Geography Study Notes: Flows & Accessibility
Hey everyone! Welcome to your study notes for Transport Development. This topic might sound a bit technical, but it's actually all about things we experience every single day. We're going to explore how people and things move around (that's flows) and how easy it is to get from one place to another (that's accessibility). Understanding this is super important because it explains why our cities look the way they do and how we can make them better places to live. Let's get started!
Part 1: Understanding Transport Systems: The Basics
First things first, what exactly is a transport system? Think of it like the circulatory system (veins and arteries) of a city. Instead of blood, it moves people and goods, keeping the city alive and functioning.
What Makes Up a Transport System?
Every transport system, from the MTR to the global shipping network, is made of a few key parts. Let's break them down.
• Nodes: These are the 'stops' or 'hubs' in the system. They are the points where a journey can start, stop, or change direction.
Examples: An MTR station, a bus stop, the Hong Kong International Airport, a container terminal.
• Linkages (or Links): These are the 'paths' that connect the nodes. They are the routes you travel along.
Examples: A railway track between two stations, a road, a flight path, a shipping lane.
• Networks: When you put all the nodes and linkages together, you get a network. It’s the entire web of connections.
Analogy: Think of a spider's web, with the intersections as nodes and the silk threads as linkages.
• Flows: This is the actual movement of people, goods, or information along the linkages between nodes. This is a super important concept!
Examples: The number of passengers on an MTR line during rush hour, the number of cars on the Tuen Mun Road, the amount of cargo shipped from Hong Kong Port.
• Terminals: These are special nodes that act as the main start or end points of a journey, often where you switch between different types of transport.
Examples: Hung Hom Station (where you can switch from local to cross-border trains), a ferry pier.
• Demand: This is simply the need or desire for transport. If no one needs to go from A to B, there will be no flow!
Quick Review: The 5 N's and a D
Here's a simple way to remember the parts of a transport system:
- Nodes (Stops)
- Linkages (Paths - okay, not an N, but it connects the Ns!)
- Networks (The whole web)
- Flows (Movement - also not an N, but it's what happens on the network!)
- Terminals (Big start/end nodes)
- Demand (The reason for it all)
Did you know?
The Hong Kong MTR system is one of the most efficient and profitable in the world. It carries over 5 million passengers on an average weekday, creating massive daily flows across its network!
Key Takeaway
A transport system is a network of nodes (stops) and linkages (paths) that allows for the flow of people and goods, driven by demand.
Part 2: Diving Deeper into Flows & Patterns
We've defined flows as the movement within a network. Now, let's look at the different kinds of flows and how they create patterns that geographers study.
Types of Flows
In geography, we mainly talk about two types of flows:
1. Personal Travel: This is you, me, and everyone else moving around. It includes commuting to school or work, going shopping, or travelling for holidays. The patterns of personal travel often create 'peak hours' or 'rush hours'.
2. Freight Transport: This is the movement of goods and raw materials. From the food in your supermarket to the phone in your hand, almost everything has been part of a freight transport flow, often involving ships, trucks, and planes.
Transport Patterns
Flows aren't random; they form predictable transport patterns. These patterns can be influenced by:
• Time: Flows change throughout the day. For example, the flow of people into Central is highest in the morning and reverses in the evening.
• Location: Some routes are much busier than others because of the location of important nodes. The MTR's Tsuen Wan Line is busier than the Disneyland Resort Line.
• Modal Choice: This refers to the choice of transport mode (e.g., bus, MTR, ferry, car). People make this choice based on transport cost (money, time, and convenience), creating different flow patterns for different modes of transport.
Key Takeaway
Flows are the lifeblood of a transport network. They consist of people (personal travel) and goods (freight), and they create clear patterns in space and time that are shaped by factors like cost and convenience.
Part 3: The Big Question - What is Accessibility?
Don't worry if this seems tricky at first, it's actually a very simple idea. Accessibility is just a way of answering the question: "How easy is it to get somewhere?" A place with high accessibility is easy to get to, while a place with low accessibility is difficult to reach.
Defining and Measuring Accessibility
Accessibility isn't just about distance. A place might be close by on a map, but if there's a mountain or a harbour in the way with no direct route, its accessibility is low!
Common Mistake to Avoid!
Don't confuse physical distance with accessibility. Accessibility is about the time, cost, and effort it takes to travel, not just the kilometres. For example, Ma Wan island is physically close to Tsing Yi, but its accessibility depends entirely on the bridge (a linkage).
Here are the factors that determine accessibility:
• Connectivity: How well-connected is a node to other nodes in the network? A node with many linkages has high connectivity. Geographers can even measure this with formulas like the Beta Index, which compares the number of links to the number of nodes.
$$ \beta = \frac{\text{Number of Links (e)}}{\text{Number of Nodes (v)}} $$
A higher Beta value means a more connected and accessible network! You don't need to memorise the formula, just understand the idea: more links = better connections.
• Distance Decay: This is a core concept in geography! Distance decay is the idea that the further away you are from a place, the less interaction you will have with it. The 'friction of distance' (cost, time, effort) makes interaction decline with distance.
Analogy: Think of the ripples when you throw a stone in a pond. They are strongest near the centre and get weaker as they spread out. In the same way, the influence of a city centre like Central is strongest nearby and fades as you move into the New Territories.
A classic example is land rent theory. Land is most expensive in Central because it has the highest accessibility. As you move further away, accessibility decreases, and so does the land price. This is distance decay in action!
Key Takeaway
Accessibility measures how easy it is to reach a location. It depends on the connectivity of the transport network and is affected by distance decay, where interaction decreases as distance, time, and cost increase.
Part 4: Putting It All Together: Transport and Our City
So, why do we care so much about flows and accessibility? Because they have a massive impact on the shape and structure of our cities, a concept known as urban morphology.
How Transport Shapes Hong Kong
The development of transport technology has completely changed Hong Kong's layout.
• Evolution of Transport and Urban Form: In the past, cities had to be very compact because people walked. The invention of trams, then buses, and finally the MTR allowed the city to spread out. New Towns like Sha Tin and Tuen Mun could only exist because of efficient transport linkages connecting them to the urban core.
• Space-Time Relationship: Technology has "shrunk" our world. The High-Speed Rail doesn't move Hong Kong closer to Guangzhou in physical space, but it drastically reduces the time-distance, increasing accessibility and strengthening the flow of people between the two cities.
A Modern Solution: Transit-Oriented Development (TOD)
One of the most important modern strategies in transport planning is Transit-Oriented Development (TOD). This is a very common feature in Hong Kong!
• What is it? TOD is a style of urban planning that focuses on creating compact, walkable, mixed-use communities centred around high-quality public transport nodes (especially MTR stations).
• The Goal: To maximise accessibility to public transport and services, encouraging people to drive less. This reduces traffic congestion, accidents, and air pollution.
• Hong Kong Examples: Look at almost any major MTR station! Kowloon Station (with Elements mall and residential towers), Tsing Yi Station (Maritime Square), or Tseung Kwan O town centre are all perfect examples of TOD. Everything you need – shops, homes, offices, transport – is right there, creating a highly accessible and convenient environment.
Final Key Takeaway
By understanding and managing flows and improving accessibility, planners can shape a city's growth. Modern strategies like Transit-Oriented Development (TOD) help create more sustainable and efficient urban environments by building our communities around effective transport networks.