Network Analyst Fall 2024 PDF

Network Analysis  Network components Network - a system of interconnected elements, such as edges (lines) and connecting junctions (points), that represent possible routes from one location to another An edge has a length through which some commodity flows (water, electricity...

Network Analysis  Network components Network - a system of interconnected elements, such as edges (lines) and connecting junctions (points), that represent possible routes from one location to another An edge has a length through which some commodity flows (water, electricity, cars). Electrical transmission lines, pipes are examples of edges. A junction occurs at the intersection of two or more edges Fuses, switches, service taps are examples of junctions.  Two types of networks in GIS 1. utility and river networks– travel is possible in one direction (water distribution lines, electrical lines, gas pipelines, telephone services, and water flow in a stream) 2. transportation networks can allow travel on edges in both directions (street, pedestrian, and railroad networks)  Transportation networks Can do the following types of analyses: 1. Route 2. Closest facility 3. Service area 4. OD cost matrix 5. Location-allocation The following slides give examples of each technique  Network analysis can accommodate turn restrictions, speed limits, height restrictions, traffic conditions at different times of the day.  1.Route Finds the most efficient travel routes effective routes for county health inspectors routes for visiting nurses route emergency response crews to incidents 2. Find closest facility  3. Create service areas based on travel time or distance how many hospitals are within 5-, 10-, and 15-minute drive times of schools. CA – coverage area Story Map about homele ssness in Worcester Story Map - access to DTA Office in Worceste r Interactive “15-minute” city map Network analysis tools in QGIS 4. Create Origin-destination cost matrix Origin-destination cost matrix is a table that contains the total travel distance or time from each origin to each destination Land Value Uplift and Commuter Rail Access Noah Berkowitz, Tucker Beckett Fall 2019 Vector Final Project 5. Location-allocation analysis Census Block centroids Permanent clinics Question: where should we add clinics to increase population access? Question: How many people are within 10 min drive from a permanent clinic? Steps: create 10-min drive service area around each hospital; then select block centroids that fall inside service area Answer: 60% of population is within 10 min drive from a permanent clinic  Mobile clinics Libraries can be used as mobile clinics There are 10 libraries, but enough funding only to open 4 mobile clinics. Let the algorithm select which libraries should be used for mobile clinics… If 4 mobile clinics are added… 93% of population is within 10 min drive from a clinic (permanent or mobile) More info about this case study - here Workflow for Network Analysis in ArcGIS 1. Create and build a network dataset from line features 2. Use this network dataset in Network analysis  Network dataset Contains information about how roads relate to one another, such as which roads are connected, which turns between connected roads are allowed or prohibited, and other information that affects what travel paths are possible and how long travel takes.  Sources of road data MassGIS ESRI data - Open Street Map downloads: – https://download.geofabrik.de/ I recommend you download data in shapefile format. Description of the shapefiles content is here – BBBike  Helpful Tutorials from ESRI – Create a network dataset – Create and use a network dataset with public transit data – Find the shortest path and generate directions with Route – Identify the closest facility – Service a set of orders with a fleet of vehicles – Visualize the reachable area with Service Area – Calculate the travel time between origins and destinations with OD Cost Matrix – Choose the best location with Location-Allocation  Additional hands-on exercises from ESRI 1. How to build a network dataset from local government d ata (Youtube video) 2. Creating and Deploying a Multimodal Emergency Resp onse Network (created for ArcMap, not ArcPro) Data for the Tutorial –download here