GIS 2, Final Project:

Creating a Dasymetric Map for Two Counties in

Minnesota By:

Hamidreza ZoragheinMelissa Cushing

Caitlin LeeFall 2013

General Outline

Study area Delineating residential areas

Rural residential areas Urban residential areas

Redistributing population density variation Another approach: Area Modified Weighting Limitations and outlooks

Study Area

Two counties in Minnesota Criteria:

Diversity in population density Having both urban and rural areas

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Delineating Residential Areas

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Different approaches for rural and urban areas Rural Areas

NLCD Block boundary density

Urban Areas NLCD

Rural Areas

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Block Areas

Block Boundari

es

Raster Boundari

es

Polygon to Line

To Raster

Focal Stats.

FocalOutput

RasterCalc.

Rural Mask

RuralLandcove

rNLCD 21,

22First

Refinement

SecondRefineme

nt

Extraction

Shrink Clear Boundary

Dense Cells

Mosaic

Rural Areas

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Some patterns which don’t pass the threshold (33)

Some patterns which pass the threshold

Pics fro Uhl (2011)

Urban Areas

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Three different approaches were tested: Extraction of classes 21, 22 Extraction of classes 21, 22, 23 Extraction of classes 21, 22, 23, 24

Further Refinement Applying NHD layers

Urban Areas

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Urban Landcove

r

Water Areas

To Raster

Extraction

Initial UrbanMask

Rasterized

Water

TimesFinal

UrbanMask

Urban Areas

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Redistributing Population Density Variation

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Urban Areas DEM Slope Road Density Distance to Flow Lines Distance to Rivers

Rural Areas DEM Slope Road Density Distance to Flow Lines

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Creating Random Points

ModifiedPop

DensityCalculation

Attributing Points byMod Pop Density

Extracting Rasters to

Points

Summarizing

by Tracts

CorrelationCoefficientsCalculation

Reclassifying

andMasking

ApplyingThe

Weights

Tool(s): Zonal Statistics as Table

Tool(s): Raster to Polygon,Create Random Points

Tool(s): Spatial Join

Tool(s): Extract Values to Points

Tool(s): Summary Statistics

Tool(s): Excel

Tool(s): Reclassify,Times

Tool(s):Weighted Sum

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Redistributing Population Density Variation

Residential Area

Elevation Slope Distance to Rivers

Distance to Flows

Road Density

Urban (21, 22, 23)

**-0.2666 -0.0898 *-0.1923 *0.1788 ***0.4469

Urban (21, 22, 23, 24)

-0.12736 -0.1888 ***-0.3712 **0.2953 ***0.4788

Rural 0.01238 -0.2318 - **0.5267 *0.4386

Another Approach

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Based on: Polygon three class method (Eicher and Brewer 2001) Sampling along with Area refinement on the above (Mennis 2003)

Applied on: Urban part of the study area

Type of the method here: Vector based

Another Approach

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

VectorizingLand Cover

Removing Unlikely Classes

Consolidating

Classes

SamplingPop

Density for Classes

Overlaying Tracts on

Land Cover

Calculating Elements per Tract

Pop Density per Class per

Tract

Tool(s): Extraction

Tool(s): Raster to Polygon

Tool(s): Dissolve

Tool(s): Select by Location

Tool(s): Union

Tool(s): Summary Stats, Join, Calculate Field

Tool(s): Join, Calculate Field

Land Cover Class

Sampled Pop Density

Number of Sampled Tracts

Class Fraction

21 1307.199 19 0.10522 1959.088 60 0.15823 2342.447 43 0.18924 2417.448 15 0.19541 1055.519 14 0.08542 589.123 1 0.04781 775.014 4 0.06290 1138.81 1 0.09295 823.109 1 0.066

Sampling Method: CentroidClass i Fraction=

, ,

Another Approach

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Limitations and Outlooks

Residential Area

DelineationRural AreaStudy Area Urban Area

Population Density

Redistribution

Another Approach

Limitations & Outlook

Limitations Lack of statistical analysis and validation Not utilizing parcel data Not very good for rural areas

Outlooks Using smaller areas for establishing the correlations (e.g. block groups or blocks) Simulation Create random points based on the area of the tracts Using parcel data Exploring other potential related variables Exploring other sampling strategies and making comparisons

Resources

Eicher, C. L., & Brewer, C. A. (2001). Dasymetric Mapping and Areal Interpolation: Implementation and Evaluation. Cartography and Geographic Information Science, 28(2), 125–138. doi:10.1559/152304001782173727

Mennis, J. (2003). Generating Surface Models of Population Using Dasymetric Mapping∗. The Professional Geographer, 55(1), 31–42.

Uhl, J. H. (2011). Master ’ s Thesis : “ Limiting and Related Variables for Dasymetric Analysis of U . S . Census Demography .” University of Colorado Boulder.

Thank you for your patience!

Questions?