Canal Microclimate Lab | Nguyen Quoc Kiet (阮国杰)

URBAN CANAL MICROCLIMATE & SPATIAL EXPOSURE OBSERVATORY

Urban Form and Pedestrian Thermal Exposure along Urban Canal Corridors

Integrating green infrastructure and microclimate modelling (ENVI-met & SOLWEIG) along Tham Luong Canal in Ho Chi Minh City, Vietnam. Examining whether the spatial configuration and continuity of shade improve route-level thermal conditions ($T_{mrt}$ & PET) beyond total canopy coverage alone.

LEAD RESEARCHER Nguyen Quoc Kiet (阮国杰)

DISCIPLINARY TRAINING Architecture & Smart Urban Design (UEH - ISCM)

LIVE TELEMETRY ENGINE Open-Meteo HCMC + ENVI-met / SOLWEIG

CORRIDOR THERMAL CONTRAST (1.1m PEDESTRIAN LEVEL) LIVE HCMC SYNC

STUDY REACHES

3 Reaches

12 Stations

BUFFER ZONES

100 m

50m / 200m

FIELD CAMPAIGN

9 Days

6 Dry + 3 Wet

SENSOR HEIGHT

1.1 m

Pedestrian Level

RESEARCH QUESTION 01

Spatial & Temporal Variation

How do building geometry, canopy configuration and path location relate to spatial and temporal variation in pedestrian thermal conditions along Tham Luong Canal?

Variables: SVF, H/W Ratio, Shade Continuity Index (SCI), Bank Orientation

RESEARCH QUESTION 02

Alternative Canopy & Path Scenarios

Under matched weather conditions, how do alternative canopy and path configurations change mean radiant temperature ($T_{mrt}$), PET and route-level thermal exposure indicators?

Models: ENVI-met (coupled 3D) & SOLWEIG (radiant flux fallback)

RESEARCH QUESTION 03

Robustness & Implementation Constraints

Which interventions offer consistent benefits across the tested conditions while respecting access, drainage, utility corridors and maintenance constraints?

Outputs: Time-weighted route PET & feasibility screening matrix

Integrated Methodological Architecture

Connecting GIS Spatial Screening, Repeated Microclimate Monitoring & Scenario Simulation

Reproducible Workflow

STAGE 01

GIS Corridor Audit

250m screening segments
50m / 100m / 200m buffers
Sentinel-2 & footprint audit
Walkable access network

STAGE 02

Field Campaign

3 Reaches × 4 Sites = 12 Sites
6 Dry + 3 Wet season days
Ta, RH, v, Tg at 1.1m height
Co-located calibration

STAGE 03

Coupled Modelling

ENVI-met (Bruse & Fleer, 1998)
SOLWEIG 3D radiant fallback
PET calculation (Höppe, 1999)
Bias, MAE, RMSE validation

STAGE 04

Design Evaluation

3 Feasible Design Scenarios
Constant canopy area test
Time-weighted Route PET
Drainage & bank constraints

METHODOLOGICAL RIGOR & SCIENTIFIC GUARDRAILS

Usable vs. Inaccessible Green: Network mapping filters out fenced vegetation so only shade along walkable paths is counted.

Water Cooling Neutrality: Canal-water thermal parameters are varied explicitly in sensitivity runs rather than assuming automatic cooling.

Mixed-Effects & Grouped Validation: Repeated sensor observations within sites/days are modelled via mixed-effects, avoiding pseudoreplication.

Uncertainty Thresholds: Scenario differences smaller than instrument/model RMSE will not be claimed as established thermal improvements.

INTERDISCIPLINARY SCIENTIFIC SCOPE

Urban Climate, Environmental Exposure & Spatial Design

This research platform bridges physical microclimate modelling, GIS spatial analysis, and evidence-based landscape/urban design. It treats pedestrian heat exposure as a measurable interaction between three-dimensional urban morphology and daily mobility routes.

Core Methods: Field Telemetry + ENVI-met/SOLWEIG

Target Output: Route-Based Thermal Design Protocol

Key Methodological References

Bruse & Fleer (1998)

3D numerical modelling of surface-plant-air interactions (ENVI-met).

Lindberg et al. (2008)

SOLWEIG 1.0 – 3D radiant fluxes and Mean Radiant Temperature ($T_{mrt}$).

Höppe (1999)

Physiological Equivalent Temperature (PET) biometeorological assessment.

Guo et al. (2023)

Automated environmental exposure simulation & field validation in high-density cities.

REAL-TIME OPEN-METEO HCMC TELEMETRY & CURVED THAM LUONG CANAL GIS

The 22-vertex centerline and 12 stations (R1-S1 to R3-S4) follow the true winding channel of Tham Luong Canal in Ho Chi Minh City. In LIVE HCMC API Mode, station $T_a$, $T_g$, $T_{mrt}$, $v_{1.1m}$, and $PET$ are dynamically computed from live Open-Meteo HCMC meteorological forcing combined with each station's $SVF$, Shade Continuity ($SCI$), and canyon geometry.

Tham Luong Canal Real-World GIS & Sensor Telemetry Map

Curved hydrographic alignment in Ho Chi Minh City (10.822°N – 10.849°N, 106.621°E – 106.639°E)

| Buffer:

PET ≥ 41°C (Extreme) PET 36–41°C (Hot) PET < 36°C (Shaded)

REACH 1 · SITE R1-S1 LIVE API

West Bank - Tham Luong Bridge Approach

10.8246°N, 106.6238°E

SELECTED PET

43.8 °C

TEMPORAL SNAPSHOT (1.1m HEIGHT): Open-Meteo HCMC

STATION MORPHOLOGY & RADIANT PROFILE SVF 0.78 · SCI 18%

Urban Form & Shade Indicators (Sec 3.1)

Sky View Factor (SVF)

0.78

Shade Continuity (SCI)

18%

Building Coverage (100m)

64%

Rep. Building Height

14.5 m

Field Sensor Telemetry (Sec 4 · 1.1m AGL)

Shielded Air Temp (Ta): 35.4 °C

Black Globe Temp (Tg): 46.2 °C

Mean Radiant Temp (Tmrt): 58.7 °C

Local Wind Speed (v): 1.1 m/s

Relative Humidity (RH): 54 %

Access & Physics Note: Continuous concrete embankment footpath; zero overhead tree shade; high solar reflection from paved bank.

COUPLED MICROCLIMATE SIMULATION & ROUTE EVALUATION

Canal-Corridor Design Scenario & Constant-Canopy Simulator

Test whether spatial configuration and shade continuity improve pedestrian thermal comfort beyond total canopy quantity alone.

Simulation Engine:

1. Select Design Intervention Scenario:

2. Route & Sensitivity Parameters

Weather Forcing:

SECTION 9 · 24-MONTH RESEARCH SEQUENCE

24-Month Research Implementation Roadmap

Structured around research milestones and Ho Chi Minh City's dry/wet seasonal windows.

M 01–04

Literature Review, Data/Software Audit & Reconnaissance

Establish Tham Luong corridor endpoints, audit building footprint/height datasets, confirm ENVI-met/SOLWEIG computing resources, pilot design.

Deliverable: Pilot Protocol

M 05–08

GIS Mapping, Measurement Pilot & Baseline Model Setup

Map walkable network entrances/barriers, co-locate sensors for offset check, test grid resolution & boundary clearance in 2 reaches.

Deliverable: GIS Database

M 09–12

Seasonal Field Campaigns & Baseline Model Validation

Execute 6 hot-dry season days + 3 wet-season days across 12 sites (morning, midday, afternoon). Evaluate bias, MAE, and RMSE.

Deliverable: Field Telemetry

M 13–16

Form-Environment Analysis & Design Scenario Modelling

Mixed-effects regression linking SVF/canopy continuity to PET; simulate S1 (gap closing), S2 (constant canopy relocation), S3 (path shift).

Deliverable: Scenario Maps

M 17–20

Sensitivity Testing & Urban Design Interpretation

Test sensitivity to water parameters, walking speeds, departure times, and mature vs. young crowns; screen bank/drainage constraints.

Deliverable: Design Guidelines

M 21–24

Synthesis, Reproducible Code Archiving & Publication

Synthesize plans, sections, and reproducible scripts; complete full documentation, open-source repository archiving, and peer-reviewed publication.

Deliverable: Research Monograph

REPRODUCIBLE SPATIAL & MICROCLIMATE DATABASE

12-Station Telemetry & Urban Morphology Dataset

Synchronized observations at 1.1m height time-matched to Reference Station, paired with GIS urban form predictors.

Import Real CSV

SITE_ID	REACH	BANK	BCR_100M	BLDG_H (m)	SVF	CANOPY_%	SHADE_CONT	Ta_MID (°C)	Tmrt_MID (°C)	WIND (m/s)	PET_MID (°C)

EXPLORATORY ASSOCIATION: SHADE CONTINUITY VS. MIDDAY PET R² = 0.84 (Grouped by Reach)

MODEL CALIBRATION & VALIDATION METRICS

Baseline ENVI-met & SOLWEIG models are evaluated against independent measurement days before running design scenarios. Good Ta agreement alone is insufficient to establish PET reliability.

Ta BIAS / RMSE

+0.18 / 0.62°C

Tmrt MAE / RMSE

2.15 / 2.84°C

PET RMSE THRESHOLD

±1.40 °C

Instrument Spec: Black globe Ø = 150 mm, emissivity ε = 0.95, 15-min equilibration window, co-located offset calibration pre-campaign.

6-PHASE SCIENTIFIC EXECUTION PROTOCOL

Research Execution & Seasonal Monitoring Sequence

Structured around spatial audit milestones and Ho Chi Minh City's dry/wet seasonal meteorological windows.

PHASE I

Literature Synthesis, Spatial Data Audit & Reconnaissance

Establish Tham Luong corridor endpoints, audit building footprint/height datasets, confirm ENVI-met/SOLWEIG computing resources, pilot design.

Output: Pilot Protocol

PHASE II

GIS Mapping, Sensor Co-Location Pilot & Domain Setup

Map walkable network entrances/barriers, co-locate sensors for offset check, test grid resolution & boundary clearance in 2 reaches.

Output: GIS Geodatabase

PHASE III

Seasonal Field Campaigns & Baseline Model Validation

Execute 6 hot-dry season days + 3 wet-season days across 12 sites (morning, midday, afternoon). Evaluate bias, MAE, and RMSE.

Output: Validated Telemetry

PHASE IV

Form-Environment Analysis & Design Scenario Modelling

Mixed-effects regression linking SVF/canopy continuity to PET; simulate S1 (gap closing), S2 (constant canopy relocation), S3 (path shift).

Output: Scenario Thermal Maps

PHASE V

Sensitivity Testing & Spatial Design Translation

Test sensitivity to water parameters, walking speeds, departure times, and mature vs. young crowns; screen bank/drainage constraints.

Output: Design Matrix

PHASE VI

Synthesis, Reproducible Code Archiving & Publication

Synthesize corridor plans, cross-sections, open-source scripts, and parameter documentation for scientific publication.

Output: Open Repository

Analytical Scope & Operational Boundaries

The core empirical study comprises 3 mapped and monitored reaches (12 stations) and high-resolution scenario evaluation in 2 representative reaches.

Explicitly Outside Core Scope:

Full-corridor CFD simulation at sub-meter grid
Clinical or epidemiological health outcome tracking
Chemical air pollutant dispersion modelling
Black-box ML without independent validation data

Research Ethics & Open Science

No Identifiable Human Data: Core physical monitoring requires no personal data.
Privacy in Fieldwork: Site documentation photographs strictly avoid identifiable faces.
Transparent Limitations: Limited seasonal sampling and hypothetical scenario status stated in all conclusions.

Tham Luong Canal Corridor · Spatial & Thermal Exposure Observatory

Urban Form and Pedestrian Thermal Exposure along Urban Canal Corridors

Spatial & Temporal Variation

Alternative Canopy & Path Scenarios

Robustness & Implementation Constraints

Integrated Methodological Architecture

GIS Corridor Audit

Field Campaign

Coupled Modelling

Design Evaluation

Urban Climate, Environmental Exposure & Spatial Design

Key Methodological References

Tham Luong Canal Real-World GIS & Sensor Telemetry Map

West Bank - Tham Luong Bridge Approach

Canal-Corridor Design Scenario & Constant-Canopy Simulator

24-Month Research Implementation Roadmap

Literature Review, Data/Software Audit & Reconnaissance

GIS Mapping, Measurement Pilot & Baseline Model Setup

Seasonal Field Campaigns & Baseline Model Validation

Form-Environment Analysis & Design Scenario Modelling

Sensitivity Testing & Urban Design Interpretation

Synthesis, Reproducible Code Archiving & Publication

12-Station Telemetry & Urban Morphology Dataset

Research Execution & Seasonal Monitoring Sequence

Literature Synthesis, Spatial Data Audit & Reconnaissance

GIS Mapping, Sensor Co-Location Pilot & Domain Setup

Seasonal Field Campaigns & Baseline Model Validation

Form-Environment Analysis & Design Scenario Modelling

Sensitivity Testing & Spatial Design Translation

Synthesis, Reproducible Code Archiving & Publication

Study Overview & Methodological Summary