Impact of human activities of the Hydrological Cycle

• Deforestation: increases run off, increases potential soil erosion, decrease in transpiration (cloud formation impacts local rainfall patterns), may lead to more extreme river flows as water not being intercepted by tree roots.
• Irrigation: Taking water from ground water storage or river can reduce river flow, lowers water tables and increase evaporation/transpiration by placing water in surface stores e.g. ditches and canals, increased farming opportunities because irrigating crops removes water from the hydrological system as they grow.
• Urbanisation: Removes vegetation and replaces it with impermeable concrete and drains, speeds up overland flow which leads to higher river levels, more concrete increases rate of evaporation from these surfaces as rate of percolation through land surface decreases, reduces amount of water returning to ground storage possibly reducing water table.
• Mining: Silting up of lakes, rivers and reservoirs reduces water storage capacity in these areas, mining also leads to reduced vegetation cover which increases run off and higher evaporation and cloud formation altering the rain fall pattern.