Demonstration Bioengineered Revetment in Bac Kan, Vietnam ADB TA - PowerPoint PPT Presentation

Using Vetiver Grass in Thanh Mai Demonstration Bioengineered Revetment in Bac Kan, Vietnam ADB TA 8102-VIE: Promoting Climate Resilient Rural Infrastructure in Northern Vietnam James Ramsay - Nguyen Dinh Ninh

OVERVIEW PROJECT NAME Promoting Climate FUNDED BY Global Bioengineered DEMONSTRATION MODEL Resilient Rural Environment revetment in Infrastructure in Facility (GEF) Thanh Mai Northern Vietnam through Asian commune, Bac Development Kan Bank (ADB) and United Nations Development Programme (UNDP)

SITE SELECTION Thanh Mai commune, Cho Moi district, Bac Kan province A tributary of Cau river SRIDP protects 2.42 km of riverbank on the Thanh Mai river in Thanh Mai and Cao Ky 2 possible sites for demonstration bioengineering measures: in Thanh Mai and Cao Ky Thanh Mai site was chosen for: (i) erosion that is threatening community infrastructure (roads, power lines), (ii) suitability for demonstration measures

LOCATION OF DEMONSTRATION SITE

SECTION SELECTED FOR BIOENGINEERING MEASURES

TECHNICAL MEASURES 6 vegetative treatments Demonstration of bioengineering measures on 106 m of Thanh Mai riverbank 1 toe protection treatment

BIOENGINEERING MEASURES APPLIED Segment Length TECHNIQUE Toe protection Bank protection (m) 1 25 Vegetated riprap Brush layers 2 25 Vegetated riprap Live poles 3 25 Riprap Live fences Fascines 4 31 Vegetated riprap Vetiver grass lines

SPECIES AND TECHNIQUES USED Bioengineering Species Name Local English Name Technique Name Brush layers Homonoia riparia Pượu Willow-leaved water croton Live fences Homonoia riparia Pượu Willow-leaved water croton Ficus benjamina Si Benjamin’s fig, Weeping fig Live poles Ficus benjamina Si Benjamin’s fig, Weeping fig Fascines Ficus benjamina Si Benjamin’s fig, Weeping fig Vegetated riprap Ficus benjamina Si Benjamin’s fig, Weeping fig Grass Chrysopogon zizanioides Vetiver Vetiver

Ficus Benjamina (Si)

Homonoia riparia (Puou)

Vetiver Grass

CROSS-SECTION K0

CROSS-SECTION K3

CROSS-SECTION K6

CROSS-SECTION K9

Thanh Mai Revetment after Construction

Vegetated riprap using ‘Si’ cuttings

Brush layers using ‘Puou’ cuttings

Planting vetiver

Planting vetiver

IRRIGATE VETIVER GRASS

SUMMARY AND RESULTS TO DATE • Planting date: 12-14 April 2015 • Latest observation date : 20 April 2015 • General Observation and Results to Date of Techniques • Toe protection: survived flood during construction • Bank protection: too early to assess • Homonoia riparia - Brush layers • Homonoia riparia - Live fences • Ficus benjamina - Live fences • Ficus benjamina - Live poles • Ficus benjamina – Fascines • Ficus benjamina – Vegetated riprap • Chrysopogon zizanioides - Vetiver Grass rows • Effectiveness of Vetiver compared with Other Plants from Results to Date: too early to assess • Recommendations : continue monitoring; bring visitors to raise awareness

Benefits of bioengineering in general or with Vetiver grass Low cost: 20-40% as much Environmentally as conventional friendly measures Short construction Cost-effective time (only 2 months) Uses local labour