If animals eat grass in a pasture to a certain level, grass will grow again and provide food for animals in the future, as long as the carrying capacity of the land is not exceeded by the pressure of too many animals. Flow resources, such as water, wind, and sunlight, are neither renewable nor nonrenewable because they must be used as, when, and where they occur. The energy in a river can be used to generate electricity, which can be transmitted over great distances. However, that energy must be captured by turbines as the water flows past or it will be lost. The location of resources influences the distribution of people and their activities on Earth.
People live where they can earn a living.
Human migration and settlement are linked to the availability of resources, ranging from fertile soils and supplies of freshwater to deposits of metals or pools of natural gas. The patterns of population distribution that result from the relationship between resources and employment change as needs and technologies change. Technology changes the ways in which humans appraise resources, and it may modify economic systems and population distributions. Changes in technology bring into play new ranges of resources from Earth's stock. The population of the Ruhr Valley in Germany, for example, grew rapidly in response to the new importance of coal and minerals in industrial ventures.