MAFVF User Manual

Overview

MAFVF (Multi-Scenario Adaptive Framework for Delineating Valley Floors) is a robust tool designed to facilitate the delineation of valley floors across diverse landscapes. This framework provides the core model, sample datasets, and step-by-step instructions for users. For further details on the methodology, please refer to the upcoming publication by Wenjie Sun et al. (in preparation).

1. Data Overview

The following table outlines the data utilized within the MAFVF framework, including descriptions and file paths.

Data	Description	Path
DEM	The Digital Elevation Model (DEM) of the study area, projected for analysis.	MAVAF/data/LP_DEM.tif
Initial Drainage Network	The initial drainage network derived from terrain texture analysis.	MAVAF/data/LP_river.shp
Final Drainage Network	The final drainage network, processed with longitudinal profile adjustments.	MAVAF/test/river_merge17.shp
ArcGIS Toolbox	Core model for MAFVF methodology.	MAVAF/method.atbx

2. Software Configuration

• ArcGIS Pro Version: 3.1.6

3. Step 1: River Segmentation

We have already derived the initial drainage threshold based on terrain texture indices from the example DEM data and have extracted the initial drainage network, which is projected and stored in MAVAF/data/LP_river.shp.

In this step, we compute the average river gradient from the longitudinal profile of the drainage network. The first task is to segment the river network.

1. Open ArcGIS Pro and load the method.atbx toolbox.
2. Double-click the step1 model.
3. Input the following parameters:
   • river MAVAF/data/LP_river.shp
   • workspace MAVAF/test
   • DEM MAVAF/data/LP_DEM.tif
4. Click "Run" to output the segmented river network as river_500clip.shp.
   • Estimated time: 2 seconds.

4. Step 2: River Gradient

After segmenting the river network, we proceed to calculate the average gradient for each river segment.

1. Double-click the Step2 model.
2. Input the following parameters:
   • workspace: MAVAF/test
   • river_500clip MAVAF/test/river_500clip.shp
   • DEM MAVAF/data/LP_DEM.tif
3. Ensure a folder named table exists in the MAVAF/test/ directory.
4. Click "Run" to generate gradient data for each river segment.
   • Estimated time: 4 minutes.

After processing, merge the river segments and output the result as MAVAF/test/river_merge.shp. Open the attribute table to observe the resul field, which contains the average gradient for each river segment. Export all features where resul < 17 and save them as MAVAF/test/river_merge17.shp.

5. Step 3: Slope Accumulation & SOSA

In this step, we compute the Slope Accumulation and Slope of Slope Accumulation (SOSA) for the study area.

1. Double-click the Step3 model.
2. Input the following parameters:
   • workspace MAVAF/test
   • DEM MAVAF/data/LP_DEM.tif
   • river_merge17 MAVAF/test/river_merge17.shp
3. Click "Run" to generate the Slope Accumulation (LP_DEM_SlopeAcc.tif) and SOSA (LP_DEM_SOSA.tif) rasters.
   • Estimated time: 2 seconds.

6. Step 4: Delineate Valley Floor

In this final step, we delineate the valley floor based on changes in the frequency histograms of Slope Accumulation and SOSA, as detailed in the methodology section of the paper.

1. Double-click the Step4 model.
2. Input the following parameters:
   • workspace MAVAF/test
   • slope accumulation MAVAF/test/LP_DEM_SlopeAcc.tif
   • slopeacc_threshold 1870
   • SOSA MAVAF/test/LP_DEM_SOSA.tif
   • SOSA_threshold 84.6
   • DEM MAVAF/data/LP_DEM.tif
3. Click "Run" to delineate the valley floor and output the results as LP_DEM_valleyfloor.shp.
   • Estimated time: 2 seconds.