The study and mapping of land surfaces, including relief (relative positions and elevations) and the position of natural and constructed features.

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Topography: How to convert raster into vector layers?

(nb:This project is part of the #Wikipedia #wikimaps project) 1. Question: How to create vector topographic maps from raster image ? How to convert raster topographic image into closed vector ...
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458 views

How to limit a specific area in order to have a topographic 3D map using MatLab?

I am using MatLab, I want to build a topographic 3D map, I am following this guide, I have been doing the steps listed on the section Draping Geoid Heights over Topography, and I do not have any ...
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159 views

cut/fill calculation tool to investigate if there is enough material to achieve a 30 degree slope

This is a cut/fill problem. We have pits that have been dug in the ground, usually rectangular. They have a bund wall around them. They are being rehabilitated by pushing the bund back into the pit. ...
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179 views

How to calculate Gradient from DEM?

I have a digital elevation model for a catchment area and I would like to calculate the gradient by cells. Is that possible and does anybody know the steps?
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2answers
394 views

A library/software to create DEM from a topographic map

In one of my projects I need to digitize video clips showing some natural landscape. Specifically I need to know distances between different areas and elevation levels. I have a topographic map of ...
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262 views

How can I calculate raster cell area for upslope contributing area

I am new to spatial analysis, and urgently trying to follow this tutorial to generate a topographic wetness index for my area of interest: ...
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2answers
119 views

viewshed analysis for observers wearing visors?

I'm starting with a DEM, and looking to identify every point that can be directly "seen" from any point in a particular polygon on an overlaid layer defining an area on that DEM - like any other ...
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1answer
87 views

What function should I use to assess the degree of elevational change (rocky cliffs etc.) of a DEM?

I have a DEM of my research area and I want to assess how the topography/elevation changes. I am specifically looking to see what areas may be good suitable bat-roosting habitat so I am trying to ...
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1answer
522 views

What are Bands, Dimensions, and Histograms in QGIS?

First; I can see a band as synonymous with a channel in an image editing program like GIMP, is this correct? If so then bands play the role of color mixing and masking. Are there any other ...
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33 views

Library for parsing scientific PDS files?

Does a library exist for parsing the PDS files that scientific planetary data gets shipped as? For example, here's a link to to the lunar topographic data from the Lunar Reconnaisance spacecraft ...
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1answer
171 views

I want to create my own topographic map

I need to create topographic maps for scales between 1:100,000 and 1:500,000. This is due to the fact that the official topographic maps in my country are offered in 5k, 10k, 25k, 50k, 100k and 500k. ...
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1answer
3k views

Calculate Topographic wetness index in SAGA

i am currently working on a project which involves the quantification of the wetness in certain areas. However it produces quite different results from what i expected. I'll describe the steps i have ...
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1answer
428 views

ArcGIS Online Topo Maps

ArcView 10.1 does not have this kind of topo map to "Add Data". Where do I find this type of topo map, preferably free. ArcGIS online does not seem to offer this type of topo, unless I am not seeing ...
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3answers
958 views

What are common methods for converting raster digital elevation data to vector contours?

In researching this I have found many references to the opposite, creating elevation data from contours, but nothing regarding contour creation. Preferably, I am looking for open source solutions like ...
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1answer
690 views

USGS Topographic Map Online API

I am creating a website for a non-profit organization and would like to plot points on a map similar to this: http://www.arcgis.com/home/item.html?id=931d892ac7a843d7ba29d085e0433465 I am currently ...
4
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1answer
887 views

Terraserver replacment - source for US Topo maps?

Now that Terraserver has been shut down (or at least that's how it appears), is there an alternative WMS server for US topo maps? Probably too much to hope to find one that provides vector layers ...
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1answer
260 views

Plotting Smith and Sandwell global seafloor topography grids

Does anybody have any experience with plotting Smith & Sandwell 2-minute Mercator-projected grids in ArcGIS? I've downloaded one in two formats: ers and img. I've found tools for processing .img ...
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1answer
416 views

How to restrict or block certain paths in NetworkX graphs?

I am trying to calculate shortest path between 2 points using Dijkstra and A Star algorithms (in a directed NetworkX graph). At the moment it works fine and I can see the calculated path but I would ...
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1answer
1k views

Map Grid Index / Reference for Canadian Topo Map

Does anyone know where I can find some kml at different resolutions to show the grid reference for the Canadian topographic maps (CanTopo and toporama). Much like is displayed on the map here: ...
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4answers
2k views

How to aquire a topographical map of Britain?

First of all, let me say that I know next to nothing about GISs. I'm trying to find / make / aquire a topographical map of britain. I want to use it as a height map in Dwarf Fortress so it needs to ...
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3answers
743 views

Australian Topo Map GeoTIFFs

Does anyone know if Australian topo map GeoTIFFs are made available anywhere (preferably for free)? LINZ makes them available in New Zealand - http://www.linz.govt.nz/topography/topo-maps/index.aspx ...