|of these articles treats the former province Punjab in British India, for other meanings sees Punjab (term clarifying).|
This concerns the largest closed irrigation area of the earth, which reaches the quadruple of the irrigation surface of the Nile (26,000 km ²) with an irrigation surface of 102.000 km ² nearly.
geographical concerns it the current level of the five left-sided Induszuflüsse Jhelum, Chenab , Ravi, Beas and Sutlej wedge-shaped approaching after southwest. The western delimitation of the Punjab is formed by the Suleimangebirge at the border to Afghanistan. Northward the salt rank and the Himalaya limits, to the south the desert Thar and eastward a low Wasserscheide to course - the low country for the Punjab. The area of the Punjab is formed mainly by quart eras washing subjects, which are appropriate for 10 to 15 meters over the lows.
Traditionally only the surfaces in direct proximity of the rivers in the early summer were watered, as the flood of the summer monsoon was led on the fields. During British colonial rule by the building by dams and channels the possibility was created of using by all-season irrigation surfaces lain also more highly agriculturally and of obtaining several harvests in the year.
In the year 1960 India and Pakistan in the Indus Water Treaty regulated the water use in the Punjab. Afterwards India may the upper runs of the rivers Ravi, Sutlej and Beas to its national territory lead away, must for the fact however surely provide that Pakistan has access to the water of the rivers Indus, Chenab and Jhelum. In order to make possible and prevent on the other hand inundations during the summer monsoon on the one hand an all-season irrigation, further dams and channels were put on.
The expansion of the irrigation country had serious ecological effects. By the all-season water supply the ground-water level rose strongly, so that expanded surfaces swampy. In the southern part of the Punjab the climatic conditions with high temperatures and strong evaporation lead however small precipitation (see climatic diagram Multan) to the salting of the soils. In the soil solved salts arrive with the capillary ascending of the water at the surface, where they settle and lead on a long-term basis to the Unfruchtbarkeit of the soil. By the plant of wells deep up to 100 m and evacuating the groundwater one tries to solve this problem.