Observation While Creating Layouts – Seasonal Data Quality

[abir]

While preparing my map layouts for the InVEST model outputs, I noticed a few interesting differences in the seasonal data.

For post-monsoon 2007, the river streams are not appearing properly in the output, which affects the visual representation and possibly the interpretation of the hydrological patterns. I observed a similar issue with 2017 data as well.

However, the pre-monsoon and monsoon datasets are looking very good, with well-defined river networks and clear spatial patterns.

I am attaching my layout maps for reference so the community can see these variations.
Would appreciate any insights on why the post-monsoon data for certain years might show incomplete or unclear stream networks, and if there are recommended preprocessing or parameter adjustments to improve this.

My logfile 2007-

InVEST-seasonal_water_yield-log-2025-07-02–20_50_55.txt (37.8 KB)

2017 -

InVEST-seasonal_water_yield-log-2025-07-02–20_26_07.txt (39.2 KB)

but all the other years of post monsoon well and good

[abir]

@megannissel @swolny @jesseG @esoth please guide me

[swolny]

It looks to me like the stream patterns are still there in the post monsoon maps, they are just much lighter, and harder to see than in the pre monsoon maps.

The User Guide describes how the quickflow values are assigned to streams:

Quickflow for pixels located in streams is set to the precipitation on that pixel, which assumes no infiltration, only runoff.

So perhaps the pre monsoon maps have lower values + patterns of precipitation that cause the streams to not stand out much compared with the surrounding landscape. If the underlying values look correct to you, you can consider trying different methods of symbology that enhance the difference between values, such as the stretch type, gamma or contrast enhancement (in QGIS).

~ Stacie