# GIS in Geology Lesson 2 7.10.2010. Miloš Marjanović.

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GIS in Geology Lesson 2 Miloš Marjanović

Principles of modeling in Geology
Introduction Model definition and modeling scope Geological model GIS definition, relations and rolls GIS-Geology integration Material formats and resources in Geology Geological modeling procedure using GIS

Principles of modeling in Geology
Model definition and modeling scope: No uniform deffinition, but Model is a simplified representation of reality – system (Küne, Stachowiack, Stainmüller) They are crucial for scientific development in any discipline (Physics, Chemistry, Biology, Geology, Meteorology, Urban planning, Psychology…) due to interoperability, comparativeness, generalization, communication and other model features Classifications of the model by Temporal state: static, dynamic Dimension and resolution: 0-nD; macro-micro Indeterminism: deterministic, probabilistic, stochastic Data type: raster, vector Modeling techniques: white, gray, black-box models A system is modeled consecutively through model building, model application and model assessment What is a model?

Principles of modeling in Geology
Geological model What is Geological model? Difficult to define (observational empiricism, perceptional limitations, uncertainty) Intuitively developed through practice (depends on education, training and experience) A way of transferring or presenting information that captures the essence of the character of the soil/rock mass in a simple form that meets the objectives (Sullivan) So it is a PROCESS not a RESULT! Modeling principles: From general to particular (regional to local) Balancing the complexity (scale vs. information, accuracy vs. representativeness) Think 5-dimensionally Extrapolate Always regard lithology, soil/rock properties, groundwater and structures Simplification to the essence

Principles of modeling in Geology
Building a Geological model Formulation of hypothesis Observation/measurement Merging Re-examining and testing of hypothesis Developing of modeling skills Clustering of data (sorting patterns) Selecting important Perception of details and “getting the whole picture” Learning habits (new discovery says “learn different things simultaneously and in different rooms, with different music”) Reasoning Simplification Using scientific methodology Obtain good mentoring Savants

Principles of modeling in Geology
Term GIS? A System, analysis or science? GIS in relation to other disciplines Purpose: to visualize, analyze combine, merge together… Fields of application Geological mapping Mineral mapping Hazard/Risk zonation (analysis) Hydrogeological modeling (Schalstad, Dynlam, Trigg) Site selection (road route, windmill farm location, building construction site) RS - spectral signature in relation to geology, vegetation… Geophysical GIS is an organized assemblage of computer hardware, software, geographical data and personel designed/trained to efficiently capture, store, update, manipulate analyze and display all forms of geographically referenced information (Voženílek) Contouring and surface modeling General statistics Spread- sheets Desktop and Web publishing Geostatistics Desktop mapping Image Processing (IP) Database Management Systems (DBMS) Computer Aided Drawing (CAD) Artificial Intelligence(AI) Geographic Information System (GIS)

Principles of modeling in Geology
GIS-Geology integration GIS data structure revolution Storage Generation of new data Editing data Visualization Integration Isolated Loose Tight Full

Principles of modeling in Geology
Material formats and resources in Geology Maps Borehole logging https://www.geofond.cz Satellite and aerial imagery Geophysical data GPS data Field logs (digital or hard-copy archived)

Principles of modeling in Geology
Material formats and resources in Geology Logic, Nominal, Ordinal, Scalar & Directional Data 2-2,5D objects Raster - pixels Vector - vertices, lines, surfaces 3D objects Blocks - voxels Boreholes and interpolating surfaces Thematic surfaces

Principles of modeling in Geology
Geological modeling procedure using GIS Knowledge (about object, area or phenomenon of interest) Conceptual model: Providing a theoretical framework of a case study (example of mineral exploration, landslide analysis) Selecting necessary vs. available conditions Deciding what type of analysis is feasible Expectations

Principles of modeling in Geology
Embedding GIS Step MODEL BUILDING Building spatial database (the most time-consuming) Selecting the area and scale (motif) Selecting the working projection Data assemblage – input Spatial database for different research levels and end-users Scale concept: Small scale: preliminary investigation (zonation) Medium scale: (further research, e.g. mapping, directed by the small scale research) Large scale: (detailed analysis of the selected areas)

Principles of modeling in Geology
Input model types Raster Vector Spatial data input requirements Geo-referencing Digitizing (manual, scanning) and converting Calculating (interpolation) and processing (raster oriented algebra, e.g. different filters, enhancements…) Conversion to target data type

Principles of modeling in Geology
Step MODEL APPLICATION Spatial analysis, processing and modeling of inputs Reclassification Morphometric calculations Buffering Statistics Querying Type of modeling technique/approach “White box” (physically-based) models “Grey box” (statistical) models “Black box” (AI approach) models

Principles of modeling in Geology
Step MODEL APPLICATION Integrating the input models in some fashion (heuristic, deterministic, statistic, probabilistic, artificial intelligence) Two maps integration Multiple maps integration

Principles of modeling in Geology
Step MODEL ASSESSMENT Statistical comparison of expected vs. obtained results Accuracy (%) Chi-Square-Tests Entropy/Uncertainty Kappa-index ROC curves (AUC)

Geological background and rock unit contact map
Temporary outputs of processing/modeling stage (contact distance buffers, density distributions etc) Geochemical data maps of different components (from tables) Geophysical maps (also from table or profile or cross-section data) Geological background and rock unit contact map Final map of mineral potential of sulphidic mineralization (favorability map, ranging from 0-1) Temporary output maps, conecting some of the sources together (e.g. geological and geochemical) A - Stratigraphic factor B - “Heat factor” C - Alteration factor Outline scheme for Mineral exploration example

GIS in Geology Exercise 1 Miloš Marjanović

Exercise 1 Explore geological survey web pages of different countries world-wide, and make your selection (choose a country) Make a short (2 pg. max) report on your assignment. The report should regard: Description of the Web Map service provided by the chosen survey Comment of the interface according to your appeal (is it user- friendly, interactive, good or poor graphic design, versatile – provides many different geological thematic layers and metadata) Maps’ availability for public (cost-free) use and to which extent Your suggestions for improvement (if any) One of the exercise term will be reserved for your oral and interactive presentation of this exercise