Table. Zones of natural drainability

1. Intensively drained

deep ground water flow moving with different speed

100-300 m in loams, 500-700 m in pebbles

ultrafresh in all climatic conditions

> 50-10 (on irrigated canals)

do not participate, automorphous soils.

pre-mountain trains and upper parts of cones of withdrawal made of pebble-strongly corrugated pre-mountain planes and alluvial terraces, high river shelves made of loamy sediments

2. Drained

ground water flow moving with speed of >100-200 mm/day

300-500

the same

different on irrigated lands от 4-5; in humid zones more than 3

shallow table causing water lagging

alluvial terraces, ground water seepage zones, made of pebble with loamy soil

3. Slightly drained

slow ground water flow 25-100 mm/day.

150-300

fresh in humid climate brackish in arid climate

different on irrigated lands 0-3-4 m in humid regions 1,5-3 m.

shallow table causes water logging in arid climate slight salinization

middle and lower river terraces, central parts of cones of withdrawal made of sediments with loamy top soil, thickness 50-10 m. middle and lower river terraces

4. Very slightly drained

very slow flow - 5-25 mm/day

50-150

fresh in humid climate, saline in arid climate, salinity grows from steppe to desert

different on irrigated lands 0 до 2-3;

in humid regions <1.0-1.5 m

shallow table caused water -logging in arid climate, soil salinization

broad river terraces, watershed, pre-mountain planes, river deltas, depessios between cones, lake and lake-glacial planes made of thick loamy sediments underlain by sandy or sand-clayey deposits.

5. Without outflow

ground water basin <5 мм/day

<50

then same

different on irrigated lands- 0 -1-3; in humid regions <0.5-1 m

then same

modern and ancient river deltas, pre-mountain-sea depressions, sub-aeral deltas, plain planes, lake-glacial planes made of clayey sediments underlain by sands, sand clayey deposits or bedrock