By 1972, sand dunes had increased in height by as much as 5 meters and the water productivity of wells was declining. Increased population and demand for animal products lead to overgrazing. Herd sizes increase and put pressure on grazing lands, which, at the same time, are decreasing because of overcultivation. Such overgrazing has several effects. Replaces perennials with annual species that are short-lived and do not hold soil against erosion.
Compacts soil under trampling hoofs at water holes and in wet season pastures.
Destabilizes dunes when crest vegetation is eaten. Salinization and alkalinization occur when poor irrigation practices waterlog the soil and allow salts to come to the surface or be carried in by the water when the lack of drainage fails to leach them away. Salinization also occurs around river estuaries when overuse of wells lowers the water table and allows coastal salt and brackish water to infiltrate. A major problem in Bangladesh is caused by a backflow of salt water into river systems, which cover about 38 per cent of the country, where 33 percent of the population lives. Deforestation leading to flooding also causes an increase in the concentration of salts in estuarine and other floodplain areas.