1. The document discusses using LIDAR topographic data to develop tools for conservation planning. It explores how LIDAR data can be used to target practices to improve water quality by identifying pollutant pathways and opportunities for treatment. 2. The document examines challenges in using LIDAR data such as accounting for accuracy errors, determining the appropriate scale of analysis, and modeling hydrologic flow across different landscapes and existing conservation practices. 3. It emphasizes that while LIDAR data shows great detail and potential for conservation planning, its accuracy on non-hard surfaces and representation of actual flow routing needs to be validated, and it cannot replace on-site knowledge.

1. The Challenges of Developing Conservation Planning Tools Using LIDAR Topographic Data M.D. Tomer, D.E. James, D.B. Jaynes National Soil Tilth Laboratory, USDA-ARS T. M. Isenhart, and S. Krogh Iowa State University

2. Map of research site showing sampling transects, and the wetness index which indicates the relative frequency of saturated soil conditions.

3. Placement of buffers Placement of wetlands Terrain analysis tools to target specific conservation practices

4. Precision Conservation Effective targeting of conservation practices to improve water quality requires knowledge of what pollutants are being transported, pathways they are being transported along, timing of their transport, and what opportunities exist to trap or treat them.

5. Aspects of targeting Dosskey et al. (2002) Helmers et al., 2005 Where? When? What pathway? TILE DRAINAGE SUBSURFACE OVERLAND

6. Using LiDAR data to plan and target conservation practices Source: USGS

8. Delineation of nutrient interception wetlands

9. Issues to address: Accuracy analysis, patterns/implications of errors. Appropriate scale of analysis may vary not only with scale of planning, but type of practice being planned. Hydrologic routing: Across vegetation boundaries–moving from field to watershed scales raises issues inherent to method of data acquisition. Across glacial terrain with potholes and subsurface drainage. Across existing terraces

10. Lidar coverage of Walnut Creek

11. Accuracy/error analysis

12. Accuracy/error analysis

13. Influence of scale: Flow accumulation pathways on 1, 5, and 10 m grids. “ Channel” thresholds shown are identical at each scale. Scale

14. Hydrologic routing Lidar image: processed DEM at 1 m grid Note detail shown in roads, ditches, fence lines, tillage, and vegetation boundaries. This affects flow routing!

15. Hydrologic routing - boundaries Grass Waterways

16. Hydrologic routing - boundaries

17. Mapped changes in surface elevation from 2002 to 2005 Hydrologic routing - boundaries

18. Landscape connectivity: In tile drained landscapes, ponded areas often have a surface inlet and direct conduit to the stream Terrain Modeling: Ponding Runoff Hydrologic routing - potholes

19. Hydrologic routing - potholes

20. Hydrologic routing - potholes

21. Effect of existing conservation practices on hydrologic flow routing Hydrologic routing - terraces

22. Learning to use Lidar terrain data for conservation planning How to represent / model hydrologic modifications and conservation practices already placed on the landscape? May be most important question at both field and watershed scales. Extraordinary detail may or may not represent actual flow routing, especially along boundaries (fences, buffers, etc.). “Scaling up” may or may not address this issue, depending on the particular application.

23. Learning to use Lidar terrain data for conservation planning Accuracy assessment - need to document error effects? Contracted accuracy assessments generally on hard surfaces, not in tall grass, forests, and tilled and untilled fields. Lidar DEMs have great potential as powerful conservation planning aide but are not a substitute for first hand knowledge gained by site visits and landowner contacts.