An open source version of the Nonpoint-Source Pollution and Erosion Comparison Tool Dave Eslinger, Shan Burkhalter, Matt Pendleton 10 May, 2012

Outline Background Getting started –Installation –Activation Basic analysis Advanced analysis

Background Why this tool? Why open source? What does OpenNSPECT do? What do you need to run it? What does it produce? Who else has used it? How can you get involved?

Why this tool? Hawai‘i managers needed a simple, quick screening tool –Usable in a public setting –Could run on a laptop Initially applied in Wai‘anae region in O‘ahu, Hawai‘i –Pressure from residential development –Sensitive coastal habitats 2004: Esri ArcGIS 8.x extension –Updated for 9.0, 9.1, 9.2, : OpenNSPECT

Why Open Source? N-SPECT Requirements –Esri ArcGIS Desktop –Spatial Analyst Extension ArcGIS 10 changes Customer requests –“easy, online and free” MapWindow –GeoTools 2007 EPA BASINS

Open Source and ESRI versions Strengths –Speed –“Free” –Community support Weaknesses –Different program learning curve, anxiety, distrust –Some features missing –Community support

What does OpenNSPECT do? Water quality screening tool Spatially distributed (raster-based) pollutant and sediment yield model Compares the effects of different land cover and land use scenarios on total yields User friendly graphical interface within a GIS environment

Processes Simulated Topography determines flow direction and slope Soil characteristics, land cover, and precipitation determine runoff Runoff, land cover, and pollutant coefficients determine pollutant loads Runoff, topography, soil characteristics, and land cover determine sediment loads

Uses Existing Approaches Rainfall runoff –Soil Conservation Service (SCS) curve number technique Nonpoint pollutant –Event mean concentration technique Sediment erosion –Universal Soil Loss Equation (USLE) Modified (MUSLE) Revised (RUSLE)

Assumptions/Limitations Omitted processes – Stormwater drainage – Stream diversions – Snowmelt – Landslides No time component for – Runoff dynamics – Sediment redeposition – Pollutant dynamics Source: NASA Earth Science Enterprise

What do you need to run it? National sources* –Land cover data –Topography –Precipitation –Soils data –Pollutant coefficients –Rainfall erosivity Local sources –Water quality standards –Additional pollutant coefficients *Local “tuning” improves accuracy

Topography Defines flow direction, stream networks, watersheds Default –U.S. Geological Survey (USGS) 30 m resolution digital elevation model Resolution impacts processing speed and file size

Land Cover Foundation for runoff quantity, sediment yield, pollutant yield Default –Coastal Change Analysis Program (C-CAP) –30 m resolution Flexible –Can easily substitute any land cover grid

Soils Runoff and erosion estimates are dependent upon soils and land cover Default –SSURGO soils † –County level resolution Infiltration rate –Hydrologic group Soil erodibility –K-factor † Soil Survey Geographic Database provided by the Natural Resources Conservation Service

Precipitation Derived from point estimates or modeled –OSU PRISM data Annual average Single event rainfall

Pollutants Pollutant coefficients –Event mean concentrations –Land cover specific Defaults –Nitrogen –Phosphorus –Lead –Zinc User–definable –New pollutants –New coefficients –Different criteria

What does it produce? Runoff volume Accumulated runoff Sediment yield Accumulated sediment load Pollutant yield Accumulated pollutant load Pollutant concentration

Baseline Runoff Flow directions derived from topography Precipitation grid provides amount of rainfall Uses soils and land cover data to estimate volume of runoff Validated Flow direction

Baseline Erosion Estimates total annual sediment load delivered to coast Provides a conservative estimate –A “worst-case” scenario

Baseline Nitrogen Estimates total annual pollutant load delivered to coast Focuses attention on source areas

Baseline Nitrogen Estimates total annual pollutant concentration Focuses attention on source areas

Who else is using it? Pelekane Bay, Hawaii Sediments from extreme events.

Who else is using it? Kingston Lake Watershed Association, near Conway, SC Nutrient loads under different growth scenarios

Getting involved OpenNSPECT: –Nspect.codeplex.com –MapWindow.org Esri N-SPECT: – NSPECT listserver – community

Questions? Project Contacts: Dave Eslinger, Project lead Shan Burkhalter Matt Pendleton

Example Application Makaha Valley, O‘ahu, Hawai‘i Annual time scale “What-if” scenario 1. Baseline 2. Land cover change New residential development 3. Comparison

Land Cover Change Scenario Develop a subdivision Change scrub/shrub vegetation to low intensity development

Nitrogen (Pre-Change) Baseline –Low nitrogen runoff Add scenario

Nitrogen (Post-Change) Compare baseline estimate to the new estimated load Can calculate the difference in annual nitrogen load

Questions? Download OpenNSPECT: Today’s Trainer: Dave Eslinger Project Contacts: Dave Eslinger, Project lead Shan Burkhalter Matt Pendleton

Outline Background Getting started –Installation –Activation –Import new data Basic analysis Advanced analysis

MapWindow GIS Free Open-source Desktop GIS Developer driven applications (plugins) –OpenNSPECT –BASINS –3D Viewer

Installation Two-part installation 1.MapWindowGIS 2.OpenNSPECT Contents of C:\NSPECT TODAY adding –HI_Sample_Data –Unzip into C:\NSPECT\ FolderSubfolderFile BinFixPath.dll NSPECT.dll vbalFlBr6.dll HelpAdvanced Applications of OpenNSPECT NSPECT.chm TechnicalGuide.pdf UsersManual.pdf Tutorial.pdf MetadataSeveral.met files ProjectsWaianae.xml Waianaedata 1 Agriculture.shp annual_prec dem_30 Development.shp event_prec_1 event_prec_2 event_prec_3 Golf_Course.shp landcover landcover.lyr rfactor soils.shp soils1 soilsk1 workspace wsdelinWaianae_15 1 basinpoly.shp dem2b demfill flowacc flowdir lsgrid nibble wshed nspect.mdb

Activation Open MapWindowGIS MapWindow Pull-Down Menu, select Plug-ins > OpenNSPECT

Import Landcover OpenNSPECT/ Advanced Settings/Land Cover Types Options/Import Browse to coefficient file Import with new LC name

Import Pollutants OpenNSPECT/ Advanced Pollutants Pick Pollutant Coefficients /Import Pick LC type Browse to coefficient file Import with new Coefficient Set name

Text change in Tutorial Change both “NitSet” to “NitSet05” –Page 4 –Page 13

Outline Background Getting started Basic analysis –Baseline Exercise 1 - Accumulated effects Exercise 2 - Local effects –Conclusion Advanced analysis

Basic Analysis Baseline analyses –Objective Run a basic analysis with OpenNSPECT and produce baseline runoff, erosion, and pollutant load data sets for an annual time scale. –Important Learning Objectives: Gain familiarity with the OpenNSPECT user interface. Learn which data sets are necessary to run the model. Understand the properties associated with the Pollutants tab. Understand the properties associated with the Erosion tab. Understand the function of the Local Effects Only option. Learn to visually assess the data output.

Exercise 1 Baseline analysis (accumulated effects) –Accumulated runoff, nonpoint source pollutants, and eroded sediments are estimated. –Accumulated effects include: Expected pollutant or sediment concentration at a cell. Contributions from upstream cells. Page 3

Exercise 2 Baseline analysis (local effects) –Local effects of runoff, nonpoint source pollution, and erosion are estimated. –Local effects include expected pollutant or sediment concentration at a cell without upslope contributions. Page 5

Exercises 1 and 2 Results Baseline runoff, sediment loads, and nitrogen concentrations (accumulated and nonaccumulated) –Model outputs are representative of the landscape conditions during the time at which the input data was collected. Visual interpretation –Topography was associated with the shape and density of drainage networks. –Land cover types were associated with various degrees of sediment and pollutant loads.

Exercise 1 Results

Exercise 2 Results

Outline Background Getting started Basic analysis Advanced analysis –Management scenario Exercise 3 – Accumulated and Local effects –Alternative land use Exercise 4 - Accumulated effects

Advanced Analysis Management scenario analyses –Objective Run an analysis that incorporates a hypothetical management scenario and examines the potential changes to runoff, erosion, and pollution. –Important Learning Objectives: Understand the properties associated with the Management Scenarios tab. Learn to incorporate a management scenario. Learn to quantitatively evaluate the data output. Understand the relative contributions of different land cover classes to nonpoint source pollution.

Exercises 3 Management scenario –Integration of a hypothetical land management scenario Grassland and scrub/shrub converted to low intensity developed land. –Local effects of runoff, nonpoint-source pollution, and erosion are estimated. –Accumulated effects of runoff, nonpoint-source pollution, and erosion are estimated. –Comparison to baseline results. Page 7

Exercise 3 Results Nitrogen yields (mg) A.Baseline conditions B.Low density residential management scenario C.Difference between A and B –The 0.2 km 2 development is predicted to yield an additional 86.7 kilograms of nitrogen under the alternative land management scenario (a 138 percent increase). Baseline Management Comparison % Change

Exercise 3 Results Nitrogen yields (mg) –This translates to a 0.5 percent increase in the accumulated nitrogen load for the entire 14.1 km 2 watershed.

Advanced Analysis Alternative land use scenario analysis –Objective Run an analysis with a new land use scenario and produce modified runoff, erosion, and pollutant load data sets for an annual timescale. –Important learning objectives: Understand the properties associated with the Land Use tab. Learn to parameterize a new land use scenario. Learn to quantitatively evaluate the data output.

Exercise 4 Alternative land use scenario (accumulated effects) –Integration of a hypothetical land use scenario New pollutant coefficients defined for a golf course. –Accumulated effects of runoff, nonpoint source pollution, and erosion are estimated. –Comparison to baseline results. Page 11

Exercise 4 Results Net decrease in accumulated nitrogen load –Land cover beneath the golf course polygon was recoded. –SCS curve numbers control runoff volume. –Runoff volume controls pollutant load.

Questions? Download OpenNSPECT: Today’s Trainer: Dave Eslinger Project Contacts: Dave Eslinger, Project lead Shan Burkhalter Matt Pendleton