Water Users Association and Irrigation Management - Institute for ...

as they severely limit the choice of crops, reducing crop diversity and adversely affecting
the diets and nutritional status ofthe rural people.
Evidences are available extensively on the extent and severity of the problem and the many
indirect ill effects associated with it. The direct environmental consequences of abandoned
land due to soil salinity and waterlogging problems is that, it creates a demand for more
new land to be brought under cultivation. Despite the knowledge gained through the
centuries regarding salinity and waterlogging and its deleterious etlects, it continues to
remain as a serious problem in present day irrigated areas. The following section examines
various factors that foster the advent of waterlogging and salinity.
Factors contributing to irrigation induced salinity and waterlogging
Although salinity and waterlogging is a technical problem, most of the time it is essentially
human-induced. The factors contributing to the existence of waterlogging and salinity are a
complex web of technical, economic, political and social elements. It is caused by the
interaction of a large number of factors such as groundwater recharge, drainage, over
irrigation, cropping patterns, groundwater pumping for irrigation, soil characteristics,
seepage from channels and distributaries (Bowonder & Ravi 1984).
Canal irrigation particularly in the arid and semi-arid areas, has been widely viewed as the
major cause for waterlogging and salinity. Introduction of irrigation in any area inevitably
results in a disturbance of the ground water balance that existed prior to irrigation. Because
of seepage from the water conveyance system and deep percolation losses from the field
during irrigation, the rate of recharge of the ground water increases, resulting in the
progressive rise of the water table which, if unchecked, leads to waterlogging and salinity
in irrigated lands.
Thus, canals, which seemed to be a solution for scarce water supply for crops and other
uses, became a reason for land degradation. Large areas in the region commanded by the
irrigation canals and their distributaries are increasingly becoming waterlogged and saline
necessitating massive rehabilitating programs. Nonetheless, an attempt is made to look at
some of the contributing factors of salinity and waterlogging in detail.
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