KGA Irrigation Toolsដំណើរការជាបាច់

CSV to DEM and Contour

បម្លែង CSV នៃចំណុចស្ទង់ ទៅជា DEM GeoTIFF និងបន្ទាត់កម្ពស់ (Shapefile ឬ GeoPackage)។

រកឃើញនៅឯណា: Processing ▸ Toolbox ▸ KGA Toolbox ▸ KGA Irrigation Tools ▸ CSV to DEM and Contour
លេខសម្គាល់ algorithm: kga:csvtodemcontour
ប្រភេទឧបករណ៍: Batch algorithm

ទិដ្ឋភាពទូទៅ

Converts a surveyed point CSV straight into a DEM GeoTIFF and contour lines, in one pass.

This is the survey-file route: one CSV of levelled points, one interpolation pass, contours out the other end. To contour an area you have no survey for, Generate Contour for ROI downloads the free Copernicus DEM and contours that instead, and will also use a local DEM you already have.

CSV columns: No, Easting, Northing, Elevation, Code. A dual side-by-side layout — two blocks of columns on one sheet, as some total stations export — is detected automatically.

ប៉ារ៉ាម៉ែត្រ

Parameters for CSV to DEM and Contour
ឈ្មោះ	ប្រភេទ	តម្លៃលំនាំដើម	ការពិពណ៌នា
Input Point CSV	File (`*.csv`)	—	The survey file.
Output Folder	Folder destination	—
DEM Resolution (m) [0 = auto-detect]	Number, optional	`0.0`	Auto-detect derives a cell size from the point spacing. Set it when you need a specific grid.
Interpolation Method	Enum	`IDW`	`IDW`, `Linear`, `Cubic`, `Nearest Neighbour`.
CRS – EPSG Code	Integer	`32648`	The CRS the Easting/Northing values are already in. `32648` is WGS 84 / UTM zone 48N, which covers most of Cambodia.
Generate Contour Lines	Boolean	`True`	Off, only the DEM is produced.
Contour Interval (m)	Number (min 0.01)	`1.0`
Contour Smoothing – Gaussian σ (0 = off)	Number (min 0.0)	`1.0`	Smooths the surface before contouring, so the lines are not ragged. `0` contours the raw grid.
Contour Output Format	Enum	`Shapefile (.shp)`	Or `GeoPackage (.gpkg)`.
Add output layers to QGIS map canvas	Boolean	`True`

របៀបប្រើ

Open KGA Irrigation Tools > CSV to DEM and Contour.
Pick the Input Point CSV and an Output Folder.
Set the CRS – EPSG Code to the system the survey was recorded in. Getting this wrong is what puts the DEM in the wrong hemisphere.
Leave DEM Resolution at 0 for the first run and look at what the auto-detected cell size gives you.
Choose the Interpolation Method — IDW is the safe default for scattered survey points; Linear and Cubic assume a denser, more even sample.
Set the Contour Interval and press Run.

លទ្ធផល

In the output folder, named after the input CSV:

{name}_DEM.tif — the interpolated DEM as a GeoTIFF.
{name}_Contour_{interval}m.shp (or .gpkg) — the contour lines, when Generate Contour Lines is on.

Both are added to the map canvas when that box is ticked.

កំណត់សម្គាល់ និងដែនកំណត់

Requires numpy, pandas and scipy, all bundled with QGIS.
The EPSG code is the CRS the numbers are already in, not one to reproject to.
Smoothing changes the surface, not just the lines. A Gaussian σ of 1 is a light touch; raise it only if the survey is noisy, and remember the contours then no longer pass exactly through the surveyed elevations.
Cubic can overshoot beyond the range of the input points at the edges of the survey, producing elevations no one measured. Check the DEM's min and max against the CSV.
For a DEM you already have, or an area you want contoured straight from the free Copernicus DEM, use Generate Contour for ROI.

មើលផងដែរ

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