Lecture Series in Water, Soil and Atmosphere ( ) Unit 1: Interaction Soil / Vegetation / Atmosphere

Transcription

1 Dept. Water, Soil & Atmosphere Institute of Hydraulics and Rural Water Management University of Natural Resources and Life Sciences Vienna Lecture Series in Water, Soil and Atmosphere ( ) Unit 1: Interaction Soil / Vegetation / Atmosphere Willibald Loiskandl 1

2 Introduction Mission Statement The Institute of Hydraulics and Rural Water Management is focusing specifically on the part of the water cycle where the water gets in contact with the soil. Since water is fundamental to all life, it is our mission to maintain its various functions in an optimum and sustainable manner and to safeguard its use and protection.

3 Introduction Rural Water Management Definition Land Management Every planning and activity to design and use given natural potential efficiently and to maintain vital life conditions sustainably Water Resources Management Management of Surface- and Groundwater resources

4 Introduction Content Definition saturated/unsaturated zone Working environment Water in Soil Soil water management Soil processes Water and solute movement Monitoring/ Measuring concepts SPAC, Soil-Water-Plant Relationship Applied Soil Physics Analyses of soil physical and chemical properties in the field and laboratory.

5 Saturated/Unsaturated Hydrology: Science dealing with the distribution and movement of water Water resource: Management and use of water Water management: water for human uses and environmental requirements Soil physics: Emphasise on the state and transport of matter (especially water) and energy in the soil. unsaturated zone Hydrologic (water) cycle: Water from precipitation until it has been returned to the atmosphere by evaporation and is again ready to be precipitated!

6 Saturated/Unsaturated Saturated zone ground water flow Input: Percolation water from unsaturated zone, baseflow Output: Baseflow, capillary rise Driving force gravity Unsaturated zone Percolation and capillary rise Input: Infiltration, Interflow Output: Interflow, evapotranspiration, drainage Driving force gravity and capillarity soil surface unsaturated zone capillary fringe water level saturated zone

7 Saturated/Unsaturated Soil Subsystem and boundary conditions solarisation irradiation precipitation evapotranspiration surface flow infiltration leaching capillary rise convection, dispersion, ad-/desorption, decay reactions, sources and sinks Root uptake ground water

8 Content System concept (THOMPSON A. Stephen, 1999) System: components and processes. System analyses: a way of looking at the world. Physical environmental system describes the flow and storage of the physical quantities of mass, energy and movement. Subsystems: soil, groundwater, atmospheric subsystem. Observer (modeller, analyst) designs a system or subsystem according to needs. Everything inside the boundary is part of the system. Open system: mass and energy are able to cross the boundary. Closed system: allows only energy to cross the boundary (For most purposes planet earth!).

9 Saturated/Unsaturated Soil Subsystem and boundary conditions Basin-scale hydrologic system (water cycle) Components Storage Soil subsystems unsaturated zone

10 Saturated/Unsaturated Soil Subsystem and boundary conditions WATER BALANCE: N + I + (Z) = ET + D + R - ΔW N... Precipitation I... irrigation Z... source from soil (or from rivers etc.) ET... evapotranspiration (evaporation and transpiration) D... Drainage R... surface runoff ΔW... change of stored water in soil profile

11 Rainfall 100% Landscape 56% Green / Blue Water Rainfed agriculture 4.5% Irrigated Agriculture 70% of blue water Irrigated agriculture 2% Evaporation 1.3% Cities & Industry 0.1% Ocean 36% Green Water Soil Moisture from Rain Blue Water Rivers, Lakes Groundwater After Molden (ed) Water for Food, Water for Life. A comprehensive assessment of water management in agriculture. London, Earthscan and Colombo, IWMI.

12 For soil water Y. Gusev and V. Novak (2007) distinguished three major functions in terrestrial ecosystems: Soil water is the most active link in the interchange of continental waters Soil water is an element of the global climatic system (owing to its location at the atmosphere-lithosphere interface, soil water notably contributes to the formation of climate) Soil water is the most important factor governing the existence and development of the vegetation cover, which is the basic link in the trophic chain of land ecosystem. Also for soil processes (transport of water, solute and heat and chemical and microbiological activities in soil)

13 5.8.4 Water retention Key messages Water retention capacity and soil moisture content will be affected by rising temperatures and by a decline in soil organic matter due to both climate change and land-management changes Projections (for ) show a general reduction in summer soil moisture over most of Europe, significant reductions in the Mediterranean region, and increases in the north-eastern part of Europe Maintaining water retention capacity is important to reducing the impacts of more frequent intense rainfall and droughts Quelle: Impacts of Europe's changing climate 2008 indicator-based assessment

14 Climate change new uncertainties for the future of the agricultural sector More erratic climatic conditions frequency increase of extreme events (floods, hurricanes, heat waves, severe droughts) (Parry, 2000) Biomass production of plants (crop yields), are fundamentally determined by climatic conditions, i.e. the stable availability of energy radiation, temperature) and water (rain) Other environmental and anthropogenic factors soil fertility, crop varieties and farming practices, also influence crop yields. Many adaptation options are available to adjust agricultural practices to the changing conditions, but they differ between regions. Quelle: Impacts of Europe's changing climate 2008 indicator-based assessment

15 Quelle: Impacts of Europe's changing climate 2008 indicator-based assessment

16 Water availability key between climate change and land use Quelle: IWMI

17 Soil Water management Soil water management can be defined as active involvement in controlling soil water content at an optimal state for all given purposes, including environmental needs. An optimal state is often a compromise between competing uses and needs to account for long term sustainability of the soil water system. Loiskand W. and G. Kammerer.(2011). SOIL WATER MANAGEMENT in Encyclopedia of Agrophysics, Jan Glin ski, Horabik Jo zef & Lipiec Jerzy (eds.), DOI / , Springer Science+BusinessMedia B.V. 2011

18 Soil Water management In a changing world, due to climate change and human interventions on land use soil water management is still of growing importance. Subsurface water (water in the vadose zone and groundwater) forms the major volume of terrestrial water resources. For soil water Y. Gusev and V. Novak (2007) distinguished three major functions in terrestrial ecosystems: Soil water is the most active link in the interchange of continental waters Soil water is an element of the global climatic system (owing to its location at the atmosphere-lithosphere interface, soil water notably contributes to the formation of climate) Soil water is the most important factor governing the existence and development of the vegetation cover, which is the basic link in the trophic chain of land ecosystem. Also for soil processes (transport of water, solute and heat and chemical and microbiological activities in soil)

19 Soil Water management Region Neusiedlersee Vineyard Soil types Tillage practises

20 Soil Water management

21 Soil Water management, Irrigation Wasseraufnahme der Pflanzen

22 Soil Water management Farmers at Godino are working on an emergency drain of an over-irrigated field, to conduct excess water. (Source: Loiskandl 2006)

23 Soil processes Thank you! Continuation Processes in soil