Optimización de los criterios y técnicas aplicados a la ordenación y restauración hidrológico-forestal de cuencas hidrográficas, desde sus inicios hasta el presente

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Extreme Events in Ecuador
Events of extreme precipitation are automatically related with the El Niño Southern Oscillation (ENSO) phenomenon. Much has been written about its occurrence, its cyclicity or not, an increase in frequency and/or intensity. None of those aspects will be addressed in this document. We will limit to the consequences of an El Niño episode for Ecuador.
An El Niño episode causes the normal rainy season in the coastal plains of the provinces of El Oro, Guayas, Los Ríos and Manabí, which lasts from January to April, to be much more intense (precipitation can be as much higher as 4 –5 times the normal values), and also longer (November-June). In the Andes mountains the exceptional rainfall occurs on the westward oriented slopes of the Western cordillera up to an altitude of approximately 3000 m.
The consequences in the coastal plains are flooding of agricultural and inhabited areas. In the mountains the main problem is landsliding, with consequent road blocking and burial of villages with loss of lives in some cases. In general, conditions are too high and agriculture is almost impossible during an El Niño episode. This lack of agricultural production is of big impact for the country, obliging to import food, amongst other problems.
Most damage typically occurs during and after intensive rainfall with duration of 10 to 24 hours, falling on land already saturated by previous rainfall events.
Since an El Niño phenomenon hits a large part of Ecuador the consequences for the national economy are considerable. It is estimated that losses equal 10% of the annual GIP in the 1982-1983 Niño and 14% of annual GIP in the 1997-1998 one.
Loss of human lives is common in the Sierra by burial under landslides, and in the Coastal area by flooding. During the last El Niño events hundreds of lives were lost. The damage to infrastructure is in the sierra mainly by landslides destroying roads (including the Panamerican highway) and villages, and in the coastal area usually on the north-south road bridges crossing rivers coming down from the western slopes of the Andes which are washed away. A particular type of event is the damming of rivers by landslides, causing flooding upstream the dam, and causing a flash flood downstream upon overtopping and breakthrough of the landslide dam.

Institutional Analysis

The institutional panorama in relation to forest and water management in general, and in relation to extreme events in particular, is quite chaotic in Ecuador, and has been changing constantly over the last 20 years.

Figure 1 gives a summary of involved laws and institutions from the Constitution to the local governments of municipalities and non-governmental organizations.

The whole of this legislation is quite complete but not clear to the actors and is therefore not applied in practice. For example, in spite of a series of legal prohibitions, deforestation continues at an alarming rate and the agricultural frontier climbs higher in the Sierra, destroying the paramos so important for regulation of the water cycle.

A general tendency is decentralization of environmental competences from national institutions (Ministry of Environment, Ministry of Agriculture,...) to local governments (Provincial Councils, Municipalities, ...). This has the advantage of a “closer to the scene” management, but permits also that each institution establishes its own rules contributing to a fractionization of the policy. During this decentralization process, it is common that competence between institutions is overlapping and conflicts arise.
In relation to extreme events, at national level only mitigation responsibilities exist in institutions like Civil Defense. However in case of emergencies usually the Army is in charge of actions such as evacuation of affected population, emergency constructions etc.

Two institutions exist for reconstruction of infrastructure after the last El Niño event. Their action is limited to the coastal plains. No reference is made to prevention by e.g. forestation or catchment management in general in their action plans.

When mentioning extreme events, in Ecuador automatically reference is made to El Niño, in spite of the presence of other natural risks like earthquakes and volcanoes.

Most important consequences of an El Niño event are the loss of human lives, destruction of infrastructure and the impact on national economy through loss of agricultural production.

Legislation on environmental protection / catchment management / water rights etc is very extensive. However two major drawbacks exist:

  • There are contradictions on responsibilities between different national institutions on the one hand and between national and local government on the other hand. This results in a lack of consistent policy making.

  • Legislation is quite “strong” on some subjects but the means to apply the legislation and control actions are few, which results in widely spread violation of the rules.

The majority of institutions don’t have a policy for prevention and management of extreme events. Usually action is limited to reaction when events occur.

Common perceptions on forest and water in Ecuador

  1. It is a deeply rooted belief in the Andes region of Ecuador (Sierra) that forests “produce” water.

  2. Usually, but not as generalized as previous, forests are believed to produce clouds and therefore attract rainfall. In this same context a traditional belief in rural communities is that those clouds also can be formed by smoke of burning large areas of grassland or forests, resulting in widespread intentionally initiated forest fires in dry periods with water shortage.

  3. Forests are considered to regulate water flow. The regulation process is believed to be located in the vegetation itself, or in the best case, in the litter layer, but generally there is no consciousness about the role of the soil in the regulation process.

  4. Much more attention is given to the benefit of forests for maintenance of low flows, than to the benefit of forests for the reduction of peak flows. All forestation programs that have in their motivation a relation to water resources refer to protection of low flows, and none of them has as main motivation the reduction of peak flows.

  5. Until some 15-20 years ago, previous was believed to be valid for any forest, including exotic species like pine and eucalyptus. Nowadays this has changed and only native species forestation is believed to be contributing to regulation of water flow and especially protection of low flows.

  6. Peak flows of extreme events are not necessarily believed to be related with deforestation of the catchment. No such programme as forestation of upland areas in the sierra to prevent flooding in the coastal plain which regularly occurs during El Niño events exists. Planners of prevention/mitigation action in the areas most affected by El Niño, usually don’t look much upstream and for sure not higher than 1200 m altitude (catchment highest points are 3000-5000 m altitude).

  7. Increasing occurrence of landslides is generally believed to have something to do with deforestation. In this, little distinction is made between different types of landslides.


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