"SOIL SEALING A PROSPECT OF STARVATION (FOR SOIL BUGS) AND FLOODING (FOR US)"

Transcription

1 "SOIL SEALING A PROSPECT OF STARVATION (FOR SOIL BUGS) AND FLOODING (FOR US)" Presented by Juraj Kohutiar NGO People and Water, Slovakia (in cooperation with ENKI, Czech Republic)

2 SOIL SEALING AND WATER CYCLE

3 FRESHWATER STOCKS ON EARTH

4 SOIL SEALING - PAVEMENT Free surface Paved surface Pavement impact: infiltration decreases (groundwater recharge decreases) evaporation decreases (air humidity decreases) runoff increases (through sewage to rivers and sea)

5 SOIL SEALING IN CITIES about 20 billion m3 of rainwater sluiced from municipalities of Europe annually

6 SOIL SEALING BY DEFORESTATION AND AGRICULTURE Deforestation / some forms of farming cause: increase of runoff (and erosion) lower infiltration (groundwater recharge) lower evaporation (change of regional climate)

7 WATER BALANCE OF THE INVESTIGATED TERRITORY Precipitation (mm/ year) Volume of water circulating Runoff (indicator of soil sealing) Europe km3 36 % Slovakia km3 34 % Prešov, SK (City center) mil. m3 72 % Plot of land 630 0,5 mil. m3 37 % Residential house m3 76 %

8 RUNOFF FROM URBAN AND FOREST ENVIRONMENTS Decrease of runoff is overlooked flood prevention measure

9 SOIL SEALING DESTROYS SMALL WATER CYCLE(S) ON LAND

10 EARTH WATER BUDGET Evaporation km³/year Atmosphere Precipitation km³/year Evaporation km³/year Precipitation km³/year Land Oceans Runoff km³/year There is more water in small water cycle than in large water cycle!!!

11 SOIL SEALING AND ENERGY FLOWS

12 VALUES OF SOLAR RADIATION on a clear day and on a cloudy day (recorded on 18 July 2006 and 3 August 2006, in Třeboň, Czech Republic).

13 THE DISTRIBUTION OF SOLAR ENERGY IN VEGETATION Rg global radiation, Rn net radiation, a albedo (reflected radiation), H sensible heat, L E latent heat x evapotranspiration s flow of heat to the soil, B accumulation of heat in the biomass, P consumption of energy for photosynthesis

14 THE DISTRIBUTION OF SOLAR ENERGY ON SEALED SOIL H s H Rg global radiation Rn net radiation a albedo (reflected radiation) H sensible heat s flow of heat to the soil

15 PHOTOES OF VEGETATION IN INFRARED AND VISIBLE SPECTRUM The cooling effect of transpiration is much stronger in comparison with the effects of reflectance.

16 TEMPERATURES ON THE LAND WITH AND WITHOUT WATER

17 A TREE AS AN AIR-CONDITIONING UNIT a crown of 10 m in diameter evaporates 400 l/day consumes 280 kwh (of solar energy) cools with a power comparable to that of more than 10 airconditioning units

18 PHOTO OF A CITY SQUARE - INFRARED CAMERA The cooling effect of evapotranspiration is much stronger in comparison with the effects of reflectance.

19 HOT CLIMATIC UMBRELLA OF A CITY Soil sealing resulting in the lack of evapotranspiration in urban areas is the main reason of urban heat island effects.

20 DISTRIBUTION OF SOLAR ENERGY ON LAND WITH AND WITHOUT WATER Most solar energy is changed into sensible heat in a dry land, most solar energy is consumed in phase change in a wet land.

21 SATELLITE INFRARED PHOTOGRAPHS OF REGIONS WITHOUT AND WITH SUFFICIENT WATER Higher temperature differences are in Mostecko with damaged vegetation (left), than in Trebonsko (right) covered by ponds and wetlands.

22 SOIL SEALING AND CLIMATE CHANGE

23 IMPACTS OF SOIL SEALING ON PRECIPITATION Rising air flows push precipitation away to colder and more humid areas

24 PRECIPITATION IN MOUNTAINS AND LOWLANDS DANUBE WATERSHED

25 On Tuesday, July 22d [1494], he [Christopher Columbus] departed for Jamaica. The sky, air, and climate were just the same as in other places; every afternoon there was a rain squall that lasted for about an hour. The admiral writes that he attributes this to the great forests of that land; he knew from experience that formerly this also occurred in the Canary, Madeira, and Azore Islands, but since the removal of forests that once covered those islands they do not have so much mist and rain as before. /Christopher Columbus biography by his son Ferdinand/

26 GROWTH OF EXTREME WEATHER WITH DECLINE OF SMALL WATER CYCLE The less water soil sealing allows in small water cycle, the more frequent and more severe are extremes of weather

27 DESTRUCTION AND RENEWAL OF SMALL WATER CYCLE There is a hope of recovery by returning the lost water back to the land.

28 RAINWATER HARVESTING FROM ROOFS IN CITIES

29 RAINWATER HARVESTING EXAMPLES Rainwater harvesting moderates microclimate, erosion, floods, droughts, fires and enhances water sources and biodiversity.

30 SUMMARY

31 Old water paradigm New water paradigm protects surface water as the main source and reserve of water protects groundwater and soil water as the main treasure of water

32 Old water paradigm New water paradigm soil sealing has minimal impact on the water cycle soil sealing has a fundamental impact on the water cycle soil sealing has minimal influence on global warming soil sealing may be important factor in global warming

33 Old water paradigm New water paradigm vegetation is not ideal from the point of global warming (low albedo) water and vegetation alleviate unwanted temperature differences; rainwater is an inconvenience, needs to be quickly removed rainwater is an asset that needs to be retained (especially in soil/plants)

34 THANK YOU! MERCI! DANKE!