Aerial Surveying, Digital Terrain Model, and Flood Tender - 42443971

Procurement Summary

Country: Burkina Faso

Summary: Tender For Aerial Surveying, Digital Terrain Model, and Flood Hazard Assessment

Deadline: 30 Apr 2020

Posting Date: 26 Apr 2020

Other Information

Notice Type: Tender

TOT Ref.No.: 42443971

Document Ref. No.: 1268167

Competition: ICB

Financier: Self Financed

Purchaser Ownership: -

Tender Value: Refer Document

CPV Classification

71354200 - Aerial mapping services
71355000 - Surveying services

Purchaser's Detail

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Tender Details

Expression of Interest are invited for Aerial Surveying, Digital Terrain Model, and Flood Hazard Assessment in Ouagadougou.
request for expression of interest for selection # 1268167
This Request for Expression of Interest is for a Firm Selection. Please log in as a valid Firm User if you wish to express interest in this selection.
Selection Information
Assignment Title
AERIAL SURVEYING, DIGITAL TERRAIN MODEL, AND FLOOD HAZARD ASSESSMENT IN OUAGADOUGOU
Publication Date
23-Apr-2020
Expression of Interest Deadline
30-Apr-2020 at 11:59:59 PM (Eastern Time – Washington D.C.)
Language of Notice
English
Selection Notice
Assignment Country
· BF - Burkina Faso
Funding Sources
The World Bank Group intends to finance the assignment/services under:
· BB - BANK BUDGET
· TF0A8981 - GFDRR MDTF for Provide Technical Support to Strengthen Climate Resilience in Burkina Faso
· TF0B2135 - Resilient Mass Transit in Ouagadougou
Individual/Firm
The consultant will be a firm.
Assignment Description
SELECTION FOR CONSULTANTS BY THE WORLD BANK GROUP

REQUEST FOR EXPRESSIONS OF INTEREST

Electronic Submissions through World Bank Group eConsultant2

https://wbgeconsult2.worldbank.org/wbgec/index.html

Assignment Title: AERIAL SURVEYING, DIGITAL TERRAIN MODEL, AND FLOOD HAZARD ASSESSMENT IN OUAGADOUGOU
I. OBJECTIVE
1. The main objectives of the Consultancy are the following:
(1) To conduct aerial (drone-based) surveys to generate high-resolution drone imagery and terrain datasets, including a digital elevation model (DEM), for the area of interest (AOI).

(2) To conduct a flood hazard assessment and mapping of flood-prone areas in the AOI.
II. BACKGROUND
2. Ouagadougou, the capital of Burkina Faso, is located in the north-soudanian climatic zone within the watershed of the Massili river. With a single rainy season from May to September, rainfall events are caused by Mesoscale Convective Systems which produce intense and heterogenic rainfall in time and space. Ouagadougou is highly vulnerable to extreme hydro-meteorological events. During the 2009 West Africa floods, 150, 000 people fled their homes, mostly in Ouagadougou, where a record-breaking 263 mm rainfall was recorded. Heavy flooding in Ouagadougou in August 2015 left parts of the city under water for days. In July of 2018, heavy rains resulted in significant flooding and caused road traffic disruption.
3. Flooding poses a recurrent threat to Ouagadougou for a number of reasons: (i) the city is naturally prone to seasonal flooding, given its flat topography, its network of river side channels, and the soils poor water retention and infiltration capacity; (ii) the three dams that contribute so much to the identity of the city are silted up and can no longer fulfil their role as an outflow, buffer as well as potable water supply for the conurbation; in addition, the drainage system is poorly maintained, while the uncovered gutters tend to be used as waste disposal and clogging by litter reduces the network drainage capacity; (iii) rapid settlement growth and soil sealing are additionally straining the drainage capacity, while uncontrolled urban development in hazard area results in an increase in direct flood hazard exposure.
4. With World Bank financing, a mass transit system is currently being developed to improve urban mobility along a high priority corridor of about 30 km. Technical feasibility studies for the project are ongoing to identify the axes which will become the backbone of this network. One of the potential axes being studied is the East-West axis between Saaba and Tanghin (on RN1 and RN4). However, other alternatives will also be analyzed. At this stage, four main corridors are the most likely to be selected for the future mass transit system. The current Consultancy assignment will complement the already ongoing technical feasibility studies by providing analytical outputs that will help improve the flood resilience of the mass transport system.
5. The Consultancy outputs will also inform the Burkina Faso - Strengthening Climate Resilience project, co-financed by the WB and Green Climate Fund, aiming at improving the countrys hydrometeorological, climate, early warning services and access to such services by targeted sectors and communities. The Project is implemented by the Ministry of Transport, Urban Mobility and Road Safety.
III. SCOPE OF WORK AND EXPECTED ACTIVITIES
Task I: Drone survey and DEM
6. The first task of the Consultancy will be to conduct a drone-based aerial survey of the AOI, here defined as the parts of the Ouagadougou city a priori considered flood-prone (60 km2), followed by the development of a high-resolution DEM. The Consultant shall carry out the following activities:
(i) Authorizations and Flight Planning: The Consultant shall request and obtain authorizations from the local civil aviation authority and other relevant government entities to operate aerial surveying platforms within the project area.
(ii) Ground Control and Aerial Survey: Ground control points (GCPs) should be surveyed or derived from reliable existing sources to ensure accuracy of the final products. An RTK/PPK-capable platform is highly desirable, in order to avoid ground control target placement, while still guaranteeing high positional accuracy.
(iii) Data Processing and Delivery: All data collected shall be of high quality (e.g. minimal lens distortion, no blur, nadir views, sufficient overlap, adequate exposure, etc.) to allow for the generation of professional orthomosaic and terrain products.
Task II: Flood hazard assessment and mapping
7. Building on the DEM, the Consultant shall carry out the following activities:
(i) Review of past flood events and flood modeling studies: The analysis shall synthesize existing information on the flood event regarding type/source of flooding, extent and intensities of the floods as well as flood damage and other consequences.
(ii) Land use and Geomorphologic Analysis: Based on the drone survey and the DEM, the Consultant shall conduct a land use analysis and a geomorphologic analysis of the sub-catchment, to identify the relevant physical and environmental basin characteristics, including its hydraulic infrastructure, water resources of the donor basins, as well as the major drainage and flood conveyance channels.
(iii) Methodology for Rainfall-Runoff Model: The Consultant shall define the methodologic approach for the rainfall-runoff model.
(iv) Flood Hazard Assessment: The Consultant shall assess the flood hazard in the AOI for different probabilities of occurrence (e.g., low-medium-high) to identify (a) flooding extent, (b) flooding intensities (depth/velocity) and (c) general flows (direction of current).
IV. TECHNICAL PROPOSAL
8. The Consultant proposal for the assignment should present a comprehensive, timebound plan for satisfactorily undertaking the two Tasks. The Consultant is invited to comment on the Terms of Reference and suggest amendments and other approaches if deemed suitable given the nature of the interventions and the country context.
V. REQUIRED QUALIFICATIONS OF FIRMS AND PERSONNEL
9. The firm must possess the following qualifications:
Extensive experience in hazards maps from geomorphological approach and 2D modelling;

Demonstrated prior experience in supervision of ground control, aerial surveys, and associated data processing and established partnership with a local drone company to ensure the aerial survey given the current travel restrictions in and out BF;

Ability to secure the necessary permits, clearances, flight permissions of manned and/or unmanned aerial surveying platforms in Burkina Faso in a timely manner;

Experience in Burkina Faso is mandatory as well as knowledge of the national institutions involved in Hydrometeorology and flood risk management;

Long-term partnership with researchers that have done prior flood modeling in Ouagadougou and have developed a multi-models platform for hydrology.

Strong references from recent flood modeling assignments in Francophone Africa;

Written and spoken proficiency in French and in English is mandatory
VI. EXPECTED OUTPUTS AND SCHEDULE OF DELIVERY
Task I: Drone survey and DEM
10. A drone-based aerial survey shall be conducted to deliver a DEM in fulfillment of the following technical requirements:
acquisition parameters: average density 3.9 ppm²; GSD 19 cm

expected accuracy: 10 cm (1?)

survey of control surfaces (5 x 5 grids equidistant from 1 m to 1.5 m) by a certified surveyor; linkage to the local geodetic framework; delivery of data in world coordinates

request for orthophotos that can be processed at a later date
11. an accurate dem of potentially submerged areas is required for a correct modeling of flood depth and velocities. an orthomosaic should be generated for the surveyed area for visualization and feature-digitizing purposes. all deliverables shall be provided in electronic format, as direct download links and/or as digital copies through physical media storage devices, and must include:
detailed flights plans (kml format) and risk management plan;

orthomosaic at 10 cm gsd (or better);

dem at 30 cm gsd and 10cm vertical resolution (or better);

all raw frames with associated external orientation/position metadata

a brief report summarizing the methodology and the completed activities.
task ii: flood hazard assessment and mapping
geospatial databases and modelled graphs with collected data (including, information on the different probabilities and parameters on hazard intensities (e.g. inundation depth and velocity);

high-quality, geo-referenced flood hazard maps for different return periods and intensities;

summary of completed activities and technical report on the methodology of flood hazard assessment and ma

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