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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3
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1answer
580 views

Recommendations for creating contour map from depth points

I am trying to put together a safe routes map for a local lake. I have an old paper map that has a grid of various depths as points. I would like to draw contour lines through these points and create ...
1
vote
0answers
24 views

I have a .adf file and want to select an elevation range [closed]

I'm super new to GIS. I downloaded a USGS 30m resolution map of a bay, and now I want to specify all areas that are between 0m and -30m elevation. I need to find where a defined area contains 0 and ...
1
vote
0answers
28 views

How to create buffers having regard to topography with QGIS

I want to create buffers of 25 kilometers around points in a point-shapefile with q gis. So far so good. My problem is that I don't need an air-line distance of 25 km around the points, but a "real ...
1
vote
0answers
59 views

Strategies and methods that Datums and Coordinate Systems use to account for movement of the earth's surface

Are there datums and coordinate systems that address the issue of shifting coordinates through time? If so, what are some of the strategies and methods that the datums and coordinate systems use to ...
5
votes
4answers
2k views

What's the difference between hypsography and topography?

I've recently come across some data that has been labeled "hypsography". I looked it up and it sounds like topography. But this data source has data labeled "topography" separate from its ...
2
votes
1answer
52 views

Understanding concept of ArcGIS for Flex?

I am a complete newbie to GIS. I am trying to download topographic data from a website that displays a map that can be zoomed in and out. The website is setup with: This application is using ...
5
votes
1answer
101 views

How to add a topographic map to a shapefile?

I wonder how it's possible to add this topographic information (elevation) to the map of Santa Cruz Island and all of the Galápagos Island that I have here. library(rgdal) library(rgeos) ...
2
votes
1answer
38 views

Quebec GIS Data

I'm looking for basic political borders for the province of Quebec, as well as property parcel data and topography. Any suggestions for inexpensive/free data?
5
votes
1answer
769 views

Calculating Topographic Exposure with Raster Calculator

I need you help trying to calculate Topographic Exposure (TOPEX) on a DEM in ArcGIS. I am trying to figure out wind exposure on a DEM with 25m cells. There is a great blog post where someone explains ...
0
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0answers
397 views

How can I calculate raster cell area for upslope contributing area

I am new to spatial analysis, and trying to follow this tutorial to generate a topographic wetness index for my area of interest: ...
6
votes
1answer
4k 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 ...
7
votes
3answers
454 views

Is there a difference between the Planchon & Darboux and Wang and Liu depression filling algorithms? Other than speed?

Can anyone tell me, based on actual analytical experience, if there is a difference between these two depression filling algorithms, other than the speed at which they process and fill depressions ...
1
vote
0answers
120 views

Interpolate vector layer and raster layer data into regular grid data using QGIS

I'm new to using GIS software. I obtained two different sets of data: Topography data (raster, .asc) Bathymetry data (shapefile, .shp, etc) I include topography data using Add Raster Layer and ...
0
votes
0answers
42 views

Terrain elevation in QGIS

How can I get started with creating a map with elevation just like this one: Basically I need a map that looks like the one above. Can someone tell me where can I get the data, and how do I process ...
3
votes
4answers
147 views

How can Identify highs on a DEM?

I have a DEM and I want to find each hill and create a polygon for its area, effectively the out closed contour that encloses the hill. I can do this visually but I'm about to work on a larger area so ...
1
vote
0answers
43 views

Error when using SAGA's “topographic correction” algorithm in QGIS

I'm trying to do topographic correction of Landsat images using SAGA's "topographic correction" algorithm from QGIS' processing toolbox. I was able to do it using Minnaert Correction with slope and ...
3
votes
5answers
4k views

Add UTM labels to grid in qgis

I try to use qgis to create a custom topographic map for outdoor use: UTM, 1:50000. What these maps usually have is a 1km x 1km grid, which at the bottom is labeled with a shorthand for the ...
7
votes
0answers
104 views

FLAG - fuzzy landscape analysis in GIS

I am trying to identify wetlands using different topographic indexes, e.g. TWI/CTI. And I would like to try out a method called FLAG (fuzzy landscape analysis in GIS), but I don't really understand ...
5
votes
1answer
131 views

Why does the peak of a mountain appear bright on Radar images

Why does the top of a mountain appear bright on a SAR (radar) image. I know that the peak of a mountain is subject to a layover effect, thus appearing closer on the radar image than the bottom part of ...
4
votes
3answers
187 views

Ways to determine winding topographic characteristics of a river

Are there any methods and/or technical guides on how to classify the degree of winding of river bodies? I have the following polygon layer of roughly 100,000 water bodies and would like to write an ...
4
votes
1answer
935 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 ...
2
votes
0answers
78 views

How do you merge overlapping .asc files in QGIS with topography and bathymetry?

Firstly, apologies for any incorrect terminology - this is my first time trying to manipulate GIS data. I have two files. The first is higher resolution (SRTM) topography data for a region of islands ...
1
vote
2answers
83 views

Topographical Elevations for Central Africa and Cameroon

I am using QGIS and I have been faced with the problem of topographical maps. From searching online I could only find data for the United States. Google maps offers elevation contours, however I am ...
0
votes
0answers
90 views

From DEM to Topographic Wetness Index in SAGA GIS

I have DEM in GeoTIFF format and I wish to calculate Topographic Wetness Index in SAGA GIS. TWI tool in SAGA GIS expects that user provides two values - 'slope' and 'catchment area'. Since there's ...
5
votes
4answers
907 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 ...
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vote
0answers
53 views

Calculating “sun time” on areas with high mountains? Topography available

I'm wondering how to proceed if you want to calculate how a location on land will get direct sunshine at a given time on a given date (compared being in the shadow of the mountains)? The area is very ...
1
vote
0answers
58 views

Why does the “local maxima” module in SAGA GIS put so many “maxima” points on lakes and plains?

SAGA GIS puts too many maxima points on plains and lakes. Why does it happen? Is there a way to avoid this? It's not really a big problem (the value is correct) except for the size of the SHP files in ...
0
votes
0answers
56 views

How to make a map showing the slopes of the terrain

I am not too familiar with techniques, and was looking for ways to make a slope map for a given area. It ended with finding this site and posting the question. We are in the process of zoning a new ...
3
votes
3answers
594 views

Gdal: how to get the max and min altitudes of my topographic raster?

Given a .tiff topographic raster image. How to get the altitudes of the highest and lowest point/pixel ?
1
vote
1answer
715 views

Can we create topographical map of private land using GPS elevation data?

Is there a way to create a relatively precise topographical map of a private land using GPS elevation data? As the land is a little bit over 100,000 square meters, the available regional topographical ...
11
votes
5answers
9k views

How to calculate Topographic Ruggedness Index in ArcGIS Desktop?

Does anyone know how to calculate Topographic Ruggedness Index in ArcGIS without access to command line ArcInfo Workstation? "The topographic ruggedness index (TRI) is a measurement developed by ...
0
votes
1answer
106 views

How do I take a contour .shp file and create a separate layer for each elevation?

The end result is to have a .dxf file in which each different elevation resides in a different layer. If at all possible I would like to be able to do the organizing in tile mill, or through some ...
1
vote
1answer
52 views

raster topo map with gaps to DEM

I'm trying to create a DEM from this raster map: I managed to clean all the shapes and text. I tried to write a program which finds the curve pieces and connects them. But, I realized that it is ...
9
votes
5answers
3k 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 ...
2
votes
0answers
37 views

3D topographic progress compensation by the least squares method

I'm looking for an explanation of the least squares method used in the case of a correction of 3D point network. We have reference points with known coordinates XYZ. We calculate intermediate points ...
1
vote
1answer
65 views

How to combine depth and topography .asc file?

I have a .asc file produced from a hydraulic model. The .asc file contains depth data of flood inundation. I want to superpose the depth asc file with my topography .asc file so I can identify where ...
1
vote
0answers
226 views

Finding Color Palettes?

Anybody can help me to find the three color palettes of the following map?
3
votes
1answer
188 views

Correcting for local topography in calculating TRI from DEM in ArcGIS

I'm currently investigating the use of different equipment in calculating TRI from elevation data using ArcGIS. From the methods available ...
1
vote
1answer
126 views

How to display steep slopes with the use of Contours?

I am using Arc Map 10.1. I have downloaded contour data as a shapefile. Is there any way to use the contours to display steep slopes so 15%-25% or 25% and greater.
1
vote
0answers
97 views

How can I enhance a topo map I am making as a Christmas gift? [closed]

I am using ArcGIS for Desktop 10.2. I am making a topo map for my girlfriend's brother as a Christmas gift. He is one who will appreciate a good map that was "drawn" in 1958. I know you can ...
2
votes
1answer
971 views

European Mountains Shapefile Data Sources

I am trying to locate a GIS freely downloadable shapefile (preferably polygon) of European main mountain chains (not an elevation data), eg Alps, Carpathian Mountains. I tried variuos sources , ...
2
votes
0answers
55 views

Creating QGIS multi-layer Topo Map of Lorraine Region of France?

I have a project I'm working on where I need a QGIS multi-layer Topo Map go the Lorraine Region of France between Metz and Nancy as a starting point, but I don't know where to start. What I need is a ...
2
votes
1answer
303 views

What is Google's source for topographic data?

I'm looking for as detailed as possible topographic data for a certain area and have found information displayed by Google Maps to be far more detailed than what is provided by 7.5 minute maps (from ...
4
votes
2answers
158 views

Software for amateur topographic surveys

I'm interested in doing rough topographic surveys using my tripod-mounted Brunton transit compass for azimuth readings and laser rangefinder (and maybe an optical level), so obviously going to be much ...
1
vote
1answer
148 views

Learning about bathymetry?

Besides reading about bathymetry, I would like to work on some hands-on training that I can learn about bathymetry. Is there any good bathymetry out there that I can get some training with the ...
2
votes
1answer
926 views

Detailed topographical map of Istanbul

I need to acquire a very detailed topographic map of Istanbul, Turkey without any markers. Do you know such sources who provides these kind of maps? I tried to Google it, but the results were far ...
1
vote
2answers
289 views

Mercator vs. Web Mercator for Large Scale Topographic Maps

I have 8 terabytes of imagery that is in either lon/lat or UTM projection that I will be using for the basis of large scale topographic maps. I have been studying the differences between Mercator and ...
2
votes
1answer
98 views

How can I properly clip a shape file to get the section I want using QGIS?

I've tried the other "how to clip" instructions here, but consistently get an empty shapefile from the clip. QGIS Version: 2.4.0-Chugiak OS: MacOS 10.10 Input File: San Diego (South Map) 1999 Topo ...
3
votes
1answer
59 views

Looking for detailed relief tiles

A few days ago I stumbled over a map which had beautifully rendered, detailed topographic tiles of the whole world. It was similar to google-physical with a strong contrast (shadow/light) and ...
2
votes
0answers
473 views

Find Average Elevation - ArcGIS Desktop

I am working with 2 shapefiles. One contains the boundaries of a city, the other contains polylines representing the topographic features of the area. Essentially, the polylines make a topographic ...