Which of the following factors are responsible for the dispersal of human settlements?

1. Scarcity of water
2. High density of existing population
3. Low soil fertility
4. Fear of invasion

The factors that influence patterns of settlement are:

Economic and Human Influences Generally, the promise of material reward is the most important factor in human settlement. In this case, the interest in gaining more profit in proportion to labor exerted is central in dictating settlement patterns. These are necessary, but not sufficient causes of settlement. Parts of this variable include the promise of employment and a stable economy.

Physical Influences The physical environment is next in importance. In agricultural settlement, the nature of the soil and access to both water and transport are essential ingredients in making sense out of settlement patterns. But even further, things such as the safety and stability of the existing settlement is equally important. Besides, the existing density of population, if high, leads to dispersal of population.

Technological Influences A more specific consideration is the existence of well-established patterns of communication, transportation and markets, which are all central to this variable. To some extent, it is connected to the physical environment, as the technological makeup of the existing settlement exists as an adaptation to the nature of the topography and the availability of resources.

Historical Influences Ethnic compatibility, speaking the same language and the basic cultural forms of co-existence cannot be left out of this discussion. The historic nature of settlement speaks to the specific language and cultural norms that make up a society, making it easier for one that shares these to fit in, and discouraging strangers. This not only makes it easy for similar settlers to fit in, but also makes the community more and more cohesive. Fear of foreign invasions to an area leads to migration to safe places.