If you get error messages like below, you come to the right place.
It means you are trying to write more data than the data table can hold. For example, you will get this message if trying to write string “I’m a long string” to a text field that could be 4 letter long.
It seems ArcSWAT don’t check the length of the data against the maximum length of the field when writing those data tables. Whenever you have a longer string, you will get this error message.
Solution is simple: either make your string shorter or increase the length of those fields. As we don’t want to change our data, the latter is better. But how?
The secret is in SWAT2012.mdb. It has tables with name like ***rng, e.g. solrng and hrurng. These tables defines the structure of those data tables we need in our project database, including the maximum length of a text field. Take table solrng as example as shown below. Each row defines one column in table sol. Amost of all these columns, SOIL is defined as TEXT(4) which means it’s a text column and could have maximum length of 4 letters. The column SOIL, SLOPE_CD and SNAM is similar.
Below is a list of these template tables and the corresponding table in project database. As you could see, most of the tables in project database is generated based on their template tables.
|Template Table in SWAT 2012||Corresponding Data Table in Project Database|
You may have know the solution of the error. Yes, we could increase the length of the text fields by changing their definition, i.e. change TEXT(4) to TEXT(n) where n is a number that big enough to hold all possible strings, say 100. We could usually get which table has problem, like the one we give at the beginning. It says the sol table has problem. So we go to the solrng table and increase the length limitation of all possible text columns and then try to write the data table again. If you don’t want to guess which column should be changed, just change all of them to 100. It should be good enough for most of the case.
Hope you find this helpful and happy SWAT modelling.