Journal of Coastal Research SI 39 1436 - 1440 ICS 2004 (Proceedings) Brazil ISSN 0749-0208

CASTRO, A. F.; GRIGIO, A. M.; SOUTO, M. V. S.; AMARO, V. E. and VITAL, H. 2006. Modeling anddevelopment of a geographic database: Application to the elaboration of oil-spill environmental sensitivity maps incoastal areas on the Rio Grande do Norte State. Journal of Coastal Research, SI 39 (Proceedings of the 8thInternational Coastal Symposium), 1436 - 1440. Itajaí, SC, Brazil, ISSN 0749-0208.

The study area is located between Galinhos and São Bento do Norte beaches, northern coast of the Rio Grande doNorte State. This area is characterized by natural factors and the human interference huge in the surroundings due tothe Guamaré Petroliferous Pole nearby, the greater terrestrial oil producing in Brazil. The first part of this workconsisted to elaborate a Geographic Database to store all the data collected on this study. This dataset was stored as avirtual library to assist men decisions from the results presented as digital thematic maps, tables and reports. Thesecond stage of this work consisted on elaborate the Oil-Spill Environmental Sensitivity Maps. These maps arecartographic products that supply full information to the decision making, contingency planning and assessment incase of an oil spilling incident in any area. They represent the sensitivity of the areas related to oil spilling, throughbasic data such as geology, geomorphology, oceanographic, social-economic and biology. Thus using the availabledata were possible to develop sensitivity maps of the study area on different dates (June/2000 and December/2000)and to perceive that there was a difference on the sensitivity index generated. The area on December presented moresensible indices to the oil than June presents because hydrodynamic data (wave and tide energy) allowed a fasternatural cleaning on June. This presented a medium index (3 to 4) to the long shore and a high index (10) to themangrove areas highly vulnerable to oil spill.

ADDITIONAL INDEX WORDS: Geographic information systems, geographic database, oil-spillenvironmental sensitivity maps.

ABSTRACT

Modeling and Development of a Geographic Database: Application to theElaboration of Oil-spill Environmental Sensitivity Maps in Coastal Areas of theRio Grande do Norte State.

A. F. de Castro†; A. M. Grigio† M. V. S. Souto† V. E. Amaro‡ and H. Vital‡; ;

INTRODUCTION

Currently, the worry with environmental factors is a realitypresents in all society's sectors, mainly between researches andprofessionals that work directly with environment. There is abig worry to organize the space, doing this changes attack theminimum possible the environment. From this worry, manystudies about environmental impacts have been realized tovalue and protect the regions more sensitive in relation tomodifications; and the Geoprocessing lets the efficient and fasttreatment of environmental data, doing the execution ofprocessing of data and guaranteeing confidences in the finalsresults obtained.

This technology is becoming a indispensable tool in thestudies about Environmental Impacts. In view of this newtendency the present work was performed with the mainobjective to elaborate oil-spill environmental sensitivity mapsof coastal areas of the north of the Rio Grande do Norte State,Brazil, based in the Geographical Information Systems (GIS)and Geographical Database (GD). This necessity appeared dueto the Guamaré Petroliferous Pole nearby.

The study area is inserted in the geologic context of PotiguarBasin, located of the Northeast Brazil, northern portion of RioGrande do Norte State coastal zone. The area is limited fromSao Bento do Norte to Galinhos city, with approacheddimension of 600 Km (Figure 1).

The local geologic context is the domain of Potiguar Basin(Cretaceous); with some sediments of the Barreiras Group

(Tertiary), with sand soil and clay-sand soil that recovercalcareous rocks of the Jandaíra Formation (this occur only insub superficial). In Galinhos estuarine band predominate recentalluvium with clay-sand soil with organic matter.

The whole area belongs in the coastal zone and has sedimentsand sedimentary rocks represent cenozoic deposits of coastaldeposition systems ( , 1996). The area were stronglymarked by deposition and erosion coastal processes caused bywind, currents, waves and tides action ( , 2000).

The geomorphology has a monotonous landscape near thecoast, marked by ample tide plain. In these littoral areasaltitudes generally are situated to the mean sea level ( ,1988). This region suffers continuous geomorphologic erosionor deposition modifications caused mainly by marineprocesses. The depositions forms are mobile and fixed dunes,beach cusps and sand plains without strong geomorphologicfeatures. The marine cliffs are one erosion type caused bydirectly wave action ( , 1996).

CARACTERIZATION OF STUDY AREA

2

CALDAS

HUSTEDT

DANTAS

CALDAS

JUSTIFICATION

The main justification to this study was the localization of theGuamaré Petroliferous Pole in a strongly dynamic coastal zone;where the development of an environmental database withgeographic information basis served to elaborate oil spillenvironmental sensitivity maps. The environment monitoringof these areas, where activities of prospecting, exploration andtransport of oil occur, have the goal to prevent and to minimizeaccidents with oil and gas. This necessity is evident in theMinistry of Science and Technology Edict nº 552, fromDecember 8, 1999, which defines the general lines of NationalPlan of Science and Technology of Sector of Oil and Natural

† Post Graduation Program on Geodynamics andGeophysics, CCET/Federal University of the State ofRio Grande do Norte (UFRN), Campus Universitário,Natal-RN, 59072-970. PRH-ANP 22angelica@summer.com.br;grigioma@yahoo.commikesouto@bol.com.br

‡ Geology Department, Post GraduationProgram on Geodynamics and Geophysics,CCET/ UFRN, C.P. 1639, Natal-RN, Brazil,59072-970. PRH-ANP 22.amaro@geologia.ufrn.br;helenice@geologia.ufrn.br

Journal of Coastal Research Special Issue 39, 2006,

Gas CTPETRO. This CTPETRO objective is the preparation ofcontingency plan to oil spill at oceanic and coastal areasinfluenced by offshore exploration and production in Brazil,with the participation of the operators.

The preparation of the contingency plan is important: (i) tomap the sensitive areas to oil-spill and, (ii) to do provisionalmodels of the oil-spot from Environmental GeographicDatabase which include several stages of environmentalmonitoring. The Environmental Sensitivity Index (ESI) showsthe area sensitivity in the presence of oil.

:

: the main aspects of the coastaldynamics (winds, chains, waves, tides);

: monthly survey of topographicalprofiles of the beach zone and ambient characterization;

: information about grain size analysisof of sedimentary samples collected in the area;

: satellites and aerial photographsimages;

: category that include different type ofmaps that can be constructed after the stage of field control(Use of Soil Map, Geology Map, Vegetation Map,Geophysical Map, Geomorphology Map, among others).

In the second stage, the packages are detailed, identifying theclasses that each one of them belongs and the relationshipbetween them. The category was chosen tobe more detailed in the follows stages (Figure 3).

In the third and last stage, it effectuates the definition of

OIL-SPILL ENVIRONMENTALSENSITIVITY MAPS

METHODS

The environmental sensitivity of coastal line classifies thecoastal sections in habitats, in accordance with itsgeomorphology characteristics, sensitivity to the oil-spills,natural persistence of oil and conditions of cleanness/removal.

The system of sensitivity classification is based ongeomorphologic characteristics of the coastal areas: degree ofexposition to the energy of waves and tides, declivity of thecoast and type of the substratum that affect its permeability andmobility.

The ESI is based in geomorphologic characteristics of thecoast, very important for the determination of the degree ofimpact and permanence of the spilled oil, as well as, in manycases, for the types of cleanness procedures employed. Thegeomorphology is determinative for the type and density ofbiological communities present in the area (MMA, 2002).

Each ESI indicates the sensitivity of the coast in a range from1 to 10, in accordance with the physical characteristics, if is sandbeach, cliff, mangrove, tidal flats etc. The ESI on this studywere based in the Specifications and Technical Norms forElaboration of Environmental Sensitivity Maps for Oil Spills(SAO Maps) elaborated by Ministry of Environmental in 2002,based on the sensitivity classification adopted by NOAA. Afterdeterminate the ESI, each index is represented by a colour in theOil-Spill Environmental Sensitivity Maps. This map presentsthe reaction of environment in the presence of oil. The coloursare applied to coastal line, limit between land and water(Table 1).

The first part of this study was the development of aGeographic Database with environmental data useful todetermine the ESI.

To development this database it was necessary to follow theessentials stages in the development any database described in

(1997), (2000) and (2001):, where from specifications requisites, the

entities will be represented through its attributes and itsrelationships will be stored in database; , usedto define how the entities will be stored in database (in Tables,for example); and , stage where detailsimplementation are defined, describing the structure storageand the methods to access the data.

The Conceptual Model adopted in this work was the, a model developed by research group in geographic

database of Institute Computer Science of Federal University ofRio Grande do Sul, Brazil. The GeoFrame is a conceptualframework offers a classes diagram basics to help the designerin the conceptual modelling geographic data ( .,1989).

The GeoFrame does a boarding top-down composed of threestages. First, for each geographic area, the diverse themes (andsub-themes) are identified. In the second stage, a sub-project ofclasses for each theme is identified. Still in this stage, aspecification association is done between classes from differentthemes. In the last, the analysis is done and the modelling ofkind spatial representation to each geographic phenomenon isidentified (C , 2003).

The GeoFrame first stage was defined the geographiclocation of study area and the more generic themes to berepresented. The data of study area are from some distinctsources and of different categories. They were grouped inpackages according to its similar characteristics (Figure 2)

GOMES FILHO HEUSER

FILHO

ASTRO

1º)Conceptual Model

2º) Logical Model

3º) Physical Model

GeoFrame

et al

et al.

�

�

�

�

�

Hydrodynamic Data

Beach Profiles Data

Sedimentary Data

Remote Sensing Data

Thematic Maps

Hydrodynamic Data

Figure 1. Location of the study area, showing São Bento doNorte and Galinhos cities.

Journal of Coastal Research Special Issue 39, 2006,

Table 1. Definition of ESI from specific data (modified of table NOAA)

Coastal GeomorphologyDegree of exposition

to Waves

Slope

Intertidal

Kind of

Substratum

Penetration Oil in

the Substratum

Definition

ESI

Exposed cliff, impermeableartificial structuresPlatforms eroded by action ofwavesFine and medium sand beaches

Beaches of sand and gravelBeaches of sand and gravelBeaches of gravel and rip-rapExposed flat intertidal areasProtected cliffsProtected flat intertidal areasSalt marshes, mangroves

High > 30º Cliff Impermeable 1

High < 30º Rocky substratum Impermeable 2

--- < 5º Fine and medium Semi-Impermeable 3

--- 5 - 15º Coarse grain size Permeable (= 25 cm) 4--- 8 - 15º Sand and gravel = 50 cm 5--- 10 - 20º Gravel highly permeable 6

Variable high to medium < 3º Sand limited penetration 7Low > 15º Rocky substratum --- 8Low < 3º Mud Low permeability 9

Medium to low < 10º Mud sand Low permeability 10

sand (< 10 cm)

Castro et al. 1437

Conventional Object ( ), Geographic Object ( )

Geographic Field ( ) a

what isand what kind (point, line, polygon or complex object); andwhat is nd what kind (image, TIN,regular point, adjacent polygons…). Look Figure 4.

The database conceptual model was developed on ArcViewVersion 3.2 software package. To define the ESI it wasnecessary to access many database categories. Data asgeomorphology map; hydrodynamic, specific waves energyand currents direction; data of profile beach, as intertidal slopeand characteristics of substratum, such as grain size andpermeability are considered essential to define the sensitivity ofthe coastal to the oil presence.

The conclusions proved the use GIS was highly satisfactoryto environmental studies involving oil-spill, where the databaseis an important component in the attainment of confidanteresults.

The conceptual model used - Geoframe - is able to deal withall the data inserted in the GD, as well as with all existingrelationships between them. The ArcView 3.2 was satisfactoryin stocking data and as a friendly tool of easy manipulation andvisualization of the spatial information.

The ESI identified to the area between Galinhos and SaoBento do Norte cities for the months June/2000 andDecember/2000, showed that to December/2000 the coastalarea was more sensible to oil than the month of June/2000. Theincrease in sensibility index can be explained by the reductionof the wave's size because as bigger the wave faster is the naturalcleanness of the oil by sea water. Some data were essentials indetermination of IS: area geomorphology, degree of expositionto the energy of waves and tides; intertidal declivity and thesubstratum type, mainly emphasizing the oil penetration.

The potentiality of the Geoprocessing techniques was reallyvalid in the determination of the environmental indexes tomesure the ambient sensitivity to the oil spilling.

The authors thank Project Environmental MonitoringCoastal Areas (MAMBMARE) and PROBRAL 150-02(CAPES/DAAD), for the financial support, as well as to theBrazilian National Oil Agency and FINEP, through PRH-ANP22, by the master scholarship to the three firs authors.

RESULTS

CONCLUSIONS

ACKNOWLEDGEMENTS

LITERATURE CITED

The degree of exposition to the waves energy and tides andcurrents direction are considered on GD. The time ofpermanence of oil on environments of high energy of waves andtides tends to be lesser compared to sheltered environments.Therefore, as much bigger the exposition to the waves energyand tides, faster will be the natural cleanness of the beach andminor will be sensitivity to the oil. The beach slope can befavourable or not to the oil trapping. The coasts with high slopesare characterized by minimum time of oil permanence. Thesubstratum type affects parameters as permeability, mobility ofthe sediment and oil permanence, beyond the transit of vehicles

2002).One of the requirements to the GD efficiency was the

multiple consultations to verify changes in the sensitivity indexdepending on the station. On this paper, the months ofJune/2000 and December/2000 had been chosen to perceivethese possible changes.

Thus, the four categories of essential data cited previously toESI definition has been accessed on the GD. The result of thisaccess has been 4 distinct tables with a common field: . Itwas necessary to make a JOIN between tables, across the field

. From the result of this JOIN, a new field ESI was added,typed Number. The tool QUERY BUILDER from ArcViewpackage was used to find specific categories (for example:Geomorphology with beach rocks, Waves >= 30 cm, Intertidalslope >= 10º and substratum medium sand). The result would bean intersection of all these requirements. After thedetermination of the lines (or area spaces) with all thesecharacteristics, an ESI value is defined.

The ESI is defined to the whole coast susceptible to oil spill.Higher the index greater is the coast sensitivity to the oil. Forinstance a coastal portion with ESI equal to 10 is more sensiblethan a portion with ESI equal to 5. After the ESI definition to

hole coast it was possible to view each index in thegeomorphology map of study area.

The results showed that the Environmental GeographicDatabase is perfectly functional and useful to the

elaboration based on amultitemporal approach for the months of June/2000 andDecember/2000.

A table was elaborated showing all the ESI to the studyarea, defined for the GIS through the crossing of information(Table 2).

After determined the ESI of the region, these could have beenvisualized in the geomorphology map (Figures 5 and 6).

L.H.O., 1996. Geologia Costeira da Região de SãoBento do Norte e Caiçara, Litoral Potiguar. Natal, RioGrande do Norte: Universidade Federal do Rio Grande doNorte, Master's thesis, 83 p.

A.F.; M.V.; V.E. and H., 2003.Desenvolvimento e aplicação de um Banco de Dados

(CASTRO,

ALDAS,

CASTRO, SOUTO, AMARO, VITAL,

Month

Month

Oil-SpillEnvironmental Sensitivity Maps

C

Figure 2. First stage of Geoframe conceptual model: locationof geographic area and packages used.

Figure 3. Second stage of Geoframe conceptual model: detailedpackage Hydrodynamic Data and its classes association.

Hydrodynamic Data

Winds

<Atributes>

Currents

<Atributes>

Waves

<Atributes>

Figure 4. Third stage of conceptual model of Geoframe:detailing of each existing class in the package HydrodynamicData.

Hydrodynamic Data

Winds

Data Table

Currents Waves

Profile Number:Data:Direction winds

Profile Number:Profile Location:Data:Velocity CurrentDirection Current

Profile Number:Profile Location:Data:Height wave:Period:Angle:Kind of wave:

Data Table Data Table

Journal of Coastal Research Special Issue 39, 2006,

Geographic Database and Oil-spill Environmental Sensitivity Maps1438

Figure 5. Geomorphology map showing the sensitivity indexes of study area on June/2000 (ISL2( ), 3( ) and 10 ( ).

Figure 6. Geomorphology map showing the sensitivity indexes of study area on December/2000 (ISL3( ), 4 ( ) and 10 ( ).

Journal of Coastal Research Special Issue 39, 2006,

Table 2. Sensitivity indexes to study area on June/2000 and December/2000.

GeomorphologyHeightWaves

IntertidalSlope

Substratum ESI Geomorphologyeight

WavesIntertidal

SlopeSubstratum ESI

Beachrocks 45,2Medium

sand2 Beachrocks 10,7

Mediumsand

4

Beach Fine sand 40,1 Fine sand 3 Beach Fine sand 14Medium

sand4

Beachrocks 43,7Medium

sand2 Beachrocks 17,2

Fine tomedium

and3

Mangrove --- --- --- 10 Mangrove --- --- --- 10

JUNE / 2000 DECEMBER / 2000

15º

0º

16º

5º

12º

9º

Castro et al. 1439

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E.P., 1988. Gravimetria e Sensoriamento Remoto:Uma Aplicação ao Estudo da Tectônica Recente entreMacau e São Bento do Norte (RN). Natal, Rio Grande doNorte: Universidade Federal do Rio Grande do Norte,Master's thesis, 97 p.

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<http://www.ecologia.ufrgs.br/idrisi/artigos/>. Access in: 01out. 2003.

J.L., 2000. Projeto Conceitual de Banco de DadosGeográficos através da reutilização de Esquemas, utilizandoPadrões de Análises e um Framework Conceitual. PortoAlegre, Rio Grande do Sul: Universidade Federal do RioGrande do Sul, Doctor's thesis, 212 p.

M.K.N.F., 1997. Sistemas de Informações Geográficascomo Base da Interface do Sistema SAGRI SistemaInteligente de Apoio à Atividade Agrícola. Natal, RioGrande do Norte: Universidade Federal do Rio Grande doNorte, Graduation Thesis, 52 p.

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Banco deArtigos, Centro de Recursos Idrisi, Instituto de Biociências

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Geographic Database and Oil-spill Environmental Sensitivity Maps1440