The area of Iraq is 438,317 square km.
The population is (1997) 22,219,289 people.(
1)
This puts the overall population density at 51 people per square km.
Take into account that half of the country is mostly uninhabited, contrasted with the fact that large numbers of the populace fled urban areas during the war, and you get a populated area of about half of the whole country (
2)
22219289 / 219158 = 101 people per square km of inhabited country
So what if you wanted to map 100,000 dead?
100,000 / 219158 = 0.45 people per square km = less than 1 person per 2 square kilometers.
Take Baghdad alone. Population density of 950 people per square km (
3)
That means Baghdad is 5900 km (give or take, this is based on a combination of two of the above cites). If 100,000 deaths occured in Baghdad alone, you'd have 17 dead people per square kilometer, obviously clustered in areas that have been bombed.
These statistics are certainly trivial and not properly devised, but they illustrate (to me at least) that you wouldn't have buckets of blood flooding the streets, with 100,000 deaths.