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