Water Resources in the Tropics

Vocabulary flashcards covering the hydrological cycle processes, water stores, water budget equations, surface permeability, and flood types based on the lecture material.

Water stores

Places where water is contained in, categorized into freshwater stores (glaciers, rivers, lakes, groundwater, soils) and saltwater stores (oceans).

Soil

The loose topmost layer of Earth's surface where plants grow.

Pores

Small openings in the soil through which water passes into the ground due to gravity.

Soil moisture

Water that is stored in the soil.

Groundwater

Water found below the surface of the Earth, formed when water makes its way to the rocks beneath, filling up their pores and cracks.

How is groundwater formed?

A part of the water in the soil makes its way to the rocks underneath, filling up the pores and cracks of these rocks.

Hydrological Cycle order

1. Precipitation (rain or snow)

2. Groundwater (water seeps into the ground, absorbed by plants or stored as groundwater)

3. Surface Runoff (water flows from the highlands and over the ground surface into streams and rivers)

4. Evaporation (water changes into water vapour due to the Sun’s heat)

5. Transpiration (plants give out water vapour through their leaves)

6. Condensation (warm moist air cools as it rises, water vapour changes into water droplets, smaller droplets coalesce and gather to form clouds)

Evaporation

The process of water changing from liquid to gaseous state.

Transpiration

The process by which water is lost through the surface of a plant.

Condensation

The process of changing from a gaseous state to liquid state.

Precipitation

Water that falls from clouds towards the ground as rain or snow.

Infiltration

The process by which water enters the ground or soil.

Percolation

Downward flow of water through soil into the groundwater due to gravity.

Throughflow

Lateral (sideways) flow of water through soil layers.

Surface runoff

Water that travels over the surface of the ground to reach streams and rivers.

Groundwater flow

Very slow movement of water through saturated rock below the water table.

Water budget

An equation describing the flow of water in and out of a catchment area.

Inputs (Water budget)

Processes that increase the amount of water in a catchment area.

Outputs (Water budget)

Processes that decrease the amount of water in a catchment area.

Water surplus

A condition in a catchment area where $\text{Input} > \text{Output}$.

Water deficit

A condition in a catchment area where $\text{Input} < \text{Output}$.

Drought

A long period of little or no rainfall in a specific area, causing water stores such as reservoirs and groundwater to dry up.

Flood

An overflow of a large amount of water onto what is normally dry land.

River floods

Floods typically caused by sustained heavy rainfall or spring meltwater, causing water levels to rise and overflow river banks; usually occurring in rural areas.

Flash floods

Floods that take place suddenly and last for a short period of time due to sudden intense rainfall exceeding drainage system capacity; usually occurring in urban areas.

Permeability

The ease with which water can infiltrate or seep into the ground.