VLOOKUP is an Excel function to lookup and retrieve data from a specific column in table. This function is lookup a value in a table by matching on the first column. The syntax of the function as follows:

=VLOOKUP (value, table, col_index, [range_lookup])

value – The value to look for in the first column of a table.

table – The table from which to retrieve a value.

col_index – The column in the table from which to retrieve a value.

range_lookup – [optional] TRUE = approximate match (default). FALSE = exact match.

It is very useful, especially in hydrology when you need to rearrange the data based on something (For example, when rearrange rainfall/discharge time series). Here some example:

1- We want to find the state for each station ID (right side of the picture) based on the list of detailed station (left side).

2- Just use and type of the function.

=VLOOKUP (value, table, col_index, [range_lookup])

value = **station ID** ( The value to look for)

table = **list of detailed station** (the table from which to retrieve a value).

col_index = **no of column. In here, we want to retrieve a value from the state column.**

range_lookup = **TRUE** (approximate match)

3 – You can retrieve the value after completing the formula. Simple! You can complete the rest of the empty cell.