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CHAPTER 5
Challenges and Strategies
to face Agrometeorological Risks and Uncertainties - Regional Perspective in South America
Constantino Alarcon Velazco
s.t
Introduction
South America is one of the regions in the world, most exposed to a wide range of hydro-meteorological hazards, according to the EM-DAT, an international data- base on disasters, that the Office of US Foreign Disaster Assistance (OFDA) is in charge of. The Center for Research on the Epidemiology of Disasters (CRED) es- timates that between 1980 and 2005, almost 80% of the natural disasters, 30% of the loss of human life and 75% of economic loss that took place in the Region were caused by hydro-meteorological conditions and hazards.
In South America where agriculture, fishery and forestry contribute 12% of the Gross Domestic Product (GDP), the success of these activities depends basically on a favourable climate. A good rainy period, together with adequate temperature conditions and the absence of extreme weather, guarantee the success of agricul- tural production. Despite its importance, agriculture is the sector most vulnerable to natural disasters.
Natural disasters that pose the most dramatic threat to agriculture in the region are: floods, droughts, strong winds, landslides, volcanic eruptions, and climate change. While the first four have a catastrophic character, the last two represent a risk that could exert a pressure towards a change in the land-use and the imple- mentation of some adaptation measurements. This situation threatens the econom- ic development and food security in the countries.
One aspect important to the region is a better understanding of the links be- tween climate variability, with an special emphasis on El Nino/Southern Oscil- lation (ENSO), and the extreme hydro-meteorological events, since this is funda- mental to the design of appropriate preventive measurements for disaster risk re- duction.
These climatological phenomena severely affect the social, economic and politi- cal life of the affected countries. Heavy rain, prolonged droughts, intense canicula, polar cold, shortage of agricultural products, abundance of some other unexpected products, floods and others, constitute a worrisome reality.
5.2
Climatology and Geography ofSouth America
A fundamental aspect for being able to face risks and uncertainties, which South America confronts, is an understanding of its geographical location and climatol- ogy (IADB 2001).
The geographical location provides the main explanation for the extreme nat- ural phenomena that cause great disasters in the region. This region is extremely prone to earthquakes and volcanic eruptions, because its territory is located on some tectonic plates, along the Pacific Ring of Fire.
Climate variability is extreme. Evidence of it are the occurrence of severe droughts, floods, cold waves and winds caused by the EI Nino events, by the annu- al North-South displacement of the Inter-tropical Convergence Zone (ITCZ) and by the entrance of frontal systems (Fig. 5.1). Recent climate changes seem to have aggravated climate variability in the region.
The degree of vulnerability in the region, in relation to extreme natural phe- nomena is not only determined by its geographic location and climate patterns, but also by several socio-economic factors that increase the vulnerability to these natural hazards, i.e. settling of populations in some places inappropriate to agri- culture, environmental degradation, etc.
Fig.S.l. Atmospheric processes affecting climate in South America
Chapter 5: Challenges and Strategies to faceAgrometeorological Risks and Uncertainties 73
5.3
Natural Phenomena thataffect Agriculture inSouth America
The main natural phenomena affecting agriculture in the region are the following (FAG 2000):
5.3.1 Landslides
Due to the topography of the region, most of the landslides generally occur on the hillsides, and in specific places, where deforestation and improper management of the soil are the main factors for the occurrence of these factors.
5.3.2
Volcanic Eruptions
At present several existing volcanoes in the area are active and they cause a seri- ous impact on the national economies and the health of the communities. Volca- nic eruptions block solar radiation causing cooling and diminishing ofluminosity.
These impacts together with the deposit of minerals that are in high concentrations are toxic to animals, can generate great harm to agriculture and livestock.
5.3.3 Floods
Floods occur in areas near the riverside where farmers, wanting to make good use of the land, start sowing in the lowlands. When a heavy rain occurs, it causes an overflow in the rivers and devastates the crops.
Some of the problems that arise whenever there is a flood, are the following:
• Heavy precipitation causes an "increase" in the river water level. This is more evident when there is an £1 Nino event.
• Flood-plain inundation and damage to the houses, transportation, farm pro- duction, and in some cases with loss of human lives.
• Slow drainage of inundated areas which results in pools of stagnant water. This situation generates health problems for the population.
• Flow attacks to the banks of the main riverbed, causing permanent changes in the river course and loss of productive areas.
5.3.4 Droughts
Drought is considered a natural disaster that originates from a deficiency of pre- cipitation over an extended period of time, causing harm to the different activities of the population. The damages caused by effect of droughts are much stronger in areas of extreme poverty.
Drought causes negative impacts such as: reduced water availability for irriga- tion purposes; delay in the sowing dates and less crop yield; loss of productivity in natural prairies and dry-land crops; increased erosion on plains and high areas;
environmental stress in hydromorphic areas; soil salinization due to the reduction in the volume of water for irrigation and drying up of wet areas; effect of frosts due to the delay of the sowing in drylands; intensification of freatic water tables and drying up of wells; and advance of desertification in the arid, semi-arid and sub- humid ecosystems.
The degree of severity of droughts can be intensified due to some other climate factors depending on each region and these include high temperatures, strong winds and low relative humidity.
5.3.5
Extreme temperatures including heat waves and cold waves
During periods of heat waves, the extreme high temperatures together with a high vapor pressure deficit can generate intense evapotranspiration. This situation is generally intensified with the occurrence of the El Nino events.
Frosts occur only in the Inter-Andean region where it affects the small-scale crops. Generally farmers carry out their activities in the frost-free periods in order to avoid the negative effects caused by the occurrence of this phenomenon.
5.3.6
The Climate Change
The effects of projected climate change on crop yields in the region are uncertain.
The effects include both positive and negative impacts as follows:
• The changes in the number of humid months induced by the changes in precipi- tation and evapotranspiration could mean greater changes in the spatio-tempo- ral distribution of agricultural systems.
• The increase in the area of climate types described as semi-arid and sub-hu- mid dry, implies greater risks ofland degradation when inadequate agricultural practices are performed.
• In relation to temperature, the impacts are positive when it increases in a colder climate, as well as the fertilization with atmospheric CO2 •In warmer climates the increase of temperature could be critical when the thermal stress increases and it accelerates the development cycles of crops. On the other hand, the in-
Chapter S: Challenges and Strategies to fate Agrometeorologital Risks and Untertainties 75 crease of night time temperatures implies an increase in respiratory losses and consequently diminished yields.
• With regard to precipitation, reduction in the arid, semi-arid, and sub-humid dry zones could reduce crop yields, while in the humid zones where excessive precipitation is the norm, a reduction in the amount of precipitation could be beneficial.
5.3.7
EI Nino - La Nina Phenomenon
The main climatic characteristics in South America, during the £1 Nino event are frequent anomalies (Fig. 5.2). Together with an increase in the temperatures in the western coasts of the Pacific Ocean, it modifies the atmospheric circulation pat- terns, pressure, precipitations, rivers discharge and the water level of the lakes. £1 Nino causes above normal rains, and droughts in several places.
5.3.8 Strong winds
High speed winds not only favor excessive evapotranspiration but also can cause the breakage of some parts of the plants and harm structures of the plant that ac- tively contribute to the crop yield.
COLOMBIAãVENEZUELA SURINAME fRENCH Gl Precipitation reduction ir year. except In March to Colombia receives inten, insummer
ECUADOR PERU BOLIVI In the western coast Inten summer. Absence of rain Andean regions of Ecuad.
Bolivia
~ There Is evidence0 marked effects of r
'ains in Amazona,
,robability of forest fires
NORTHEAST
I\bsence of rains during the rainy season, february to May
OUTHEA§T Klerate increase in the nperatures. No change in rains
recipitations in the spring , rains during May to June
UAY. URUGUAY normal in the nonneast or "'!lentlna, Uruguay and Paraguay, mainly in spring to summer.
Fig.S.2 Impacts ofEl Nino - Southern Oscillation (ENSO) phenomenon in South America
5.4
Vulnerability of the Region
Vulnerability in the Region is aggravated because of the location of human activi- ties in some places of great risk, natural resources subject to excessive pressure of poverty, lack of environmental management policies, excessive centralization, lit- tle agricultural technology, and lack of education of the population to prevent and face risks (OAS 1993).
Main causes of vulnerability in the region are the fast and un-regulated urban- ization, rural and urban poverty, deterioration of natural resources, inefficient public policies, and the delays and mistakes in infrastructure investments. In the region, there is little investment concerning mitigation of natural hazards and the response is mainly under emergency situations.
Vulnerability of natural forests, mountain ecosystems and agriculture is reflect- ed in the following aspects (WMO 2007):
• Deforestation of rainy tropical forests is altering the hydrological cycle in the region causing a shortage in precipitation as a consequence of reduced evapo- transpiration. These deforested areas have lost all protection to face climate variability, making them more vulnerable to floods and soil degradation.
• In the subtropical forests of the semi-arid regions, where precipitation is expect- ed to be reduced, the loss of vegetative cover is generating desertification.
• The vegetation in the prairie ecosystems is highly dependent on precipitation.
Overgrazing and inadequate management practices are generating high deserti- fication areas.
The mountain ecosystems play an important role in South America because:
• They constitute places with considerable human settlements (Bolivia, Colombia, Ecuador Peru and the Highlands of Chile)
• They perform an hydrological regulating function and at the same time the al- titudinal gradient formed by the Andes mountains is a source of rich biodiver- sity.
• At present the mountains are threatened by global warming which is altering the runoff regimens of the rivers, making the irrigated areas vulnerable to the occurrence of droughts (Peru, Bolivia, Chile y Argentina).
Most of the agricultural lands is going through a process of degradation due to in- appropriate management and use. Non-irrigated agricultural land depends on pre- cipitation which makes them vulnerable to seasonal to inter-annual variations of precipitation.
Inappropriate management of soils has led to a stage where agricultural activi- ties are taking place in fragile areas that are not suitable for such practices. This has resulted in a situation in which almost all the countries have a generalized and ir- reversible erosion in terms of agricultural productivity. The irrigation systems, not efficient enough, are responsible for the salinization of the river waters, sedimenta- tion of the river beds and reservoirs. All these practices are increasing the vulner- ability of agriculture.
Chapter S: Challenges and Strategies to faceAgrometeorological Risks and Uncertainties 77
5.5
Capacities and Resources inthe region
toface Agrometeorological Risks and Uncertainties
Capacities and resources in the region vary from one country to another, however in facing natural disasters there are some aspects in common between the coun- tries in general, which include the agro-meteorological phenomena.
5.5.1
Economic status of the countries
In the region most of the countries have reached a certain degree of macro-eco- nomic stability which is enabling governments to better respond to the impacts of disasters and they are investing more in the prevention and reduction of risks and uncertainties.
5.5.2
Government policies
As a consequence of the increasing incidence of disasters, which has made the re- gion extremely vulnerable, several governments have included disaster preven- tion in their political agenda. This political commitment is demonstrated in the assumed compromises in relation to the International Strategy for Disaster Reduc- tion (ISDR).
5.5.3
Creation and strengthening of specialized institutions
The new political orientation is leading some countries to create new inter-insti- tutional and sector integrated systems for disaster prevention and response. Other countries are initiating modernization of the national agencies specializing in di- saster mitigation.
Some governments have created regional institutions, such as the International Center for the Research of El Nino Phenomenon (CIIFEN), aimed at promoting, complementing and starting scientific and applied research projects, necessary to improve the understanding and early warning of the ENSO and the climate vari- ability at a regional scale. Projects such as the Disaster Prevention in the Andean Community (PREDECAN) contribute to vulnerability reduction of the popula- tions and of the material goods that are exposed to danger and natural risks in the countries of the Andean Community of Nations. The Network of Social Studies for Disaster Prevention in Latin America (The Network), which is constituted by non- governmental institutions and researchers in all the region, informs and advises the governments about their policies and gives advise to other regional and inter- national organizations.
The United Nations agencies also provide support to the region to improve pre- vention and response to disasters, and they constitute a considerable resource. Itis worth mentioning the work of the Economic Commission for Latin America (CE- PAL) in the assessment of the economic impacts of natural disasters. These evalu- ations provide important information for planning reconstruction and prevention purposes.
Institutions such as UNDP, UNESCO, WMO, FAO, CAF,!DB and the World Bank are promoting the necessary scientific capacity building to reduce risks. With important bilateral assistance from Europe, Japan, Canada, the United States and some other countries, national efforts are being promoted by means of regional, national and local projects to evaluate risks, and for preparedness in case of an emergency situation and prevention.
The local non-governmental organizations and the civil society of the Americas are playing an important role in the prevention and response to natural disasters, and in many cases with support from international NGOs.
5.5.4
Risk identification and analysis
Countries in the region identify the main natural disasters to which they are most exposed and assess their frequency, intensity, duration and localization (risks maps). The identification of certain risks is being used to define the necessary mea- surements for prevention and mitigation and planning of the socio-economic ac- tivities in each country (WMO 1993).
5.5.5
Monitoring networks and early warning
Most countries have monitoring and early warning networks, however it is impor- tant to point out the necessity to modernize the hydro-meteorological information network; modernize Meteorological Services and the means by which forecasting is made in the region; improve early warning systems and improve communication between the scientists responsible for evaluating the atmospheric and hydrological conditions and also between those in charge of providing early warnings.
5.5.6
Information on the risks fordecision making
Most of the Governments in the region have understand that it is necessary to have:
• The projections on the incidence and the estimation of impacts of natural disas- ters in order to prioritize preventive actions.
• The information on risks for the adoption of preventive policies and prepared- ness and for the establishment of specific objectives and priorities related to in- vestment.
Chapter 5: Challenges and Strategies to fate Agrometeorologital Risks and Untertainties 79
• The information on risks and vulnerabiltiy of natural disasters to develop pri- vate insurance and other market tools to combat risks.
• Research carried out in the region, with the purpose of analyzing the existing assessment methodologies, their use and to provide relevant and precise infor- mation to the persons in charge of formulating policies, action plans for the pre- ventions and institutional development.
5.6
Defining Policies and Tools toface Agrometeorological Risks and Uncertainties
The efficient management and planning of agricultural activities requires policies and tools that allow communities to face agro-meteorological risks and uncertain- ties (WMO 2006). Among these we can consider the following:
• Mitigation of the impacts of agro-meteorological risks and uncertainties re- quires multi-sectorial and multi-disciplinary actions.
• Defining adequate strategies for land use based on forecasted risks, selection of varieties, and types of crops or change the sowing dates to reduce crop loss.
• Improve irrigation techniques and most efficient use of water, likewise, to man- age water more efficiently and to prevent flooding and soil erosion.
• Adopt appropriate soil management systems to minimize the erosion during both rainy and dry events.
• Improve prairie management and adjust livestock numbers on the grazing lands according to the provisions of climate risks.
• Restoring degraded ecosystems.
• Promote the creation of early warning systems of adverse agro-meteorological phenomena
• Carry out evaluations and agro-climate zoning to determine the most favorable conditions for agriculture as well as extreme conditions that are anomalous and recommend appropriate measures to control them.
Several of these actions can be improved by means of an early warning system for adverse climate phenomena to reduce uncertainties through a better understand- ing of the dimensions of risk. On the other hand, all the information about the generation and evolution of climate phenomena generated daily by different insti- tutions should be used. At present several institutions provide forecasting systems for El Nino events which include NCEP of the National Oceanic Atmospheric Ad- ministration, USA; MMS from the University Corporation for Atmospheric Re- search, USA etc.
5.7
Strategies to cope with Agrometeorological Risks and Uncertainties
Given the high recurrence of extreme agro-meteorological events, the South Amer- ican region must generate strategies to prevent and mitigate their impacts. In this
sense, the agro-economic planning at a short and long term and at a local, regional or national scale, should be formulated more rationally including among its vari- ables, the agro-meteorological and agro-climatic information (WMO 2004). For example, real time climate data can be used to predict production 2 or 3 months in advance, as this provides sufficient advance information for decision making in buying/sales processes and for distribution and commercialization of products.
The agro-climatic analysis on a long term scale makes it possible to carry out crop zonation and identify the most suitable periods for their cultivation. They can also efficiently contribute to the planning and management of risks, by balancing the water requirements with water availability in the region.
When putting into operation the strategies one should recognize that the most important element in long term is prevention. Within this principle the following strategies are proposed.
• Implement and strengthen early warning systems for agriculture by establish- ing and strengthening national and regional monitoring and surveillance sys- tems that allow the identification and dissemination, in advance and in a re- liable manner, of the imminent occurrence of meteorological events that may cause harm to the agricultural sector.
• Strengthen international cooperation by implementing and operating these sys- tems by means of surface networks, satellites, communication, exchange of ex- pertise and experts.
• Develop and apply methods to evaluate the vulnerability of the countries by integrating biophysical, socio-economic and historical information and create charts for risks, vulnerability, potential impacts and risks reduction strategies.
For this purpose, it is important to carry out some activities to identify the most critical zones concerning floods, droughts and wildfires, so that the necessary actions to reinforce or install early warning systems can be identified.
• Strengthen the capacity to analyze the agro- meteorological risks and uncertain- ty information.
• Develop scenarios and climate forecasts at the short, medium and long term at the regional level for the agricultural sector in order to define climatic anoma- lies scenarios related to climate variability or to climate change, in terms of in- tensity, distribution, seasonality, considering the most representative variables for the agricultural sector in the region.
• Establish and standardize regional methodologies to evaluate the influence of climate variability and climate change in the productions of crops.
• Promote efficient irrigation systems and soil management systems to maximize the use of precipitation and to reduce the risks of erosion.
• Evaluate socio-economic impacts of agro-rneteorological risks and uncertain- ties through a knowledge of the phenology of the plants, an inventory of the most frequent impacts of the different climate variables and possible scenarios of the effects or positive impacts of climate anomalies on crops.Itis necessary to have the information on the rise in production costs, loss of infrastructure and goods, loss of agricultural land, reduction of farm income, migration from the countryside to the city and impacts on employment and labor.
• Implement a Regional Information System for agriculture through the gener- ation of data and information for decision making and agriculture planning