This is an usual Fortran error, which means that the dimension of array IDOP is 1000 and that you tried to address IDOP(1002).

If you have the fortran sources of SWAT, your may try to increase the dimension of IDOP (and to compile again SWAT). Otherwise your might be interested to the answer given in https://groups.google.com/g/arcswat/c/2XuPwAnEPgQ

Best

Pierre

Hi, if you would like, you could join the Iranian Telegram group for the SWAT model and ask there too:

https://t.me/SWATMODEL

Hi, the problem came from the tillage management operation in SWAT (I’m certain of this), and it is likely related to the operation timing (I’m not 100% sure). Here are two possible causes for the error, and I suggest you test them out so you can narrow down to the real cause.

1. If you edited the tillage operation in SWAT (I assume you use the ArcSWAT), then however you edit it, that most likely caused this problem. In this case, double check the way you edit the operation to see if there’s anything unreadable and/or problematic. Refer to the theoretical manual and input-output manual of SWAT for details on this.

2. If you never touched the operation setting itself, my best guess is that there’s something wrong with you land cover input. In this case, use another LC product other than the one you‘re using, and create a new ArcSWAT simulation file while keeping everything else the same as before. See if the problem goes away.

You can ask me again if neither option works.