CE 394K Semester Project

Tony Vessa

12-06-2002

Table of Contents

Introduction

Background

Web Downloadable Data

Web Downloading

Data Available for Water Quality Modeling

Assessment Tools

Conclusions

References

 

Introduction

Engineers are known for their love of analyzing data.  Numbers tell a story and are the heart of most engineering professions.  There is nothing more exciting than solving a problem through an in-depth analysis.  Unfortunately, the numbers don’t just appear, and there is nothing more tedious than creating or finding data to be analyzed.  I have found that in the real world, it seems that engineers spend ninety percent of their time collecting data rather than analyzing it.  Not only is data collection tedious, but data storage is nearly impossible.  Companies spend millions of dollars on a yearly basis gathering data that has already been gathered.  This sad fact is the reason that the EPA’s BASINS database is an environmental engineer’s perfect dream.  Not only has the data been collected, but it is stored in a manner that is easily accessible and readily available. This paper will focus on two of the many components of the BASINS application.  First, the readily accessible data that is perfectly compatible with the ArcGIS suite, and secondly, the assessment functions of the BASINS software. 

 

Background

The Environmental Protection Agency (EPA) originally created the Better Assessment Science Integration and Non-point Sources (BASINS) software application in 1996.  The three objectives of the BASINS software are: to facilitate examination of environmental information, to support analysis of environmental systems, to provide a framework for examining management alternatives (About 1.) The BASINS suite is directly integrated with ArcView, making the data completely compatible with the ArcGIS suite. 

 

BASINS’ stated primary goal is to fully support the development of Total Maximum Daily Loads (TMDL), “which requires a watershed-based approach that integrates both point and non-point sources.” (BASINS 3) To do this, BASINS compiled and standardized scattered watershed data into a downloadable format that is compatible with leading GIS software—ArcGIS created by ESRI. Traditionally, watershed based assessments involve many separate steps and types of software for preparing data, summarizing information, developing maps and tables, and applying and interpreting models.  The BASINS software centralizes the data and applications in order to facilitate the necessary functions of watershed management.  The heart of the BASINS software includes:

1.    nationally derived environmental and GIS databases (the 48 continuous states and the District of Columbia);

2.    assessment tools (TARGET, ASSESS, and DATA MINING) for evaluating water quality and point source loadings at a large or small scales;

3.    utilities including local data import and management of local water quality observation data;

4.    two watershed delineation tools;

5.    utilities for classifying elevation (DEM), land use, soils, and water quality data;

6.    an in-stream water quality model (QUAL2E);

7.    a simplified GIS based non-point source annual loading model (PLOAD);

8.    two watershed loading and transport models (HSPF and SWAT);

9.    a postprocessor (GenScn) of model data and scenario generator to visualize, analyze, and compare results from HSPF and SWAT; and

10.                       mapping, graphing, and reporting formats for documentation.  

(http://www.epa.gov/waterscience/basins/basinsv3.htm) 

                    Figure 1 HUC Regions

Web Downloadable Data

Included with the software suite, BASINS offers a goldmine for centralized data storage.  Downloadable from the web, the BASINS data provides coverage files and database files for a variety of data.  The data is arranged into the 8 digit Hydrologic Unit Codes (HUCs.)  The United States is segregated into 21 (figure 1) regions that encompass a drainage area or a series of Drainage areas.  There are 18 regions in the continental Unites States, and 1 region in Alaska, Hawaii, and the Caribbean Islands.  Each of these regions are divided into sub-regions.  There are 222 total sub-regions that are defined by areas drained by a river system, a river reach, a closed basin, a group of streams, or tributaries within that reach.  In turn, each sub-region is again subdivided into 352 hydrologic accounting units, which are divided into cataloging units.  The cataloging unit is an area representing a part of a drainage basin, a combination of drainage basins, or a distinct hydrologic feature.   An example HUC is 12090205, which encompasses the area around Austin, Texas (Figure 2).

 

                            Figure 2 8 digit HUC regions in TEXAS

Web Downloading

Once the 8 digit HUC has been selected, the BASINS data can be downloaded at (http://www.epa.gov/ost/ftp/basins/gis_data/huc)  Locate the appropriate HUC and simply click on the link.  This link brings you to a choice of Demg, core, dem, or pcs3 data.  The Demg data is digital elevation data that can be used for stream assessment; the core data is the bulk of the data and will be discussed in depth below; the pcs3 data is the BASINS 3.0 permit compliance system data; and the dem data is the digital elevation modeling data. 

Building base-maps for areas located in the United States are quite easy using just the BASINS data (depending on the applications.)   The downloadable data is found as shapefiles that was created specifically for the ArcGIS suite.  As seen in the various pictures, the data houses the EPA region, HUC outlines,  Hydrologic Accounting Unit designations, major roads, and major urban areas can be found (not exhaustive.)

                    Figure 3  Austin Area road, suburban, and river maps

Downloading the Core data can be a tedious task.  It is approximately an 8MB file with approximately 210 files.  The files are perfect for building base-maps or analyzing water quality in the appropriate HUC.  In fact, I believe that the majority of the data that was used in Dr. Maidment’s homework exercises came from the BASINS database.  Below is an in-depth list of the files and a description of each.

 

Table I  Detailed description of files available in BASINS data

FileName

Description

mad

Federal, State, Tribal, or Local Government Managed Areas for CONUS in BASINS

quadname

1:250,000 Scale Quadrangles of Landuse/Landcover GIRAS Spatial Data of CONUS in BASINS

urban       

1990 TIGER Urbanized Areas/Polygons for CONUS, Alaska, and Hawaii in BASINS

xxppl (xx=state)

Populated Place Point Locations for CONUS, Alaska, and Hawaii       in BASINS

rf1

U.S. EPA Reach File 1 (RF1) for the Conterminous United States in BASIN

statsgo

State Soil Geographic (STATSGO) Database for CONUS, Alaska, and Hawaii in BASINS

dem

USGS 300 Meter Resolution, 1-Degree Digital Elevation Models (DEM) for CONUS, Alaska, Hawaii, Puerto Rico, and the U.S. Virgin Islands

fhards

DOT/FHA Major Roads for CONUS, Alaska, and Hawaii in BASINS

acc

Hydrologic Unit Boundaries of the Conterminous United         States in BASINS

dam

National Inventory of Dams in BASINS

st

State Boundaries in the United States for BASINS

epa_reg

USEPA Regional Boundaries in the United States for BASINS

cnty

Counties and County Equivalents Boundaries in the United States BASINS

ecoreg

III Ecoregions of the Conterminous United States in BASINS

stat

EPA's STORET Water Quality Monitoring and Data Summaries for CONUS

wqobs

EPA's STORET Water Quality Observation Data for CONUS

bac

EPA's STORET Bacteria Monitoring Stations and Data Summaries for CONUS

wdm

NOAA's National Climatic Data Centers (NCDC) Weather Management (WDM) Stations Point Locations in the United States, Puerto Rico, and the U.S. Virgin Islands

gage

USEPA STORET Stream Flow Data from Gaging Stations in CONUS

lfwa-adf

1996 National Listing of Fish Consumption Advisories for the United States

nsi

USEPA National Sediment Inventory (NSI) Version 1.2 for the Conterminous U.S.

cwns96

1996 EPA/OW Clean Water Needs Survey (CWNS) for the United States and U.S. Territories

ifd

EPA/OW Industrial Facilities Discharge Database for CONUS

pcs3

EPA/OW Permit Compliance System for BASINS Version 3 in CONUS

pcs

EPA/OW Permit Compliance System for CONUS

tri

USEPA Toxic Release Inventory Facilities in the United States

cerclis

PA Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) or Superfund for the United States

rcris

EPA/OSW Resource Conservation and Recovery Information System (RCRIS) for the United States

mines

SBM Mineral Availability System (MAS)/Mineral Industry Location in CONUS

 

        Figure 4 Austin Area Rivers, USGS Sites, and TRI Sites

 

 

Data Available for Water Quality Modeling

Water quality data can be found for both point and non-point sources.  The Point source locations can be selected from the downloadable point source compliance system (the pcs or pcs3 files) or manually entered.  The non-point source data can be found in the wqd files downloaded from the core data on the internet.   The water quality data is given in a database format in 5 year increments from 1970 to 1994 and a 3 year interval from 1995 to 1997.  The observations are taken periodically throughout the timeframe and summarized within the wq_d#### files.  The #### are the two surrounding years.   For example, for water quality data from 1970 to 1974, you would use the wq_d7074 data.  The data is a statistical summary that gives the: number of observations during the timeframe, mean, 15th percentile, 25th percentile, 50th percentile, 75th percentile, 85th percentile, and standard deviation.  The test reference levels and water quality standards are also given in the water quality tables.  Most typical water quality parameters are located in this database.  The specific measured parameters and their units can be found below:

                Table II Detailed Water Quality Parameter Table

PARM_NAME

UNITS

TEMPERATURE, WATER

C

SPECIFIC CONDUCTANCE

UMHOS/CM AT 25C

OXYGEN, DISSOLVED

MG/L

BOD, 5 DAY, 20 DEG C

MG/L

PH

SU

ALKALINITY, TOTAL (AS CACO3)

MG/L AS CACO3

RESIDUE, TOTAL NONFILTRABLE (TSS)

MG/L

NITROGEN, AMMONIA, TOTAL

MG/L AS N

AMMONIA, UNIONZED

MG/L AS N

NITROGEN, KJELDAHL, TOTAL

MG/L AS N

NITRITE PLUS NITRATE, TOTAL 1 DET.

MG/L AS N

NITRITE PLUS NITRATE, DISS. 1 DET.

MG/L AS N

PHOSPHORUS, TOTAL

MG/L AS P

PHOSPHORUS, DISSOLVED ORTHOPHOSPHATE

MG/L AS P

CHLORIDE,TOTAL IN WATER

MG/L

SULFATE, TOTAL

MG/L AS SO4

ARSENIC, DISSOLVED

UG/L

BARIUM, DISSOLVED

UG/L

CADMIUM, DISSOLVED

UG/L

COPPER, DISSOLVED

UG/L

IRON, DISSOLVED

UG/L

LEAD, DISSOLVED

UG/L

SILVER, DISSOLVED

UG/L

ZINC, DISSOLVED

UG/L

CHLOROPHYLL-A UG/L SPECTROPHOTOMETRIC ACID. METH

UG/L

ALDRIN IN WHOLE WATER SAMPLE

UG/L

GAMMA-BHC(LINDANE),WHOLE WATER

UG/L

DDE IN WHOLE WATER SAMPLE

UG/L

DIELDRIN IN WHOLE WATER SAMPLE

UG/L

ENDRIN IN WHOLE WATER SAMPLE

UG/L

HEPTACHLOR IN WHOLE WATER SAMPLE

UG/L

HEPTACHLOR EPOXIDE IN WHOLE WATER SAMPLE

UG/L

 

Because water quality data (all data for that matter) has not historically been standardized and centrally located, I feel that the lack of data, not technology, is the constraint in water quality management.  The BASINS data site provides a model for future systems, but much work is yet to be done.  In of itself, the wealth of data stored in such a standardized fashion and in a centralized location is enough to be excited about the BASINS suite.  However, the data storage is only the beginning.  The EPA also provides a software suite to aide water quality analysis.

 

                Figure 4 BASINS System Overview

Assessment Tools

The BASINS suite provides multiple uses for TMDL and water quality analysis.  Not only does the BASINS software provide data, but it analyses it also.  The assessment component of BASINS allows users to quickly evaluate selected areas, organize information, and display various results using information provided by the BASINS website or data manually entered.  Three levels of assessment tools –TARGET, ASSESS, and Data Mining—were created to provide the capability for regional, watershed, and stream specific analyses.  The three components work in conjunction to allow the user to perform regional assessments, identify hot spots at a watershed scale, define water quality and point source discharge conditions with the watershed boundaries, and access and review summary data at a site-specific scale.  (BASINS 69) 

                                Figure 5 Assessment Overview

 

The TARGET function allows broad-based evaluations of watershed water quality and point source loadings.  This tool analyzes a large specified area (best for areas with multiple watersheds) and ranks the watersheds using point and non-point source data.  The watershed ranking is based on the evaluation parameters and threshold limits selected by the user.  Preliminary conclusions based on the available data can be drawn for a wide range of environmental data within the BASINS database—directing attention and resources to critical or endangered watersheds.  The TARGET function will rank the watersheds using either water quality targets or permitted discharges. The key inputs required for the TARGET tool are: time period, monitoring parameter, desired statistical summary, and the threshold criterion.  With these inputs, TARGET outputs a map displaying the average monitoring value computed for each watershed, a bar chart that shows the distribution of cataloging units with respect to the number of stations exceeding the selected threshold value, and a bar chart summarizing the distribution of cataloging units with respect to the average monitoring values as seen below. (BASINS 74)

                        Figure 6 TARGET Output example

 

The ASSESS component is similar to the TARGET function, and uses the same data.  Instead of a large scale analysis, it allows a more detailed analysis on a single watershed (or limited sets of watersheds.)  The ASSESS tool is specifically designed to find relationships between the condition of a water body and potential pollution sources over time and space.  Using the water quality statistical summaries database, it evaluates and provides a comparative view of the water quality condition at each station.  The ASSESS analysis compliments the TARGET analysis by allowing more detail to the watersheds identified as areas of concern.  Relationships between in-stream water quality conditions and potential sources and causes and the evaluation of monitoring programs are possible when using the two functions congruently.   Similar to TARGET, the key inputs are: watershed, time period, monitoring parameter, and statistical summary.  This can be done for either water quality or permitted discharges.  A similar output is given.

                                Figure 7 ASSESS output example

 

The Data Mining tool allows users to retrieve and graphically visualize water quality, bacteria, and point source loading data.  The Data Mining function is a dynamic link between the map interface and related data tables.   Data Mining was developed to use in conjunction with TARGET and ASSESS.  It allows the examination of impaired streams (ASSESS) within critical watersheds (TARGET.)  Combined with upstream land use distribution and point source locations, potential pollution and causes can be examined.   “Data Mining complements both TARGET and ASSESS by letting users move progressively from a regional analysis to a watershed-scaled analysis to a more detailed analysis at the station level.” (BASINS 14 )  If the appropriate data is available, the Data Mining tool will link the following tables and maps:  Water Quality Station Table, Water Quality Parameter Table, Water Quality Data Tables, and Water Quality Data Mining View.

                Figure 8 Data Mining output example

 

Conclusions

Although only a few functions were reported on in this paper, I hope that it is evident that the BASINS software is not just a great tool for water quality management, but an ideal template for future GIS applications.  Data management is becoming more crucial as technology becomes faster.  Not only does BASINS provide easy data, it provides a software suite to analyze the data.  This is one stop shopping to the extreme.

 

Through this paper, I have been able to explore the world of water quality analysis through GIS applications.  I did not get into the detail that I was hoping to, nor did I cover as much information.  I hope to further explore the assessment functions of BASINS, and I would also like to become familiar with the modeling aspects of the software as well.  

References

“About BASINS”, EPA, May, 2002  http://www.epa.gov/waterscience/basins/basinsv3.htm

Arc Hydro: GIS for Water Resources” Ed by David R. Maidment, published by ESRI Press, 2002, ISBN 1-58948-034-1

“Better Assessment Science Integrating Point and Non-point Sources Version 3.0 User's Manual”, US EPA, #823-B-01-001 June, 2001

"Modeling Our World", by M. Zeiler, ESRI Press, 1999, ISBN 1-879102-62-5