce

Gino Mathews from Peru gave a presentation on erosion control training for rural communities in the Peruvian highlands. The training aims to take the skills of indigenous people who have a long history of working with earth and rock to construct agricultural terraces and apply these skills to the mining industry.  People from local communities can then become employed in erosion and sediment control for the mining companies from the exploration phase all the way through mine post-closure.  In the process, cooperation between the mining companies and local communities is fostered, indigenous people get good-paying jobs without migrating to cities, and the mining companies can legitimately claim that they are helping local communities and using the skills of local people to protect the environment.  Seems to me like the type of project IECA’s SOIL Fund should get involved with.  IECA can provide skilled erosion control professionals like Gino Mathews to provide the training and the mining companies can provide funding.   

 

Photo from presentation by Gino Mathews illustrating the terrific skill of indigenous Andean people in construction of agricultural terraces on precipitous slopes.

Paula Pereira talked about the use of bioengineering for stream bank restoration.  She co-authored a paper (“Protection and Recuperation of Stream Course Margins Using Bioengineering”) describing methodologies used and monitored in the states of Bahia and Minas Gerais, Brazil.  Sediment retainers, wooden fences, and berms packed with live cuttings resulted in satisfactory stream bank protection.  These low cost BMPs were easy to install and environmentally compatible.  Senhorita (that’s Portuguese for señorita) Pereira is employed by DEFLOR Bioengenharia based in Belo Horizonte, Brazil.  Another DEFLOR employee, Luiz Lucena, spoke on erosion mitigation using bioengineering along the Atlantic coast of Brazil.  

Examples from Paula Pereira’s presentation showing stream bank stabilization using live cuttings planted along layers of soil which have been covered with natural fabric blankets.

Ricardo Schmalbach spoke about various erosion control techniques used on the Rio Magdalena, the principal river in Colombia which drains northerly to the Caribbean.  Record floods along the Magdalena during the winter of 2010-2011destroyed large areas of agricultural and industrial facilities, ports, and roads.  More than 500,000 people were displaced and 100,000 are still homeless.  Dr. Schmalbach described the use of “megabolsas” (huge sandbags weighing several tons each) to repair a critical broken jetty along the Magdalena.  Geotextile bags with a capacity of 13.5 cubic meters are filled with sand, dropped into the water from dump trucks, and positioned with excavators (track hoes) to build dikes.

 

Construction of a flood control dike along the Rio Magdalena in Colombia using “megabolsas.” The huge bags are compacted and consolidated by both their own weight and by the passage of trucks across them as more megabolsas are added.

photo from presentation by Ricardo Schmalbach

We tend to think of El Salvador as a poor, backward Central American nation.  Thus, it was encouraging to learn that state-of-the-art erosion control techniques employing heavy equipment were used in construction of a new 290km highway in the northern part of the country (“Slope Protection on the Northern Highway, El Salvador” by Oscar Alfredo Rivas Cerna).  To protect cut and fill slopes from failure in the tropical climate, geomat incorporating a double-twist hexagonal mesh attached to a filament-reinforced polypropylene was installed.  It was secured with rod anchors placed in a mortar slurry on a 2-meter-spaced grid across the slope.  30,000 square meters of this mesh were used on slopes which had a high probability of failure.  On another 12,000 square meters of slopes with relatively lower stability hazards, natural fibrous geomat (such as coir) was used to promote natural revegetation.

 

Using a hydraulic elevator for emplacement of hexagonal mesh and erosion control blankets and for drilling holes for rod anchors, Northern Highway, El Salvador. 

photos from presentation by Oscar Alfredo Rivas Cerna.

You may have seen my earlier postings from Bali and Thailand discussing the use of vetiver grass for erosion control.  Oscar Rodríguez Parisca of the Central University of Venezuela pointed out that climate change will bring ecological, economic and social impacts to vulnerable populations in developing countries (“Adaptation to climate change through the use of vetiver systems:  A tool for soil conservation and community development”).  He pointed out that use of vetiver is a simple, low cost option for soil stabilization that is tolerant of environmental extremes and is, therefore, suitable for communities adapting to climate change.  Examples were presented showing applications of vetiver systems to various types of impacts.

 

Examples of use of vetiver for erosion control in Venezuela: coffee plantation (upper right) & bauxite mine reclamation (lower left). 

photos from presentation by OscarRodríguez Parisca.

Julie Etra (IECA’s VP for International Development) and I were the only “gringos” who spoke at the conference.  Julie talked about the challenges of identifying appropriate best management practices for erosion control and revegetation in arid areas.   For example, revegetation of disturbed sites will often fail unless it is combined with rainwater harvesting to provide adequate moisture for germination and initial growth of native vegetation. 

When wattles are installed in low rainfall environments, they are of little use if vegetation plantings have insufficient moisture for survival. 

photo by Pablo A. Garcia-Chevesich from presentation by Julie Etra.

 

Julie had an easier time presenting in Spanish than I did as she had the good fortune of attending a private high school in Spain and now lives part of the year in southern Mexico.  Luckily for me, Julie and Gustavo Salerno (IECA Region I board member from Argentina) translated the English presentation of my erosion survey in Ecuador (including PowerPoint slide captions) into excellent Spanish.  All I had to do was practice it a few times before the conference, and Julie was there for my presentation to help me with questions from the audience.

 

Muchas gracias to Gustavo Salerno and Julie Etra for their translation of my presentation into Spanish!     

Spain: IECA Iberoamerican Conference held in Europe for the first time

On the morning of October 2, I took a brisk walk from my hotel in Granada, Spain to the Palace of Conferences and Expositions for the start of CICES 2012, the 6^th biannual conference of IECA’s Iberoamerican Chapter.  This was my first visit to Spain and the first conference I would attend that was totally in Spanish.  A dozen years ago, the Spanish part would have been less of a problem as I was coming off of five years of Spanish study and an intensive one-month immersion course in Quetzaltenango, Guatemala.  However, in the intervening years, I had barely used my Spanish and was really rusty.  At least the subject of the conference was a subject with which I was quite familiar (erosion and sediment control) so I would hopefully be able to figure out what was going on just by looking at the pictures.  And, for the most part, my assumption was correct and some of the Spanish that was buried in the back of my brain was roused from its long sleep.

Conference participants hanging out in the lobby of “El Palacio de Congresos y Exposiciones”.

 

Vendor displays at the conference

After introductions, the first presentation was by Gustavo Salerno, an Argentine engineer and member of the Board of Directors of IECA’s Region 1.  He gave an excellent presentation, Hacia una solucion integral en el control de la erosion y los sedimentos (Toward a comprehensive solution in controlling erosion and sediments) which provided an overview of the global importance of contemporary erosion and sedimentation and identifying the gravity of the problem. 

Left: Valentin Contreras (Spain), Chair of the conference organizing committee; Right: Gustavo Salerno (Argentina), one of the keynote speakers.

Señor Salerno noted that the significance of erosion depends largely on climate and is particularly serious in places like India and South America because of heavy rainfall, a preponderance of steep slopes, and intensive land use.  Of course, we at IECA are focused on erosion associated with highly visible, large construction projects such as highways, pipelines, and power lines.  However, agriculture is responsible for 60% of erosion worldwide whereas urban development accounts for 20% and mining 10%.  Salerno pointed out that erosion from agriculture could be greatly reduced by contour plowing which, as I had seen in many of the countries I had just visited, is still not used as widely as it could be.

Gustavo Salerno then focused on pipeline projects and presented examples of stream crossing design to reduce erosion.  He spoke of the gasoducto verde (“green” gas pipeline) concept which is increasingly being adopted on South American construction projects.  He described elements of the gasoducto verde including narrowing the pipeline right-of-way to the narrowest width possible in rainforests.  The importance of project planning was also stressed.

The next presentation was by a Spaniard, Rosa Arce Ruiz, Professor of Civil Engineering at the Polytechnic University of Madrid.  It was titled “Soil in the development of transportation, industrial, urban, and residential infrastructure”.  Professor Arce started off with a summary of the history of international regulations and proclamations for the protection of soils.  She stressed that “el suelo es un elemento vivo” (soil is a living entity), and documented the stresses on Spanish soils because of deforestation and urbanization.  Deforestation is occurring to provide more land for cultivation, grazing, and wood exploitation.  I was interested to learn that Spain is the most arid country in Europe (so salinization of soils is a large issue), and the Spanish environmental impact assessment law mandates the protection of soils.

Paolo Cornelini spoke about the use of natural engineering to revitalize riparian environments.

 

We had a presentation from an Italian professor, Paolo Cornelini, who is vice-president of the Italian Association for Natural Engineering.  His presentation was titled “The restoration and conservation of soil in the vicinity of river networks.”  Professor Cornelini reminded us that el rio es una ecosystema (the river is an ecosystem).  He described how the functioning of this ecosystem can be disrupted by disturbances to a river’s morphology, hydrologic regime, and vegetation.  Erosion (such as bank erosion and bed scouring) is a fundamental element interfering with the natural morphology of a river.

In order to “re-naturalize” a river’s disrupted ecosystem it is necessary to restore both its morphology and biodiversity.  Professor Cornelini showed us examples of river “re-naturalization” projects in Italy and South America.   Professor Cornelini showed us examples of river “re-naturalization” projects in Italy and South America.  The emphasis was on use of more vegetation and less technology such as “living” wattles and gabions containing seedlings and placed strategically in riparian areas.  Along the river channel, they recreated the natural step-pool sequence.   He presented an example from northeastern Italy in the Alps near the border with Slovenia.  The concrete channel was torn out and replaced with cobbles.  To stabilize cut banks, vegetated crib walls with vegetated block stone bases were used.  Fifteen plant species were used and after a few years, more than 200 species had colonized the restored riparian area.

Graph from Rodolf Gil’s presentation showing how the percentage of organic matter in agricultural soils decreases over time when conventional plowing is used.

The next presentation was by an Argentine agricultural engineer, Rodolfo Gil, from the Soil Institute at the National University of Buenos Aires.  After giving an introduction to the components of agricultural soils, Professor Gil illustrated how the percentage of organic matter in soil progressively decreases with the number of years of cultivation.  However, this decrease can be slowed by use of direct seeding in contrast to conventional cultivation with plowing.  Direct seeding with crop rotation increases soil porosity and water capacity.  Use of this method has expanded significantly in Argentina over the past 35 years.  And, use of sustainable agriculture (adopting plants and cultivation methods to the local environment) has become increasingly popular in contrast to less sustainable monoculture (single crop) agriculture.

Newly-elected& retiring officers of the IECA Iberoamerican Chapter. L to R: Ricardo Schmalbach (Ecuador & Colombia), Paul Gonzalez (USA), Paula Pereira (Brazil), Valentin Contreras (Spain), Beatriz Fernández (Spain), Nicky Araujo (Costa Rica& Panama), and Juan Carlos Hernández (Guatemala).

 

Later that day, the Iberoamerican Chapter of IECA held a meeting to elect new officers. Lead conference organizer, Valentin Contreras of BonTerra Iberica (a Granada-based company specializing in erosion and sediment control products), was elected President taking over from Rafael “Nicky” Araujo of Costa Rica and Panama.  For the first time, two women were elected chapter officers:  Beatriz Fernández of Spain and Paula Pereira of Brazil.  Juan Carlos Hernandez of Guatemala was also elected, and he has taken on the challenge of chairing the organizing committee for the next CICES Conference which will be held in Antigua, Guatemala in 2014. 

Coming next: Highlights of some of the papers presented at CICES.

View of the Alhambra from the site of our fiesta at the end of the first day of the conference.

Fiesta participants were treated to a performance by a flamenco dancer.