texas a&m university, zachry department of civil...

Texas A&M University, Zachry Department of Civil Engineering, Instructor: Dr. Francisco Olivera, CVEN 658

Civil Engineering Applications of GIS, Siting of Municipal Solid waste Landfill, Balaji Ganesan, 12/02/2010.

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Abstract:

Landfill is one of the primary methods for municipal solid waste disposal. In order to reduce the

environmental damage and to protect the public health and welfare, choosing the site for landfill is of utmost

importance. There are several primary factors such as soil characteristics, water bodies, land use and road

network should be considered for choosing a site for landfill. The study was carried out for choosing a landfill

site in Brazos County, Texas, USA. The possible potential sites for landfill can be determined with the help of

GIS. The application of GIS in siting a landfill results in saving money and time. The data for each criterion was

converted in to grid layers and was used to run the suitability analysis to determine the site for landfill. The

buffer maps for each criterion was created based on the EPA regulations for landfill. The feature class was

converted to raster data in order to do spatial analysis. The various grid layers are reclassified into new integer

grids based on the potential factors. Finally, all the integer grids are combined and ranked together using raster

calculator for selecting a potential landfill site.

Contents

Introduction…………………………………………………………… 1

Literature review………………………………………………………. 2

Methodology………………………………………………………….. 2

Applications, results and discussion………………………………….. 2

Conclusions…………………………………………………………… 12

Introduction

The rise in urban population and industrialization resulted in stringent environmental regulations in

order protect the environment and public welfare. The process of selecting a site for landfill is cumbersome and

time consuming and needs to be dealt with large amount of spatial data. Moreover, while choosing a site it is

very important to consider the state/federal laws concerning landfill, amount of waste generated and amount of

waste to be land filled and the impacts of the landfill on the surroundings. The factors for choosing the landfill

are considered on environment, engineering and social/cultural aspects [1].

Nowadays, GIS is widely used in land use suitability analysis since GIS can correlate and analyze the

spatial relationship between several maps which are used for choosing the landfill site. The basic idea for

selecting the site is that the prepared thematic maps are superimposed on one another and the most suitable site

is decided based on the several factors we considered for choosing the site. Apart from saving time and cost,

using GIS will also help us in monitoring the site with the developed digital data bank. The large amount of

geographical data can be correlated easily with GIS and the results can be visualized through graphical

representations.[2] In this project, the suitability analysis is carried out with raster data.



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Literature Review

Several studies were made in analyzing the suitability of a site selection. In most of the case the study was

done using models like Index modeling, Multiple Criteria Decision Making, Weighted Linear combination and

Boolean analysis. Usually, the decision maker sets weight for all the parameters which are considered before

choosing a site for landfill. By using these models, we could be able to site an accurate location for landfill. The

following literatures were reviewed for this study.

Sumathi, V.R., Natesan, U., Sarkar, C., 2008. GIS Based Approach for Optimized Siting of Municipal

Solid Waste Landfill. Waste Management 28, 2146-2160

Gomes, E.G., Estellita Lins, M.P., 2002. Integrating Geographical Information Systems and Multi-

Criteria Methods: A Case Study. Annals of Operations Research 116, 243-269.

Daneshvar, R., Fernandes, L., 2003. Customizing ArcMap Interface to Generate a User-friendly Landfill

Site Selection GIS Tool. Environmental Informatics Archives, Volume 1, 428-437.

Mahini, S.A., Gholamalifard, M., 2006. Siting MSW Landfills with a Weighted Linear Combination

methodology in a GIS Environment. Int. J. Environ. Sci. Tech., 3(4): 435-445.

A simple approach is done using ArcGIS in order to determine the suitable site for landfill in Brazos

County, Texas. Without doing any modeling this study was carried out. This approach can give us the basic idea

about the site and can be suitable only if the study area is small. This approach is used not only for landfill but

also for siting a location for schools, construction of parks etc.

Methodology

The maps for all the site selection criteria for Brazos County, Texas was created using ArcGIS with the

data obtained. The parameters considered for selecting the site were

Proximity to Rivers

Proximity to Lakes

Distance from Roads

Distance from Railroad

Distance from Airport

Distance from Residential Area

Distance from Commercial Area

Elevation

For accurate results, we can further add more parameters like Air Quality Index, Ground water table data,

geology, flood data, wetlands etc. The basic approach is that to build a suitability model through which we can

able to determine a suitable location for Landfill. The above said input datasets are scaled to 1 to 5 by

reclassifying. Then appropriate weights are given using weighted overlay analysis to get the final output by

setting the percentage of influence of each datasets. [3]

Application, Results and Discussion

The suitable site for landfill in Brazos County, Texas was studied using Spatial Analysis tool in ArcGIS.

In the map created using the data collected, buffers are created using Multiple Ring Buffer function for different

distances. The buffer shape file was then converted into raster data using Feature to Raster function. The values



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of the input raster data can be modified and prioritized using the function Reclassify. The same procedure is

followed for all the shapefiles created using the data obtained. The data was collected from ESRI, TIGER,

Geocommunity, Google Earth(Airport) , TAMU-Library. The GIS files for Rivers, County Boundary from city

of College Station website [4]. Brazos County was downloaded from Centre for Geospatial Technology, Texas

Tech University. The Elevation data was obtained from Texas Natural Resources Information System. The

Landuse data was obtained from Evan Library, Texas A&M University, Texas. The GIS file for Rail road was

downloaded from ESRI.

Road & Rail Network Map

Using the data obtained, the road map ( Fig.1) was created in ArcGIS. For finding the suitable location,

first buffers were created around the roads. Using the function Multiple Ring Buffer option, buffers were created

for 15m, 150m, 250m, 350m and 500m. The buffer shape file was then converted to raster file using the

function Feature to Raster. The grid cell values are prioritized such that the longer distance was rated one and

so on. The final map is shown in Fig.1 and Fig 2.

Fig 1. Road Map – Brazos County Fig.2. Road Network - Reclassify



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Rivers & Lakes Map

The river map was created and using the function Multiple Ring Buffer, buffers are created for distance

of 30m, 100m, 200m, 300m, and 500m. The buffer shape was converted in to raster data and reclassification

was done. The final maps for rivers are shown in Fig.3 & Fig.4 and for lakes are shown in Fig.5 & Fig.6

Fig.3. River Maps – Brazos County Fig.4. Rivers Map - Reclassified



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Fig.5. Lakes Map – Brazos County Fig.6. Lakes Map - Reclassified

Residential & Commercial Area Map

The Landuse map was created using ArcGIS. The residential areas were selected using the function

Selection by Attributes and a separate layer was created for this selection. Buffer for the selection layer was

created using Multiple Ring Buffer for 15m, 150m, 250m, 350m and 500m. The new buffer layer was converted

in to a new raster data and reclassification was done. Similarly commercial area map was created. The maps

residential are shown in Fig.7 & Fig.8 and similarly the maps for commercial area are shown in Fig.9 and

Fig.10.

Airports Map

The Airports map for Brazos County was created using Google Earth. The Geographic Coordinates for

all the airports in Brazos County was taken from Google earth. A new dBase table was created in the Arc

Catalog. The co-ordinates are added in the attribute table using the function Edit. The table data was exported in

order to create a new shape file giving the corresponding coordinate system. The buffer distance in the new

shape file was created for each point using the function Multiple Ring Buffer for 100m, 200m, 300m, 400m and

600m. The buffered shape file is then converted into raster data and reclassification was done. The Maps are

shown in the Fig.11 and Fig.12.



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Airport Name Longitude Latitude

Coulter Field -96.33246 30.71658

Easterwood field -96.36385 30.58853

st.Joseph Heliport -96.34746 30.65714

TAMU Flight station -96.48357 30.63353

Tom j Moore Airport -96.22468 30.38465

Varisco Airport -96.5383 30.65603

Fig.7. Land Use Map – Brazos County Fig.8. Residential Map - Reclassified



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Fig.9. Land Use Map – Brazos County Fig.10. Commercial Map – Reclassified

Municipal Solid Waste disposal sites Map

The municipal solid waste disposal site for the state Texas was obtained from TCEQ. In the attribute

table, the sites for Brazos County were selected using the function Selection from Attributes. It’s a point shape

file and buffer distances were created for 30m, 150m, 250m, 350m and 500m. The buffered shape file was then

converted into raster data using function Feature to Raster. Similarly the grid values are prioritized using the

function Reclassify. The maps are shown in the Fig.13 and Fig.14.

Elevation

The Elevation map for the state Texas was obtained. The Brazos County was selected from the shape

file. A separate shape file for Brazos County was created using the function Clip. The same is converted in to

raster data using the function Feature to Raster. Using the function Slope, the slope for the raster data was

determined. The maps are shown in the Fig.15, Fig.16 and Fig.17



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Fig.11. Airports Map – Brazos County Fig.12. Airport Map – Reclassified



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Fig.13. MSW sites Map – Brazos County Fig.14. MSW sites Map – Reclassified



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Fig.15. Elevation Map – Texas Fig.16. Elevation Map- Brazos County



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Fig.17. Slope Map – Brazos County

Suitability Analysis

The raster maps created for all the parameters are over laid to each other in order do the suitability

analysis. Using the Weighted Overlay Analysis, the values of all the datasets can be evaluated and ranked. The

default scale evaluation of 1 to 9 by 1 was used for the analysis. All the raster data was added to the weighted

tool. The reclassified values are shown in the field values. The percentage of influence of all the data sets can be

specified. In this study, the percentage of influence was set equal for all the datasets. The final map is shown in

the Fig.18.



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Fig.18. Overlay Analysis Map – Brazos County

Conclusion

This is a simple approach for selecting a site for Landfill. Several models like Multi Criterion Decision

Making, Index Modeling and IDW have been made in order to find the accurate location for landfill. This study

can be further made accurate by choosing more parameters like Air quality Index, flood plain data, wetlands,

parks etc.



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References:

[1] Daneshvar, R., Fernandes, L., 2003. Customizing ArcMap Interface to Generate a User-friendly Landfill

Site Selection GIS Tool. Environmental Informatics Archives, Volume 1, 428-437.

[2] Sumathi, V.R., Natesan, U., Sarkar, C., 2008. GIS Based Approach for Optimized Siting of Municipal Solid

Waste Landfill. Waste Management 28, 2146-2160.

[3] http://webhelp.esri.com/arcgisdesktop/9.3/pdf/Spatial_Analyst_Tutorial.pdf

[4] http://www2.cstx.gov/gisdownloads/default.asp

http://webhelp.esri.com/arcgisdesktop/9.3/pdf/Spatial_Analyst_Tutorial.pdf

http://www2.cstx.gov/gisdownloads/default.asp

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