What causes the TSS drop down suddenly?

I opened the cohesive sediment module to simulate TSS (Total Suspended Solids). However, throughout the whole lake domain, the simulated TSS all decreased dramatically and suddenly in around May, and they never increased in the following months (Figa). The TSS boundary condition of inflows do not have this pattern. Also, I generated the sediment bed with all parameters stay default. What I am confused is that what the simulated result so strange? Although I haven’t calibrated sediment module, why did TSS concentration have such a strange pattern? Please tell me what you think, which will be very helpful for me in the next step.
a-3.jpg

I guess it’s because I didn’t open Wave module. However, when I open Wave Module (Internal Wave Model), simulated TSS became very high (Fig-b). Could someone give me some advice?

hi there,I recommend you to take a look to this Webinar on Tra Khuc Sediment Transport simulation. Model Build Process Pt 2. - Tra Khuc Sediment Transport - YouTube is not just simply turn on the sediment model and apply to the study case. You have to understand about your site areas soil characteristics as well as some critical shear stress relates to the erosion and deposition processes. Hope this helps.