1. Punjab has a network of canals for irrigation. Many of them are unlined. The water seeps through such canals and causes water-logging in the neighboring fields. The problem is further aggravated (forced) sometimes by intense (strong) rainfalls.
2. Also in the areas where the canal water is used excessively for irrigation. Soils become waterlogged. The salts in the soil and sub-soil get dissolved in water and during evaporation reach the surface due to capillary action.
3. A layer of these salts covers the topsoil rendering (expose) it fertile.
4. Thus, in some areas, water-logging is accompanied by the formation of alkali soil, which is unfit for cultivation.
5. This is how the Punjab region is affected by salinity.
