Diffusion, its types and specific barriers to diffusion that might have developed

Diffusion, its types and specific barriers to diffusion that might have developed Diffusion is a process of distributing aspects of a culture to another area or people (Geo 171 Slide 5). It is important to acknowledge that diffusion is not limited to the transfer of cultural aspects because it also involves diseases such as cholera. There are four types of diffusion namely contagious, relocation, hierarchical and stimulus (Geo 171 Slide 6). Contagious diffusion corresponds to the quick and widespread transfer of a characteristic throughout a population. It usually starts with a single person and moves throughout the population in a swift manner. People usually embrace the idea or disease at a similar time making it contagious. Relocation diffusion entails the spread of an idea or disease through physical movement. Stimulus diffusion entails the spread of underlying ideology though the idea itself may fail to transfer. Hierarchical diffusion focuses on transfer of ideas from major sources of authority to minor ones.
An examination of the cholera situation by Pyle illustrates diffusion based on two modes. The first is geographical because the causative agents moved over space (Pyle 59). The approach focuses on the frictional effects associated with distance. The second major diffusion mode is hierarchical that involves movement of the causative agent from large urban areas to small urban areas.
The barriers to diffusion include absolute, permeable and transformative (Geo 171 Slide 6). The absolute barrier is associated with the immovable and infinite nature of space. Permeability may support or hinder diffusion by controlling its entry into an organism or society. Decreased permeability limits diffusion. Transformative barriers are evident in the inability of a diffusing agent to adapt to new environments.
The patterns of diffusion of cholera in the US changed because of the evolving transportation network (Pyle 74). For example, in 1832, the transportation network was crude. In addition, the people were in close contact with the environment. In 1849, the disease moved down the urban hierarchy. In 1866, the size of the city played a crucial role in spread of disease (Pyle 74).
Works Cited
Geo 171. Culture and Diffusion. 2015. Print
Pyle, Gerald. The Diffusion of Cholera in the United States in the Nineteenth Century.
Geographical Analysis 1 (1969): 59–75. Print