Natural water resources and Global/Regional Water Crisis ProfX C Wang School of Environmental Municipal Eng. Xian Univ of Architecture Technology
Natural Water Resources and Natural Water Resources and Global/Regional Water Crisis Global/Regional Water Crisis Prof. X. C. Wang Prof. X. C. Wang School of Environmental & Municipal Eng. School of Environmental & Municipal Eng. Xi ’an Univ. of Architecture & Technology Univ. of Architecture & Technology
1. Hydrologic Cycle of the World Hydrologic cycle- the movement of water between air sea, lakes and rivers. land soils, glaciers, and living organisms. Total water in the world-1. 8 m3 (enough to uniformly cover the entire earth to a depth of 2. 7 km) Ocean coverage-about 70%
1. Hydrologic Cycle of the World 1. Hydrologic Cycle of the World ¾ Hydrologic cycle – the movement of water between air, sea, lakes and rivers, land, soils, glaciers, and living organisms. ¾ Total water in the world – 1.4 x 1018 m 3 (enough to uniformly cover the entire earth to a depth of 2.7 km) ¾ Ocean coverage – about 70%
Solar Energy Air Mass Front Warm-Moist Rain Air Mass Snow ( Cold-Dry)Transpiration Transpiration Snow and Ice Evaporation Rain Transpiration t,线 Soil Moisture Rivers Soil Moisture Lakes Groundwater Ocean Groundwater Atmosphere 0. 035% of All Fresh Water The Hydrologic Cycle Horiz. Advection of 100 Units Precipitation Evaporation Water Vapor Evapo- Precipitation = Mean In transpiration on Lands Ann. Global O cean Ocean from Precip Surface Lands 85.7cm Runoff ean Worldwide Hydrologic Cycle
Worldwide Hydrologic Cycle Worldwide Hydrologic Cycle
Break down of water resources 97.2 of all water 2,8% of all water Rivers 0.03% Lakes Ice sheet 0.3% and Oceans Soil Moisture 0.06% Glaciers 75% Storage 97% of All Water of all fresh Groundwater(<760 m)11% Reservoirs later Groundwater(760-3800 m)14% Continents Oceans ( Percentages Refer to Fresh Water Total
Rivers 0.03% Soil Moisture 0.06% Lakes 0.3% Groundwater (< 760 m) 11% Ice Sheet and Glaciers 75% of All Fresh Water Groundwater (760 – 3800 m) 14% Storage Reservoirs Oceans Continents (Percentages Refer to Fresh Water Total) Oceans 97% of All Water Break down of water resources Break down of water resources 97.2% of all water 2.8% of all water
Characteristic Residence Time of water in Various Compartments of the Hydrosphere Atmosphere 9 days Rivers 2 weeks Soil moisture Months Large lakes 10 years Shallow groundwater Ten to hundreds of years Mixed layer of ocean 120 years World ocean 3000 years Deep groundwater Up to 10,000 years Antarctic ice cap 10,000 years
Characteristic Residence Time of Water Characteristic Residence Time of Water in Various Compartments of the in Various Compartments of the Hydrosphere Hydrosphere ¾ Atmosphere 9 days ¾ Rivers 2 weeks ¾ Soil moisture Months ¾ Large lakes 10 years ¾ Shallow groundwater Ten to hundreds of years ¾ Mixed layer of ocean 120 years ¾ World ocean 3000 years ¾ Deep groundwater Up to 10,000 years ¾ Antarctic ice cap 10,000 years
Atmospheric Water Vapor Solar E Precipitation 100% Evaporation 30 Water Table Hydrologic Cycle in a River basin
Hydrologic Cycle in a River Basin Hydrologic Cycle in a River Basin
2. Annual Precipitation Uneven distribution of rainfall throughout the world-10800 mm/yr at Cherrapunji, India 8690 mm/yr at Buena Vista, Columbia, but 30 mm/yr at Cairo, Egypt, 80 mm/yr at riyadh, Saudi arabia Uneven distribution of rainfall throughout China -1600-2200 mm/yr at Guangzhou and Hong Kong, but less than 80 mm/yr at Kashi Xinjiang
2. Annual Precipitation 2. Annual Precipitation ¾ Uneven distribution of rainfall throughout the world – 10800 mm/yr at Cherrapunji, India, 8690 mm/yr at Buena Vista, Columbia, but 30 mm/yr at Cairo, Egypt, 80 mm/yr at Riyadh, Saudi Arabia. ¾ Uneven distribution of rainfall throughout China – 1600-2200 mm/yr at Guangzhou and Hong Kong, but less than 80 mm/yr at Kashi, Xinjiang
Tibet At。cama australia LEGEND Semi-arid to Arid zone Scale Extreme arid zone World Arid Zones
World Arid Zones World Arid Zones
3. Quantity of Water Available and Global Water Crisis esh Water Groundwater Surface Wat accessible All Surface Fresh Water 2.8% Water Sources As a Percentage of Total Supply
3. Quantity of Water Available and 3. Quantity of Water Available and Global Water Crisis Global Water Crisis Water Sources As a Percentage of Total Supply Water Sources As a Percentage of Total Supply
Reasons for Water Shortage Low percentage of accessible water Unequal distribution of accessible water Rapidly rising demand with population Increase Pollution of water supplies close to urban areas
Reasons for Water Shortage Reasons for Water Shortage ¾ Low percentage of accessible water ¾ Unequal distribution of accessible water ¾ Rapidly rising demand with population increase ¾ Pollution of water supplies close to urban areas