GIS IN GEOTHERMAL GIS IN GEOTHERMAL RESOURCES RESOURCES

DEVELOPMENTDEVELOPMENTBYBY

J. MunganiaJ. Mungania

What is GIS?

Geographic Information System {GIS}• Management• Analyses• Display

of ‘geographic information’

These are datasets that model geography (features, activities and events on the Earth’s surface & Subsurface)

using generic GIS data structures

GIS comprises Hardware, software and experts

Applications in geoApplications in geo--sciencessciences

• Geo-databasesSpatial databases that represent information in terms of GIS data model (Features, raster, topologies etc) ~ Management

•Geo-proccessing:Using information transition tools that derive new datasets (information) from existing datasets. Use of analytical functions e.g. Statistical Suitability, analysis

•Geo-visualization:Different map views of underlying geographic information are constructed into Set of intelligent maps showing various feature relationships, window into database for querying and analysis – display/presentation

Why GIS for KenGen?Why GIS for KenGen?Most data/information for geothermal resources Most data/information for geothermal resources is spatial in nature is spatial in nature (exploration, drilling, steam fields, wells etc)(exploration, drilling, steam fields, wells etc)

Vast amount of data/information that require Vast amount of data/information that require collating synthesizing collating synthesizing (KenGen, (KenGen, KplcKplc, MoE, Mines , MoE, Mines dptdpt, , UnivUniv, etc), etc)

DataDataùùÁÁInformationInformationùùÁÁ KnowledgeKnowledgeùùÁÁ Decision/actionDecision/action

UnsharedUnshared ‘‘There is nothing like good dataThere is nothing like good data……..’’

•• KenGen uses ArcGIS KenGen uses ArcGIS VerVer 9.1 [ESRI]9.1 [ESRI]

What Is ArcGIS 9 ?What Is ArcGIS 9 ?• ArcGIS provides a scalable framework for implementing GIS for users on

desktops, in servers, over the Web, and in the field.• ArcGIS 9 is an integrated collection of software products, that consists of a

number framework for deploying GIS:

ArcGIS ArcGIS DesktopDesktop ––GIS applications GIS applications consisting of the consisting of the 33software products: software products: ArcViewArcView, , ArcEditorArcEditorand and ArcInfoArcInfo

Server GIS:Server GIS:ArcSDE ArcSDE -- interface for interface for managing managing geodatabasesgeodatabases in in database management database management system (DBMS)system (DBMS)ArcIMSArcIMS -- internetinternet--based GIS for based GIS for distributing data and distributing data and servicesservicesArcGISArcGIS ServerServer –– totobuildbuild serverserver--sideside GIS GIS applicationsapplications

Components of ArcGIS DesktopComponents of ArcGIS Desktop

ArcGIS is a integrated, scalable system and ArcGIS desktop consists of 3 components:

• ArcView • ArcEditor • ArcInfo

With all three ArcGIS components, you can view databases managed by ArcSDE, but only with ArcEditor and ArcInfo can you write to such databases.

All three software products (ArcView, ArcEditor, ArcInfo) use the same integrated applications only with different levels of functionality:ArcMap, ArcCatalog and ArcToolbox.

ArcEditor has all the functionality of ArcView plus powerful tools for editing coverages and geodatabases.

ArcInfo provides the most functionality and includes all the capabilities of ArcEditor plus additional geoprocessing tools and a full version of ArcInfo Workstation (comprised of ARC, ArcEdit, ArcPlot, INFO, and ARC Macro Language or AML).

ArcCatalogArcCatalogArcCatalog is the tool to browse, organize, distribute, and document the GIS data

Different options to view the data:Contents – Preview – Metadata

The Catalog Tree

Individual geothermal areas/fields data folders

Individual Discipline data folders

All GIS data in a particular server

Data category folders (where applicable)

Feature classes

Data set geological mapGeo-database

ArcMapArcMapArcMap is the application to view, edit and analyze the geographic data and create professional-quality maps, graphs, and reports.

There is a map display area for viewing spatial data and a Table of Contents (TOC) in which dataset names and symbology are listed.

In ArcMap, data is organized into map documents (.mxdextension).

ArcToolboxArcToolbox

ArcToolbox is the application to perform advanced GIS analysis tasks and sophisticated geographic data processing jobs

⇒ Import/Export to/from different data formats – data conversion

⇒ data analysis / geoprocessing

⇒ data management

For ArcInfo complete set of tools (>150)For ArcView and ArcEditor more than 20 commonly used tools

Data models in ArcGIS Data models in ArcGIS

File-based: - coverages- shapefilesa georelational data model, vector data for features stored in binary files and unique identifiers link features to attributes stored in feature attribute tables

DBMS feature model:- geodatabase data modelFeatures are stored as rowsin a relational database table. Rows in table contain bothcoordinates and attributeinformation for features

ArcGIS supports two data models: File-based and database management systems (DBMS) feature models

Datasets in ArcGISDatasets in ArcGIS

Coverages• Shapefiles• DBF tables• Raster image• TIN• CAD dataset• Geodatabase

• ArcSDE connection• ArcIMS connection• Geography Network

ArcMapArcMap

ArcMap is the central element of ArcGIS

=> Used for data capture, data manipulation, visualization and data analysis

The ArcMap window consists of: - Table of Contents (TOC) on the left side, showing

which geographic layers are available to display, and - Display window on the right side

Display of data in: - Data View and - Layout View

The ArcMap InterfaceThe ArcMap InterfaceTitle bar

Menu barStandard toolbar

Table of ContentsDockable

Context menu

Draw toolbarStatus bar

Displayarea

Data View / Layout ViewData View / Layout View• Data View

• For display, queries, editing and anlaysis• Layout View

• For creating map layouts

Layers, data frames, mapsLayers, data frames, maps

The geographical data in ArcMap are structured in 4 levels:

• Map contains:Data frames, Layers,Map elements

•Data Frameorganizes layers

• Layers group

• Layersrepresent symbolizedspatial data

Map: ArcMap-file (*.mxd): Contains Titel of project, Author of project, saving with absolute or relative path

A frame on the map that displays layers occupying the same geographic area.

It Groups together, in a separate frame, the layers you want to see together on a map:

=> Always one data frame in map document when creating a map - listed at the top of the table of contents as "Layers" (possible to change the name)

=> possible to add additional data frames to a map to compare twoareas side by side in layout or to show overviews or detailed insets

=> in Layout view all of the data frames of the map can be seen

=> in Data view it is only possible to see the data frame that is active – it is shown in boldface type in the table of contents

Data frame:

On a map the geographic information is displayed as layers;

Each layer represents a particular type of feature such as streams, lakes, or highways.

A layer does not store the actual geographic data; => it references the data contained in shapefiles, geodatabases, images, grids, etc. Referencing data in this way allows the layers on a map to automatically reflect the most up-to-date information in your GIS database.

The layers in a data frame display in the same coordinate system and therefore may overlap.

To compare layers side by side or create insets and overviews that highlight an area by using layers that don't overlap, add additional data frames to your map.

Layer:

What is georeferencing?What is georeferencing?Data is referenced to a location on the earth’s surface

Geographic coordinate systemsProjected coordinate systems

Raster data

• Satellite images

• Aerial photographs

• Scanned maps / grafics

• Fotographs

• Converted raster data from other formats (e.g.GRID)

Raster data formatsdirectly supported formats

ERDAS IMAGINE ® Images

ERDAS (.lan & .gis)

BIL/BIP/BSQ

BMP

MrSID kompressed Data

JPEG

GIS

ADRG

PNG

CIB

CADRG

NITF

GRIDS (inkl. GRID Stacks)

TIFF 6.0 (“GeoTIFF”)

Data CaptureData Capture

New geometrical data:• Paper maps

• Georeferencing• Digitizing

Existing geometrical data:• ESRI products (coverages, shapefiles, geodatabases)• CAD products

• Microstation• AutoCAD

Data Capture of new geometrical data

Routine of capturing new geometrical data

• scanning of map or sketch• Geo-referencing of data• Digitising • (building of topology) => only for coverages, geodatabases• Revision and correction of data• Attributing data

Editing in Editing in ArcMapArcMap –– DigitizingDigitizing

General routine for digitizing:

a) Create new datasetsb) Geo-reference the map you want to digitizec) Preparation for editingd) Snappinge) Working with Sketchesf) Edit existing featuresg) Attributing of the now existing objects(h) Building topology

Editor toolbar:Task dropdown listEditor menu Target layer dropdown list AttributesSplit

Rotate

Sketch toolpalette

Sketch tool

Intersect tool

Arc tool

Distance-distance tool Trace tool

Midpoint tool

Important editing toolsImportant editing tools

’Split line’ – splitting a line feature

‘Edit tool’ - for working with existing features

‘Sketch tool’ - for creating new features, working with sketches

Create new Create new ShapefileShapefile

Attention:

New datasets are always created in ArcCatalog

AttributesAttributes

An attribute is a characterstic of a map feature

In an attribute table are the informations about the features of a map stored in rows and columns.- each row relates to a single feature- each column contains the values for a single characteristic

Adding newAdding new Fields in Fields in ArcMapArcMap

Feature Attribute Table

SpatialSpatial AnalysisAnalysis

Mapping distance

Mapping density

Interpolating to raster

Performing Surface Analysis

Calculating cell statistics

Calculating neighborhood statistics

Reclassifying data

Raster Calculator

MappingMapping DistanceDistance

Straight Line Distance function (for example)

Measures the straight line distance from each cell in the raster to the closest source

The source identifies the objects of interest, such as wells, roads, faults etc.

The distance is measured from cell center to cell center

SurfaceSurface AnalysisAnalysis

From original surface new patterns can be derived such as: contours, angle of slope, steepest downslope direction (aspect), shaded relief (hillshade), and viewshed.

The Slope functioncalculates the maximum rate of change between each cell and its neighbors, e.g. the steepest downhill descent for the cell

Input elevation raster Output Contour Output Slope

InterpolationInterpolation MethodsMethods in in SpatialSpatial AnalystAnalyst

There are several interpolation methods to create raster surfaces from point data in Spatial Analyst:

Inverse Distance Weighted interpolation method

Spline interpolation method

Kriging interpolation method

FindingFinding SuitableSuitable LocationsLocations

3D Analyst3D Analyst

3D Analyst is the three-dimensional (3D) visualization and analysis extension to ArcGIS.

3D Analyst adds a specialized 3D viewing application, ArcScene, to the desktop

ArcScene provides the interface for:

Viewing multiple layers of 3D data

Visualizing data

Creating surfaces

Analyzing surfaces

3D preview in 3D preview in ArcCatalogArcCatalog

ArcScene

Case study 1:Determination of priority areas for drilling exploration wells in the Menengai geothermal prospect

Examples of Input data/parameters

Geology dataGeology data Subsurface parameterSubsurface parameter

Structures (faults): Structures (faults): Channel PermeabilityChannel PermeabilityEruption centres: Eruption centres: Heat source, Vertical permeabilityHeat source, Vertical permeabilityB/H anomalies: B/H anomalies: Reservoir structureReservoir structure

GeochemistryGeochemistry ParameterParameterSoil gas CO2: Soil gas CO2: Vertical permeability Vertical permeability –– leakage zonesleakage zonesSoil gas Radon:Soil gas Radon: Heat source.Heat source.Heat flow:Heat flow: Heat source (strength & size, proximity)Heat source (strength & size, proximity)

Geophysics DataGravity: Heat sourceHeat sourceResistivity: Reservoir extent, permeability, hydrothermal fluids Reservoir extent, permeability, hydrothermal fluids

pathspaths

Others dataEnvironment/civil:Environment/civil: Access, bulk Access, bulk mtmt, slope, , slope, envienvi asp.asp.

Soil temperature

Temperature at 100cm depth > 50° C

Soil gas CO2

Suitability for priority locations of geothermal investigation wells in Menengai area – data process schema

Input data Selected parametersGeochemistry

CO2 > 3.5 %

Soil gas Radon-222

Radon> 2300 ppm

Soil gas Rn/CO2 ratio

Rn/Co2 ratio> 4000

Geology

Eruption centres

Vulcanologicalelement

Preferable inside caldera

Distance < 500m

Distance < 200mon selected faults (thermal

faults

boreholesTemperature distribution

Fumorales Distance < 1000m

Geotechnical

Slope < 15°

Caldera wall Distance > 300m

Suitability according to geoscientific information

(Geprocess)

Soil temperaturehigher 50 degreeSelection

Buffer Distance 500 to eruption centres

Geoscientifc suitability Priority

areas

DataIntergration

Using spatial analyst tools

(e.g. Wghted overlays &stataistical reclas

Priority exploration well location

Geoprocess

CO2 >3.5 %Selection

Radon >2300 ppmSelection

Rn/Co2 ratio>4000Selection

Buffer Distance 1000 to fumaroles

Buffer Distance 200 to selected faults

Derived data„Positive areas“

Non-geoscientificparameters

Surface Data

Gravitiy

Resistivity –TEM

Resistivity –MT

Resistivity at 1000m < 30 Ohm

Resistivity at 1000m < 30 Ohm

Bouguer Gravitiy–1400 to –1700 g.u.

GeophysicsTEM resistivity

Smaller 30 OhmSelection

MT resistivity<30 OhmSelection

Gravity between-1400 to-1700 g.u.Selection

Resistivity –DC

Reservoir

EnvironmentEnvironmetal

Impact AssesmentSelection Env. sensitive

Example of a geoprocessing model for geological parameters

Menengai geothermal prospect

Proposed data/info sharing model of GIS for Proposed data/info sharing model of GIS for geothermal resourcesgeothermal resources

Location, Location, desc.,detailsdesc.,details of consultants, of consultants, professional, Lab, professional, Lab, eqpteqpt, contractors , contractors traningtraning centres and service providers of centres and service providers of geothermal industry.geothermal industry.

ii??iiiiiiDirectory of Directory of res. Dev res. Dev facilities in facilities in the the regreg

Total field Doc. Proven, exploited Total field Doc. Proven, exploited potential, capacities, potential, capacities, Steamfield/pstnSteamfield/pstninfo. info. OnewrshipOnewrship. Dev status. Future . Dev status. Future plans. Full EIA study results and reportsplans. Full EIA study results and reports

ii??ii??iiiiIndividual Individual fields fields data/infodata/info

ExploExplo ––geology, geology, geochemgeochem, , geophygeophy etc etc results, records etc. results, records etc. reservreserv asses, asses, exploexplodrilling, Res characteristics, estimated drilling, Res characteristics, estimated potential. Baseline potential. Baseline envenv datadata

ii??iiiiGRA statusGRA status((explexpl & Res & Res assesmntassesmntdata)data)

Resource dist. Maps, classifications Resource dist. Maps, classifications ((ProbProb, , poss,provenposs,proven), Geol. Ass, rankings ), Geol. Ass, rankings Ref. for other documentationsRef. for other documentationsi i iiiiiiGeothermal Geothermal

Res. Res. inventoryinventory

EnvEnv. . planngplanng..

EducEduc/ Res / Res UnivUniv

Private Private DevDev

Local Local AuthAuth

Nation/Nation/statestate

Data propertiesData propertiesScale/level of userScale/level of userData Data ThemeTheme