Flood Impact PlanAt Peabody Square

Zhenyang Hua

Outline

• Background• Data and Methods• Data Processing• Outputs• What’s the next step?

Background

Date Description of Damage Amount of Damage

October, 1996 Property damage, business loss, loss of

function, traffic delays, and road closure

$7,227,537.00

April, 2004 Property damage, business loss, loss of

function, traffic delays, and road closure

$5,807,736.00

May, 2006 Property damage, business loss, loss of

function, traffic delays, and road closure

$9,546,938.00

Figure 1 Major Damage History (Data source: FEMA Website)

Data

• LiDAR Terrain Data from MassGIS• Road data from MassGIS• Building Structure data from MassGIS• Water Body Layer from digitization• Special Need Population data from assumption• Facility Site Data from assumption

Methods

• Return Period:• 100-year Flood• 200-year Flood

Problems:• Too specialized or too academic• What is a 100-year flood?• How deep is the water on average in a 100-year flood?• How much damage losses meets a 100-year prerequisite?

Methods

• The flood inundates 3 meters elevation areas is called a level-3 flood

• The flood inundates 5 meters elevation areas is called a level-5 flood

• So,

7 meters elevation areas level-7 flood

9 meters elevation areas level-9 flood

Data Processing

Raster Analysis to generate different

elevation layers for flood level classification

Flip the color ramp to show the flood inundation

map

Narrow down the impact areas along the rivers and create the

unaffected inundated areas

Data Processing

Intersect road layer with flood impact

areas to get the impacted roads

Intersect critical facilities and special need

population with flood impact areas

to support the emergency plan

Data Processing

Data Processing

Outputs

• In a level-3 flood, Harmony Grove Road will be inundated but only several buildings will be influenced.

• In a level-5 flood, Walnut Street will be inundated with several streets crossing it.

• In a level-7 flood, Central Street and Lowell Street will be inundated and at the crossroad where city hall and some other critical facilities are located, the ground level is close to the river surface level when there is no flood.

• In a level-9 flood, the flood impact areas will expand slightly, which means more water will stay in the area close to the river, which will increase the impact and damage to these areas.

What’s next step?

• To use a hydrology model to simulate different flood levels

• To create Maps to show the inundation depth of the impacted areas

• To import the real critical facilities and special need population information