Mark the urban area where there’s shortage (8)
I believe the answer is:
scarcity
'shortage' is the definition.
(thesaurus)
'mark the urban area' is the wordplay.
'mark' becomes 'scar' ('scar' can be a synonym of 'mark').
'the urban area' becomes 'city' (city is a kind of urban area).
'scar'+'city'='SCARCITY'
'where there's' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for scarcity that I've seen before include "Something uncommon" , "Want" , "Shortness of supply" , "Lack - dearth" , "Poverty" .)