In the rural areas of the alluvial plain and in the lower Diyala region, settlement almost invariably clusters near the rivers, streams, and irrigation canals. The bases of the relationship between watercourse and settlement have been summarized by Robert McCormick Adams, director of the Oriental Institute of the University of Chicago. He notes that the levees laid down by streams and canals provide advantages for both settlement and agriculture. Surface water drains more easily on the levees' backslope, and the coarse soils of the levees are easier to cultivate and permit better subsurface drainage. The height of the levees gives some protection against floods and the frost that often affect low-lying areas and may kill winter crops. Above all, those living or cultivating on the crest of a levee have easy access to water for irrigation and household use in a dry, hot country.

Although there are some isolated homesteads, most rural communities are nucleated settlements rather than dispersed farmsteads that is, the farmer leaves his village to cultivate the fields outside it. The pattern holds for farming communities in the Kurdish highlands of the northeast as well as for those in the alluvial plain. The size of the settlement varies, generally with the volume of water available for household use and with the amount of land accessible to village dwellers. Sometimes, particularly in the lower Tigris and Euphrates valleys, soil salinity restricts the area of arable land and limits the size of the community dependent on it, and it also usually results in large unsettled and uncultivated stretches between the villages.

Fragmentary information suggests that most farmers in the alluvial plain tend to live in villages of over 100 persons. For example, in the mid-1970s a substantial number of the residents of Baqubah, the administrative center and major city of Diyala Governorate, were employed in agriculture.

The Marsh Arabs (the Madan) of the south usually live in small clusters of two or three houses kept above water by rushes that are constantly being replenished. Such clusters often are close together, but access from one to another is possible only by small boat. Here and there a few natural islands permit slightly larger clusters. Some of these people are primarily water buffalo herders and lead a seminomadic life. In the winter, when the waters are at a low point, they build fairly large temporary villages. In the summer they move their herds out of the marshes to the river banks.

The war has had its effect on the lives of these denizens of the marshes. With much of the fighting concentrated in their areas, they have either migrated to settled communities away from the marshes or have been forced by government decree to relocate within the marshes. Also, in early 1988, the marshes had become the refuge of deserters from the Iraqi army who attempted to maintain life in the fastness of the overgrown, desolate areas while hiding out from the authorities. These deserters in many instances have formed into large gangs that raid the marsh communities this also has inducaa9 uced many of the marsh dwellers to abandon their villages.

The war has also affected settlement patterns in the northern Kurdish areas. There, the persistence of a stubborn rebellion by Kurdish guerrillas has goaded the government into applying steadily escalating violence against the local communities. Starting in 1984, the government launched a scorched-earth campaign to drive a wedge between the villagers and the guerrillas in the remote areas of two provinces of Kurdistan in which Kurdish guerrillas were active. In the process whole villages were torched and subsequently bulldozed, which resulted in the Kurds flocking into the regional centers of Irbil and As Sulaymaniyah. Also as a military precaution, the government has cleared a broad strip of territory in the Kurdish region along the Iranian border of all its inhabitants, hoping in this way to interdict the movement of Kurdish guerrillas back and forth between Iran and Iraq. The majority of Kurdish villages, however, remained intact in early 1988.

In the arid areas of Iraq to the west and south, cities and large towns are almost invariably situated on watercourses, usually on the major rivers or their larger tributaries. In the south this dependence has had its disadvantages. Until the recent development of flood control, Baghdad and other cities were subject to the threat of inundation. Moreover, the dikes needed for protection have effectively prevented the expansion of the urban areas in some directions. The growth of Baghdad, for example, was restricted by dikes on its eastern edge. The diversion of water to the Milhat ath Tharthar and the construction of a canal transferring water from the Tigris north of Baghdad to the Diyala River have permitted the irrigation of land outside the limits of the dikes and the expansion of settlement.

Data as of May 1988