gis and geostatistics

8/15/2019 GIS and Geostatistics

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GIS & Geostatistics in Plant Diseases

Epidemiology and Management

Amjad Shahzad


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What is GIS

Difference between GIS and GPS

GPS Data Collections

GIS software output

What is Geostatistics

GPS, GIS and Geostatistics Disease Epidemiology

Presentation Overview


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Key tool to improve farm practices

Make sense to organize farm information in spatialdatabase

Valuable tool for;

Monitoring, Predicting, Managing & Fighting for diseases

and pests

Cost effective & efficient tool – targeting disease controlinterventions

Information Management


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Global Information System

Computer software program

Assemble, Store , manipulate and display large amount ofdata from GPS and other sources

Free available & can be installed on desktop computer

Relates the geo-referenced information

Integrate layers of spatial information - uncover possiblerelationships

GIS


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Vector and Raster

GIS

Data sets, map features;

Points

Lines

Polygons

Organized and manipulated

in the database

Data sets are organized;

Matrix of numerical value

Referenced spatially by

rows and column positions


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Global Positioning System

Satellite system

Projects information to GPS receivers on the ground

Enable users to determine latitude and longitude coordinates

System of navigation satellites – US Department of defense

NAVSTAR System

Important tool for spatially referencing agricultural data

GPS


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GPS Receivers – Satellite Signals

position determination in spherical coordinate system

Distance and direction calculation

Geostatistical analysisElevations can be added in 3D spatial considerations

GPS


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Global Positioning System (GPS)

An agricultural producer may use a handheldGPS receiver to determine the latitude andlongitude coordinates of a water source next toa field or vineyard.

Examples of GPS and GIS

Global Information System (GIS)Following a chemical spill, maps obtained

from a GIS system can reveal

environmentally-sensitive areas that

should be protected during response.


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Digital Mapping

Examine landscape that would be impossible with othertools

Measurement of landscape structures

Resource Mapping

Diseases Mapping

Integration of multiple layers of variables

Modeling resources

GIS Applications


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Analysis of spatially distributed variables

Statistical model – estimation across continuous areas

Prediction / estimation of values at unsampled locations

Create surface map based on point samples andobservations

“Surface map – map with shaded area keyed to variable”

Geostatistics


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Surface map – appropriate

Variable (Pathogen propagule density , Disease incidence,insect vector abundance) exhibit positive correlation

Can be misleading

Adjutant fields are highly dissimilar Abrupt differences defined by field boundaries

Geostatistics


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Used to analyze spatial disease distribution

Spatiotemporal analysis – cabbage downy mildew

Used in regional risk assessment programs

Used for the management of plant viruses

Used for the study of inoculum patterns

Applications of Geostatistics


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Exploratory data analysis

Spatial auto-correlation modeling

Estimation at unsampled locations (surface maps)

Estimates reliability evaluation

Geostatistical Analysis


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Cotton Leaf Curl Virus (CLCuV)

Case study

CLCuV Sampled Locations

Sampled locations

Cotton growing areas of Punjab


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Case study

GPSApplication


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Case study

DiseaseData


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Case study

GISApplication


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Case study


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Response to plant disease problem

Case example

Situation

Confirmed case of a plant disease in a small test plot.


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Case example


Facts

Disease spores may be spread by wind

Combine used in the field was not disinfected

Two neighbors borrowed the machine Combine traded or shipped from dealer by rail

Estimated range of disease movement is one mile


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Case example


Response Task

Surface map for the possible affected areas

Notify all farmers within one mile of the infected fields,

neighbors, fields, highways and railroad


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Case example


Collection of Vector Data for the area

Information;

Aerial photograph – GPS receivers

Graphic image

In to GIS database


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Case example


Collection of Raster Data for the area

Information;

wind direction

Wind speed

Wind duration

In to GIS database


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Case example


Other queries can be

run, to obtain maps of

highways and railways . .


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Case example


. . . and to identify affected

farms within a designated

quarantine area.


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Case example


If the established GIS

database is extensive,

detailed information may

be obtained, such as

producers’ names, phone

numbers, and exact

locations, facilitating

rapid response efforts.


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References

Davis, G., W. Casadyand R. Massey. 1998. Precision Agriculture: An

Introduction. Publication Number WQ450. University of Missouri-Columbia.

Geographic Information Systems as an Integrating Technology:Context, Concepts, and Definitions". ESRI. Retrieved 9 June 2011.

Hameed, S., S. Khalid, Ehsan-Ul-Haq, A.A. Hashrni. 1994. Cotton leafcurl disease in Pakistan caused by a whitefly transmitted

geminivirus. Plant Disease 78, 529. Nadeem A.I., Z. Weng , M.R. Nelson, Z. Xiong. 1997. Cotton leaf

crumple virus and cotton leaf curl virus are two distantly relatedgeminiviruses. Molecular Plant Pathology on-line.


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References

Nadeem, A. 1999. Applications of Geographic Information Systemsand Geostatistics in Plant Disease Epidemiology and Management.Plant Disease. 83. (04); 308-319

Nelson,M.R., T.V. Orum, R. Jaime-Garcia and A. Nadeem. 1999.Application of Geographic Information Systems and Geostatistics inPlant Disease Epeidemiology and Management. Plant Disease83:308-319

Pfost, D., W. Casady and K. Shannon. 1998. Precision Agriculture:

Global Positioning System (GPS). Publication Number WQ452.University of Missouri-Columbia.

Star, J., and Estes, J. 1990. Geographic Information Systems: AnIntroduction. Prentice Hall, Englewood Cliffs, NJ.


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References

Theller, L., and B. Engel. 2004. Constructing a Geographic InformationSystem for Biosecurity. Center for Advanced Applications in GIS, Ag andBiological Engineering Department, Purdue University.


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Thank you!


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Degradation of freely available signals of GPS satellites

by US Department 0f Defense – Selective ability Precision and accuracy of GPS readings are reduced

“Accuracy - Closeness of a measured or computed value toits true value”

“Precision – Closeness of repeated measurements of thesame quantity”

Selective Ability


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Epidemic

Epi = upon, among

Demos = peopleEpidemic = What is among the people

“Change in the diseases intensity in a host population overtime and space”

Study of epidemics

Science of disease in populations

Spread of disease in space and time

Epidemiology

gis and geostatistics

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