slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
A COLLABORATIVE RESEARCH PROJECT BETWEEN NIB AND UON Year II Project Highlights By PowerPoint Presentation
Download Presentation
A COLLABORATIVE RESEARCH PROJECT BETWEEN NIB AND UON Year II Project Highlights By

Loading in 2 Seconds...

play fullscreen
1 / 43

A COLLABORATIVE RESEARCH PROJECT BETWEEN NIB AND UON Year II Project Highlights By - PowerPoint PPT Presentation


  • 131 Views
  • Uploaded on

ASSESSING AND IMPROVING THE PERFORMANCE OF CONVEYANCE SYSTEMS: CASE STUDIES of AHERO, BURA and MWEA IRRIGATION SCHEMES. A COLLABORATIVE RESEARCH PROJECT BETWEEN NIB AND UON Year II Project Highlights By Gichuki F., Wanjogu R. K., and Okinyi ., M. D. Date: 3 rd July 2014.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'A COLLABORATIVE RESEARCH PROJECT BETWEEN NIB AND UON Year II Project Highlights By' - trey


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

ASSESSING AND IMPROVING THE PERFORMANCE OF CONVEYANCE SYSTEMS:CASE STUDIES of AHERO, BURA and MWEA IRRIGATION SCHEMES

Mwea, Ahero and Bura Irrigation Schemes case studies

A COLLABORATIVE RESEARCH PROJECT BETWEEN NIB AND UON

Year II Project Highlights

By

Gichuki F., Wanjogu R. K., and Okinyi., M. D.

Date: 3rd July 2014

presentation outline
Presentation outline
  • Development and research objectives
  • Project elements and its organization
  • Year I highlight
  • Year II Results and their implications
  • Project outputs
introduction
Introduction
  • Irrigation in Kenya faces serious challenges which have negatively affected the productivity, profitability and sustainability of most irrigation schemes. The following is a partial listing of the main challenges
    • High pumping costs;
    • High levels of siltation; unpredictable flooding & drought
    • High conveyance and application losses;
    • High mismatch between water demand and supply;
    • Inadequate drainage of excess water and removal of excess salts; and
    • Inequity in water delivery in different irrigation blocks and irrigated fields.
    • Inadequate irrigation skills among farmers and other stakeholders

Source: NIB Strategic Plan 2008-2012

MIS, AIS & BIS water loss study-NIB & UON

rationale for conveyance system research
RATIONALE FOR CONVEYANCE SYSTEM RESEARCH:
  • Low efficiency (30-70%) of conveyance and distribution system with major implications on:
    • Scheme water intake sub-system
    • Operation and maintenance of conveyance sub-system
    • On-farm sub-system
rationale for conveyance system research implication on water intake subsystem
RATIONALE FOR CONVEYANCE SYSTEM RESEARCH:Implication on water intake subsystem
  • Irrigation scheme withdraws 30-70% more water than it needs – This increase potential for water use conflicts in dry seasons;
  • Large intake infrastructure are required resulting in high development costs
  • High pumping (O&M) costs
rationale for conveyance system research implication on conveyance subsystem
RATIONALE FOR CONVEYANCE SYSTEM RESEARCH:Implication on conveyance subsystem
  • 30-70% more silt brought into the scheme;
  • Large conveyance infrastructure are required resulting in high development costs
  • High conveyance (O&M) costs
rationale for conveyance system research implication on on farm subsystem
RATIONALE FOR CONVEYANCE SYSTEM RESEARCH:Implication on on-farm subsystem
  • 30-70% more silt brought into the fields;
    • May enhance soil fertility
    • Will over time raise field levels making it less commandable
  • 30-70% more salts brought into the field will enhance the rate of salt build up
  • May enhance drainage problems
  • High on-farm (O&M) costs
hypothesis
Hypothesis
  • The main hypothesis of this research is that the performance of water delivery and application sub-systems can significantly be improved-hence irrigated agriculture- by reducing irrigation water loss.

AIS & BIS water loss study-NIB & UON

key issues that will addressed
Key issues that will addressed
  • Assess performance and opportunities and constraints for improving performance;
  • Identify innovative solutions that will enhance the performance of the water delivery and water application sub-systems;
  • Evaluate technical performance of the innovative solutions;
  • Evaluate costs and benefits of performance improvements;
  • Formulate strategies and plans for performance improvements;
  • Identify investment priorities; and
  • Propose financing/ options.

AIS & BIS water loss study-NIB & UON

main deliverables outputs
Main deliverables (outputs)
  • Reports on the status and performance of irrigation subsystems for the past 5 years- from abstraction point thru conveyance to the farm
  • Report on cause, effect and magnitude of conveyance and distribution losses in MIS, AIS and BIS
  • Options for reducing irrigation water losses and improving delivery performance including lining options
  • Information on improving delivery performance will be available to irrigation engineers, managers, farmers and policy makers

AIS & BIS water loss study-NIB & UON

anticipated outcomes and impacts
Anticipated outcomes and impacts
  • Enhanced adoption of water saving technologies;
  • Increased irrigated areas, cropping intensities and crop yields;
  • Increased yield, production and net benefits;
  • Increases in farmer contribution to O&M expenses;
  • Irrigation water savings;
  • More efficient and productive use of water.
  • More equitable water allocation among sectors and users;
  • More reliable yields and production.
  • Reduced environmental degradation;
  • Reduced impacts of extreme events, particularly flood and destruction of irrigation infrastructure;
  • Reduced mismatch between water demand and supply;
  • Reduced water use conflicts associated with more equitable water distribution;
  • Yield, production and profit increases; and
  • Reduced variability in irrigated agricultural production

AIS & BIS water loss study-NIB & UON

objectives
Objectives

Overall goal:

  • To generate and enhance utilization of data, information and knowledge on irrigation water management in ways that promote innovation and effective and efficient utilization of the resources.

AIS & BIS water loss study-NIB & UON

year 1 highlights ahero system
Year 1 Highlights : Ahero system

AIS & BIS water loss study-NIB & UON

year 1 highlights ahero system1
Year 1 Highlights : Aherosystem

AIS & BIS water loss study-NIB & UON

year 1 highlights bura system
Year 1 Highlights : Burasystem

AIS & BIS water loss study-NIB & UON

year 1 highlights bura system1
Year 1 Highlights : Burasystem

AIS & BIS water loss study-NIB & UON

year 1 highlights mwea system
Year 1 Highlights : Mweasystem

AIS & BIS water loss study-NIB & UON

year 1 highlights mwea system1
Year 1 Highlights : Mwea system

AIS & BIS water loss study-NIB & UON

soil permeability test results
Soil Permeability test results

AIS & BIS water loss study-NIB & UON

year ii methodology loss assessment
Year II Methodology: Loss assessment
  • Canal loss mainly comprise of seepage, evapotranspiration (EVT) & leakages
  • The water balance (inflow/outflow) method used for quantifying canal loss-this will not interrupt irrigation program
  • Seepage rates measured using inflow/outflow, ponding and seepage meter methods
  • Calibration and possibly repair of all measuring/regulating canal structures to facilitate flow measurements-critical in this study

AIS & BIS water loss study-NIB & UON

methodology loss assessment
Methodology: Loss assessment

AIS & BIS water loss study-NIB & UON

methodology loss assessment1
Methodology: Loss assessment

Ponding method

To eliminate the effect of wind, the rate of drop was measured at each end of the pool and averaged. Staff or hook gauges attached to existing structures or stakes driven into the canal bed were used as shown in the figure below.

AIS & BIS water loss study-NIB & UON

preliminary results loss assessment
Preliminary results: Loss assessment

AIS & BIS water loss study-NIB & UON

preliminary results loss assessment1
Preliminary results: Loss assessment

AIS & BIS water loss study-NIB & UON

preliminary results seepage losses in unlined canals
Preliminary results: SEEPAGE LOSSES IN UNLINED CANALS

--------------------------------------------------------------------------------------------------------------------

Character of material Seepage loss in Cumecs per Million sq. m of wetted perimeter

_____________________________________________________________________

Impervious clay Loam 0.90 to 1.20

Medium clay loam under laid with hard pan at depth 1.20 to 1.80

of not over 0.60 to 0.90m below level

Ordinary clay loam silt soil 1.80 to 2.70

Gravelly or sandy clay loam, cemented gravel, 2.70 to 3.70

Sand and clay

Sandy loam 3.60 to 5.20

Loose sandy soils 5.20 to 6.10

Gravelly to sandy soils 7.00 to 8.80

Porous gravelly soil 8.80 to 10.70

Very gravelly soils 10.70 to 21.30

___________________________________________________________________

methodology water balance modeling
Methodology: Water balance modeling

Thiba system linkages

AIS & BIS water loss study-NIB & UON

methodology water balance modeling1
Methodology: Water balance modeling

Elements of the water balance model

AIS & BIS water loss study-NIB & UON

preliminary results water balance model
Preliminary results: Water balance model

AIS & BIS water loss study-NIB & UON

preliminary results water balance model1
Preliminary results: Water balance model

AIS & BIS water loss study-NIB & UON

preliminary results water balance model2
Preliminary results: Water balance model

AIS & BIS water loss study-NIB & UON

on going simulation studies
On-going simulation studies

Design, operation and maintenance issues for example what is the effect of changes on cropping calendar and system layout

AIS & BIS water loss study-NIB & UON

preliminary simulation results mwea
Preliminarysimulation results - Mwea

AIS & BIS water loss study-NIB & UON

slide36

Economics of canal lining

AIS & BIS water loss study-NIB & UON

economics of canal lining c alculation
Economics of canal lining: Calculation

Annual benefits:

  • (a) Saved seepage water by lining:
  • Let, the rate of water is sold to the cultivators = c/cumec
  • If m cumecs of water is saved by lining the canal annually, then the money saved by lining = c. m/yr

Saving in maintenance cost:

  • Let, the average cost of annual upkeep of unlined channel = Cuc
  • If p is the percentage fraction of the saving achieved in maintenance cost by lining the canal, then the amount saved = pCuc
  • The total annual benefits = c. m/yr + pCuc
economics of canal lining c alculation1
Economics of canal lining: Calculation

Annual Costs:

  • Let, the capital expenditure required on lining is LC and the lining has a life of N years.Annual depreciation charges = LC/N.
  • Interest of the capital LC = LC(r/100) [r= percent of the rate of annual interest]
  • Average annual interest = LC/2(r/100) [v Since the capital value of the asset decreasesfrom LC to zero in N years]
  • The total annual costs of lining = LC/N + LC/2(r/100)
economics of canal lining c alculation2
Economics of canal lining: Calculation

Benefit/Cost ratio example:

Annual Benefits

(a) Seepage loss

  • Seepage loss in unlined canal @3.3 cumec per million sq. m = (3.3/106)* 18,800 cumec/km= 62,040* 10-6cumec/kmFor seepage loss in lined channel at 0.01 cumesc per million square meter of wetted perimeterSeepage loss in unlined canal = (0.01/106)x18,800= 188*10-6cumecs/kmNet saving = (62,040* 10-6 - 188* 10-6) cumec/km = 0.06185 cumec/kmAnnual revenue of water = 35 ksh
  • Annual revenue saved per km of channel = (0.06185*35) = 216,480.

(b) Saving in maintenance

  • Annual maintenance cost of unlined channel for 10 square meter = 10
  • Total wetted perimeter per 1 km length = 18,800 m"
  • Annual maintenance charge for unlined channel per km = 18,800
  • Assume that 40% of this is saved in lined channel
  • Annual saving in maintenance charges = (0.4* 18,800) = 7,520
  • Total annual benefits per km = (216,480 + 7,520) = 224,000
economics of canal lining c alculation3
Economics of canal lining: Calculation

Benefit/Cost ratio example:

Annual Costs

  • Area of lining per km of channel= 18.5*1000= 18500 m2
  • Cost of lining per km of channel @ 1800 per 10 m2= (18500*1800/10) = 3,330,000.Assume, life of lining as 40 years
  • Depreciation cost per year = (3,330,000/40) = 83250Assume 5% rate of interest
  • Average annual interest = C/2 (r/100) = 3,330,000/2*(5/100) = 83,250
  • Total annual cost = (83,250 + 83,250) = 166,500Benefit cost ratio = Annual benefits/Annual costs = 224,000/166,500 = 1.35Benefit cost ratio is more than unity, and hence, the lining is justified.
economics of canal lining c alculation4
Economics of canal lining: Calculation

Benefit/Cost ratio example:

Benefit cost ratio = Annual benefits/Annual costs = 224,000/166,500 = 1.35Benefit cost ratio is more than unity, and hence, the lining is justified.

slide42

List of project outputs

  • Solving Conveyance and On-farm Water Management Problems
  • Irrigation Water Research: Priority issues and the potential outcomes and impacts
  • Benchmarking irrigation performance: Issues, Concepts and Methods
  • Water Conveyance Study: Ahero Irrigation Scheme Case Study
  • Water Conveyance Study: BuraIrrigation Scheme Case Study
  • Water Conveyance Study: Mwea Irrigation Scheme Case Study
  • AheroIrrigation water loss assessment
  • Bura Irrigation water loss assessment
  • MweaIrrigation water loss assessment
  • Irrigation water measurement: Developing flow rating curves
  • Ahero Flow Measurement
  • BuraFlow Measurement
  • MweaFlow Measurement
  • A literature review on seepage assessment and remediation

AIS & BIS water loss study-NIB & UON

slide43

THANK YOU

AIS & BIS water loss study-NIB & UON