Waterlogging refers to soil saturation from high water tables, preventing air and oxygen flow needed by crops. It is caused by over-irrigation, inadequate drainage, flooding, and high water tables during monsoons. Waterlogging can be permanent, periodic, or temporary, and often leads to soil salinization in irrigated areas due to prevented leaching of salts. Major waterlogged areas in Bangladesh include wetlands, floodplains, coastal areas, and areas with artificial irrigation. Waterlogging hampers soil microbial activity, reduces nutrient availability, increases soil pH, and favors weed growth. Reducing measures include dams, embankments, and bridges/culverts to restrict water flow.

2. INTRODUCTION
 Water-logging refers to the saturation of soil with water. Soil may be
regarded as waterlogged when the water table of the groundwater is too
high to conveniently permit an anticipated activity, like agriculture.
 In agriculture, various crops need air (specifically, oxygen) to a greater
or lesser depth in the soil. Water-logging of the soil stops air getting in.
How near the water table must be to the surface for the ground to be
classed as waterlogged, varies with the purpose in view. A crop's
demand for freedom from water-logging may vary between seasons of
the year, as with the growing of rice (Oryza sativa).
 In irrigated agricultural land, water-logging is often accompanied
by soil salinity as waterlogged soils prevent leaching of the salts
imported by the irrigated water.
 From a gardening point of view, water-logging is the process whereby
the soil blocks off all water and is so hard it stops air getting in and it
stops oxygen from getting in.

3. Looking over the shoulder of a Peruvian farmer in the Huarmey delta
at waterlogged and salinised irrigated land with a poor crop stand. This
illustrates an environmental impact of upstream irrigation developments
causing an increased flow of groundwater to this lower-lying area, leading
to adverse conditions.

4. CAUSES
 · Over irrigation.
 · Canal irrigation in areas adjoining agricultural lands where
subsoil water table steadily rises.
 · Inadequate drainage.
 · Surface flooding.
 · Presence of high water table.
 · During monsoon & soon after some areas remains totally
submerged by the discharge of the rivers & accumulation of
runoff from the surrounding catchment.
 · Water logging conditions are also caused in depressions along
roads, canals & railway sides during rainy season.
 · Sea water comes to a particular area during high tidal surges.

5. TYPES OF WATER LOGGING
 1) Water logging due to permanent submersion of land.
Such as ponds, rivers, etc.
 2) Water logging from periodical submersion such as
coastal & estuarine land inundation by soil water or runoff
of freshwater over lands etc.
 3) Temporary water logging by stagnation of water as a
result of heavy rainfall.
 4) Water logging by coming out of water table to the
surface & swampy areas in valleys are mostly caused by the
phenomenon.
 5) Water logging from artificial irrigation of agricultural
lands in polders areas.

6. MAJOR WATER LOGGED AREAS
 · The chanal Beel in Natore.
 · The Haor basin, the eastern part of Sylhet,
Mymensingh & Moulovibazar.
 · The Kaptai Lake in Chittagong.
 · Riverine flood plains of Ganges, Brahmaputra,
Meghna, Tista & other small rivers of the country.
 · Haors, Beels, baors & other natural & artificial ponds.
 · The coastal areas of Chittagong, Cox are Bazar,
Noakhali, Patuakhali, Barisal & the Sunderbans.

7. PROBLEMS DUE TO WATER
LOGGING
 · It creates anaerobic condition in soils for which
microbial activity is hampered.
 · The availability of nutrient elements in soil is reduced
& leaching loss is higher.
 · Increases soil pH in coastal & dry area which leads
salinity & alkalinity.
 · Pollutes soil water & favors excessive weed growth.

8. MEASURES TO REDUCE IT
 · Construction of dams & embankments along the
coast to restrict saline to enter the agricultural lands.
Could be an effective measure of reducing the water
logging.
 · Providing adequate number of bridges & culverts,
along the roads, railroads, highways, across the canal
etc could be a handy measure against water logging.

9. THANK YOU