Watershed Analysis Using Remote Sensing and GPS

Transcription

1 25 th Annual Louisiana Remote Sensing and GIS Workshop Baton Rouge, 2009 Watershed Analysis Using Remote Sensing and GPS Warren L. Kron, Jr. Quang Tran Baton Rouge City-Parish Planning Commission José E. Villalobos-Enciso Louisiana State University April 15 th, 2009

2 Presentation Outline Objectives Data Availability Methodology Watershed delineation Post Processing Expected Results Conclusions

3 Objectives Implement the integrated micro-watershed management approach in the EBRP Environmental Planning Process Continue with the Hydrologic Modeling to Mitigate the Nonpoint Source Pollution in Urban Watersheds Focus on Stormwater Management

4 Data Availability 10 water quality subsegments (LDEQ) 369 consolidated subwatersheds (LSU)

5 Data Availability Stormwater Best Management Practices Source: LSU and City-Parish Planning Commission

6 Data Availability EBRP Two (2) Foot Contours ELEVATION_CONTOUR_LINE CNTR_TYP_D ELEVATION CONTOUR_ID GEOMETRY_sk INTER =X4H INTER =X4H INDEX =X4HI INTER =X4HI INTER =X4HI INTER =X4H INTER =X4Hia INDEX =X4Hi INTER =X4Hi Record: 1 of Source: U.S. Army Corps of Engineers (2001)

7 Data Availability EBRP Digital Elevation Model Source: U.S. Army Corps of Engineers, 2001 USGS DEM

8 Data Availability EBRP consolidated sub-watersheds, stream network, and DEM Source: LSU (2007) and U.S. Army Corps of Engineers (2006)

9 Methodology Data Collection Watershed delineation Slope and Soils analysis Computation of geomorphic parameters Multivariable Analysis to account for both the spatial covariance among watershed characteristics and land use Determination of hydrological homogeneous regions, using the watershed characteristics through both ordination and classification Establishment of Watershed-BMP clusters

10 Watershed delineation There are inconsistencies between USACE stream network, LSU watersheds, and GeoMedia Grid analysis stream network A weekly field survey with the DPW has been initiated to verify the correct stream segments

11 Watershed delineation Grid Analysis Compiled with Fieldwork 2006 Aerials fieldverified

12 Watershed delineation Recent Land Developments 1998 Aerials 2005 Aerials

13 Watershed delineation Field Surveys GeoMedia OnDemand used to create metadatabase containing point features for field collection To make the field work more efficient, only the southwestern portion of EBRP was exported Attributes collected include: Event ID, Vegetation, Watershed, Left and Right Bank, Deposition, Quality Indicators, Flow type, Flow direction, and other comments GPS Unit (Trimble GeoXH 2008 with Zephyr antennae) providing sub-meter accuracy Digital Camera to provide visual recordation of the site

14 Post Processing Import field data to GeoMedia desktop GIS QA/QC steps to ensure data integrity Develop Google Mash-up webpage

15 Post Processing Google maps: EBRP Stream & Watershed Survey

16 Post Processing After Parish-wide Stream Surveys are Complete Redigitize stream network based on data collected in the field Re-run analysis of stream network using GeoMedia Grid to correct watershed boundaries Smooth watershed boundaries into continuous lines for more accurate representation on the base map Discontinuous watershed boundaries

17 Expected Results Methodology to contrast Storm Management Plan (water quality impact, and drainage studies) Guideline to target BMP s to specific watershed cluster Encouragement to utilize natural topography and vegetated waterways to convey runoff Principles to regulate impervious areas (e. g. rooftops, sidewalks, plazas, parking lots, drives) Method to analyze detention volumes Information to promote increment of runoff water residence time on site Localize potential areas for detention ponds and constructed wetlands

18 Further Development Contribute information to the establishment of a comprehensive Stormwater Management Plan Promote Green Infrastructure urban forestry, green roofs, wetlands, and vegetated swales Regulate impervious areas rooftops, sidewalks, plazas, parking lots, and driveways Promote complementary solutions porous pavement, rain barrels, retention basins, and treatment facilities Provide information to examine Rainfall and Design Storm Data, Detention Volumes and Peak discharge rates Provide spatial data to avoid the segmentation and isolation of ecosystems and their natural resources Estimate time of stormwater runoff

19 Conclusions EBRP consolidated subwatershed study provides a basis for the modeling work and a watershed-based framework for addressing runoff-related problems and BMP opportunities Provides more information to improve the Environmental Planning Process Supplies detailed information to the National Hydrologic Database Bayou Duplantier watershed

20 Questions and Comments? City of Baton Rouge Parish of East Baton Rouge Planning Commission G.I.S. Division (225) Warren L. Kron, Jr., GIS Senior Analyst Quang Tran, GIS Analyst, Project Development Section José E. Villalobos-Enciso, Doctoral Candidate, LSU