Field of Action Spatial, Regional and Urban Development Planning
Click to enlargeSource: Lukas Pollmüller/photocase.com
Click to enlargeSource: Lukas Pollmüller/photocase.com
Impacts of Climate Change
Table of Contents
Task of spatial planning
The task of spatial planning is to record the various demands on space resulting from a wide range of human activities and needs, to weigh them up against each other and to coordinate the implementation of the results. Spatial planning controls on a large scale where in space which uses are located (e. g. settlements, transport infrastructures, recreational areas, agricultural production areas).
Effects of climate change on land use
According to the German Spatial Planning Act (ROG), spatial significance is defined as the use of space or the influence on the spatial development or function of an area. Climate change and its impacts are highly spatially significant. The impacts potentially influence all areas of spatial development and a variety of spatial uses. They affect the activities, uses and demands of many economic sectors (e. g. agriculture, forestry, tourism), the spatial demands of a wide range of population groups, as well as natural systems and their ecosystem services (e. g. protective effect of forests, provision of water, production of food). Priority climate impacts with spatial planning relevance are in particular: Flood risks in river basins, dangers from sea-level rise and increased storm surge levels in coastal regions, stresses from heat in settlement areas, impairment of water supply and water availability due to prolonged dry periods and threats to biodiversity.
Flood risks: Depending on regional and local conditions, floods, inundations, flash floods and landslides may increase in river basins as a result of extreme precipitation. This increases the risk of damage to settlement areas and their infrastructures. An increase in damage from inland flooding and flash floods is also due to the expansion of settlement areas and post-densification and a corresponding increase in the existing values of infrastructures and buildings in floodplains. Land at risk is no longer available for sensitive uses due to more frequent flooding.
Sea level rise and storm surges: Due to sea level rise, storm surges could occur more frequently in the future with high water levels. The consequences are coastal flooding, reduction of wetlands, coastal erosion and increasing salinisation of agricultural land. Coastal erosion results in more frequent break-off on steep coasts and removal of material on flat coasts, accelerating coastal retreat. Flooding can damage coastal housing and infrastructure and threaten populations in low-lying coastal areas. Other consequences include saltwater intrusion into groundwater and agricultural soils, which can render irrigated cropland and drinking water reservoirs unusable as a consequence.
Extreme temperatures and heat waves: Higher extreme temperatures, less cooling at night, as well as more frequent and more intense periods of heat, combined with dense building development, a high proportion of sealed surfaces, too little green space, and waste heat from industry, buildings and traffic, increase the formation of heat islands in inner cities. This can lead to high heat stress for urban residents, with consequences for their well-being and health. This applies in particular to the elderly, people in need of care and sick people, as well as small children and pregnant women. Heat, combined with drought, can also affect green spaces and protected areas and thus biodiversity in urban areas.
Water supply and availability: Rising temperatures and changing precipitation conditions can have a fundamental impact on the quantity of groundwater resources. Thus, in the course of climate change, a decrease in groundwater recharge is to be expected. With more frequent dry periods, areas could be increasingly affected by temporary water shortages in the future. If the usable water resources are restricted, this will affect almost all spatial functions (e. g. settlements, open spaces, transport, water and energy infrastructures). In addition, it can be assumed that more frequent heavy rainfall events may endanger the quality of drinking water through the contamination of near-surface sources, which in turn requires additional effort for drinking water supply.
Threat to biodiversity: From the perspective of spatial planning, the shifting of vegetation zones, range shifts of species and changes in habitats due to climate change play an important role for the concerns of biodiversity and nature conservation. Changes in the geographical distribution of species (e.g. spread of warmth-loving species, decline of cold-tolerant species, displacement by immigrant species) have consequences for the species inventory, the species composition and thus for the structure of habitats and entire ecosystems. Particularly endangered habitats are forests, wetlands (e. g. bogs due to increasing summer drought, coastal habitats (e. g. salt marshes due to higher water levels) and protected areas. The change in the natural potential of protected areas due to climate change will have an impact on the protection and conservation objectives.
Land use conflicts
The increasing discrepancy between the demand for space and the availability of space, in particular the shortage of available land, leads us to expect increasing conflicts over space and land use as a result of the consequences of climate change. Settlement development, commerce, tourism, coastal protection and nature conservation, drinking water supply, agriculture as well as forms of regenerative energy production for climate protection that depend on the use of land (e.g. solar open space plants, wind farms, biomass cultivation) are in competition for land. For example, in water management, problems result from increasingly competing groundwater withdrawals during dry periods (agriculture vs. drinking water supply), and problems arise in creating new retention areas that could be used as floodplains in the event of an inland flood (e. g. agriculture vs. flood control).
Cross-relationships with other fields of action
Spatial planning is characterised by a high degree of connectivity with other fields of action that occupy land or indirectly influence the use of space. Cross-relationships exist in particular with the field of action of the economy (e.g. designation of suitable sites for industry, commerce and service facilities), the energy industry (e.g. designation of wind power sites), transport planning (e.g. expansion of transport infrastructure), nature conservation (e.g. designation of protected areas) and water management (e.g. securing flood plains). There is also often a close connection between planning and health aspects. For example, the urban structure, i.e. the dimensioning and design of open spaces, streets, built-up areas and individual buildings, has an influence on summer heat generation and ventilation and thus on the well-being and health of the urban population.
Due to its cross-sectional character, spatial planning plays a decisive role in shaping the respective living environment, i.e. the conditions for living, working and leisure activities. Consequences of climate change can be mitigated by using space in a way that is as climate-adapted as possible.
Adaptation to Climate Change
Importance of spatial, regional and urban land use planning for climate adaptation
Spatial planning has an important role to play in climate adaptation. Due to the very different sectoral climate impacts with their interactions as well as their spatial diversity, which continues down to the local level, there is a need for interdisciplinary and inter-area coordination in the assessment of spatially relevant risks and opportunities as well as the identification of possible adaptation measures. In this respect, spatial planning in Germany has an established planning system in which overall planning and sectoral planning can work together.
Climate adaptation is anchored at the federal level in the German Spatial Planning Act and in the guiding principles of spatial planning. The concrete planning consideration of the requirements of climate adaptation takes place regionally and communally at the level of land and regional planning or urban land use planning. At these different planning levels, as well as in the context of close coordination with the respective spatially relevant sectoral planning (e.g. water management, landscape planning, nature conservation, transport), spatial planning has numerous opportunities to influence adaptation to climate change.
Indicator from the DAS monitoring: Land used for human settlements and transport infrastructure
Contributions of regional planning to climate adaptation
Regional planning, as a link between different levels, (specialised) departments and public and private actors, is suitable for developing and implementing regional action strategies for climate adaptation. In this way, it can concretise federal and state requirements in a region-specific and cross-sectoral manner and bring them together with the interests of the municipalities. In principle, regional planning contributes to climate adaptation by determination (e.g. designation, clearance, securing) areas for uses that reduce climate risks and damage potential. Relevant fields of action for climate adaptation in regional planning are considered in many regions: Preventive flood protection in river basins, reduction of hazards in coastal regions, protection against heat and heavy precipitation in settlement areas, conservation and protection of water resources and preservation of biological diversity.
Flood protection: Large-scale retention areas can be secured for flood hazards (e. g. through dyke relocations). For this purpose, regional planning can define priority areas for preventive flood protection in which flood protection has priority and must be observed as a binding requirement. Other spatially significant uses (e. g. housing development, commercial development) that are not compatible with the objective of flood protection are excluded or can be subject to restrictions on use. When defining a reserved area, flood protection has a special weight in the balancing of competing interests. It does not completely exclude the admission of conflicting uses such as residential development if the construction method is adapted to the existing flood hazard (e. g. stilted construction, "floating houses").
Indicators from the DAS monitoring: Priority and restricted areas for (preventive) flood control | Settlement use in flood-risk areas – case study
Coastal protection: Coastal protection endeavors to adapt the technical protection facilities (e. g. dikes) along the coast to sea-level rise and rising storm surge levels in terms of construction and technology. Regional planning can support coastal protection in this respect by defining the areas required for the upgrading of dikes to prevent changes in use. Furthermore, it can secure the sand and clover extraction sites necessary for dike construction. In order to reduce the potential for damage in coastal regions, regional planning can designate safety areas along coastal sections that are threatened by erosion. With regard to building development, specifications can be formulated for areas protected from storm surges as well as for areas not protected.
Protection against heat stress in urban regions: The protection and designation of climate-active open spaces such as cold-air production areas (e. g. meadows, farms) and fresh-air production areas (e. g. forests) as well as cold-air and fresh-air corridors in densely populated areas by regional planning contribute to ensuring sufficient ventilation of the settlement structure and to minimise or completely avoid climatic stresses for the population in urban regions. Accordingly, cold and fresh air production areas are to be kept free of settlement. Crosswise large buildings, dense plantings as well as afforestation or fillings, which impair the transport of cold air, should be excluded by specifications on the respective areas.
Indicator from the DAS monitoring: Priority and restricted areas for special climate functions
Protection of water resources: With regard to the conservation and protection of water resources, spatial planning can support water resource management. To this end, land and regional planning can define priority and reserved areas for drinking water and groundwater protection in order to secure water resources in planning terms. This concerns both the protection and conservation of groundwater resources and the use of groundwater. Specifications for controlling water consumption can exclude water-intensive uses (e. g. commerce, industry, settlements) in areas that are particularly affected by drought. In the future, another task of spatial planning could be to secure suitable areas for precautionary measures against water scarcity by means of priority or reserved areas, and to reserve these areas in the long term, which (could) be needed for the following measures, among others: the expansion or new reservoirs for (drinking) water supply or the construction of polders and rainwater retention basins for the temporary storage of water surpluses for delayed use as industrial water, for agricultural irrigation or for the renaturation and rewetting of bogs and floodplains.
Indicator from the DAS monitoring: Priority and reserved areas for groundwater / drinking water
Protection of biodiversity: By designating priority and reserved areas for nature and landscape, regional planning can contribute to the establishment of an ecological network (biotope network). In this way, it can secure or impose restrictions on the use of areas that are important for the adaptation of animal and plant species to climatically induced changes, e. g. the climate change-induced migration of species due to range shifts. As a supplement, regional green corridors can be secured as priority areas.
Indicator from the DAS monitoring: Priority and reserved areas for nature and landscape
Source: Peter H / Pixabay
Contributions of urban land use planning to climate adaptation
Within the framework of urban land use planning spatial planning can also contribute to reduce the sensitivity of settlement structures to climate change at the municipal level. Urban land use planning is organised in a two-stage planning procedure; a distinction is made between preparatory urban land use planning (land use plans) and binding urban land use planning (development plans). Urban land use planning derives its scope of action from the German Federal Building Code (BauGB). With the amendments to the Building Code (BauGB) in 2011 and 2013, the federal government has given climate adaptation a higher priority by giving it additional legal weight in the consideration of planning law. The amendment in 2013 also laid the legal foundations to ensure that climate adaptation goals are also taken into account in urban redevelopment and rehabilitation measures. Contributions of urban land use planning to climate adaptation come in particular from the possibilities of representation and specification in land use and development plans.
The following starting points are presented in the areas of action: flood protection, coastal protection, protection of settlement areas from extreme weather events, protection of water resources and precautionary measures for biodiversity and nature conservation.
Flood protection: Flood protection concerns are anchored in the BauGB as a planning guideline to be observed when drawing up urban land use plans. Areas necessary for flood protection, the construction or expansion of flood protection facilities, and water runoff can be shown or specified in the land use or development plan. The designation of new building areas in flood plains established under water law is only permissible under strict conditions.
Coastal protection: In view of rising sea levels and an increased risk of flooding, consideration of coastal protection requirements in urban land use planning is particularly important in settlement areas with limited spatial conditions. Within the framework of urban land-use planning, land-use and development plans can show or determine separate areas for flood protection and flood protection facilities in order to secure the necessary areas for the widening or relocation of dykes. In addition, restrictions on use and development can be formulated for low-lying areas behind dykes in order to reduce the potential for damage and to concentrate residential development in areas that are less at risk.
Protection of settlement areas against extreme weather events: In order to adjust the settlement and open space structures, land use planning can make representations or specifications in land use or development plans or in local building regulations and statutes in order to counter increased heating of densely populated settlement areas and the resulting heat stress on people as well as heavy rain events and the associated risk of flooding.
Protection against heat stress: With regard to the issue of heat, there are opportunities in particular to implement measures to protect green and open spaces that are important for the settlement climate and to ensure sufficient ventilation of the settlement structure. Keeping areas that are important for the urban climate free can be ensured through appropriate land-use designations and specifications in urban land-use plans (e. g. as green spaces). Ensuring better ventilation of an area can be achieved in the development plan by specifying the minimum size of building plots, the height of buildings and the orientation of buildings. There are also possibilities in urban land use planning to implement measures for the greening and shading of traffic areas and properties to improve the microclimate by specifying plantings in development plan areas. Furthermore, it is possible to stipulate green roofs and façades in the development plan in order to reduce urban climate deficits.
Protection against heavy rainfall: With regard to the issue of heavy rainfall, measures can be taken up in land use plans that primarily serve to secure and reclaim communal retention areas, reduce the degree of sealing in settlement areas and protect buildings and infrastructure from the negative effects of heavy rainfall events. Specific measures for water-sensitive urban development can be stipulated in development plans. These include, for example, restrictions on soil sealing and unsealing measures, near-natural rainwater management (e. g. surface infiltration in troughs, infiltration trenches and cisterns), determination of green roofs and water-permeable surfaces for rainwater retention, determination of emergency waterways and specification of multifunctional land uses (e. g. green spaces with retention function). Flood-adapted construction methods can be ensured in endangered areas through urban land use planning, for example through a stilted construction method, minimum heights of (ground floor) floors, use of water-resistant materials or specifications for backwater systems in sewer networks.
Protection of water resources: Urban land use planning can support climate change-adapted water management and the protection of water resources, in particular through decentralised rainwater management measures and by reducing the degree of sealing in settlement areas. Both can contribute to the local infiltration of precipitation water and to groundwater recharge.
Protection of biodiversity: Biodiversity is an environmental issue to be taken into account in the preparation of urban land use plans. The integration of its concerns can be achieved in the land use plan in particular through the representation of open and green spaces (e. g. parks, allotments, cemeteries) for the protection, maintenance and development of soil, nature and landscape. Their designation lays the foundation for urban biotope networking. By linking regional green corridors with inner-city green areas, urban land use planning can enable animal and plant species to move to climatically more suitable areas if habitats are endangered as a result of climate change. In addition, there are control options within the framework of development plans by specifying permissible plant species for new and compensatory plantings, which can be considered a measure against the spread of invasive species. This also applies to the selection of climate-adapted plant species.
Further measures
Improving the data basis and guiding principles: In order to adapt land use to the changing climate, the data and knowledge basis for planning must be improved. The vulnerability of individual areas must be identified in a targeted manner and, based on this, guiding principles and requirements for climate-adapted spatial structures and development must be developed.
Designing an open and participation-oriented adaptation process: In an adaptation process, open communication about climate change, climate impacts and adaptation strategies and measures is a central task. To this end, various actors from politics, administration and civil society must be involved. This is particularly important when climate change-related adaptation needs are accompanied by land use conflicts. Timely involvement of the actors enables their respective interests to be taken into account at an early stage. In addition, a broad range of expertise and experience can be utilised and the acceptance of the results developed can be increased as well as their implementation promoted. Due to its cross-sectoral perspective, spatial planning is fundamentally suited to take on the task of the "promoter" of a spatial adaptation process. As a cross-sectoral actor, it has the necessary prerequisites to activate networks, to stimulate, coordinate and moderate the cooperation of different actors and to act as a mediator between different interests.
Flexibility of plans: Decisions on climate adaptation planning have to be made under high uncertainty and long-term foresight. Therefore, planning is needed that is able to react flexible to changing circumstances. A comprehensive plan with definitive statements should therefore not be drawn up from the outset, but rather a chain of successive strategic decisions should be made, each offering differentiated solutions at its level. A static allocation of spatial functions should therefore increasingly be replaced by dynamic spatial development with reversible spatial functions. To ensure this, a time limit on spatial uses would be necessary. One possibility would be to apply interim uses, i. e. uses of space that are only permitted for a limited period of time. Another instrument to increase flexibility could be target agreements that specify the result to be aimed for, but not the way to achieve it.
