Locating irrigation typologies: Spatially disaggregated informal irrigation maps for Nigeria' Oladel

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Locating irrigation typologies Spatially
disaggregated informal irrigation maps for
Nigeria.Oladele O.I, Adeoti A.I and Braimoh .
A.KDepartment of Agricultural Extension and
Rural Development, University of
IbadanDepartment of Agricultural Economics,
University of IbadanGlobal Land Project, Sapporo
Nodal Office, Hokkaido University,
JapanCorresponding author oladele20002001_at_yahoo.
com
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Introduction

• Informal irrigation technologies and practices
  can provide cost effective and rapid avenue for
  farmers to improve household food security and
  incomes in Nigeria.
• A demand supply gap that exist for water in many
  parts of the world
• Many policy makers, researchers, NGOs and farmers
  are increasingly pursuing various innovative,
  technical, institutional and policy interventions
  to enable the efficient, equitable and
  sustainable utilization of water resources.

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Informal Irrigation Agriculture in Nigeria

• Informal irrigation technologies constitute an
  element of such innovative intervention
  approaches.
• A major proportion of the agriculture population
  in Nigeria is supported by informal irrigation.
• This is predicated on the fadama development
  programme of over 500,000ha available in the
  country
• The economic benefits of the fadama exceed the
  effort made.

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Agroecological Zone of West Africa
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Use of informal irrigation

• Informal irrigation, that is practiced by farmers
  without the reliance on planned, constructed
  irrigation infrastructure, is widespread,
  throughout Nigeria.
• The informal practice has largely arisen due to
  the freedom of individuals or groups to react to
  market demand or their own needs, and their
  ability to maintain their own systems.
• The failures of large scale irrigation schemes
  paved way for the development of small-scale
  irrigation schemes, which are concentrated on the
  fadama.

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Exploring the irrigated agriculture potential

• The large potential for developing irrigated
  agriculture in Nigeria can be explored through
  informal irrigation.
• The challenge really is, what technology to
  promote in what area so that it has maximum
  impact on farmers livelihoods.
• Accurate knowledge of the distribution of
  informal irrigation is an important tool in
  planning and evaluating informal irrigation
  contribution to food security and poverty
  reduction.
• There exist a dire lack of extensive and
  comparable data about informal irrigation, and
  thus the need for more research on types, use,
  intensity of use, distribution and factors
  affecting the distribution in sub- Saharan
  African.

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Mapping Informal irrigation

• Global, continental and regional maps of informal
  irrigation distribution in the past have been
  largely based on expert opinion and more recently
  on climatic suitability.
• Informal irrigation mapping is to help identify
  areas where small-scale water-related
  interventions systems will have maximum
  anti-poverty impacts, identify appropriate
  interventions that can benefit from water-related
  physical and institutional interventions, and
  verify the anti-poverty impacts of the chosen
  interventions.
• Spatial maps pinpoint areas that need attention
  to accelerate economic growth and focus poverty
  reduction.

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Importance of mapping Informal irrigation

• Maps have the advantage of providing a more
  revealing picture and some of its determinants
  within prescribed areas.
• New estimates can be used to generate updated
  maps that provide a more dynamic trend of poverty
  levels and more importantly provides the possible
  monitoring of targeting.
• Distribution of informal irrigation is governed
  by a large number of factors relating to the use,
  the farming system, and farmers socio-economic
  conditions.
• Predominant among these are climatic and
  environmental factors, particularly those that
  affect the use and application of informal
  irrigation such as temperature, precipitation,
  humidity, water sources, and vegetation

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Objective

• The objective of this study is to produce an
  informal irrigation distribution map that would
  constitute a useful tool for development planners
  in Nigeria.
• The recently created IWMIs Global Map of
  Irrigated provides the opportunity for producing
  empirical models and maps of irrigation
  distribution at a regional and eventually at a
  continental level.
• The strategy is to undertake a spatial
  statistical analysis of informal irrigation
  prevalence in relation to those potential
  bio-physical environmental factors involved in
  the distribution of irrigation and intensity of
  use which are readily available at any map
  location.
• The resulting model could then be used to
  predict informal irrigation distribution for
  the whole of West Africa.

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Data for Mapping

• Data to be used in used in this study for
  modeling and mapping informal irrigation
  distribution are
• long-term averages of monthly rainfall,
• monthly averages of daily minimum and maximum
  temperature,
• drainage density
• farmers population density.
• Agro-ecological zones (AEZ)
• Length of the growing period,
• Equatorial Forest zone (gt 270 days),
• Guinea Savanna zone (165270 days),
• Sudan Savanna zone (90165 days)
• Sahel zone (lt 90 days).
• This approach is based on the assumption that
  the factors affecting informal irrigation
  distribution, such as rainfall, would be
  different in the four AEZ.

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Factors for mapping
Bio-Physical factors
Socio-Economic factors

• Meteorology (rainfall)
• Agro-ecological Zone (LGP)
• Potential ET (isograms)
• Water resources (surface water, ground water,
  flood inundation)
• Topography (slope, landform)
• Vegetation Current landuse (Fallow,
  Agricultural land)
• Soil (Texture, depth, Fertility )
• Crop types

• Accessibility (road, market)
• Proximity (settlement)
• Land tenure system
• Labor force
• Credit system (budget, interest)
• Extension system
• Social custom and Gender issue
• 8. Farmers incentive

Technical Facility factors
Eco-Environmental factors

• Agronomical technology
• Water Mangment Facility technology

• Water borne disease
• Bio-diversity

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Methodologies for mapping

• Presently there existed no gold standard of
  mapping because of the wide array of
  applications, which can be adapted for informal
  irrigation mapping. The different methods
  according are
• Small-area estimation of Household level data,
  Community level data (Bigman et al., 2000)
• Weighted basic-needs index, using Principal
  components analysis, Factor analysis and
  Ordinary least-squares
• Combined qualitative-plus-secondary data
  primarily based on qualitative assessment, and
  primarily based on secondary data
• ?Extrapolated participatory approach based on
  calibrated participatory assessment (Ravnborg,
  1999 Kristjanson et al., 2005)
• ?Direct measurement using Household survey data
  and Census data

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Procedure and combination of tools

• GIS maps will be prepared separately for each
  indicator to identify the linkages between water,
  land and poverty at the first instance in
  overlaying analysis, and to recognize water poor
  areas as the second main purpose.
• Survey process and methodology will include
  identification and description of broad
  socio-economic, legal and institutional framework
  related to informal irrigation technology,
• Collection of available secondary information for
  the identification, mapping and analysis of
  different use of informal irrigation technology
  based on farming system in order to help in the
  characterization.
• The Participatory Rapid Appraisal will enable
  stakeholders to become involved in conducting
  and sharing their own investigations and
  analysis.
• Focus Group Discussions will be held for the
  restitution and validation of information. This
  will cover important issues such as listing,
  prioritization and discussion on the use,
  problems encountered and strategies to overcome
  the identified problems in relation to informal
  irrigation

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Work flow for mapping

• Identification of factors
• Bio-Physical factors
• Technical Facility factors
• Socio-Economic factors
• Eco-Environmental factors

Selection of indicators or parameters for
evaluation
Acquisition of R/S imagery ICONOS and Landsat
Gathering spatial distribution of indicators
GIS database
RS/GIS data Processing
Survey of informal irrigation distribution and
mapping in the benchmark site
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Conclusion

• From the foregoing the paper has described the
  need and importance of mapping informal
  irrigation technology
• The various methods of mapping and the procedure
  to be followed for mapping informal irrigation
  technology.
• The characterization will be based on user
  factors, socioeconomic, environmental and
  technical factors.
• These factors will take cognizance of crop types,
  farm sizes, water sources and inputs from
  national agricultural census data.
• Irrigation typologies based on crop types will be
  super imposed into the agro ecological maps.
• The expected output will be to generate informal
  irrigation maps of Nigeria and spatial
  distribution of informal irrigation in Nigeria