MONITORING IRRIGATION SUPPLY AND DEMAND ON IRRIGATION SYSTEMS AS AN INSTRUMENT TO OPTIMIZE WATER USE UNDER DROUGHT CONDITIONS

Transcription

1 MONITORING IRRIGATION SUPPLY AND DEMAND ON IRRIGATION SYSTEMS AS AN INSTRUMENT TO OPTIMIZE WATER USE UNDER DROUGHT CONDITIONS By Juan Antonio Sagardoy Alonso Irrigation Management Consultant and BARAKAT, Ashraf WUEMED Workshop (September 2005) 1

2 Summary of presentation 1. The capacity of the irrigation networks to respond to crop water requirements. 2. Monitoring the demand and delivery of water. A M&E case study. 3. Concluding remarks. WUEMED Workshop (September 2005) 2

3 Modernization or Improvement of the Management of Irrigation Systems WUEMED Workshop (September 2005) 3

4 The capacity of irrigation networks Irrigation networks have a limited capacity of response to evolving farmers needs: 1. They were mostly designed to satisfy the demand for cereals but now cropping pattern are changing. 2. The high water losses of traditional open canal systems are not compatible with the present high demand for water 3. Climate change is increasing the water demand of crops. WUEMED Workshop (September 2005) 4

5 The responses to improve irrigation networks 1. Irrigation networks are replaced by more efficient ones. Modernization processes 2. Irrigation networks are managed more efficiently and resources are allocated in a more effective manner WUEMED Workshop (September 2005) 5

6 The modernization plan of Spain The irrigation modernization programme is part of the National Irrigation Plan (PNI) approved in 2002 where the irrigation investments up to year 2008 were defined The Plan assumes that by year 2008, 50% of the targets will be reached and the rest in the remaining 6 years The modernization programme covers: ha up to year 2008 WUEMED Workshop (September 2005) 6

7 Summary of the Spanish Investments in the National Irrigation Plan Investments up to year 2008 Modernization and Consolidation Completion of new irrigation areas under execution Social irrigation systems Private irrigation systems with gov. subsidies Other progra mmes Total Total of all regions in million Pesetas Total all regions in million Euros WUEMED Workshop (September 2005) 7

8 Average Investments Average investment per hectare 5000, ,00 /ha 3000, , ,00 0,00 Norte Nordeste Meseta Sur Sur y Este Seiasas WUEMED Workshop (September 2005) 8

9 The M&E case Study: The Consorzio della Capitanata WUEMED Workshop (September 2005) 9

10 Improving the management of existing irrigation networks The amount of paper generated on the topic of improving the management of existing irrigation systems is extremely large. The point to be made here is that within that context Monitoring and Evaluation remains a useful management tool but with limited diffusion and application. WUEMED Workshop (September 2005) 10

11 M&E system for Water Users Organizations (WUOs( WUOs) The management objectives of WUO s Managers should develop their objectives and measure through indicators how well these objectives are achieved. Operation Objectives (15) Maintenance Objectives (8) Management Objectives (4) Environment Objectives (2) Technical assistance Objectives (3) Financial Objectives (6) WUEMED Workshop (September 2005) 11

12 The case study area Consorzio per la Bonifica della Capitanata Foggia WUEMED Workshop (September 2005) 12

13 The irrigation systems of Fortore and Sinistra Ofanto Irrigable area Number of Districts Number of Reservoir and Total Capacity Number of farmers Sinistra Ofanto 22,156.9 ha 7 Districts 5 Reservoir 194,000 m District ha Reservoir V4: 28,000 m WUEMED Workshop (September 2005) 13

14 Water distribution Indicators Relative irrigation supply: V Supplied RIS 100% = N.I.R Total volume of water delivered at farm level V.Wt = Vf I.Area Average need of irrigation water at farm level.w N a = N.I.R I.Area WUEMED Workshop (September 2005) 14

15 Operations Indicators Satisfaction of yearly irrigation needs S.N.y = V.Wt N.W a Evolution of the cropping pattern E.C.P = C.P % WUEMED Workshop (September 2005) 15

16 Net Irrigation Requierments Computations WinGENERA Software WUEMED Workshop (September 2005) 16

17 Relative Irrigation supply V Supplied RIS 100% = N.I.R year Apr May Jun Jul Aug Sep WUEMED Workshop (September 2005) 17

18 Total volume of water delivered at farm level-district 4. 4 V.Wt = Vf I.Area m3/ha year WUEMED Workshop (September 2005) 18

19 Average need of irrigation water at farm level (m3/ha) -District ,000.W N a = N.I.R I.Area 5,000 m3/ha 4,000 3,000 2,000 1, year WUEMED Workshop (September 2005) 19

20 Satisfaction of yearly irrigation needs - District S.N.y = V.Wt N.W a year WUEMED Workshop (September 2005) 20

21 Evolution of cropping pattern -District E.C.P = C.P % fruit trees olive trees ve gitable s artichoks wine grape tomato spinach asparagus year WUEMED Workshop (September 2005) 21

22 Final considerations WUEMED Workshop (September 2005) 22

23 Final remarks Existing computer methodologies can be used to determine crop irrigation requirements at any level of the distribution system by pipes or canals. This allows to compare irrigation needs with the actually distributed water. Such comparison permits to identify the critical areas of the system at any time of the growing season or year. Furthermore the relative irrigation supply is particularly useful to manage drought situations as it allows to distribute the water in the most needed areas and at the critical times of crop development WUEMED Workshop (September 2005) 23

24 Final remarks This information should be complemented with other indicators (for example, evolution of cropping pattern) to identify possible reasons of the critical situation. In some cases, farm surveys may be needed to determine reasons of farmers behaviour. The information developed is not only useful for the actual operation but also for planning purposes as it gives a historical record of farmers behaviour WUEMED Workshop (September 2005) 24

25 Final remarks The M&E system of the case study has used only existing available data or data resulting from processing of original data. Therefore the cost of its use is negligible. The application of the M&E system to other irrigation systems will require an adaptation process consisting mainly in selecting relevant indicators that respond to the specific objectives that managers wish to achieve and availability of data WUEMED Workshop (September 2005) 25

26 Thank you for your attention! WUEMED Workshop (September 2005) 26