Groundwater (why are groundwater reserves important? (source of approx.…
why are groundwater reserves important?
source of approx.
33% water in the country
42% irrigation water
comes from groundwater as it contains nitrates and phosphates
can be used to
Thames basin groundwater - 300 public supplies sources
Human activity affecting groundwater
pollutant groundwater in City of Merida, Mexico.
Population over half a million, obtain water from bore holes outside the city, with no sewage or storm water drainage.
renewable resource as too many people rely on it
hydrostatic uplift and swelling pressures on foundations and structures
water tables in London has risen by as much as 20m.
Reduced long term viability of irrigated agriculture in the High Plains of Texas.
irrigation began in 1930s, declining water levels by u to 50m
of groundwater if irrigation leaches out of salts present in soil and unsaturated zones
Kathmandu Valley, Nepal
40% of water supply lost through old broken pipes
absence of strict regulatory mechanisms lead to exploitation of groundwater use.
conservationists delayed sandstone mountains which encircle the valley as an official protected area