Tagged Questions
1
vote
1answer
58 views
How to find the watershed area for each point in the river network using DEM？
As title, I want to find the watershed area, but using QGIS.
I have following files to work with：
stream network shapefile(polyline)
point shapefile clipped from the polyline shapefile
a whole ...
0
votes
0answers
26 views
GRASS - Creating an Attribute Based on Driving Distance
Is it possible to calculate the driving distance for each node of one layer (fire stations) to each node of another (address points)? After doing so, I need to sort all of the distances from shortest ...
7
votes
3answers
201 views
Howto setup and use a remote GIS workstation (QGIS,GRASS,PostGIS)?
I'm using QGIS (and sometimes GRASS and PostGIS) on my 2009 MacBookPro for my thesis project.
I was wondering (during an endless batch generalizing in QGIS) if I can set up a server so I can work from ...
2
votes
1answer
38 views
Help with GRASS V.Net.Path
GRASS has extensive and brilliant documentation, but I still have a bit of trouble using v.net.path. in the example for shortest path, it says: "
#Shortest path: ID as first number, then cat1 and ...
2
votes
0answers
53 views
How to join nodes to network lines ( and not the other points)
I'm trying to do a shortest path analysis on my network. In order to prepare the network and attach polygon centroids to the roads, I used GRASS' V.NET operation=connect. the problem with this ...
0
votes
1answer
33 views
GRASS: Loss of data using v.net
I'm trying to build a network in GRASS in order to find the shortest path from any settlement out of 1120 (points), to one waste treatment facility out of 27 (points). I plan to use v.net.distance ...
1
vote
2answers
62 views
Error using Grass v.net
I'm trying to connect my network to a points layer with a threshold of 4500 meters. I have about 11000 or so entries in my polyline and about 24 in my points layer.
I have alreday used v.distance, ...
4
votes
4answers
192 views
How to Find Dead-ends in a Road Network
I'm trying to remove all the dead-end roads in a road dataset (lines) that are less than 100m long.
How do I identify roads that are dead-ends (no exit)? The 100m part is easy. I know how to use Arc ...
1
vote
2answers
189 views
Network distance computations using GRASS
I'm an ArcGIS user who's interested in learning to use GRASS. Can anyone point out resources that will help me in learning how to obtain network distances between (1) residential locations (points) ...
9
votes
3answers
1k views
How to connect lines in a network?
I have a shapefile of lines and another of polygons. When two or more lines intersect a polygon they should be connected (snapped), but sometimes during manual digitization this doesn't occur. I need ...
10
votes
3answers
541 views
How to simplify a routable network?
I have a network graph that I need to simplify in the sense of reducing the number of edges. The idea would be to merge nodes that are located close together and remove the connecting short edges.
...
3
votes
2answers
143 views
Can GRASS v.net.iso split between nodes?
Can GRASS's v.net.iso module split networks between nodes on the network, i.e., if I am finding the area within a cost of 400, and there is a line segment with a cost of 800 leaving the center node, ...
