Sustainable Land Development: Biodiversity, Natural Disasters, and Topographic Gradient

Abstract

Inappropriate land development has been causing various problems, such as environmental destruction, biodiversity loss, climate change, and increased natural disaster risks. Aiming to avoid such issues and achieve sustainable land development, this study shows a method of dividing a region or municipality into development-restrictive areas and allowable areas. First, it presents three significant land attributes related to judging the appropriateness of development: (1) biodiversity, (2) natural disaster risk, and (3) topographic gradient. Then, regarding these land attributes, the following three sections illustrate ways to define problematic areas for development. Section 3 examines how to delineate sites contributing more to biodiversity, considering both significant areas for biodiversity and conservation practices. The fourth section outlines ways to avoid high-risk areas from predicted climatic and tectonic hazards, aiming to reduce natural disaster risks. Section 5 examines topographic gradient standards for determining steep-sloping areas. Finally, this study demonstrates how to integrate these three kinds of spatial data in the Geographic Information System (GIS) and delineate development-restrictive areas.

1. Introduction

Inappropriate land development, such as uncontrolled exploitation and urban sprawl, has been causing various problems worldwide. Such issues generally include deforestation, environmental destruction, biodiversity loss, climate change, and increased natural disaster risks.

For example, recently in Japan, a large number of problems occurred due to hasty land development. After 2012, the new policy for expanding renewable energy utilization accelerated the construction of photovoltaic power plants nationwide [1]. Following this rapid expansion, many troubles occurred in most prefectures of the country [1, 2], as exemplified in Figure 1. In addition, the number of problematic cases reported by the media reached 159 as of August 2021 [2]. According to Japan’s Ministry of the Environment, major issues with such solar power plants were as follows: (1) erosion and its impact on water quality, (2) landslides, (3) harmful impacts on animals, plants, and ecosystems, and (4) scenic destruction [1]. Meanwhile, the problematic cases mostly occurred in newly deforested areas or sloping sites [1].

Figure 1.

Examples of solar power plants constructed in deforested or steep-sloping areas in Japan.

As the above example suggests, developing problematic areas for development leads to cause issues. Therefore, in order to avoid such issues and pursue sustainable land development, it is beneficial to define development-restrictive areas in advance.

Focusing on this point, this study illustrates how to divide a region or municipality into development-restrictive areas and allowable areas. First, the next section shows three main land attributes related to judging the appropriateness of development: (1) biodiversity, (2) natural disaster risk, and (3) topographic gradient. After that, concerning these three land attributes, Sections 3, 4, and 5, respectively, illustrate ways to define problematic areas for development. Lastly, Section 6 demonstrates how to integrate these three sorts of cartographic information in the GIS and delineate development-restrictive areas.

2. Strategy for sustainable land development

2.1 Sustainable urban design guidelines

We are producing sustainable urban design guidelines, based on the system control approach. As the United Nations “Sustainable Development Goals” implies, achieving sustainability is a goal-oriented challenge. The science of system control can be applied to all goal-oriented tasks [3, 4]. Moreover, that science has produced remarkable results in many fields, in particular engineering. Therefore, by applying system control, we have been progressing in research on sustainable design [3, 4].

The main process of producing sustainable urban design guidelines is shown in Figure 2. The production process starts with identifying environmental, social, and economic problems related to cities. Next, based on the specified problems, requirements for the sustainable urban design are also identified. After that, the requirements are converted into design guidelines, so that users can efficiently conduct spatial planning and urban design on local maps [4]. The sustainable urban design guidelines consist of three steps: (1) development-restrictive/allowable areas, (2) spatial relationships among city components, and (3) principles of designing city components [4].

Figure 2.

The main process of producing sustainable urban design guidelines and the aim of the first step.

This study focuses on the first step of sustainable urban design guidelines. The first part is intended to solve or prevent problems related to land development and meet requirements for sustainable land development. Examples of such issues have been illustrated in the introduction. Meanwhile, the requirements for sustainable land development include nature and biodiversity conservation, environmental protection, avoiding natural disaster danger areas, and consideration for the landscape.

2.2 Main land attributes related to judging development

In order to define development-restrictive and allowable areas, this study examines the relationship between land attributes and development. As demonstrated on the left side of Figure 3, there are three significant land attributes related to judging the appropriateness of development: (1) biodiversity, (2) natural disaster risk, and (3) topographic gradient [4].

Figure 3.

Strategy for delineating development-restrictive areas and allowable areas.

2.2.1 Biodiversity

“Biodiversity” is a key area when seeking nature conservation and environmental preservation [5]. Efforts to conserve biodiversity also help meet global goals for greenhouse gas emissions to mitigate climate change. Moreover, such biodiversity and nature-based solutions help protect us from climate change impacts, securing ecosystem services [5, 6, 7].

2.2.2 Natural disaster risk

“Natural disaster risk” is connected with one of the requirements, “avoiding natural disaster danger areas.” Geomorphologically, the Earth’s surface is shaped by tectonics and climate [8]. As this simple statement implies, natural disasters can be divided into two categories: “tectonic” and “climatic” [9, 10]. Tectonic disasters include catastrophes caused by earthquakes and volcanic eruptions. Meanwhile, examples of climatic disasters are serious damage resulting from floods and droughts.

2.2.3 Topographic gradient

“Topographic gradient” is mainly associated with two requirements for sustainable design, “environmental protection” and “accessible and universal design” [4]. Vegetation removal on steep-sloping sites often triggers significant environmental issues, such as soil erosion, landslides, increased downstream runoff, and flooding [11, 12, 13]. Meanwhile, as slopes become steeper, the provision of infrastructure and accessible design becomes more difficult and expensive [12]. Furthermore, “topographic gradient” is also associated with another requirement, “consideration for the landscape,” because developing steep-sloping areas frequently leads to serious disfiguration of the scenic landscape [11, 12].

2.3 Development-restrictive and allowable areas

This study shows a method of dividing a region or municipality into development-restrictive and allowable areas, based on the strategy demonstrated in Figure 3. “Development-restrictive areas” means sites where land development, including vegetation removal and construction, should be prohibited. Development-restrictive areas are the unions, or amalgamations, of the following sites: (1) areas contributing more to biodiversity, (2) high-risk areas from predicted natural disasters, and (3) steep-sloping areas [4].

On the other hand, “development-allowable areas” means sites where land development can be permitted. Development-allowable areas are the intersections, or overlaps, of the following: (1) areas contributing less to biodiversity, (2) low-risk areas from predicted natural disasters, and (3) gradual-sloping or non-gradient areas [4].

3. Biodiversity

Area-based conservation efforts are the cornerstone for halting the global biodiversity crisis [14, 15]. As shown on the left side of Figure 4, site-based biodiversity conservation can be divided into two main categories: (1) identification of significant areas for biodiversity and (2) conservation practices [16]. Currently, there has been a steady increase in the coverage of both identified significant areas and conservation areas. However, further and urgent expansion is necessary [14, 15]. The main coverage targets are listed on the right side of Figure 4.

Figure 4.

Current situation of area-based biodiversity conservation and main coverage targets.

3.1 Identification of significant areas for biodiversity

The most authorized approach to designate important areas for biodiversity is the identification of Key Biodiversity Areas (KBAs). KBAs are nationally identified sites that contribute significantly to the global persistence of biodiversity, in terrestrial, freshwater, and marine ecosystems [17]. The KBA approach builds on a methodology originally developed for specifying Important Bird and Biodiversity Areas (IBAs). After that, it was expanded to cover a wider range of taxa and conservation initiatives, such as the Alliance for Zero Extinction (AZE) [18]. In 2016, the International Union for Conservation of Nature (IUCN) published “A Global Standard for the Identification of Key Biodiversity Areas,” providing a set of globally standardized criteria and quantitative thresholds [17].

In addition to sites of global biodiversity significance, there must be areas of national or regional biodiversity importance. Such sites should also be identified as significant areas for biodiversity [19].

3.2 Conservation practices

Area-based conservation practices consist of “protected areas” and “other effective area-based conservation measures (OECMs)” [20].

3.2.1 Protected areas

Protected areas form the foundation of national biodiversity conservation strategies [21]. IUCN defines a protected area as “A clearly defined geographical space, recognized, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values” [21]. The definition is expanded by the following management categories [21]:

• Category Ia: Strict nature reserve.

• Category Ib: Wilderness area.

• Category II: National park.

• Category III: Natural monument or feature.

• Category IV: Habitat/species management area.

• Category V: Protected landscape/seascape.

• Category VI: Protected areas with sustainable use of natural resources.

3.2.2 Other effective area-based conservation measures (OECMs)

OECM is a conservation designation for areas that are achieving effective in situ biodiversity conservation outside of protected areas [20]. Those concerned with conservation have recently recognized the importance of OECMs [20]. In addition, while protected areas must have a primary conservation objective, this is not necessary for OECMs. OECMs may be managed with conservation as a primary or secondary objective. Otherwise, long-term conservation may simply be the ancillary result of management activities [20].

3.3 Coverage and its targets

Efforts to identify significant areas and conservation practices are in progress. However, the coverages of KBAs and conservation areas are not yet sufficient. The world needs a further and effective increase in the coverage of such areas to halt biodiversity decline [14, 15].

3.3.1 Key biodiversity areas

Global KBA coverage has been increasing. More than 16,000 KBAs have been mapped worldwide [22]. KBAs have been identified in over 200 countries. KBA sites cover approximately 4% of the world’s surface [18]. However, defining and delineating KBAs is an ongoing process [18]. Further efforts in KBA identification are necessary for many countries, taxa, and ecosystems [15, 18, 22].

3.3.2 Coverage of KBAs by conservation areas

In January 2018, 21% of KBAs were estimated to be completely covered by protected areas. However, 35% of KBAs had no protection through systems of conservation areas [18]. Currently, the average coverage of KBAs by conservation areas is 43.2% [22]. Therefore, prioritization of conservation efforts is necessary to cover all KBAs with conservation areas, namely protected areas or OECMs [15, 19].

3.3.3 Global coverage of conservation areas

Between 2010 and 2019, the world’s protected areas expanded from 14.1% to 15.3% of the terrestrial areas and from 2.9% to 7.5% of the marine areas [14]. According to the official document on the UN biodiversity conference released at the end of 2022, currently, 17% and 10% of the world’s terrestrial and marine areas, respectively, are under protection [23].

In December 2022, the UN Convention on Biological Diversity agreed to a new plan to preserve nature with the latest Global Biodiversity Framework. This framework has four overarching global goals and 23 targets for 2030. “Target 3,” one of the most prominent targets, calls for a significant increase in the areas covered by conservation status. This target requires conserving at least 30% of Earth’s land and sea areas by 2030 through protected areas or OECMs [23].

4. Natural disaster risks

4.1 Natural hazards and disaster risks

Figure 5 shows the relationship between natural hazards and disaster risks. Natural hazards are extreme natural events that can harm humans and their activities. Natural hazards can be divided into two main categories, “climatic” and “tectonic” [8, 9, 10]. Climatic hazards occur when a region has certain weather conditions, for example, heavy precipitation can lead to flooding. Tectonic hazards, such as earthquakes and volcanic eruptions, are caused by the movement of tectonic plates.

Figure 5.

Factors influencing natural disaster risks.

Disaster risk is widely recognized as the consequences of the interaction between a hazard and the characteristics that make people and places exposed and vulnerable [24]. Accordingly, there are three key elements that determine disaster risks: (1) intensity of natural hazards, (2) exposure to natural hazards, and (3) vulnerability to natural hazards. As demonstrated on the left side of Figure 5, “climate change impacts” intensify climatic hazards.

Meanwhile, as shown on the right side of Figure 5, there are two disaster risk reduction strategies, “reducing exposure to hazards” and “reducing vulnerability to hazards.” Exposure reduction is essential to reduce natural disaster risks, especially when considering land use. Theoretically, if neither humans nor their activities exist within the impact range of natural hazards, disasters will be less likely. Therefore, locating or relocating human activities outside hazardous areas reduces disaster risk. On the other hand, vulnerability reduction strategies include structural and nonstructural disaster prevention measures. Structural measures are physical methods, such as dams, flood levees, ocean wave barriers, earthquake-resistant construction, and evacuation shelters [25]. Nonstructural measures use knowledge, practice, or agreement to reduce disaster risks and impacts, such as public awareness raising, training, and education [25].

4.2 Climatic hazards

Climatic hazards occur when a region is in extreme weather conditions. For instance, as shown in the central part of Figure 6, heavy rainfalls and cyclones can cause flooding and landslides [9, 26]. Meanwhile, dryness and heat waves can trigger droughts and wildfires [27].

Figure 6.

Current main climatic hazards, disaster risks, and exposure reduction.

Recently, the frequency and intensity of climatic hazards have been increasing. According to the Intergovernmental Panel on Climate Change (IPCC), human-induced climate change is already affecting many weather and climate extremes in every region across the globe [27]. Evidence of changes in extremes, such as heat waves, droughts, heavy precipitation, and tropical cyclones, has strengthened since the 1950s [27].

Continued global warming will further intensify the global water cycle, the severity of wet and dry events, and global monsoon precipitation [27]. For example, at 2°C global warming and above compared to 1850–1900, heavy precipitation and associated flooding events are projected to become more intense and frequent in the Pacific Islands, across many regions of North America and Europe, and in some regions in Australasia and Central and South America [27]. Region-specific changes also include the intensification of cyclones and increases in river floods [27]. Meanwhile, several regions in Africa, South America, and Europe are projected to experience an increase in the frequency and/or severity of droughts. Such increases are also projected in Australasia, Central and North America, and the Caribbean [27]. Warming and increased dry conditions are also projected to increase wildfires [27].

Sea level rise has accelerated due to increasing rates of ice loss from the Greenland and Antarctic ice sheets, as well as continued glacier mass loss and ocean thermal expansion [28]. Sea level rise will continue throughout the twenty-first century [27]. Increases in cyclone winds and rainfall, and increases in extreme waves, combined with sea level rise, exacerbate extreme sea level events and coastal hazards [28].

As shown in the right side of Figure 6, when considering land use, exposure reduction to climatic hazards is crucial to reduce climatic disaster risks. For instance, efforts to avoid flood-prone riverside areas contribute to reducing damage from river flooding.

4.3 Tectonic hazards

As demonstrated in Figure 7, two major tectonic hazards are earthquakes and volcanic eruptions. Tsunamis are mainly caused by submarine earthquakes. Tsunamis are also generated by underwater volcanic eruptions. In addition, earthquakes and volcanic activity can initiate landslides [26], although these relations are omitted from the diagram.

Figure 7.

Main tectonic hazards, disaster risks, and exposure reduction.

An earthquake originates in a sudden release of energy in the Earth’s lithosphere that produces seismic waves. When seismic waves reach the Earth’s surface, they cause ground shaking. In general, the severity of ground shaking increases as the magnitude increases, and it decreases as the distance from the causative fault increases [29].

Underwater tectonic events generate tsunamis by displacing a substantial volume of water or perturbing a sea [30]. Tsunamis cause destruction both locally and at very distant locations from the area of tsunami generation [29]. Tsunami waves encroach upon the land and destroy things.

Volcanoes are often found where tectonic plates are converging or diverging. Volcanic eruptions occur when hot materials from the Earth’s interior are thrown out of a volcano. Such materials, namely “volcanic ejecta,” include lava, rocks, and gas compounds [31].

As shown on the right side of Figure 7, exposure reduction to tectonic hazards primarily requires people to consider avoiding high-risk areas from ground shaking, tsunami hits, and volcanic ejecta. For example, it is effective for municipalities to anticipate future tsunami risks and locate facilities on higher ground for safety.

5. Topographic gradient

5.1 Categorization of slopes

As outlined in Section 2.2.3, developing steep-sloping areas causes various problems, such as adverse effects of removing vegetation. In order to avoid issues caused by developing steep slopes, it is necessary to consider judging standards for regulation. How do we define a steep slope? There is no common definition of “steep slopes” [13]. However, many municipalities, especially in North America, define steep slopes as areas with 15% or more gradients [11, 12, 32]. Moreover, the Southern Tier Central Regional Planning and Development Board in New York State classifies slopes into three categories by gradients: (1) gradual (10% or less), (2) moderate (10–15%), and (3) steep (15% or more) [11]. Based on these examples, this study has divided slopes into four categories, as shown in Figure 8(a).

Figure 8.

(a) Categories of slopes, (b) examples of slopes.

In addition, examples of slopes with a 10% and 20% gradient are demonstrated in Figure 8(b). For instance, a 10% slope has a 10 m vertical rise over 100 m of horizontal run.

5.2 Topographic gradients and development restrictions

This section examines the relationship between topographic gradients and development restrictions from four aspects of slope development issues: (1) adverse effects of removing vegetation, (2) grading and construction burdens, (3) accessibility, and (4) landscape.

5.2.1 Adverse effects of removing vegetation

Removing vegetation and disrupting natural drainage patterns on steep slopes can trigger various problems. Potential consequences include soil erosion, landslides, an increase in downstream runoff, flooding, and decreased water purity [11, 12, 13, 33]. In order to minimize such adverse effects, reasonable control of development is necessary. Soils with a slope of 15% or more should always involve severe limitations to development [34]. In addition, land development on slopes of 10% or more in environmentally sensitive areas will have similar potential to increase issues, such as surface runoff and soil erosion [34].

5.2.2 Grading and construction burdens

As slopes become steeper, grading and infrastructure provision become more complex and expensive [11, 12]. For example, constructing roads on steep slopes often calls for substantial grading and extra-wide rights of way to accommodate road slopes [12]. As shown in Figure 9, retaining walls are often necessary to support soil laterally when slopes are steep. Sewer and water systems are especially challenging and costly to plan and construct on steep slopes [11].

Figure 9.

A residential site developed on a steep-sloping area in Tokyo.

When the gradient exceeds 15%, the cost of building on the site begins to increase significantly because construction becomes more challenging [35]. Typically, the development requires deeper excavation, more concrete, retaining walls, and specialized solutions for drainage and sewer systems [35].

5.2.3 Accessibility

As topographic features become steeper, incorporating accessibility and universal design into the developed areas needs greater planning. As shown in Figure 9, the built environment in hilly areas often includes inclined roads and long stairways, which are hard to go up and down, especially for physically challenged people.

In addition, Japan has recently faced mobility issues, resulting from the age of the slope dwellers. In many hilly residential areas developed on the outskirts of megacities, aging has hindered the physical abilities of many residents. As a result, such older dwellers have started suffering from limited physical and social activities due to the steep slopes and long stairways [36].

According to a study on housing land development and accessibility, the maximum slope for general residential land should be 1 in 5, or 20% [37]. Meanwhile, the maximum gradient advisable for pedestrian ramps, which is also suitable for prams and trolleys, is 1 in 10, or 10% [37]. This figure significantly influences the design of pedestrian networks in various housing projects. In addition, ramp gradients are becoming more important with the increasing provision of ramps for the physically challenged in new projects [37].

5.2.4 Landscape

Steeply sloping areas often offer significant views of hills and valleys. Thus, developing such areas frequently leads to serious disfiguration of the scenic natural beauty [11, 12].

Generally, as the topographic gradients of the developed area become steeper, the more easily the landscape changes come into view from many places in the city or town areas. Therefore, in order to maintain scenic hillside landscapes, municipalities should take measures to control development and construction on steep-sloping sites. For example, Cardinia Shire Council in Victoria, Australia, manages development and construction in areas with a slope of greater than 10%, mainly for retaining scenic landscapes and amenity values [38]. Moreover, the Council strictly limits land development in areas with slopes in excess of 20% [38].

The above examinations from the four aspects can be integrated into the following. Generally, steep slopes, namely areas with a slope of 15% or more, should always involve restricting land development. In particular, land development in slope areas in excess of 20% should be strictly limited. Meanwhile, restrictions on developing areas with environmental sensitivity, landscape importance, and walkability-oriented design should start at 10% of a topographic gradient.

6. Integration: defining development-restrictive areas

The previous three sections illustrate how to define areas contributing more to biodiversity, natural disaster-prone sites, and steep-sloping areas. Based on these preparations, this section shows how to integrate the three sorts of cartographic information and delineate development-restrictive areas. In addition, nowadays, the Geographic Information System (GIS) has become increasingly common in handling spatial data; accordingly, the following proceeds with the explanation on the assumption that a GIS is used.

Figure 10 illustrates an example of combining the three sorts of geographical information in a GIS and defining development-restrictive areas. The left side includes necessary spatial data, such as hazard maps and relevant specified areas. The right side demonstrates how the prepared GIS data layers are overlaid and integrated.

Figure 10.

An example of the process for delineating development-restrictive areas.

Concerning “topographic gradient,” planners draw up a map layer on which steep-sloping areas are shown. In this case, it is helpful to color the map of the relevant region or municipality according to gradient classifications: 0–10% (gradual), 10–15% (moderate), 15–20% (steep), and 20% + (very steep). An example of such coloring has been demonstrated in Figure 8(a).

As for “natural disaster risks,” the planners create data layers by natural hazard type. In the case of Figure 10, two types of hazards, namely river flooding and landslides, are predicted in the region or municipality. Accordingly, a data layer showing river flooding high-risk areas and one displaying landslide high-risk areas are prepared. If reliable hazard maps are open to the public, such maps can be utilized.

When handling data on “areas contributing more to biodiversity,” it is helpful to divide them into “significance” and “conservation.” This division is based on the categorization illustrated in Figure 4. The data layer of “significance” represents significant areas for biodiversity, such as Key Biodiversity Areas (KBAs). Meanwhile, the “conservation” layer displays conservation areas, namely protected areas and OECMs.

After preparing the necessary data layers, the planners place them on top of one another and integrate the spatial data. In this case, the unions, or amalgamations, of the relevant areas shown on the data layers correspond to development-restrictive areas.

The last part of this section compares development-restrictive areas with the coverage targets of conservation: (1) covering KBAs with conservation areas, and (2) conserving 30% of Earth’s land and sea areas by 2030. These two coverage targets have been shown in Subsections 3.3.2 and 3.3.3, respectively. Through the integration process, significant areas for biodiversity, such as KBAs, are taken in development-restrictive areas. Therefore, if the development-restrictive areas are given conservation status, all KBAs are naturally covered with this status. Meanwhile, development-restrictive areas contain natural disaster-prone sites and steep-sloping areas, in addition to areas contributing more to biodiversity. Thus, if development-restrictive areas are actually preserved, the coverage ratio of conservation areas to the Earth’s surface must expand greatly. In short, defining development-restrictive areas substantially contributes to meeting the two coverage targets of conservation.

7. Conclusion

In order to pursue sustainable land development, this chapter demonstrated a method of dividing a region or municipality into development-restrictive and allowable areas. First, Section 2 showed three land attributes closely related to judging the appropriateness of development, namely “biodiversity, “natural disaster risk,” and “topographic gradient.” Then, regarding these land attributes, the following three sections illustrated ways to define problematic areas for development, respectively. Finally, Section 6 demonstrated how to integrate these three kinds of spatial information in the GIS and delineate development-restrictive areas.

The second section illustrated how to produce guidelines for sustainable land development, based on the system control approach. In order to deal with various land development-related problems inclusively, this section identified the three significant land attributes mentioned above. After that, it demonstrated a strategy for defining development-restrictive and allowable areas, as shown in Figure 3. In addition, development-restrictive areas are the amalgamations of the following: (1) areas contributing more to biodiversity, (2) high-risk areas from predicted natural disasters, and (3) steep-sloping areas.

Section 3 presented the overall picture of current area-based biodiversity conservation efforts. Figure 4 concisely illustrated how to define sites contributing more to biodiversity, dividing them into two categories: (1) significant areas for biodiversity and (2) conservation areas. The diagram also showed the main coverage targets of these site-based conservation efforts.

Section 4 demonstrated the whole picture of area-based natural disaster risk reduction measures in the three diagrams. Figure 5 portrayed the relationship between natural hazards and disaster risks, dividing them into “climatic” and “tectonic.” Next, Figure 6 demonstrated how to avoid risky areas from main climatic hazards, also considering climate change impacts. Meanwhile, Figure 7 showed how to avoid high-risk sites from main tectonic hazards.

Section 5 examined topographic gradient standards for determining problematic areas for development. It first classified slopes by gradient into categories, such as gradual and steep. After that, this section considered the relation between gradients and development restrictions from four aspects: (1) adverse effects of removing vegetation, (2) grading and construction burdens, (3) accessibility, and (4) landscape.

Lastly, Figure 10 in the sixth section illustrated how to prepare necessary GIS data layers and integrate them. Displayed sites on the data layers are steep-sloping areas, high-risk areas from predicted natural hazards, significant areas for biodiversity, and conservation areas. The unions of these sites are equivalent to development-restrictive areas. In addition, preserving development-restrictive sites helps satisfy the world’s conservation coverage targets, as well as avoid various problems concerning land development.

Our next work is case studies based on this method. Through such practical work, we are aiming to refine this method and contribute to sustainable land development.