SUMMARY: This article describes the methods and expected
results of a research project for assessing Uruguay's vulnerability to
climate change and adaptation options regarding agriculture and
coastal resources. The study methodology has four basic steps: 1)
Data collection and compilation, 2) Development of climate change
scenarios, 3) Application of simulation model and other methods to
evaluate physical and socioeconomic impacts, 4)
Evaluation of adaptation options. The impact assessment for
the agricultural sector will address the main winter crops
(wheat and barley) and summer crops (maize and rice), and
grasslands-livestock production. Crop simulation models and
soil nutrient dynamics simulation models will be calibrated
and validated. Models will be run under a series of scenarios
(baseline, GCMs, analogue and incremental scenarios).
Adaptive responses will be analyzed using cost-benefit
analysis techniques. Coastal resources analysis will include
initial application of a simple model using biophysical and
socioeconomic data under selected sea-level rise scenarios,
in order to identify and classify coastal units according to
sensitivity. More detailed models will be selected and
validated for studying the most sensitive areas. IPCC
adaptation options will be evaluated by conducting a cost-
benefit analysis for each coastal unit. Results will be made
available as inputs for an integrated coastal zone
management plan. An education and outreach strategy for
the dissemination of relevant information regarding both
sectors to support policy and decisionmaking will be
implemented.
Climate change has been identified as one of the priority areas for further research within the context of Uruguay's National Research Program on Global Change (Comisió n Nacional Sobre el Cambio Global, 1995). The present article describes the context and methods for conducting a two-year sectoral vulnerability and adaptation assessment within the framework of the Uruguay Climate Change Country Study, initiated in late 1994 with support of the U.S. Country Studies Program. This study is being carried out by the Comisió n Nacional Sobre el Cambio Global (National Committee for Global Change) of Uruguay with participation of the University of the Republic, several Government agencies, and nongovernmental institutions interested on the issue.
The impact assessment focuses on two sectors of particular relevance to the Uruguayan economy: agriculture (including crops as well as grasslands and livestock) and coastal resources. The purpose of the study is to evaluate the impact of climate change on natural systems and human activities in these sectors by analyzing their sensitivity to selected climate change scenarios and evaluating possible options for adapting to, and where possible taking advantage of, new environmental conditions. The results of this analysis will be used to promote public awareness regarding climate change and to formulate national strategies.
The country is located on the northern margin of the Rí o de la Plata, one of the widest estuarine bodies in the world. It is one of the five countries which make up the Rí o de la Plata Basin, a vast region undergoing rapid urban and industrial development. The Basin encloses an extensive hydrological network. Its regime has been affected by dams for hydroelectric generation and surface drainage of lowlands. Future modifications are foreseen as a result of the development of a navigation waterway (Hidroví a) connecting the northern countries of the Basin to the Rí o de la Plata.
Further, a large part of Uruguay's coastline lies on the Southwestern Atlantic Ocean, next to the confluence of the Brazil and Malvinas Currents. This complex system is known to significantly affect regional atmospheric circulation patterns.
Uruguay's population amounts to little more than 3 million. About 11 percent of the Gross Domestic Product (GDP) corresponds to agricultural production, 25 percent to industries‹ which are mostly devoted to processing of agriculture and livestock products‹ and 64 percent to the commercial and services sectors and others. Tourism, which mostly seeks Uruguayan coasts, accounts for a significant portion of the latter.
Dominant soils in the country are Mollisols and Vertisols. They are characterized by a high variability in their water-holding capacity, their ability to supply nitrogen through mineralization and their ease for tilling. Farm management practices in the crop-growing area include rotating grain crops with pastures for livestock raising. Commonly, a period of about two to three years of crops is followed by four years of pastures (typically a mixture of white and red clover, birdsfoot trefoil and tall fescue). As a result of this system, soil conditions may vary depending on factors such as the time since the pasture was plowed, the length of the pasture and cropping stages, or the soil tillage practices.
Most of the beef and sheep products, as well as the barley and rice grain, are exported. Beef, wool, hides, and cereals account for about one-third of total exports.
Over the century, agricultural research has been devoted to improving the production of dry matter of pastures during the seasons of lower yields, i.e., in the winter due to low temperatures, and in the summer due to the lack of soil water. The introduction of species with high production potential and nutritional value during these seasons has increased the forage supply, especially in the dairy production area.
Crops have been improved through better management, including planting dates, fertilization, and high-yield varieties adapted to Uruguay's conditions. However, the heavy dependence of above production on climate variability, particularly rainfall and temperature, causes a high vulnerability of production systems to potential climatic changes.
Little research has been conducted for assessing vulnerability and adaptation options for the Uruguayan agricultural sector, namely some studies on winter crops (Baethgen, 1994; Baethgen and Magrin, 1995) which are serving as a background for this study.
The potential long-term physical variations in the coastal area, namely land loss and storm surge variations associated with sea- level rise, and the consequent socioeconomic impacts have so far been largely neglected in the implementation of development plans, both by the public and private sectors. A first assessment of the impacts of sea-level rise in Uruguay, which was conducted by Volonté and Nicholls (1994), provides a useful basis for this study.
Data Acquisition and
Compilation
Information and data bases for the study are being made available
by
various national institutions. Historical daily climate data covering a
period of about 40 years from several weather stations throughout
the
country, as well as current climate data, will be provided by the
Direcció n Nacional de Meteorologí a (National
Meteorology
Service). Additional climate information from selected sites will be
obtained from the Instituto Nacional de Investigació n
Agropecuaria (INIA) (National Agriculture Research Institute).
Data on temperature, precipitation, and solar radiation will be compiled, digitized (when necessary), and verified. Soil maps such as a 1:1,000,000 map for the entire country with profile descriptions for dominant and associated soil groups, a 1:200,000 map of main crop- growing areas, and detailed maps with productivity indices for all soil types in the country will be used. All maps will be processed in a Geographical Information System (GIS) format.
Information on crops and pasture characteristics (e.g., phenology, quality, disease resistance, productivity), on production systems (i.e., yields, fertility requirements, and carryover effects), as well as on livestock production are available from INIA and the School of Agronomy of the University of the Republic. Additional current experimental information will be obtained, as it becomes necessary, in coordination with such institutions. Socioeconomic information will be obtained from Government agencies, nongovernmental research organizations and associations of farmers, as well as from published reports.
Geographical Zoning
The study area is the entire territory of Uruguay. For the purpose of
this study, key geographical zones will be selected combining
information on climate, soils, topography, and production systems. A
GIS (ARC/INFO Software) will be used for zoning purposes.
Representative stations within each study unit defined by means of
the
GIS will be selected for further analysis.
Development of
Scenarios
Climate scenarios will be developed to estimate potential effects of
climate change on crops and grasslands-livestock production.
The following scenarios will be run:
The GCMs present many uncertainties regarding predictions, and their ability to simulate current climate varies from region to region (Rosenzweig et al., 1993). On the other hand, different GCMs predict climate changes that are in some cases contradictory. For instance, previous studies (Baethgen, 1994) of Uruguay show similar trends in the average mean temperature for the GISS, GFDL and UKMO models, with an increase in the monthly average of about 5°C. However, they show contrasting trends in precipitation, since the GISS and UKMO models predict a general increase in total precipitation, while the GFDL model predicts a slight decrease. In spite of such uncertainties, GCMs are so far the most advanced tools to predict potential future climatic consequences of increasing radiatively active trace gases in the atmosphere. The GCMs, combined with a local baseline scenario, and incremental and analogue scenarios, are expected to provide an overview of the potential future climatic conditions which could serve as a basis for the impact assessment regarding Uruguayan resources.
Comprehensive economic development scenarios for the country are not available so far. For the purpose of this study, general trends based on historical socioeconomic data as well as estimated patterns of development with regard to the agricultural sector will be considered for the impact assessment.
Calibration and Validation of
Models
The IBSNAT-ICASA (IBSNAT, 1989) crop models will be calibrated
with
experimental data from trials carried out by INIA and the School of
Agronomy, and validated for the study area. Large datasets are
available in Uruguay to calibrate and validate phenological and
production genetic coefficients for simulation models. A few
experiments will be established to obtain other required information.
Background experience regarding validation and regional adaptation
of
CERES models for winter crops will be considered (Baethgen, 1994;
Baethgen and Magrin, 1995)
A longtime step soil nutrient dynamics simulation model, namely CENTURY (Parton et al., 1988), will be calibrated and validated for assessing climate change impacts on grassland ecosystems, while a short-time step model such as SPUR2 (Hanson et al., 1992) will be used to assess impacts on grassland-livestock production.
Impact Analysis
Once the models are adequately validated, they will be used under
the
different climate scenarios for estimating potential effects of climate
change on the:
Adaptation
Assessment
Adaptive measures will be evaluated with the application of
simulation
models to assess the options of reducing the impacts of climate
change or taking advantage of any positive new conditions that may
arise. Cost-benefit analysis of these measures will also be conducted.
The present study will attempt to propose a comprehensive set of
adaptive measures for crops and grassland/livestock production
under
the different scenarios, on the basis of their cost-benefit implications.
These options will be provided as tools for decisionmaking at the
governmental, farmer, and consumer levels.
A series of potential adaptive responses for the agricultural sector based on international and local experience have been analyzed a priori for the purpose of this study. Adaptive measures for crops production could include genetic improvement and changes in management practices and land use.
Regarding genetic improvement, for instance, it is estimated that an increase in global temperature could negatively affect rice blooming, and consequently yields. The development or selection of new varieties of rice more resistant to high temperature at the blooming stage could be attempted to reduce such impact. Selection of genotypes with lower requirements of vernalization could be considered as an adaptation measure to global warming in relation to wheat and barley.
Further, genetic improvement could account for the negative effects on crops of an increase in climate variability, namely in precipitation. For that purpose, cultivars with higher resistance to environmental variations could be developed. The existence of significant experience in agricultural research in Uruguay, mainly at INIA and the School of Agronomy, would facilitate future research aimed at the selection of crop varieties more resistant to climate change or the testing of cultivars from other regions for use under local conditions.
Regarding crop management practices, previous analysis carried out for Uruguayan winter crops (Baethgen, 1994, Baethgen and Magrin, 1995) have proposed the reduction of the impacts of predicted unfavorable conditions by improving fertilization in combination with modified planting dates. Further, the use of soils with a better water balance‹ associated with appropriate texture and depth‹ could account for deficiencies in soil water content due to changes in precipitation patterns or higher evapotranspiration. Thus, the area of Tacuarembó /Rivera located at the northeast part of the country could be more suitable for summer crops than the ones presently used in the western and southern regions of the country, since their sandy soils present higher water availability.
Irrigation of crops such as maize could account for lack of water during droughts if an increase in the variability of precipitation patterns occurs. Planting dates could also be changed according to new climatic conditions, in order to allow for the development of new cultivars. Further, fertilization could be improved in accordance with the new adapted crops cycles, although this measure by itself might not have a significant effect.
With relation to adaptation options for Uruguay, natural grasslands, changes in grazing cycles, delayed grazing, or rotating grazing could be considered. Seed sodding on natural pastures could reduce negative climate change impacts on grasslands, thus representing an appropriate method for mitigating the effects of the lack of water and excessive temperature on pasture dry matter yields. The development of combined pasture and forestry production systems could be better adjusted to conditions of climatic variability, particularly in soils which are sensitive to rainfall deficiencies.
Data Acquisition and
Compilation
There exists in Uruguay a considerable amount of information for the
analysis of the impact on coastal resources, either available at
national
institutions or collected for specific studies, which can be used for the
present assessment. However, much of the data need to be digitized
and quality controlled.
Historical daily data on coastal water temperature, salinity, and tides along the coasts of the Rí o de la Plata and the Atlantic Ocean are available from the Servicio de Oceanografí a, Hidrografí a y Meteorologí a de la Armada (SOHMA) (Navy's Oceanography, Hydrography and Meteorology Service). Further data on physical and chemical water conditions in the Rí o de la Plata was collected during a pollution study in the area (CARP- SOHMA- SIHN, 1989). Sediment distribution data for the same area have been compiled in a Sediment Atlas (SOHMA, 1993). However, oceanographic and sediment information for the oceanic area is more sparse. Long- term historical climate data is available both from the SOHMA and the National Meteorology Service. General physical data, including coastal topography, bathymetry, sediment types, and wave data, have been collected during a Government study on beaches conservation (MTOP-PNUD-UNESCO, 1979). Additional wave information will be generated through models due to the lack of sufficient field data with the assistance of the Instituto de Mecá nica de los Fluí dos e Ingenierí a Ambiental (IMFIA) of the School of Engineering.
Long-term tide gauge data collected at ports is available from the National Hydrography Office.
A series of coastline maps as well as historical and current aerial photographic records available at the Geographic Military Service and the National Office of Environment, videotapes obtained for previous studies (Volonté and Nicholls, 1994) as well as satellite imagery will also be analyzed.
Besides the existing data, a one-year coastal monitoring program will be set up to estimate the behavior of different stretches of coastline when subject to storms. Data such as beach profiles, observed wave heights, and sand grain size will be collected.
In addition to biophysical data, general qualitative and quantitative information on economic activities and other social and economic indices will be obtained from Government agencies, published reports and articles, as well as from experts and local people's judgment.
Selection of Scenarios
Among the potential impacts of climate change in coastal areas, two
main aspects will be considered for the present study: an increase in
sea-level rise and a modification of wave characteristics.
Significant effort has been devoted at the international level to develop sea-level rise scenarios. The most likely estimate of sea- level rise by the year 2100 according to the IPCC will be tested. The sea- level rise scenarios will include the current rate (0.2 m by 2100) scenario (Douglas, 1991) and the accelerated rates (0.5 and 1.0 m) scenarios (Wigley and Raper, 1992).
With regard to potential modification of wave characteristics, no conclusive studies are so far available. Sensitivity analyses will be performed in order to estimate potential changes associated with increasing and decreasing storm energy and with shifts in direction of deep water waves.
Climate change scenarios will be combined with socioeconomic considerations to achieve a comprehensive assessment of potential changes. Since economic development scenarios for the country are not available, general trends based on historic socioeconomic data, as well as estimated patterns of development for the coastal area, will be considered for the impact assessment.
Preliminary Coastal Assessment and
Zoning
The study area includes the entire Uruguayan coastal zone on the
Rí o
de la Plata and the Atlantic Ocean. For the purpose of this study, the
term coastal zone refers to the area with mutual influence of sea and
land. Specific boundaries to such area will be defined as appropriate
during the study.
The first stage of the study will consist of a screening of the entire coastal area to assess its overall vulnerability to climate change and identify those zones potentially more sensitive to sea-level rise. This preliminary assessment will be based primarily on the analysis of available information and experts judgment.
The predicted physical conditions‹ namely modification of beach profiles‹ under the selected scenarios will be determined. Erosion assessment methods, such as Bruun's Rule (Bruun, 1962, 1983) will be applied to the Uruguayan coast. Since inundation is not an important process in the area, assessment of inundation impacts will not be considered in this study. The selection and validation for the area of other simple models to further assess the effects of storms on the new equilibrium profiles will be carried out. A general analysis will be further conducted for the social and economic implications of the morphological changes, namely cost of land loss, effects on coastal structures, and effects on coastal activities.
Zoning will be carried out by means of a GIS with the results of the preliminary screening. Homogeneous coastal units will be defined and classified according to their sensitivity. Sensitivity indexes will combine both physical and socioeconomic considerations. The most sensitive coastal units will be selected for further analysis.
Biophysical Impact Analysis in Selected
Coastal Units
A second stage of biophysical impact analysis in the selected coastal
units will be carried out under the sea-level rise scenarios, in order
to
further assess potential morphological changes in the area, namely
land
loss. General procedures for the indepth analysis will be similar as
for
the preliminary assessment. At this second stage, a more detailed
model will be selected and validated for the study area to estimate
the
effects of sea level rise on the beach profile. For the purpose of this
analysis, the wave information will be transformed from deep water
to
the near-shore zone more precisely‹ e.g. in the bottom
topography‹ for each coastal unit.
During the baseline impact analysis it will be assumed that no
adaptation policy is implemented. Therefore, it can be said that the
sheer effects of sea-level rise will be determined at this stage. Once
the effects on the beach profiles are determined, a map of the
predicted shoreline will be prepared. Geological information will be
overimposed to the erosion pattern to validate the assumption about
granular material erosion. An additional study of the general effects
of
sea-level rise and the consequent shift of the shore profile on the
coastal biota will be carried out. Special attention will be paid to
benthic fauna and to the typical flora adapted to the coastal
environment.
Socioeconomic
Analysis
A qualitative and quantitative assessment of the social and economic
consequences of potential changes in coastal configuration under the
climate change scenarios, namely the values of present and future
economic activities and resources that might be lost, will be carried
out. On each coastal unit likely to be affected by sea-level rise,
information on land ownership (public or private) will be sought and
value of land, coastal infrastructure (e.g., ports, seawalls and
breakwaters, roads), beachfront houses, tourists resorts, buildings,
and
commercial establishments will be estimated. Impacts of climate
change on the coastal activities (e.g., tourism) and associated social
indexes such as the level of employment will be further assessed. On
the basis of the biophysical and socioeconomic information obtained,
a
preliminary assessment of the overall vulnerability to climate change
of
the study zones will be sought in order to analyze the response
options
that would be required for each zone under the predicted scenarios.
Adaptation Analysis
The three basic adaptation options identified by the IPCC (IPCC,
1990b), namely retreat, accommodate, and
protect, will be analyzed. Each category will be
developed to identify specific alternatives for Uruguay. For each
coastal unit the options will be compared by estimating their costs
and
benefits. In the case of options requiring maintenance, the annual
cost
will be calculated. A cost-benefit analysis will be performed using
the
information of the investment costs and the yearly maintenance
costs.
For each coastal unit the possible adaptation options will be ranked according to the results of the cost-benefit analysis, taking into account social, economic, and environmental considerations. No adaptation option will be selected, but advantages and disadvantages will be pointed out in order to provide a tool for decisionmakers. Further, the study will attempt to provide its results in such a fashion that they could be easily incorporated into the process of the formulation of an Integrated Coastal Zone Management (ICZM) Plan for Uruguay.
The different target sectors that have been identified for the preparation of an education and outreach plan are the political sector, the Government, the business and industrial sectors, the educators, and the general public. An overall survey of the degree of awareness and knowledge of these sectors regarding climate change and its impacts, as well as their interest in obtaining information on the subject and applying it to decisionmaking processes, will be conducted at an early stage of the education and outreach activities. Such a survey will be performed by means of interviews and meetings.
Further, general dissemination of information is to be achieved through workshops, seminars, and conferences; through deliverables (publications, reports, brochures), and through the local press. The basis for the formulation of a long-term education and outreach strategy on climate change will be outlined jointly with Uruguayan institutions with expertise in the educational and social communication fields.
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