G1 Extrapolation domains and land use plans for the coastal zone of Bangladesh

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by Andy Nelson, Parvesh Kumar Chandna, Md. Nasim Al Azad Khan, Md Sohel Rana. Presented at Ganges Regional Research Workshop of the Challenge Program on Water and Food/Water Land and Ecosystems (CPWF/WLE), May 2014

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G1 Extrapolation domains and land use plans for the coastal zone of Bangladesh

  1. 1. G1 partners 5th May 2014 Extrapolation domains and land use plans for the coastal zone of Bangladesh
  2. 2. “What works where?” “Area, people, livelihoods” “data, data, data” G1 in three words
  3. 3. Andy Introduction Sohel Census data, infrastructure and mouzas Nasim Water, drainage and storage Parvesh Land use/land cover and extrapolation domains Andy Sharing results and what next? Outline
  4. 4. OutputsTarget area for extrapolation domainsBest bet options in coastal Bangladesh
  5. 5. OutputsTarget area for extrapolation domainsCoastal polders cover 1m ha
  6. 6. OutputsTarget area for extrapolation domains High saline - Polder 3 Rice/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?
  7. 7. Best bet options in coastal Bangladesh Suitable areas for innovative cropping systems? Spatial analysis of suitability factors/constraints How will this change in future? Impact of future scenarios on factors/constraints How can we inform stakeholders about the opportunities? Improved dissemination/sharing of information
  8. 8. 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?
  9. 9. Andy Introduction Sohel Census data, infrastructure and mouzas Nasim Water, drainage and storage Parvesh Land use/land cover and extrapolation domains Andy Sharing results and what next? Outline
  10. 10. 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
  11. 11.  Road Network: Accessibility to remote area  Growth Center and Rural Market: facilities for rural people for economic development
  12. 12. The Map shows the River Network and water body: data generated from RapidEye satellite image (2011)
  13. 13. Development of Lowest boundary layer (Mouza Boundary) Map of Mouza Layer (Polder 3)
  14. 14. Mouza wise 2008 Agricultural census data layer
  15. 15. Mouza wise 2008 Agricultural census data layer
  16. 16. Andy Introduction Sohel Census data, infrastructure and mouzas Nasim Water, drainage and storage Parvesh Land use/land cover and extrapolation domains Andy Sharing results and what next? Outline
  17. 17. May, 2012 Base Year: 2012 KHULNA BARISAL Spatial and Seasonal Variation of Salinity in the Coastal Ganges in Bangladesh
  18. 18. Digital Elevation Model (DEM) of the Coastal Area
  19. 19. Kharif-1 Kharif-2 Rabi Avg 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
  20. 20. Gravity Drainage
  21. 21. Gravity Irrigation
  22. 22. Gravity Irrigation
  23. 23. Andy Introduction Sohel Census data, infrastructure and mouzas Nasim Water, drainage and storage Parvesh Land use/land cover and extrapolation domains Andy Sharing results and what next? Outline
  24. 24. Existing Land use in Coastal Districts of Barisal and Khulna Divisions
  25. 25. 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 ….
  26. 26. 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
  27. 27. 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%
  28. 28. 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
  29. 29. 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 Regimes Very Shallow Depth/ Excessive moist Existing Land use: Results
  30. 30. 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
  31. 31. Extrapolation Domains
  32. 32. Study Area Material and methods
  33. 33. 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
  34. 34. Aman - Rabi Traditional 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 We start with a narrative…
  35. 35. 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
  36. 36. 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
  37. 37. 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 S1 clay Loam S1 6.5 - 7.5 S1 20 - 25 S2 5 to 10 S2 0.7- 1; 0.3 - 0.5 S2 Loam S1 5.5 - 6.5; 7.5 - 8.5 S2 18 -20 S3 2 - 5 S3 1 - 1.2; 0 - 0.3 S3 Sandy loam S2 4.5 5.5; 8.5 - 9.5 S3 <18 SN <2 SN > 1.2; no inundation SN Sandy SN <4.5; >9.5 SN S1 = Most Suitable S2 = Suitable S3 = Marginally Suitable SN = Not Suitable Requirement for aquaculture
  38. 38. 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 S3 100-300 S3 0.2 - 0.5 S3 No SN Dec SN <1 SN >300 SN < 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
  39. 39. Fresh groundwater (< 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
  40. 40. Soil pHSoil texture Min temp – 8th-14th Feb Soil salinity Water salinity Example: Input datasets Flood inundation depth
  41. 41. 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
  42. 42. Existing system for validation (1)Aman – Rabi crop (2)Aus - Aman (3)Aman - Shrimp (4)Year round aquaculture Innovative systems for targetting (1)Aman (HYV) - Rabi (HVC) (2)Aus – Aman - Boor (3)Aus - Aman - Rabi crop (4)Boor - Aman (5)Aus (HYV) – Aman (HYV) (6)Year round polyculture (7) Shrimp - Rice Each one can be mapped as present and conditional system Proposed number of domains to map Material and methods
  43. 43. Year Round Aquaculture S1 = Most Suitable S2 = Suitable S3 = Marginally Suitable SN = Not Suitable Material and methods Criteria and parameters for developing extrapolation domains
  44. 44. Inundation Depth Soil pHSoil Texture Min Temp – 2nd week of Feb and March Max water Salinity levels Material and methods
  45. 45. Results … Results
  46. 46. 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 …
  47. 47. Results … Areas Suitable for Shrimp Cultivation Results existing systems … Marginally suitable = Dark Green Suitable = Light Green Most suitable = Purple Not suitable =Yellow
  48. 48. Results … Areas Suitable for Aman Rice Cultivation Results exiting systems … Marginally suitable = Dark Green Suitable = Light Green Most suitable = Purple Not suitable =Yellow
  49. 49. Results existing systems … Suitability for Shrimp-Aman Cultivation Shrimp Aman Rice Shrimp-Rice Marginally suitable = Dark Green Suitable = Light Green Most suitable = Purple Not suitable =Yellow
  50. 50. Results Improved systems… Not Suitable Marginal Suitable Marginally suitable = 330,000 ha Suitable area = 180,000 ha
  51. 51. Results Improved systems… Extrapolation Domains : Aus (HYV)-Aman (HYV)-Rabi cropping system Not Suitable Marginal Suitable Marginally suitable = 500,000 ha Suitable area = 16,000 ha
  52. 52. 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
  53. 53. Part 3: Socio-economic Indices
  54. 54. 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
  55. 55. 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
  56. 56. Andy Introduction Sohel Census data, infrastructure and mouzas Nasim Water, drainage and storage Parvesh Land use/land cover and extrapolation domains Andy Sharing results and what next? Outline
  57. 57. WebGIS – http://gangesriverbasin.blogspot.com
  58. 58. • 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 A.Nelson@irri.org for a copy of the paper
  59. 59. 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
  60. 60. 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?
  61. 61. 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?
  62. 62. Thank you IWM LGED IRRI SRDI BWDB

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