Explain hydrological drought, and the causing factors.

Hydrogical drought, is the reduction of water in all elements of the hydrological cycle, which hopefully you have studied before. This reduction of water, means not only less water flowing through our rivers and stored in lakes, but also lowered levels of groundwater flow. This causes effects including reduced crop productivity in farms, and lowers levels of water for human consumption.

Hydrological drought is not only caused by physical factors, but also is the product of human influence. The main physical factor effecting hydroloigcal drought is climatic variability, higher temperatures (drying out the ground), and lowered levels of precipitation (less moisture fed into stores). The second physical factor is how good the river catchment is at storing and catching the water, if a catchment is particularly impermeable hydrological drought is more likely to occur. Human factors include moving water out of a catchment for use and secondly increased landuse, which means increased runoff and rapid evaporation.