**2. History of urban planning in Japan**

#### **2.1 History of urban formation and urban planning**

During the Edo era (1603–1868), Edo, the city, with one of the largest populations in the world, was formed in Japan. Nationwide, many cities such as castle towns and post towns were created. According to the formulation of the cities, the population increased in whole country and concentrated into the cities.

During the Meiji era (1868–1912), the modernization of urban infrastructures such as railways, roads, buildings, and industry progressed, and urbanization and population growth accelerated.

World War I (1914–1918) brought rapid growth to the Japanese economy. As a result, the urban environment has also changed significantly. Buildings made of bricks began to be built on the wooden urban area constructed in Edo era. In addition, various functions of the city were spatially differentiated, and the formation of a complex city began.

Against the background of such urban growth, the Urban Planning Low and Urban Building Law was promulgated in 1919. For this, application of building layout and structural standards, classification by zoning into residences, factories, commercial areas, fire zones, esthetic zones, scenic zones, etc., restrictions on construction in each zone, creation of urban facilities such as roads and parks have been possible [1].

Around this time, the concentration of the population in the big cities became noticeable. In addition, the problems such as the mixture of housing and factories, overcrowding of population and buildings, and the occurrence of slums in inner urban areas began.

After World War II (1939–1945), 115 cities were designated as war-damaged cities because major cities had extensive damage.

The basic policy for the reconstruction of war-damaged areas was officially announced as follows: (1) to curb the growth of oversized cities and (2) to promote the development of small and medium-sized local cities.

In addition, following were officially announced:

(1) Industrial location and population distribution, (2) guidelines for land use planning, and (3) planning standards for major facilities such as streets, plazas, and green areas. According to these policies, reconstruction plans were drafted in each city.

Against the background of the confusion in land use such as height control (high-level), advanced use of existing urban areas, and the emergence of urban sprawl due to rapid urbanization accompanying rapid economic growth, the enactment of the New Urban Planning Law (1968) and revision of the Building Standards Law (1970) were conducted. As a result, the division of urbanization promotion areas and urbanization control areas, and the development permit system linked to the division of areas were implemented.

After that, making the master plan of urban planning as the basic policy on urban planning in each municipality (1992) was implemented.

Then, due to the appearance of the signs of low growth and maturity such as the decline of central urban areas, the policy for restructuring existing urban areas, compact cities, and intensive urban structures had begun to emphasize.

In 2014, the system of the Location Normalization Plan was established. This aim is to reorganize the urban structure into a "compact city plus network of public transportation" model by gently guiding the development of private facilities.

Since then, many local governments have drawn up a Location Normalization Plan to designate urban function induction areas and residential promotion areas within urbanization promotion areas [2].

#### **2.2 History of urban disaster prevention**

In Japan, during the Edo era, the main issue of urban disaster prevention is fire spread. The towns in this era consisted of one-story wooden buildings although having one of the most populations in the world. During the 250 years of Edo, about 50 large fire spreads occurred.

Through the Meiji Era, the modernization of the urban structure and buildings was emphasized as one of the goals of modernization.

In the Great Kanto Earthquake in 1919, huge damage was caused by the collapse of buildings. In addition, the damage caused by fire spread with unfortunately strong wind speeds of 10 m/s or more was remarkable. After that, as the policy to improve the urban structure, the strong urban structure for fire spread (noncombustible and fireproof cities) was promoted.

After WW2, Japan experienced a lot of typhoon damage. These damages were expanded due to the damage to urban infrastructures by WW2. In particular, the damage caused by the Isewan Typhoon in 1959 was enormous. This became an opportunity, and the Disaster Countermeasures Basic Law to prevent damage by huge natural disasters was enacted in 1960. This Law promotes each municipality preparing comprehensive disaster prevention including making disaster prevention plans.

Around the 1980s, the areas with high risk of fire spread by huge earthquakes such as densely built-up areas by wooden apartment buildings and the areas not designated as fire prevention areas were aimed to promote safety. Especially, improvement of the evacuation routes and the areas around the designated evacuation areas was emphasized. Therefore, construction of fire prevention zones such as surrounded by wide-width roads and fire-proof buildings around designated evacuation sites was promoted [1].

In addition, the concept of "disaster prevention living area" was proposed. This aims to promote the activities for disaster mitigation such as the planning and development of disaster prevention roads and parks and support the activities for disaster mitigation through community-based activities. This area was based on the daily living area, the same as an elementary school area surrounded by fire prevention roads.

During the period to promote the activities mentioned above, in 1995, the Great Hanshin-Awaji Earthquake occurred. Due to the weak wind speed, the damage caused by the collapse of the building was more serious than the damage caused by the fire. The inner area surrounded by wide roads, which is a fire barrier, had serious damage.

For this reason, after the Great Hanshin-Awaji Earthquake, urban disaster prevention measures for the inner areas such as improvement of densely built-up areas and making houses earthquake-resistant were actively discussed.

In addition, "mutual assistance," the community-based activities to mitigate the damage caused by disasters such as the support of evacuation and rescue to the person buried by the collapsed building, has begun to be emphasized. Most of the communities such as disaster prevention organizations formed by neighborhood

associations carry out disaster mitigation activities such as firefighting drills and evacuation drills [3].

In 2011, the Great East Japan Earthquakes occurred. The damage by the tsunami was enormous.

In recent years, many flood disasters and landslides due to heavy rain such as localized downpours of short duration occurred.

### **3. Measures to reduce natural disaster risk in residential areas**

Already explained in Section 2.1, the system of the Location Normalization Plan was established in 2014. To achieve the urban structure into a "compact city plus networks of public transportation", designating (1) urban function induction areas and (2) residential promotion areas and considering the accessibility to public transportation are required.

The policy to designate these areas that the national government has explained, the areas with high risk of natural disasters should be excluded. However, it is difficult for many municipalities to fulfill the policy (**Figure 1**).

For example, the results of the survey on the presence or absence of disaster risk in residential promotion areas have been published [5]. The survey targeted 275 cities that announced Location Normalization Plan by December 2019. There were 13 cities with red zones and 254 cities with yellow zones.

Based on the result, the national government published the policy that municipalities should make the "guideline for disaster mitigation" as the countermeasure to the risk of the designated induction areas (**Figure 2**).

Specifically, to accelerate community-based activities and the improvement of urban structure that incorporates the perspective of disaster prevention, the "disaster prevention guideline," the countermeasure for disaster mitigation in the designated residential promotion areas is described as one of the items in the Location Normalization Plan. This is expected that promote the mainstreaming of disaster prevention in formulating compact cities.

#### **Figure 1.**

*Example Designation of residential promotion area [4]. Residential promotion areas are designated considering to avoid flood inundation areas. However, the central area around the railway station is overlapped with the flood risk.*

*Trends in Urban Planning and Measures of Disaster Risks in Japan – Roles... DOI: http://dx.doi.org/10.5772/intechopen.109461*

#### **Figure 2.**

*Summary of examination of guideline for disaster prevention [6].*

The following criteria for making the guideline for disaster mitigation were published.

The future vision and aims of disaster mitigation activities should be clearly explained. The countermeasures for disaster mitigation and both urban infrastructure improvement and activities to respond to disasters are necessary (**Figure 3**).

In this way, the designation of the induction areas excluding high disaster risk areas from the long-standing perspective, the difficulty of excluding high disaster risk

#### **Figure 3.**

*Image of countermeasures for disaster mitigation [6].*

areas within the induction areas, mitigating the disaster risk by the countermeasures for disaster mitigation and both urban infrastructure improvement and activities to respond to disasters are important.
