Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Promoting Climate Resilient Rural
Infrastructure in Northern Vietnam
ADB TA 8102-VIE
“ Results of Bioengineered Rural Road...
I. INTRODUCTION
- “Promoting Climate Resilient Rural Infrastructure in
Northern Mountains of Vietnam” project was funded
b...
Project Purpose
• To assist Vietnam in taking steps to protect rural
infrastructure from the anticipated effects of climat...
Rural road erosion
Is this an effective approach?
Potential consequences
Riverbank erosion
Hard revetments do not ensure effective
protection
Hard revetments do not ensure effective
protection
Outputs
1. Climate change threats and impacts are assessed
and adaptation options identified.
2. Concept and detailed desi...
Bioengineering: definition
• “Bio-engineering is the use of plants to perform
technical surface protection (…) to control ...
Comparative strength of bioengineering structure
and civil engineering structure over time*
II. RESULTS OF 4 DEMONSTRATIONS
Implementation procedure
Preparation
Implementation
Monitoring -
maintenance
Transfer
a. Preparation
• The Inception Workshop was held in April 2013.
• The proposed demonstration sites were reviewed and an
al...
Preparation
• Concept designs for the demonstration measures were
developed.
• The TA’s training framework was developed a...
Preparation
• The feasibility study and detailed design drawings for the
demonstration measures at Sub-project 4 in Bac Ka...
Results
b. Construction
Start Finish Maintenance
SP4 26 February
2015
26 April 2015 30 June 2016
SP32 15 April 2015 26 Jun...
Measures applied at 2 riverbank demonstrations
Measures applied at 2 roadside slope
demonstrations
Cross-section
Cross-section
Construction of Thanh Mai riverbank revetment
Construction of Muoi stream revetment
Construction of embankment in Thai Nguyen
Construction of demonstration on cut slope
in Son La
Construction
• Short construction time, 2 months for a
demonstration.
• Only SP31- Son La took 2 months longer due to
rain...
Thanh Mai revetment before construction
Thanh Mai revetment after construction
April 2015
May 2015
July 2015
July 2016
March 2017
April 2015
July 2015
July 2016
March 2017
Vegetated riprap
Muoi riverbank before construction
Muoi riverbank after construction
Local people engaged in construction
April 2017
April 2017
April 2017
Initial assessment
• Riverbank revetments in Thanh Mai, Bac Kan
and Thon Mon, Son La have gone through 2
rainy seasons wit...
Initial assessment
• Revetment toe was stabilized by riprap or
vegetated gabions, using Homonoia Riparia
(North-East), Sal...
SP35 before construction
Gullies on fill slope
SP35 after construction
October 2016
October 2016
October 2016
March 2017
March 2017
March 2017
SP31 before construction
SP31 after construction
April 2017
April 2017
April 2017
Initial assessment
• Roadside slope protection demonstrations have
only gone through one rainy season.
- Slope protection ...
Initial assessment
• Randia tomentosa used at toe slope, Tiger grass used
on upper slope are native plant species.
• Vetiv...
Comparative cost
General comments
Advantages of bioengineering:
 Sustainable when properly applied
 Environmentally friendly
 Promotes l...
Lessons learned
1. Identify high-risk locations at early stage in a
project
2. Include bioengineering at earliest stage of...
Lessons learned
5. The importance of integrating hard and soft
measures
6. The limitations of bioengineering – it cannot
f...
Replication potential
- Mrs Ha Thi Huyen has used
Homonoia riparia for her
family’s field erosion
protection in reference ...
Conclusions and recommendations
1. Generally, bioengineering measures can be
effectively applied for riverbank and roadsid...
Thank you!
Upcoming SlideShare
Loading in …5
×

Promoting Climate Resilient Rural Infrastructure in Northern Vietnam: Final Workshop - Results of Bioengineered Rural Roadside Slope and Riverbank Protection Demonstrations

517 views

Published on

The ADB Capacity Development Technical Assistance project Promoting Climate Resilient Rural Infrastructure in Northern Vietnam is demonstrating how non-conventional engineering solutions can strengthen rural infrastructure, resisting the hazards associated with climate change and providing opportunities to enhance community livelihoods. The project focuses on bioengineering as a low-cost alternative to conventional slope stabilization and protection techniques

Published in: Environment
  • Be the first to comment

Promoting Climate Resilient Rural Infrastructure in Northern Vietnam: Final Workshop - Results of Bioengineered Rural Roadside Slope and Riverbank Protection Demonstrations

  1. 1. Promoting Climate Resilient Rural Infrastructure in Northern Vietnam ADB TA 8102-VIE “ Results of Bioengineered Rural Roadside Slope and Riverbank Protection Demonstrations” Nguyen Dinh Ninh – David Rojas
  2. 2. I. INTRODUCTION - “Promoting Climate Resilient Rural Infrastructure in Northern Mountains of Vietnam” project was funded by Global Environment Facility (GEF). - The ADB-administered component supports the construction of low cost, easily implementable measures to reduce the vulnerability of rural infrastructure to extreme climate events. - The project was scheduled to last for 52 months, from January 2013 to May 2017.
  3. 3. Project Purpose • To assist Vietnam in taking steps to protect rural infrastructure from the anticipated effects of climate change …. …by enhancing the capacity of stakeholders at local, provincial and national level (i) to assess climate risks, and (ii) to design and implement cost-effective, sustainable, bioengineered solutions to mitigate climate impacts.
  4. 4. Rural road erosion
  5. 5. Is this an effective approach?
  6. 6. Potential consequences
  7. 7. Riverbank erosion
  8. 8. Hard revetments do not ensure effective protection
  9. 9. Hard revetments do not ensure effective protection
  10. 10. Outputs 1. Climate change threats and impacts are assessed and adaptation options identified. 2. Concept and detailed designs developed, communities engaged, and demonstration adaptation activities implemented. 3. Strengthened capacity of project stakeholders to assess climate change impacts and select, design and implement bioengineered solutions.
  11. 11. Bioengineering: definition • “Bio-engineering is the use of plants to perform technical surface protection (…) to control erosion or help to prevent or stabilise shallow slope movements” (Lao People’s Democratic Republic, Slope Maintenance Manual, September 2008) • " Soil bioengineering is the use of living plant materials to perform some engineering function, from simple erosion control with grass and legume seeding or more complex slope stabilization with willows and other plants ” (Schiechtl, 1980)”(D.F. Polster, May 2003)
  12. 12. Comparative strength of bioengineering structure and civil engineering structure over time*
  13. 13. II. RESULTS OF 4 DEMONSTRATIONS Implementation procedure Preparation Implementation Monitoring - maintenance Transfer
  14. 14. a. Preparation • The Inception Workshop was held in April 2013. • The proposed demonstration sites were reviewed and an alternative road site (SP34 in Thai Nguyen province) identified, proposed and formally approved. • Baseline fieldwork and consultation were completed at all four sites. • Technical surveys of all four sub-projects were carried out, specifically geotechnical and hydrological.
  15. 15. Preparation • Concept designs for the demonstration measures were developed. • The TA’s training framework was developed and reported . • The Technical Core Group was approved and established. • The first formal training event was held in November 2013 involving core group members and others (Vulnerability Assessment and Adaptation Response Workshop)
  16. 16. Preparation • The feasibility study and detailed design drawings for the demonstration measures at Sub-project 4 in Bac Kan: submitted to CPMU on 23 June 2014 and approved by MARD on 31 December 2014. • The feasibility study and detailed design drawings for the demonstration measures at Sub-project 32 in Son La: submitted to CPMU on 10 November 2014 and approved by MARD on 9 March 2015. • The feasibility study and detailed design drawings for the demonstration measures at Sub-project 35 in Thai Nguyen: submitted to CPMU on 18 December 2015 and approved by MARD on 27 April 2016. • The feasibility study and detailed design drawings for the demonstration measures at Sub-project 31 in Son La: submitted to CPMU on 15 January 2016 and approved by MARD on 23 May 2016.
  17. 17. Results b. Construction Start Finish Maintenance SP4 26 February 2015 26 April 2015 30 June 2016 SP32 15 April 2015 26 June 2015 30 August 2016 SP35 23 May 2016 23 July 2016 20 July 2017 SP31 28 June 2016 10 October 2016 01 November 2017
  18. 18. Measures applied at 2 riverbank demonstrations
  19. 19. Measures applied at 2 roadside slope demonstrations
  20. 20. Cross-section
  21. 21. Cross-section
  22. 22. Construction of Thanh Mai riverbank revetment
  23. 23. Construction of Muoi stream revetment
  24. 24. Construction of embankment in Thai Nguyen
  25. 25. Construction of demonstration on cut slope in Son La
  26. 26. Construction • Short construction time, 2 months for a demonstration. • Only SP31- Son La took 2 months longer due to rainfall and floods. • Best time for construction: earthworks done in dry season, installation of bioengineering measures carried out in the middle or at the end of Spring. • 12-month maintenance: appropriate duration
  27. 27. Thanh Mai revetment before construction
  28. 28. Thanh Mai revetment after construction
  29. 29. April 2015
  30. 30. May 2015
  31. 31. July 2015
  32. 32. July 2016
  33. 33. March 2017
  34. 34. April 2015
  35. 35. July 2015
  36. 36. July 2016
  37. 37. March 2017
  38. 38. Vegetated riprap
  39. 39. Muoi riverbank before construction
  40. 40. Muoi riverbank after construction
  41. 41. Local people engaged in construction
  42. 42. April 2017
  43. 43. April 2017
  44. 44. April 2017
  45. 45. Initial assessment • Riverbank revetments in Thanh Mai, Bac Kan and Thon Mon, Son La have gone through 2 rainy seasons with major floods, yet remained intact. • Revetment toe remains stable. • Plants have had robust growth. • Riverbed at the demonstration sites remains stable.
  46. 46. Initial assessment • Revetment toe was stabilized by riprap or vegetated gabions, using Homonoia Riparia (North-East), Salix tetrasperma (North-West). • Stabilization measures used for semi- inundated upper slope included Homonoia Riparia (North-East), Salix tetrasperma (North- West). • Stabilization measures used for upper slope included Vetiver grass or blanket grass.
  47. 47. SP35 before construction
  48. 48. Gullies on fill slope
  49. 49. SP35 after construction
  50. 50. October 2016
  51. 51. October 2016
  52. 52. October 2016
  53. 53. March 2017
  54. 54. March 2017
  55. 55. March 2017
  56. 56. SP31 before construction
  57. 57. SP31 after construction
  58. 58. April 2017
  59. 59. April 2017
  60. 60. April 2017
  61. 61. Initial assessment • Roadside slope protection demonstrations have only gone through one rainy season. - Slope protection demonstration at Nhau Pass in Thai Nguyen: stable, showing no signs of erosion, plants have had good growth and provided full coverage for cut and fill slopes. - Flowers of Tiger grass have been harvested by local residents and used for making brooms. • Slope protection demonstration has not yet gone through any flood seasons → further review required.
  62. 62. Initial assessment • Randia tomentosa used at toe slope, Tiger grass used on upper slope are native plant species. • Vetiver grass is highly effective in slope erosion protection, yet relatively costly because it is not locally available, hence incurring transportation cost. • Further research of other native plant species for slope erosion protection (Rhodomyrtus tomentosa or Rose myrtle, Melastomataceae, Cortaderia selloana or Pampas grass, Imperata cylindrical or Cogon grass…) recommended.
  63. 63. Comparative cost
  64. 64. General comments Advantages of bioengineering:  Sustainable when properly applied  Environmentally friendly  Promotes livelihoods  Easy to implement and time efficient  Low cost
  65. 65. Lessons learned 1. Identify high-risk locations at early stage in a project 2. Include bioengineering at earliest stage of project planning 3. Use local knowledge of plants 4. Use low-cost investigation procedures
  66. 66. Lessons learned 5. The importance of integrating hard and soft measures 6. The limitations of bioengineering – it cannot fix deep-seated slope failures 7. The need for clear and simple design guidance 8. The importance of quality control
  67. 67. Replication potential - Mrs Ha Thi Huyen has used Homonoia riparia for her family’s field erosion protection in reference to demonstration measures used at Thanh Mai riverbank revetment. - Lai Chau and Lang Son DARD have contacted ICEM consultants to obtain reference documents and discuss potential bioengineering options for local use.
  68. 68. Conclusions and recommendations 1. Generally, bioengineering measures can be effectively applied for riverbank and roadside slope protection. 2. Certain measures (e.g. live poles on riverbank, jute net and grass seed) require revision or improvement. 3. It is important to select appropriate plant species and growing season in order to ensure the success of bioengineering measures.
  69. 69. Thank you!

×