A free and stand-alone tool integrating geospatial workflows for

GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
A free and stand-alone tool
integrating geospatial workflows to
evaluate sediment connectivity in
alpine catchments
S. Crema, L. Schenato, B. Goldin, L. Marchi, M. Cavalli
CNR-IRPI
Montefalco (PG), 16 - 18 giugno 2014
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Outline
 The evaluation of sediment connectivity in
alpine catchments
 Development of the tool for the assessment of
sediment connectivity
 The better strategy to make the tool usable
 The better strategy to make the tool open to
scientific improvements and customization
 Test application, results and remarks
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Topography-based sediment connectivity
index /1
•
Index for the spatial
characterization of sediment
connectivity developed by Cavalli
et al. (2013) following the approach
by Borselli et al. (2008)
•
Topography-based index aims at
evaluating the potential
connection between hillslopes
and features which act as targets
(e.g. catchment outlet, roads) or
storage areas (sinks, retention
basin) for transported sediment
(modified after Borselli et al., 2008)
Borselli L., Cassi P., Torri D., 2008. Prolegomena to sediment and flow connectivity in the
landscape: a GIS and field numerical assessment. Catena, 75(3), 268-277.
Cavalli M., Trevisani S., Comiti F., Marchi L., 2013. Geomorphometric assessment of spatial
sediment connectivity in small alpine catchments. Geomorphology, 188, 31-41.
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Topography-based sediment connectivity
index /2
Flow direction
D∞ method
(Tarboton, 1997)
Slope S (m/m)
S < 0.005 -> S = 0.005
S>1
-> S = 1
Weighting factor W
• Related to the impedance to water and sediment fluxes;
• C factor of USLE – RUSLE in the original model;
• Replaced by a roughness index (Cavalli et al., 2008).
High W : Low roughness and low impedance to fluxes
Low W : High roughness and high impedance to fluxes


RI

W  1  
 RI max  0.001 
W (m/m) ranges from >0 to 1
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Implementation: strategy and target
 Assessment of the need for such a tool (free,
open source and GIS independent)
 Different stakeholders interests: management
authorities/scientific community (integration
with available databases)
 Analysis of different applicable frameworks and
selection of the most suitable developing
environment
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Implementation: features
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
SedInConnect 1.0
Workflow
Input DTM
No
Use default W?
(Cavalli et al.,
2013)
Input W
Yes
All NaN flagged to target
Input
neighborhood
analysis size
No
W computation
Use
Sinks?
Use Targets?
Yes
Yes
Targets
Pre-process to flag targets
Sinks
No
Pre-process to exclude
sink.draining areas
Connectivity index computation
Output IC
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
GUI
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Application
•
Gadria and Strimm catchments
• (Eastern Italian Alps)
•
Lithology: mica-schist, gneiss,
and phyllite.
Land use: coniferous forest,
mountain grassland, bare rock
and debris.
Annual rainfall: around 500 mm
in the valley floor, strong
increase with elevation.
Gadria: area 6.36 km2, average
slope 79.1%, range in
elevation: 1394 – 2945 m.
Strimm: area 8.5 km2,
average slope 61.8%, range in
elevation 1394 – 3197 m.
•
•
•
•
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Application
•
Gadria and Strimm catchments
• (Eastern Italian Alps)
•
Lithology: mica-schist, gneiss,
and phyllite.
Land use: coniferous forest,
mountain grassland, bare rock
and debris.
Annual rainfall: around 500 mm
in the valley floor, strong
increase with elevation.
Gadria: area 6.36 km2, average
slope 79.1%, range in
elevation: 1394 – 2945 m.
Strimm: area 8.5 km2,
average slope 61.8%, range in
elevation 1394 – 3197 m.
•
•
•
•
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Application
•
Gadria and Strimm catchments
• (Eastern Italian Alps)
•
Lithology: mica-schist, gneiss,
and phyllite.
Land use: coniferous forest,
mountain grassland, bare rock
and debris.
Annual rainfall: around 500 mm
in the valley floor, strong
increase with elevation.
Gadria: area 6.36 km2, average
slope 79.1%, range in
elevation: 1394 – 2945 m.
Strimm: area 8.5 km2,
average slope 61.8%, range in
elevation 1394 – 3197 m.
•
•
•
•
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Application: outlet/targets
IC used to assess connectivity:
1. Hillslopes to outlet
2. Hillslopes to targets (e.g., channel
network)
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Application: sediment dynamics
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Final Remarks
 The need for such a tool is being verified by the increasing
interest in its usage
 Stakeholders are interested in a fast and simple connectivity
assessment to give management priorities integrating the
analysis with information on sediment availability
 Encouraging feedbacks from scientific community are pushing
towards a continuous improvement (Cost action: Connecting
European connectivity research)
 The testing of the tool permitted to compare its performance
with equivalent GIS workflows and to analyze connectivity
variability in relation to the sediment dynamics
GIT – Geology and Information Technology
9a Riunione del Gruppo di Geologia informatica - Sezione della Società Geologica Italiana
Montefalco (PG), 16 - 18 giugno 2014
Thanks for your kind attention!
Is it a sink
or a target?
Photo by: H. Kross

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