Updating a medium-scale landslide database for high-risk areas using community surveys in Vietnam

Transcription

1 On-going program of the State-Funded Landslide Project (SFLP): Updating a medium-scale landslide database for high-risk areas using community surveys in Vietnam Coordinated by: Le Quoc Hung, Pham Van Son, Nguyen Thi Hai Van et al. Add: 67 Chien Thang Street, Ha Dong District, Hanoi City, Vietnam Phone : (++84) Fax: (++84) vigmr@vigmr.vn Website: 1

2 CONTENTS I. Introduction - Master Project (SFLP) II. Aims and main tasks of on-going project III. Pilot surveys and initial results IV. Challenges

3 I. INTRODUCTION State-Funded Lanslide Project (SFLP) Full title: Investigation, assessment and warning zonation for landslides in the mountainous regions of Vietnam Carrying out by: ~500 staffs of 15 organizations in Vietnam) Leading agency : Vietnam Institute of Geosciences and Mineral Resources (VIGMR) Implemented in mountainous areas 75% area of the country mainland 37/63 provinces Goals: Establishment of a standard national database on landslides and generation of landslide hazard maps at 1:50,000 for 37 mountainous provinces of Vietnam, and at 1:10,000 for hotspot areas Design of an Early Warning System for landslides, and implementing that in a number of test areas

4 SFLP: Main outputs 1. A national database and WebGIS on landslides and related factors; 2. Landslide warning zonation maps at 1:50,000 scales for 37 mountainous provinces, and at 1:10,000 scales for hotspots areas: Landslide inventory maps Landslide susceptibility maps Landslide hazard maps Landslide risk maps 3. A pilot network of landslide monitoring stations 4. Reports and guidelines to end-users for: Using the result maps, WebGIS and database Recommendation of landslide mitigation measures; Dissemination and communication of landslide preparedness, prevention and mitigation; Proposed network of landslide monitoring and early warning for very high landslide hazard areas.

5 SFLP: Workflow A: Data collection and factor mapping B: Susceptibility and hazard assessment C: Vulnerability assessment D: Risk assessment (adapted from Castellanos Abella, E.A., de Jong, S.M., Van Westen, C.J. and van Asch, W.J., Multi-scale landslide risk assessment in Cuba. ITC, University of Utrecht. ITC Dissertation 154, 272 p. ISBN: )

6 SFLP: Results so far Results maps at 1:50,000 scale: Nr. Provinces Inventory Maps Susceptibility Maps Hazard, Vunerability and Risk Maps 1 Lai Chau Dien Bien Son La Lao Cai Yen Bai Ha Giang Tuyen Quang Cao Bang Bac Kan Bac Giang Quang Ninh Hoa Binh Thanh Hoa Nghe An Lang Son Ha Tinh Quang Binh Quang Tri other provinces - - -

7 PROJECT RESULT SO FAR (10/ /2015) Landslide inventory maps at 1:50,000 scales for 17 Northern mountainous provinces that are compiled for publication

8 PROJECT RESULT SO FAR (10/ /2017) Landslide susceptibility maps at 1:50,000 scales for 10 Northern mountainous provinces: Nghe An, Thanh Hoa, Lao Cai, Yen Bai, Lai Chau, Dien Bien, Son La, Ha Giang, Cao Bang, Bac Kan

9 SFLP: Urgent needs 1. Those maps were not regularly to be updated the environmental factors have kept changing landslides have still occurred previously-produced maps much different from present situation 2. For many high-risk areas, the authorities demand the risk maps at larger scales very difficult to construct due to the lack of necessary input data. 3. It is required to implement a program to update the landslide database for selected high-risk areas.

10 Nậm Mười after 21/7/2018 (200mm in 3 days) 3/1/2016

11 Nậm Mười after 21/7/2018 (200mm in 3 days) 3/1/2016

12 II. ONGOING PROJECT Full title: Updating a medium-scale landslide database for high-risk areas using community surveys in Vietnam Study areas: Selected 220 high risk communes in 10 Northern mountainous provinces (20,000 km 2 ) Goals: Investigating and updating the landslide database for the 220 selected highrisk communes in landslide-prone areas in Northern mountainous provinces using community surveys Mapping the landslide risk areas at 1: 10,000 scale and disseminating the result maps to the local authorities and people with community guidance

13 II. ONGOING PROJECT Deliverables An up-to-date spatial landslide database for high-risk communes; A set of landslide inventory, susceptibility and risk maps at 1: scale; Guidelines for dissemination and communication of landslide preparedness, prevention and mitigation for local authorities and people

14 II. ONGOING PROJECT Main approaches Community surveys Geological surveys Image interpretation

15 COMMUNIIY AND GEOLOGICAL SURVEYS Field note... Soil description sheet Field work... Landslide description sheet GIS and Mapping Landslide inventory Database

16 IMAGE INTERPRETATION

17 III. PILOT SURVEYS in high risk communes (835 km 2 ) of 4 landslide-pronce provinces

18 III. PILOT SURVEYS in 2017

19 III. INITIAL RESULTS: Updated database inventory mapping Xã Previous database Updated Updated unstable database slopes Interviews Nặm Lịch Xuân Lao Huổi Só Sính Phình Lầu Thí Ngài Bản Cái Nậm Mòn Bản Xèo A Mú Sung Phìn Ngan Đản Ván Pờ Ly Ngài Chiến Phố Pà Vầy Sủ Chế Là Phình Hồ La Pán Tẩn An Lương Đại Sơn Viễn Sơn TỔNG

20 III. INITIAL RESULTS: Updated database: susceptibility mapping TT Communes Area (km2) Very high (km2) High Moderate (km2) (km2) Low Very low (km2) Very high (%) High (%) Moderate (%) Low (%) Very low (%) 1 Nặm Lịch Xuân Lao Huổi Só Sính Phình Lầu Thí Ngài Bản Cái Nậm Mòn Bản Xèo A Mú Sung Phìn Ngan Đản Ván Pờ Ly Ngài Chiến Phố Pà Vầy Sủ Chế Là Phình Hồ La Pán Tẩn An Lương Đại Sơn Viễn Sơn TỔNG

21 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

22 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

23 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

24 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

25 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

26 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

27 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

28 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

29 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

30 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

31 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

32 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

33 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

34 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

35 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

36 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

37 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

38 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

39 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

40 III. INITIAL RESULTS Inventory and susceptibility maps at 1: scale

41 IV. CHALLENGES AND NEXT PLANS Updating the landslide database to propose the areas for temporal evacuation and for permament relocation Collaboration with local government for: Community education using Project resutls and deliverables; Updating landslide inventory database from communities through , WebGIS, facebook, SMS, etc.); Setup of a pilot landslide monitoring system. Collaboration with international experts for improve the survey technologies

42 Looking forwards to hearing your comments to improve our work!