The slope of a line or surface is a numerical measure of steepness or incline.

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QGIS Slope Classification Issues

I am very new to QGIS for the primary purpose of creating a slopes layer so we know where slopes are above 15% or 20% or whatever we finally decide. I have used our DEM to create a slope geotif and ...
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10 views

GRASS: v.drape, v.split and v.to.db on spearfish sample data

I am new to GRASS and started training on the spearfish sample data set in GRASS 6.4.3. I selected a bicycle tour and transformed it into a polyline. My next goal is to read out the slope and ...
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38 views

Problem for slope map

I want o create one slope map for my model but I have one big problem. I have contours lines and mass points and I create a DEM using topo to raster but if I want to create a slope map from that DEM I ...
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29 views

How do you set sea level elevation to white in terrain analysis?

I have ASTER files I am working with to create a shaded relief background for some other vector shapefiles. In experimenting with different color-elevation options, I am unable to have the Terrain ...
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In ArcMap, when using Add Surface Information, why are all avg_slope values positive?

I've got a polyline shapefile and a LIDAR elevation dataset. I've successfully used Add Surface Information (from 3D Analyst) to calculate the average slope (avg_slope) of each line segment. The ...
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53 views

Split 3D line feature at vertices based on slope change

I've already asked a question about this subject, but now I think I'm almost getting to the point. I have to split roads in ramps to calculate LS factor (RUSLE - soil erosion) These are the steps ...
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146 views

validating the calculation of slope from DEM

my purpose is to calculate and validate slope in percentage of southern california using DEM and landsat data. step 1)i used a DEM file and changed with the float type file to integer type step 2) i ...
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127 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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313 views

Calculating Accurate % Grade from GPS Coordinates

I am trying to calculate % Grade from GPS points. I am using the basic equation of (Rise/Run)×100 The problem is I am getting spikes in my GPS data (example 1 meter rise for 3 meter run), I am ...
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65 views

Issues creating slope raster layer from a point layer

I'm trying to create a slope raster layer using QGIS 2.0 on Windows XP. I started with a points layer with the Z elevation attribute. I then used the interpolation plugin to create a DEM. But, ...
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56 views

DEM/DSM from contour lines and slopes

I want to create a DEM with as much detail as possible. The problem is, that the area contains several (manmade) slopes. I got contour lines and lines that mark the location of the slopes, but no ...
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68 views

Analyse slope gradient from LiDAR .asc data

I'm new to using QGIS. I have purchased some LiDAR data which downloads as .asc format, is there a way to analyse the terrain slope angle from this data or does it need to be converted into DEM? ...
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78 views

Estimating sunlight hours from slope, aspect, and latitude

I'd like to estimate annual sun hours (or insolation, or solar radiation) for 4 points, 1 each on the four sides of the summit of a hypothetical flat-sided mountain. I have slope and aspect for each ...
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123 views

Trying to build pyramids for large raster

I finally was able to make a slope with a rather large 5m DEM. But now I it usually wont finish drawing. When ArcMap asks to 'build pyramids' it always freezes sometimes instantly after accepting ...
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72 views

3D Polyline by Slope on Surface

I wish to project (continue/extend/whatever) a polyline upslope following a specified gradient along a DEM surface. Is there any way of doing this?
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125 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?