Better Farming Series 28 - Water: Where Water Comes from (FAO, 1981, 31 p.): Water on the surface: Groundwater can become surface water

Better Farming Series 28 - Water: Where Water Comes from (FAO, 1981, 31 p.)

(introduction...)

Preface

Why we study water

(introduction...)

Rainfall

Water In the ground

The water table

Water on the surface

Evaporation

Transpiration

The process begins again

When rain falls

(introduction...)

How much rain falls

Kind of soil

Slope of the land

Plants

Water in the ground

(introduction...)

Water and the soil

Water and the subsoil

Water and parent rock

Where to find water in the ground

(introduction...)

Wells

Springs

Water on the surface

(introduction...)

Groundwater can become surface water

Surface water run- off

Where to find surface water

(introduction...)

Swamps, pond and lakes

Streams and rivers

87. When it rains, water sinks into the ground and mixes with the water already in the ground.

88. When there is more water in the ground, the water table becomes higher.

89. If the land is low and the water table is high enough, it may lie above the surface of the ground. Then there is more surface water.

Water lies above the surve of the ground

90. When it does not rain, there is less water in the ground and the water table becomes lower.

There is less water in the ground

91. Then there will be less surface water. This can be seen in dry times in swamps, lakes and streams.

92. The effect of groundwater on surface water is hard to see for it happens very slowly.

The effect is hard to see