Berlin - Wednesday , 16.07.2003

1. „Transboundary Watermanagement“ 14 - 24 July Workshop on Berlin - Wednesday, 16.07.2003

2. Ecosystem Analysis and Integrated Ground Water Management 1 Dr. H. Kehl Todays Topic of Conversation and Discussion: ”Conflicts Between Modern and Traditional Irrigation Methods as a Result of Population Growth and misspended investments in Arid Areas". Internationale Weiterbildung und Entwicklung GmbH

3. Ecosystem Analysis and Integrated Ground Water Management 2 Dr. H. Kehl As we all know: “Irrigation is essential for food production ... especially in semi-arid and arid zones with above average population growth.” FAO Internationale Weiterbildung und Entwicklung GmbH

4. Ecosystem Analysis and Integrated Ground Water Management 3 Dr. H. Kehl At present one-sixth of the agricultural land in the world is irrigated and provides more than one-third of global food production. source: FAO Internationale Weiterbildung und Entwicklung GmbH

5. Ecosystem Analysis and Integrated Ground Water Management 4 Dr. H. Kehl The food requirements of an ever-increasing world population higher necessitate agricultural production, a large share of which comes from irrigated lands, especially true in arid zones. Internationale Weiterbildung und Entwicklung GmbH

6. Ecosystem Analysis and Integrated Ground Water Management 5 Dr. H. Kehl At approximately 80 to 87% of all the available freshwater supply is used for agriculture and food production.” Therefore, only 13 to 20% is available for domestic and industrial requirements. source: FAO Internationale Weiterbildung und Entwicklung GmbH

7. Ecosystem Analysis and Integrated Ground Water Management 6 Dr. H. Kehl The efficiency of water in agricultural production is, however, low. Only 40 to 60% of the water is effectively used by crop, the remainder of the water is lost in the system, in the farm or on the field, either through evaporation, through runoff to the drainage system, or by percolation into the groundwater. source: FAO, UN-WWDR 2003 Internationale Weiterbildung und Entwicklung GmbH

8. Ecosystem Analysis and Integrated Ground Water Management 7 Dr. H. Kehl What does it mean: efficiency? In general, the term is used to quantify the relative output obtainable from a given input (e.g. investment or water). The Term„on-farm application efficiency“ or „field application efficiency“ generally refers to the fraction of the water volume applied to a farm or a field that is „consumed“ by a crop, relative to the amount applied. „In actual practice, however, the water reported to be „consumed“ in the field consists of actualEVAPOTRANSPIRATION[incl. Interception - but without percolation!].“ The Term„Crop Water Use Efficiency“ (WUE) is a physiological index and should be used. The relevant measure is the response of crop to irrigation as total biomass produced (above-ground dry matter!) per unit mass of water taken. Internationale Weiterbildung und Entwicklung GmbH

9. Ecosystem Analysis and Integrated Ground Water Management 8 Dr. H. Kehl What does it mean: efficiency? There is much evidence that, in a given climate, the growth of many crops is directly related to the amount of water they transpire, AND to the ratio of biomass below and above surface. Therefore, deep rooting crops will have a lower WUE. source: FAO, UN-WWDR 2003 Internationale Weiterbildung und Entwicklung GmbH

10. Ecosystem Analysis and Integrated Ground Water Management 9 Dr. H. Kehl Poor management of irrigation water is one of the principal reasons for this low water use efficiency in irrigation. A range of environmental problems are linked to ineffective water use, such as waterlogging, leaching of agro-chemicals and consequent ground water pollution, as well as soil and ground water salinization resulting from inappropriate applications. Internationale Weiterbildung und Entwicklung GmbH

11. Ecosystem Analysis and Integrated Ground Water Management 10 Dr. H. Kehl Studies on the economies of Sub-Saharan Africa (SSA) have generally neglected the link between economic growth and environmental quality. Internationale Weiterbildung und Entwicklung GmbH

12. Ecosystem Analysis and Integrated Ground Water Management 11 Dr. H. Kehl The key to SSA future is to achieve long-term sustainable growth and not to implement and focus on showcase “white elephant” type expensive technologies (e.g. high-tech irrigation systems) developed under differing climatic, socio-economic conditions of HDCs (Highly Developed Countries). Frequently, that was a costly fallacy! Internationale Weiterbildung und Entwicklung GmbH

13. Ecosystem Analysis and Integrated Ground Water Management 12 Dr. H. Kehl The quite recently launched Human Development Report (HDR-UNDP, July 8th 2003) emphasized in particular the self-responsibility and self-determination of LDCs, especially their farmers with their knowledge of adapted irrigation systems as a key issue for successful developments in the future. Internationale Weiterbildung und Entwicklung GmbH

14. Ecosystem Analysis and Integrated Ground Water Management 13 Dr. H. Kehl Complementary assistance comes from the FAO: „Key decision makers have tended to favour high-visibility projects with impressive works [ e.g. large Dam Projects, large-scale Center-Pivot sprinkler systems, large group well constructions for ground water utilization ], Internationale Weiterbildung und Entwicklung GmbH

15. Ecosystem Analysis and Integrated Ground Water Management 14 Dr. H. Kehl while neglecting the more modest needs of indigenous farm units, as well as the issues of reconstruction of traditional irrigation systems, of modification, of training and maintenance that are of interest to lower-lever personel without decision-making power.“ Internationale Weiterbildung und Entwicklung GmbH

16. Ecosystem Analysis and Integrated Ground Water Management Institutional change, Comprehensive, radical reform of irrigation managment, e.g. turnover to Water User Associations, Integrated, ecologically prooved basin-wide approach, The knowledge base and knowledge transfer, Education, communication and participation, Self-responsibility and self-determination of farmers. 15 Dr. H. Kehl Lessons learned from several Case Studies, UNDP-, UN-WWD- and FAO Reports and keys to success Essential Elements to move towards integrated water resources management relate to: Internationale Weiterbildung und Entwicklung GmbH

17. Ecosystem Analysis and Integrated Ground Water Management Because of population growth in SSA the traditional rain-fed agriculture can not longer feed the people. The likewise traditional Water Harvesting System is three times more effective than rain-fed agriculture. Water Harvesting holds an intermittent status between rain-fed and irrigated agriculture (in respect ofProduction Costs, Cash Crops / Cash Income, Crop Yields, Salinity Hazard, Reliability of Water Supply). 15a Dr. H. Kehl Lessons learned from several Case Studies, UNDP-, UN-WWD- and FAO Reports and keys to success Essential Elements to move towards integrated water resources management relate to: Internationale Weiterbildung und Entwicklung GmbH

18. Ecosystem Analysis and Integrated Ground Water Management 15b Dr. H. Kehl You wish to know something more about advanced techniques of Rain Water Harvesting for Crop Production? Please, visit the FAO Training Course in the Internet! The most complete and detailed „How-To Manual“ available. Strongly recommended ! URL: http://www.fao.org/ag/agl/aglw/wharv/whtoc/sld001.htm Internationale Weiterbildung und Entwicklung GmbH

19. Ecosystem Analysis and Integrated Ground Water Management Bambo drip-Irrigation system in West Sumatra Ground water for irrigation in the desert Water harvesting system with catchment area 16 Dr. H. Kehl Modern vs. Traditional Water Harvesting and Irrigation Methods Internationale Weiterbildung und Entwicklung GmbH

20. Ecosystem Analysis and Integrated Ground Water Management Group construction of a sub-surface water harvesting tank in Zimbabwe. source: Dabane Trust Water Workshop 17 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • Rain water harvesting with micro/macro catchment areas and flood water harvesting (since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

21. Ecosystem Analysis and Integrated Ground Water Management Horizontal Tunnel 18 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • Hand-dug wells (e.g. Qanats and horizontal wells, since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

22. Ecosystem Analysis and Integrated Ground Water Management This below surface building could be in Italy, Libya, Palestine, Turkey, etc. Greece & Roman Cisterns around the Mediterranean. Actually, thousands of Cisterns of different types are ruined and, therefore un-used. typical for flat country or in mountains 19 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • Runoff Collection + Cisterns (Near East, North Africa, since thousands of years) Indian Cistern Internationale Weiterbildung und Entwicklung GmbH

23. Ecosystem Analysis and Integrated Ground Water Management source: cgwaindia 20 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • Roof Top Rain Water Harvesting (Near East, North Africa, India, etc. since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

24. Ecosystem Analysis and Integrated Ground Water Management source: www - WDDA / Israel 21 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Semi-Arid Areas Only a selection: • Runoff agriculture (involves rain water harvesting, since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

25. Ecosystem Analysis and Integrated Ground Water Management runoff collection Runoff water harvesting during the rainy season to bypass the dry season. The deeper the soil the better it is suited as cropping area. infiltration source (mod.): www - Wag. Univ. Env. Sci. 22 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • Runoff Collection (e.g. also good to built up artificial ground water bodies, S-Medit. area). Internationale Weiterbildung und Entwicklung GmbH

26. Ecosystem Analysis and Integrated Ground Water Management 23 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • Canal irrigation (e.g. Iraq, since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

27. Ecosystem Analysis and Integrated Ground Water Management It was first used to pump water out of ships and was later used in irrigation. (287- 212 BD) 23a Dr. H. Kehl Traditional Irrigation and Water Harvesting in Semi-Arid Areas Only a selection: • Canal irrigation with Archimedes‘ Screw (e.g. Iraq, Egypt, since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

28. Ecosystem Analysis and Integrated Ground Water Management Open well in Tanzania with unclean and unsanitary water. Open well in Zambia proving water for cattle in the dry season. source: iirr.org Artificial pits / India source: ROPE/UK 24 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • Pits and open wells (e.g. India, Central Africa, since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

29. Ecosystem Analysis and Integrated Ground Water Management 24 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • „ZAY“ pitting holes (since thousands of years) source: FAO copied witout permision! Internationale Weiterbildung und Entwicklung GmbH

30. Ecosystem Analysis and Integrated Ground Water Management 25 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Arid Areas Only a selection: • Porous clay jars (Near East, North Africa, India, etc. since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

31. Ecosystem Analysis and Integrated Ground Water Management Irian Jaya (Indonesia) and Papua New Guinea) The entire root zone is wetted to near-saturation (source: FAO) Photos: Kehl 1989 26 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Wed Areas Only a selection: • Furrow irrigation (SE-Asia, Central Africa, India, etc. since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

32. Ecosystem Analysis and Integrated Ground Water Management Central Madagacar (near Antanarivo) Flood and basin irrigation wets the entire root zone to saturation (source: FAO) photo: Kehl 2002 27 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Semi-Arid Areas Only a selection: • Flood and basin irrigation (SE-Asia, Central Africa, India, etc. since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

33. Ecosystem Analysis and Integrated Ground Water Management Pakistan (Ganges Delta) Flood irrigation wets the entire root zone to saturation (source: FAO) source: Global Change GEO 28 Dr. H. Kehl Traditional Irrigation and Water Harvesting - Flood Water Only a selection: • Flood water harvesting (SE-Asia, Egypt in ancient time, India, etc. since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

34. Ecosystem Analysis and Integrated Ground Water Management Drip irrigation wets precisely the root zone to saturation (source: CSE-India) 29 Dr. H. Kehl Traditional Irrigation and Water Harvesting in Wet Areas Only a selection: • Drip irrigation with bamboo pipes (SE-Asia, India, etc. since thousands of years) Internationale Weiterbildung und Entwicklung GmbH

35. Ecosystem Analysis and Integrated Ground Water Management Ecuador - high mountains The dark sheets suspended in the path of the moving cloud condense it. 30 Dr. H. Kehl Modern Irrigation Methods in Semi-Arid and Semi-Arid Zones Only a selection: • Fog catcher (for harvesting dew - Chile, Ecuador - at present experiments) Internationale Weiterbildung und Entwicklung GmbH

36. Ecosystem Analysis and Integrated Ground Water Management Center Pivot System Technical very ambitious! Water Use Efficiency (WUE) of high pressure systems about 65 to 75%, depending on air humidity and wind. 31 Dr. H. Kehl Modern Irrigation Methods in Semi-Arid and Arid Zones Only a selection: • Sprinkler irrigation (e.g. portable, solid, travelling sprinklers, center pivot systems - high pressure / low pressure, etc. utilizing clean (!) ground or surface water). Internationale Weiterbildung und Entwicklung GmbH

37. Ecosystem Analysis and Integrated Ground Water Management E.g. Channel Bank Irrigation Small diameter pipes used to convey water over the channel embankment (source: FAO) WUE is about 45% 32 Dr. H. Kehl Modern Irrigation Methods in Semi-Arid to Wet Zones Only a selection: • Surface Irrigation, Auto Flood and Flood (e.g. wild flooding, contour flooding, borders, channel, basin, etc.). Internationale Weiterbildung und Entwicklung GmbH

38. Ecosystem Analysis and Integrated Ground Water Management A) Surface Drip Irrigation Water Use Efficiency (WUE) is about97% e.g. four emitter or dripper for trees e.g. one emitter for outdoor vegetable fig.source: FAO 33 Dr. H. Kehl Modern Irrigation Methods in Semi-Arid and Semi-Arid Zones Only a selection: • Localized Irrigation (e.g. drip resp. trickle, subsurface drip, bubblers, micro-sprinklers etc.). Internationale Weiterbildung und Entwicklung GmbH

39. Ecosystem Analysis and Integrated Ground Water Management 34 Dr. H. Kehl Modern Irrigation Methods in Semi-Arid and Arid Zones Only a selection: • Localized Irrigation (e.g. drip resp. trickle, subsurface drip, bubblers, micro-sprinklers etc.). B) Water Use Efficiency (WUE) is about 97% Internationale Weiterbildung und Entwicklung GmbH

40. Ecosystem Analysis and Integrated Ground Water Management 35 Dr. H. Kehl Modern Irrigation Methods in Semi-Arid and Arid Zones Only a selection: • Localized Irrigation (e.g. drip resp. trickle, subsurface drip, bubblers, micro-sprinklers etc.). C) Water Use Efficiency (WUE) is about 97% Internationale Weiterbildung und Entwicklung GmbH

41. Ecosystem Analysis and Integrated Ground Water Management fixed water not available coarse texture lost water runoff percolation Plant available water fine texture (e.g. loam) 35a Dr. H. Kehl Soil Water Availability for Plants - some Basics: Internationale Weiterbildung und Entwicklung GmbH

42. Ecosystem Analysis and Integrated Ground Water Management 36 Dr. H. Kehl Effects of Traditional & Modern Irrigation Methods: Only a selection: • The problem of Salinization occurs with nearly any type of irrigation in arid zones. Especially with sprinkler irrigation and loamy soils. • Soil structure and soil texture also have an impact on and thus on water management efficiency: water losses from evaporation or runoff are either reduced or increased when soil structure is modified. • Soils developed under arid and semi-arid conditions can be changed irreversible by irrigation, solely the soil structure is more fragile than anywhere. • Generally, on a long-term basis, large-scale sprinkler irrigation is a delicate tool that can endanger the farming system's sustainability (long-term profitability) instead of increasing it: • Potentially, it can shrink the biodiversity, cause irreversible soil property changes, can dry out underground and surface water resources, and last but not least, it can be too expensive for forthcoming generations. Internationale Weiterbildung und Entwicklung GmbH

43. Ecosystem Analysis and Integrated Ground Water Management The Salinization refers to a build up of salts in soil, eventually to toxic levels for plants. 3,000 - 6,000 ppm salt results in trouble for most cultivated plants. Salt in soils decreases the osmotic potential of the soil so that plants can't take up water from it. When soils are salty, the soil has greater concentrations of solute than does the root, so plants can't get water from soil. The salts can also be directly toxic, but plant troubles usually result primarily from inability to take up water from salty soils. 37 Dr. H. Kehl The General Pre-Condition for Arid Areas SALINIZATION = Land Degradation = Productivity is Diminished: Salinization are most commonly associated with excessive water application, rather than with too little! Internationale Weiterbildung und Entwicklung GmbH

44. Ecosystem Analysis and Integrated Ground Water Management 38 Dr. H. Kehl The General Pre-Condition for Arid Areas SALINIZATION = Land Degradation = Productivity is Diminished: • Salinization may occur with nearly any type of irrigation! EGYPT: The High Assuan Dam made year-round irrigation possible (and necessary!!) and prevented the annual floods, which led to increased salinization in the land irrigated by the canal system. Therefore, leaching and drainage takes additional water(Dregne, 1983; El Baz, 1988; Goossens et al., 1994; Mainguet, 1994). Large areas around the Egyptian Oasis Kharga and Dahkla became unproductive through irrigation mismangement with fossil water. Additionally, although best available irrigation technologies have been implemented in the Wadi Natrun area (N-Egypt) repeated cycles of groundwater led to toxic brackish water tables. Source (partly, and modified): ICS-France 2003 Internationale Weiterbildung und Entwicklung GmbH

45. Ecosystem Analysis and Integrated Ground Water Management 39 Dr. H. Kehl The General Pre-Condition for Arid Areas SALINIZATION = Land Degradation = Productivity is Diminished: • Salinization may occur with nearly any type of irrigation! Iraq: In Iraq, there is a historical record of salinization caused by canal irrigation between 2.400 and 1.700 B.D., and this problem has recurred at intervals through the present (Dregne, 1983). About 11.48 million hectares (ha) of land is cultivable. However, FAO estimates for 1998 reveal that only 5.5 million ha is put under cultivation due to soil salinity, fallow practices and the unstable political situation. 64% of the cultivated land was irrigated. Agricultural water withdrawals accounted for 52% of total renewable water resources. Source (partly, and modified): UNESCO 2003 Internationale Weiterbildung und Entwicklung GmbH

46. Ecosystem Analysis and Integrated Ground Water Management 40 Dr. H. Kehl General Pre-Conditions and Limitations for Arid Areas Limited Ground Water Resources: • RISK: The overutilization of limited (fossil) ground water resources ... • As it has been mentioned yesterday, between 1980 and 1995, Saudi Arabia consumed 75% of the proven reserves of fossil ground water in its major aquifers to irrigate wheat crops. FTGW, 1997 • Libya(Great Man-Made River) and Egypt(New Valley resp. Toshka Agribusiness Mega-Project)both, are on the way to use up their huge - but limited (!) - non-renewable fossil ground water reserves. Internationale Weiterbildung und Entwicklung GmbH

47. Ecosystem Analysis and Integrated Ground Water Management 41 Dr. H. Kehl General Pre-Conditions and Limitations for Arid Areas Limited Surface Water Resources: • RISK: Evaporation losses of limited surface water through dams ... E.g.: The water loss from Lake Nasser in the South of Egypt is one of the national problems ... the evaporated water range between 10 to 16 billion m³/y which represent 20 to 30% of the Egyptian income from Nile water . Mosalam Shaltout & El Housry, 1996 Internationale Weiterbildung und Entwicklung GmbH

48. Ecosystem Analysis and Integrated Ground Water Management 42 Dr. H. Kehl Just enough is best! "It is the universal fallacy of humans to assume that if a little of something is good, then more must be better. In irrigation (as indeed in many other activities), just enough is best." (Prof. Daniel Hillel in FAO Publ. 1997). As we have seen, agriculture is the highest fresh water consumer, especially in arid zones with LDCs. Therefore future agricultural extension policy must focus predominantly and early enough on Impact Assessment AND long-term Economic Evaluation of water harvesting techniques in arid zones. Internationale Weiterbildung und Entwicklung GmbH

49. Ecosystem Analysis and Integrated Ground Water Management 43 Dr. H. Kehl AND: New is not always better. Water from "improved wells" is often only marginally better in quality than water from traditional sources — and it generally demands a costly or risky change in management techniques. Internationale Weiterbildung und Entwicklung GmbH

50. Ecosystem Analysis and Integrated Ground Water Management 44 Dr. H. Kehl AND: Monitoring is important: to determine the nature and extent of change; to see if technical results match expectations; and to tell whether new management methods are actually adopted. Internationale Weiterbildung und Entwicklung GmbH