Error in lake incorporation
Swetasree Nag
I am seeking guidance regarding the following problem-
How can I add such small waterbodies into the gridded model as these are not generating any grid lakes. If I manually try to add lake cell then I am getting this following python error.
Please guide me in this regard.
Note
1. My study area is 830 sq.km
2. It has more than 1500 waterbodies from very tiny pond to big reservoirs
3. Have tried with creating more finer grids (like 30sqm as my DEM has 30m resolution) but it increased the number grid cells and HRUs which cant be processed at the later stage
4. My target is to incorporate every waterbodies into the model to observe their routing process for flood/drought mitigation
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Chris George
resample your DEM. But basically you cannot avoid the problem that
these water bodies are too small to incorporate effectively in a model
dependent on a DEM with this resolution.
As to the Python error, check that your lake file's RES field only has
integers in it.
Chris
On 7/10/2025 6:50 AM, Swetasree Nag wrote:
> Hi all, I am seeking guidance regarding the following problem- How can I
> add such small waterbodies into the gridded model as these are not
> generating any grid lakes. If I manually try to add lake cell then I am
> getting this following python
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Swetasree Nag
Thank you for your response.
Resampling the DEM or using a finer grid resolution does indeed result in a significantly larger number of grid cells, ultimately leading to an unmanageable number of HRUs and subbasins. For example, at a 30 × 30 m resolution, the model ends up generating more than 5 million HRUs (even with the Dominant HRU option), which becomes computationally infeasible.
Given this limitation, is there an alternative way to incorporate small waterbodies—those smaller than the grid cell size—into the model? Perhaps by representing them as wetlands or detention ponds without requiring direct stream connectivity?
Regarding the Python error:
The issue only arises when I manually add lake cells that cover less than 50% of a grid cell area. However, I have ensured that the RES field contains only valid integer values.