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10

Provided your Z units are the same as your X and Y units: You have it almost right. Adding the negative values would give you the total volume of the increase. HOWEVER, this would only be your answer if there were no POSITIVE values in the resulting attribute table. (If your resulting rendered shows any red and no blue areas) What this means is that ...


7

The best way I've found to do so is to use a combination of the raster calculator and zonal statistics. You first need to calculate the difference between the two rasters, using a filter to get either the positive or the negative difference, and no values elsewhere. In Qgis calculator this would give something like : ((A-B)>0)*(A-B) To get the positive ...


5

Using QGIS 2.18.3, it seems to work fine. I set the "County Only Above Base Level", with base level equals to 0 and I get this log: Algorithm Raster volume starting... grid_calculus "Grid Volume" -GRID "C:\Users\xxxxx\AppData\Local\Temp\processingdd38dbc0f5ec434f922835f11ed2d9d0\3ddfa5d81c1744819d54de14d3c7a8f1\DTMdiscarica.sgrd" -METHOD 0 -LEVEL 0 C:\...


5

I will try to address your question with GRASS. Your problem has a first task that is a bit challenging already, which is to get the situation before the event you want to quantify. I think the best option is to produce a raster of the original situation. To produce it, I would use some countour lines to draw "by hand" the terrain as it was before the ...


4

ArcScene is great for displaying 3D data and 3D analyst has some good 3D geoprocessing capabilities but as far as 3D editing goes it is VERY limited. You can construct 3D lines programmatically with ArcObjects but since ArcScene is not a true 3D editing environment you will not be able to create a 3D object, cross sections, vertical slices or manually ...


4

I believe you can use some map algebra (raster > raster calculator) before you can preform your volume measurements in grass. Assuming that your bathymetric data use positive values to represent the sea depth, and using your example for the range as 50 the min_depth and 200 the max_depth. For each of the raster cells you need to "remove" anything below the ...


4

The raster calculator can give you the difference between the original DSM and the new DSM. DSM_o minus DSM_n = DSM_cut-fill. You can then run saga raster volumes in processing to get the volume below the baseline (cut), volume above the baseline (fill) etc. On my machine this info goes into the log message panel under processing. The grass algorithm r....


4

A very fast way to get the volume with some python code and gdal2xyz. You have to calculate your difference raster only. Don't care about positiv or negativ value, we will distinguish between them later. Convert your difference raster file to a csv file with the OSGeo4W Shell: gdal2xyz your_raster.tif your_raster.csv Create a numpy array from this csv ...


3

You are drawing a wedge through the hummocky splooge. The methodology is fairly crude, but without a "before".. you are just guessing so why waste a bunch of time. The points you proposed to create will be fine for the deep end of the wedge, but you will need a shoreline from old imagery (pre-slide) or getting something out of some vector data to use as ...


3

QGIS can use the GRASS GIS and SAGA GIS tools that solve the problem (example uses GRID VOLUME by SAGA GIS from processing).


3

2D area is calculated from a flat surface in plan view (looking down). 3D area takes into account 3D characteristics of the surface. A 3D polygon with peaks and valleys will have a larger 3D surface area then a flattened "plan view representation" of the same polygon in 2D. Suppose you have a 3D polygon of a pyramid, the 2d area is the the pyramid's ...


3

You could use the &&& operator. It returns true if two n-d bounding boxes intersect: SELECT 'POINT Z (0.5 0.5 0.5)' &&& 'LINESTRING Z(0 0 0, 1 1 1)' AS intersects; intersects ------------ t (1 row) SELECT 'POINT Z (1.5 0.5 0.5)' &&& 'LINESTRING Z(0 0 0, 1 1 1)' AS intersects; intersects ------------ f (1 row) For ...


3

The negative volume is the amount of dirt you have used to fill the hole in projection units and your chosen z unit. In your case it is the amount of fill needed to fill the lake. So if x y z are meters it would be meters cubed. From esri help. "The attribute table of the output raster presents the changes in the surface volumes following the cut/fill ...


3

For a results object the punctuation is slightly different than the GetMessage method. print result.getMessage(0)


3

The first step is to define a grid resolution (g.region) and then convert your points to rasters with v.surf.idw. Check that the rasters look OK. Sometimes interpolating introduced artifacts. Then, subtract the lower from the upper layer to get thickness. This could be done with r.mapcalc "thick = top - bot". Finally, the volume is the thickness times the x ...


3

In ArcGIS-Create a polygon that represents the outer boundary of the reservoir. Give create a new attribute in that polygon (say 'z') and populate the attribute wit the elevation. Feed the points (as mass points) and the polygon (as a hard break) into Create TIN using the z values as the elevation values. You can convert the TIN to a raster surface and ...


3

SAGA Raster volume with [0] Count Only Above Base Level option (Base Level= 0) will be fine. If you are unsure about the output value, please ensure your CRS is in line with your expected output units (CRS can be in degrees, meters, and ft). TLNR; [SAGA Raster volume] This tool is usually used for a single raster DEM volume above/below a base level (such ...


3

You may not believe it, but you can use QGIS Hypsometric curves tool (in Processing Toolbox > Raster terrain analysis) exactly for this purpose. Please do not forget to reproject your map to a CRS beforehand which uses the units in which you need to get the area.


2

I received the following response from Support@AppliedImagery.com (the makers of QTM) The volume calculation tool enables the user to perform very accurate and fast calculations regarding the volume of objects or terrain in the model. It can also be used in conjunction with other models to calculate the difference in volume between the same areas ...


2

If you want to calculate the sum of cut and the sum of fill do the following: Go to the attribute table of the layer Sort the rows by volume Select the rows with minus (i.e. fill) (highlight them) at the bottom of the window you can click on 'show selected records' Click on the VOLUME column id and click 'statistics' Here you will have the sum for all the ...


2

On the ESRI example page for the cut/fill tool for ArcGIS 10.0 it appears that you need to multiply each volume column by its count and then add that to the other records after performing the same operation on them to get the actual amount of change. Each record contains all of the results cells that had the same volume change. Looking at their attribute ...


2

The tools that you need are located within ArcToolbox which can be accessed in ArcScene's tool bar or ArcGIS desktop. Look for this icon. Some of the tools that will allow you to calculate volume are as follows: Surface Volume (3D Analyst) Polygon Volume (3D Analyst) Cut and Fill, here is a link to another question regarding this tool If your horizontal ...


2

You can do this in Arcscene: Convert '.las' point cloud file in '.lasd' format (LAS dataset). Then, add this LAS dataset in ArcScene and digitize a 3D polygon around your salt feature. Open the attribute table of such polygon and in a new field multiply the value of area and length to compute the required volume.


2

One approach: you can clip a raster with a tool from your toolboxes, Data Management -> Raster -> Raster Processing. There are various routes with for getting volume, but if you have raster data you can use the Surface Volume tool. You should also understand the error associated with your LiDAR derived raster and the estimates of volume and how that ...


2

All the answers are found in the ArcGIS resource site. Here's the Surface Volume tool, and a more elaborate help regarding your questions.


2

Use a projected coordinate system suitable to your region. UTM is common for this. Those units appear to me to have been generated from: x=decimal degree y=decimal degree z=your layer units such as meters. So basically nonsense. Fractions of a degree / meter. For this to make any sort of logic you need to: Convert the all to the same units such as ...


2

here's some good news for you! In the latest version of Pix4Dmapper, the volume is calculated based on the DSM if the 3rd step - DSM and Orthomosaic generation is done. This is done by default, and users do not have to change any settings! Please stay tuned :) Lisa


2

I assume that what you call “DEM of the lake” is DEM of lake bottom and surrounding area. If this a case, it is a few steps procedure main ones being calculation of lake bank altitude and average lake depth. Convert lake polygon to polyline, using feature to line tool Set environment settings snap raster to DEM, cell size = one for DEM and convert polyline ...


2

Assuming that borewells’s elevations (in my example a constant raster with value 2000) and elevation of the bottom of the first geological layer (in my example a DEM raster) are two rasters with the same resolution and extension (both projected in meters), next PyQGIS code was tested to get the volume in km3. registry = QgsMapLayerRegistry.instance() ...


2

Are you aware that the output from r.clump does not have the depths? Each clump is given a unique category value, so you no longer have the cell depths. You can get the area of each clump, but not the total volume. If I understand correctly your goal, you should convert the "clumps" to a polygon vector, then use v.rast.stats to get the total depth for each ...


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