G1 partners5th May 2014
Extrapolation domains and land use plans for the
coastal zone of Bangladesh
IWM LGED IRRI SRDI BWDB
“What works where?”
“Area, people, livelihoods”
“data, data, data”
G1 in three words
Andy IntroductionSohel Census data, infrastructure and mouzasNasim Water, drainage and storageParvesh Land use/land cover and extrapolation domainsAndy Sharing results and what next?
Outline
OutputsTarget area for extrapolation domainsBest bet options in coastal Bangladesh
OutputsTarget area for extrapolation domainsCoastal polders cover 1m ha
OutputsTarget area for extrapolation domains
High saline - Polder 3Rice/shrimp &Aquaculture
Moderately saline - Polder 30 – Usually one crop per year
Low saline - Polder 43/2f
Up to two crops per year
The coastal zone in a nutshell
This zone covers:• 1.45m farm holdings, 10% of the national total• 7.3 million people and 2m laborers, many of them
poor• Irrigated area is 25%, national average is 68%• HYV rice area 24%, national average is 56%• Cropping intensity is very low compared to the
national average.• The coastal zone is one of few areas in Bangladesh
where productivity and intensity can be significantly increased.
It is a zone with huge potential, but where exactly is that potential? And then, how to unlock it?
Best bet options in coastal Bangladesh
Suitable areas for innovative cropping systems?Spatial analysis of suitability factors/constraintsHow will this change in future?Impact of future scenarios on factors/constraintsHow can we inform stakeholders about the opportunities?Improved dissemination/sharing of information
High resolution land use maps “What is the current land use?”Cropping system extrapolation domains “What works where? Now and in the future”Southwest Coastal Region Information System“Open access spatial data - webGIS”
G1 Outputs and Aims
• Emphasis on collecting and developing the best possible datasets.
• Emphasis on both spatial AND temporal data to represent the different requirements of the cropping systems through the year. Especially for water.
• Emphasis on making our spatial data freely available.• Looking to the future – where and when can these same
methods and data be used to address other research questions?
Andy IntroductionSohel Census data, infrastructure and mouzasNasim Water, drainage and storageParvesh Land use/land cover and extrapolation domainsAndy Sharing results and what next?
Outline
Activities carried out by LGED
1. Preparation of Different layers of base information:
Different layers of administrative boundary and Head quarter including Mouza Boundary (Smallest boundary layer)
Road Network (up to village road)Growth Center and Rural Market Facilities River Network and Water Body Data
2. Preparation of Mouza wise Socio-economic information
Road Network: Accessibility to remote area Growth Center and Rural Market: facilities for rural people
for economic development
The Map shows the River Network and water body: data generated from RapidEye satellite image (2011)
Development of Lowest boundary layer (Mouza Boundary)
Map of Mouza Layer (Polder 3)
Mouza wise 2008 Agricultural census data layer
Mouza wise 2008 Agricultural census data layer
Andy IntroductionSohel Census data, infrastructure and mouzasNasim Water, drainage and storageParvesh Land use/land cover and extrapolation domainsAndy Sharing results and what next?
Outline
May, 2012
Base Year: 2012
KHULNA
BARISAL
Spatial and Seasonal Variation of Salinity in the Coastal Ganges in Bangladesh
Digital Elevation Model (DEM) of the Coastal Area
Kharif-1 Kharif-2 RabiAvg WL 1.00m PWD
Avg WL 1.30m PWD
Avg WL 0.80m PWD
Opportunity for Gravity Drainage & Gravity Irrigation
1.35 mPWD Avg WL
1.84 mPWD High WL with 3hr tidal window for Irrigation
0.90 mPWD Low WL with 3hr tidal window for Drainage
Gravity Drainage
Gravity Irrigation
Gravity Irrigation
Andy IntroductionSohel Census data, infrastructure and mouzasNasim Water, drainage and storageParvesh Land use/land cover and extrapolation domainsAndy Sharing results and what next?
Outline
Existing Land use in Coastal Districts of Barisal and Khulna
Divisions
Existing Land use/Cropping System
- Data used, Material and Methods
- Results : Examples of major cropping system
- Assessment of water regimes using improved indices
- Next Steps
Extrapolation Domains
- Data used, Material & Methods
- Results : examples of existing and improved cropping systems
- Next Steps
Socio-economic Indices
- Potential Technology Adoption Index
- Livelihood Index
Data gaps, Next Steps
Contents ….
Satellite data used : IRS Resourcesat – LISS III, 23 M resolution
Pass/Row covered : 109-56 & 110-56
GPS Ground Truth : 3 times and collected more than 1000
pictures
Time : October 2011 to May 2012
Image Processing : Radiometric correction (using PIFS) & pre-
processing Image classification : Spectral Temporal NDVI
profiles, Decision rules, associations
Post classification procedures & accuracy assessment
Existing Land use: Datasets and Material & Methods
Satkhira
Khulna
Bagerhat
Narail
Sunderban
Aman Rabi Aus
Nov Jan Feb Mar Apr May
Aman Boro
Nov Jan Feb Mar Apr May
Aman-Rabi-Aus
Aman-Boro
Aman-Rabi crop
Shrimp-Aman
Aman-Fallow
Water Bodies/Ghers
Settlements
Major land use Classes
Existing Land use in 4 coastal districts of Khulna division : mainly for Aman and Boro season
Existing Land use, Khulna division
Harvest
Planting
Harvest Harvest
Planting
Planting
Overall accuracy assessment = 86%
Fallow Boro
Nov Feb Mar Apr
Aman-Rabi/Legumes/br
Fallow - Boro
Aman-Fallow
Water Bodies
Settlements
Major land use Classes
Barisal
Bhola
Patuakhali
Berguna
Jhalakati
Existing Land use in 5 coastal districts of Barisal division : Aman and Boro season only
Aman Fallow
Nov Feb Mar Apr
Waterlogged
No Water
Planting
Harvest
Overall Accuracy = 89%
Existing Cropping Systems of Barisal division Existing Land use: Results
1. Water will have greater positive values than in the NDWI as it absorbs more MIR light than NIR Light
2. Built-up land will have negative values as mentioned above;
3.Soil and vegetation will still have negative values as soil reflects MIR light more than NIR light
Improved Normalized Water Difference Index: Seasonal Change in water regimes
Nov, 2011 Feb, 2012
Mar, 2012 Apr, 2012
Shallow Depth
Medium Depth
Deep Water
Water RegimesVery Shallow Depth/ Excessive moist
Existing Land use: Results
Nov Jan Feb Mar Apr May Nov Jan Feb Mar Apr May
Nov Jan Feb Mar Apr May
Can we estimate water depth/water availability in Khals?Existing Land use: Results
Extrapolation Domains
Study Area
Material and methods
1 Expert assessment of the requirements for each cropping system.2 Identification and collection of data that either measure or act as proxies for those requirement.3 Suitability scores based on location specific characteristics relative to the cropping system requirements.4 Suitability maps for each cropping system.5 Review and revise maps with focus groups.
Characterize the cropping systems
Aman - RabiTraditional Aman rice is transplanted in Aug and harvested in Dec/Jan. Aman rice is almost entirely rain fed and uses local varieties that can withstand flood depth to 0.8 m. The Rabi crop (e.g. sesame, moonbeam) is seeded in Feb-Mar and harvested in May-Jun. The Rabi crop uses residual soil moisture with supplemental irrigation when ground water or (stored) canal water is available. Rainfall at the end of the rabbi season can negatively affect the crop, thus good surface drainage is important.
We start with a narrative…
Taos HYV - Aman HYV - Boor HYV A short duration Aus HYV is seeded in early April, transplanted in late April and harvested by end of July. The Aus crop uses seedbeds and land preparation and is irrigated when river water is fresh, with groundwater (GW) or from canal water. In this case, capacity of gravity irrigation is considered. Short duration, non photoperiod sensitive Aman HYV is transplanted by first week of August and harvested by the end of November. The Aman rice crop is completely rain fed. Its performance depends greatly on maximum inundation depth/land topography. When inundation depth > 0.4 m, drainage capacity must be considered. This, in turn depends on the difference between land elevation and the water levels at low tides and distance from canals/rivers. Boor HYV is transplanted before mid December and harvested by mid April. The Boor rice crop is irrigated with GW or river water (when fresh) or with water stored in canal networks. When river water is fresh, the ability to irrigate by gravity is considered. Storage capacity is considered when stored water is used. Distance from water source is considered in both cases.
Some are quite complex…
…a lot of data needed
Irrigation with GW
1 Fresh (< 4dS/m) ground water availability 2 Ground water pumping depth
Irrigation with SW
3 Latest month when river water <3 dS/m 4 Maximum river water salinity in April/May 5 Maximum river water salinity in August 6 Difference in high water level in April and land surface for gravity irrigation 7 Difference in high water level in March and land surface for gravity irrigation
8 Difference (m) in land surface and high water level in Mar/Apr for irrigation 9 Storage capacity 10 Proximity to river, canal, ponds, for irrigation
Drainage
11 Proximity to river, canal, for drainage 12 Maximum inundation depth/land type 13 Maximum inundation depth for > three days in May 14 Maximum inundation depth in September/October 15 Maximum inundation depth for > one week in September/October 16 Maximum inundation depth for > two weeks in September/October 17 Difference in land surface and low water level in May for drainage 18 Difference in land surface and low water level in September/October for drainage
Soil 19 Soil texture 20 Soil pH 21 Soil salinity
gher water 22 lowest water salinity during January and highest during April (ppt) 23 Inundation depth/land type
Climate
24 Weekly air minimum temperature at stocking 25 Weekly mean minimum air temperature in January 26 Two-week mean air temperature in December and January 27 Cumulative rainfall in July & August
Social and economic
28 Livelihood/asset index 29 Technology adoption index
Extensive Gher based year round brackish water aquaculture
Description
Minimum air temperature
for 1week (C)
Minimum salinity (ppt)
at PL stocking
Land type / Inundation
depth
Soil texture
Acidity (pH)
Shrimp PL is stocked in Feb when there is brackish water adequate and
suitable temperature,
brackish water Fish is stocked
few weeks later. Water is
replenished as needed. Harvest
starts after 2 month until end
of Nov.
>25 S1 >10 S1 0.5 - 0.7 S1clay Loam
S16.5 - 7.5
S1
20 - 25 S2 5 to 10 S20.7- 1; 0.3 - 0.5
S2Loam
S15.5 - 6.5; 7.5 - 8.5
S2
18 -20 S3 2 - 5 S31 - 1.2; 0 - 0.3
S3Sand
y loam
S24.5 5.5; 8.5 - 9.5
S3
<18 SN <2 SN> 1.2; no inundation
SNSand
ySN
<4.5; >9.5
SN
S1 = Most Suitable S2 = Suitable S3 = Marginally Suitable SN = Not Suitable
Requirement for aquaculture
Aman - Boor Water quality and availability in dry season
Description of Land use type(technology)
Fresh (< 4dS/m),
ground water availability
and pumping depth
Month when river water still
remain fresh
(<4 dS/m)
Internal storage
capacity in relation to land area(ML/ha)
Proximity to river, canal,
ponds (m)
Difference (m) in high water level in Mar and
land surface for
gravity irrigation
(m)
Boor rice is seeded around 15 Nov. (MS) to 15 Dec (LS). Aman rice is rain fed. Boor rice is irrigated with river water (when fresh) or with water stored in canal networks.
Yes, < 6 m
S1 March S1 > 5 S1 <50 S1 > 1 S1
Yes, 7 -20 m
S2 Feb S2 2.5 - 5 S2 50-100 S2 0.5 - 1 S2
yes, > 20 S3 Jan S3 1 - 2.5 S3100-300
S30.2 - 0.5
S3
No SN Dec SN <1 SN >300SN
< 0.2 SN
Aman - Boor Water quality and availability in wet season
Description of Land use
type(technology)
Maximum inundation depth (m) in August
Maximum inundation depth (m) for more than one week in
Sep/Oct
Difference (m) in land surface and low water level in
Sep/Oct for drainage
Aman HYV rice is transplanted in July-August, to be harvested by the end of November (Moderate Salinity zone) or December (low saline zone).
< 0.1 S1 < 0.2 S1 > 1 S1
0.1 – 0.2 S2 0.2 – 0.5 S2 0.5 - 1 S2
0.2 – 0.3 S3 0.5 – 0.8 S3 0.2 – 0.5 S3
> 0.3 SN > 0.8 SN < 0.2 SN
S1 = Most Suitable S2 = Suitable S3 = Marginally Suitable SN = Not Suitable
Water requirements for Aman - Boor
Fresh groundwat
er (< 4dS/m)
Tubewell?Tubewell depth
(m)
Month when river water (< 3
dS/m)
Storage capacity (ML/ha)
Proximity to fresh SW source (m)
Suitability for HYV
Boor rice crop
Yes
No
Shallow
Deep
< 6
7 - 20
Mar
Feb
Jan
Dec
> 20
2.5 - 5
1- 2.5
2.5 - 5
1 – 2.5
< 100
> 100
< 100
> 100
< 100
> 100
< 100
> 100
S1
S1
S2
S3
S1
S1
S2
S2
S3
S2
S3
S3
SN
SN
Groundwater Surface water
Soil pH Soil texture
Min temp – 8th-14th Feb Soil salinity Water salinity
Example: Input datasets
Flood inundation depth
Values in percent
Percentage of small farms, <1ha
Percentage of leased land
Through our partners we have obtained the 2011 population and 2008 agricultural census’ at village level. This is a huge and still untapped resource.
Example: Input dataset
Existing system for validation(1)Aman – Rabi crop(2)Aus - Aman(3)Aman - Shrimp(4)Year round aquacultureInnovative systems for targetting(5)Aman (HYV) - Rabi (HVC)(6)Aus – Aman - Boor(7)Aus - Aman - Rabi crop(8)Boor - Aman(9)Aus (HYV) – Aman (HYV)(10) Year round polyculture(11) Shrimp - RiceEach one can be mapped as present and conditional system
Proposed number of domains to map
Material and methods
Year Round Aquaculture
S1 = Most Suitable S2 = Suitable S3 = Marginally Suitable SN = Not Suitable
Material and methods
Criteria and parameters for developing extrapolation domains
Inundation Depth Soil pH Soil Texture
Min Temp – 2nd week of Feb and March Max water Salinity levels
Material and methods
Results …
Results
0-7 days - Feb 7-15days - Feb
21-30 days - Feb
15-21days - Feb
Extrapolation domains/suitable areas for Pl stocking
0-7 days - Feb 7-15days - Feb 15-21days - Feb0-7 days - Feb 7-15days - Feb
21-30 days - Feb
15-21days - Feb0-7 days - Feb 7-15days - Feb
0-7 days - March
Results existing systems …
Results …
Areas Suitable for Shrimp Cultivation
Results existing systems …
Marginally suitable = Dark Green Suitable = Light Green Most suitable = Purple Not suitable = Yellow
Results …
Areas Suitable for Aman Rice Cultivation
Results exiting systems …
Marginally suitable = Dark Green Suitable = Light Green Most suitable = Purple Not suitable = Yellow
Results existing systems …
Suitability for Shrimp-Aman Cultivation
ShrimpAman Rice
Shrimp-Rice
Marginally suitable = Dark Green Suitable = Light Green Most suitable = Purple Not suitable = Yellow
Results Improved systems…
Not Suitable
Marginal Suitable
Marginally suitable = 330,000 haSuitable area = 180,000 ha
Results Improved systems…
Extrapolation Domains : Aus (HYV)-Aman (HYV)-Rabi cropping system
Not SuitableMarginal Suitable
Marginally suitable = 500,000 haSuitable area = 16,000 ha
Results …
Shrimp TAus Aman
Shrimp-Aman
Aman
Ex. Domains at Polder Level
Marginally suitable = Dark Green Suitable = Light Green Most suitable = Purple Not suitable = Yellow
Part 3: Socio-economic Indices
Low (< -0.5)
Medium (-0.5 to 0.5)High (0.5 to 1.5)
Range of Composite Standard Score/Z Score
Very High (>1.5)
Polder 30, District Khulna
Technology Adoption Index at Mouza Level
Polder 3, District Satkhira
Results …data gaps
1. Generalized soil salinity map (2009)
2. Detailed Salinity Map (2009) which I have prepared using the actual survey data of EC from SRDI
Andy IntroductionSohel Census data, infrastructure and mouzasNasim Water, drainage and storageParvesh Land use/land cover and extrapolation domainsAndy Sharing results and what next?
Outline
WebGIS – http://gangesriverbasin.blogspot.com
• Remote sensing can be used to map seasonal rice area for all Bangladesh
• Can assess changes in cropping intensity from year to year and monitor flood extent
• Seasonal rice maps will be freely available on the webGIS
[email protected] for a copy of the paper
Key messages
1 Big potential for sustainable, increased productivity and
improved livelihoods in the coastal zone of Bangladesh
2 Based on research findings from Ganges Basin Development
Partnerships
3 Institutional data sharing has been key to developing new,
detailed maps that show the potential land use and the
potential scale of livelihood improvement
4 Our webGIS is one way to ensure the data remains open &
free
Where next in 2014/15?
1. Assess the impact of salt tolerant varieties using the extrapolation domain methodology. How many people could benefit from innovative systems that include current and future stress tolerant varieties?
2. Assess the impact of improved drainage using the same method. How many people would benefit from infrastructure renovation/improvement for increased productivity?
3. Assess changes in land use under G4 scenarios. What are the implications for land use planning in the coastal zone?
Where next in 2014/15?
4. Share spatial data results as widely as possible. What are the key research questions in the coastal zone and elsewhere? How can the methods be adopted to address them? What expertise is needed to do this?
5. Launch of the WebGIS. Still need to address who will sustain the webGIS and the spatial data it hosts?
Thank you
IWM LGED IRRI SRDI BWDB