Sustainable Planning Strategies Research Articles

Guidelines for designing a sustainable neighbourhood based on TND theory in Egypt

Neighbourhood is a particular geographic area that encloses a social network in which people interact socially. Therefore, the most appealing aspect of sustainable urbanism is certain to be the sustainable neighbourhood. This paper focusing on the urban development which contributes to the sustainable development of neighbourhood. Moreover, the problem of housing in Egypt is not a quantitative problem but lack of achieving the elements of sustainability and the new neighbourhoods are designed with the same basis as the Egyptian cities and thus will show the same results as in the existing cities. Consequently, there is absence of modern principles, lack of awareness for the importance of using new sustainable urban planning strategies in Egypt. This paper proposes a set of guidelines based on TND principles for the implementation of sustainable neighbourhood criteria of development. The methodology of this paper was literature review to analyse previous researches of sustainable neighbourhood development based on TND theory as well as, comparative analysis between national and international case studies. Furthermore, comparison between European and Egyptian case studies which used for presenting and analysing sustainable development criteria that used in real neighbourhood contexts. The outcome of this paper expected to influence decision-making in the area of sustainable urban development. Besides, helping to build a new and sustainable relationship between urban dwellers and urban space, and to increase the value of urban land and make our communities more sustainable.

Spatial patterns of urban green infrastructure for equity: A novel exploration

Abstract Urbanization processes spur the need for urban green infrastructure (GI) to support the well-being of urban dwellers and underpin a sustainable planning strategy. It is a challenge for urban planning to make cities equitable in a socio-spatial way for which strategic planning are demanded based on measured gradients of spatial equity for GI. Strategically, urban GI planning should pay tribute to the inherent spatial patterns and foster a fair distribution of GI towards spatial equity. Our aim is hence to investigate the spatial patterns of urban GI and disclose how spatial patterns affect spatial equity of GI in typical residential areas. The sample sites are in a central European city, Leipzig, the fastest growing city in Germany at present, with high pressure on urban growth. To elaborate an innovative approach, this study draws up a cascade of three methodological stages: 1) deploy the approach of an urban Morphological Spatial Pattern Analysis (MSPA) to compare urban GI patterns in three typical residential local districts, 2) use the GI-adapted Gini coefficient to measure spatial equity of GI distributions, and 3) explore the relationships between GI spatial patterns and spatial equity of GI for each residential type. In the context of three typical residential areas in Leipzig (i.e. (semi-)detached houses, linear multistorey housing estates, and perimeter blocks), a combination of the MSPA and a spatial equity measurement assists our novel exploration to disclose the relationships between the spatial patterns and the equity of GI distributions. Thus, we can prove strong similarities on the characteristics of spatial patterns in each residential type and observe a tendency of increasing equity from (semi-)detached houses to linear housing and further to perimeter blocks. As significant findings for the support of strategic urban GI planning, we discover that GI cores provide a restricted increase of spatial equity that limited to the lack of space. Furthermore, we suggest more GI bridges to enhance structural connectivity as well as spatial equity. This paper depicts the spatial equity of GI distributions in typical residential areas from morphological perspective, and thus further underpins urban GI planning for strategic networks as a key principle of the urban GI concept.

Sustainable urban planning strategies for mitigating climate change in Saudi Arabia

There is a growing attention on the role of rapidly growing developing countries in mitigating climate change, especially in curbing the emissions of greenhouse gases. Estimates show that in the year 2011, carbon dioxide (CO2) emissions from developing countries constituted about 63% of the world’s total, compared with only 37% for developed countries. Thus, developing countries must be an integral part of global actions toward combating climate change. In Saudi Arabia, the energy use per capita of 6937.23 kg of oil equivalent in 2014 was 3.6 times the global average and the per capita CO2 emission of 19.53 metric tons was the seventh highest. With sensitive ecosystems, limited freshwater resources and substantial coastal developments, the country is vulnerable to climate change. As such, the country has recently initiated some sustainable urban planning strategies in its major urban centers as part of its climate change mitigation and adaptation efforts. However, few studies have assessed the extent of the implementation of the strategies. Based on secondary data analysis, this article found that the implementation of the strategies is at infancy with urban greening, public transportation, and green building projects gradually gaining prominence. The paper recommends more focus on rising building and population density, mandating mixed land uses, as well as public enlightenment and engagement about climate change impacts and energy choices.

On the Use of Satellite Imagery and GIS Tools to Detect and Characterize the Urbanization around Heritage Sites: The Case Studies of the Catacombs of Mustafa Kamel in Alexandria, Egypt and the Aragonese Castle in Baia, Italy

The sustainable development of urban growth is a mandatory challenge to be addressed, as also highlighted in the Agenda 2030, and this requires suitable and sustainable planning strategies, as well as systematic and timely monitoring of urban expansion and its effects. In this context, satellite data (today also available free of charge) can provide both (i) historical time-series datasets, and (ii) timely updated information related to the current urban spatial structure and city edges, as well as parameters to assess urban features and their statistical characterization to better understand and manage the phenomenon. Nevertheless, it is important to highlight that the identification and mapping of urban areas is still today a complex challenge, due to the heterogeneities of materials, complexity of the features, etc. Our approach, herein adopted, addresses the challenges in using heterogeneous data from multiple data sources for change detection analysis to improve knowledge and monitoring of landscape over time with a specific focus on urban sprawl and land-use change around cultural properties and archaeological areas. Two significant test cases were selected: (i) one in Egypt, the Catacombs of Mustafa Kamel in Alexandria, and (ii) one in Italy, the Aragonese Castle in Baia–Naples. For both study areas, the changes in urban layers were identified over time from satellite data and investigated using spatial analytic tools to statistically characterize them. The results of this study showed that (i) the increase in urban areas is the main phenomenon around both heritage areas, (ii) this increase is sharper in developing countries (e.g., Egypt) than developed countries (e.g., Italy), (iii) the methodology herein adopted is suitable for both big and small urban changes as observed around the Catacombs of Mustafa Kamel and the Aragonese Castle.

Investigating domestic gardens’ densities, spatial distribution and types among city districts

Domestic gardens are the major contributor to greening the spatial plan in some compact cities. Irbid, Jordan is a densely populated city that has limited and deteriorating natural vegetation and is located in an arid to semi-arid climate. We investigated the density of domestic gardens (proportion of gardened residential units) in Irbid city and explored some properties of domestic gardens. The research focused on the city domestic garden types, their distribution, gardens proportions and association to household economic status and parcel area. Four hundred and thirty residential units were selected randomly using Geographical Information Systems (GIS). The sample size for each district was identified proportionally relative to the district’s total residential units. Parcel area, district population, household income and landscape properties information were obtained from GIS maps, homeowners’ interviews or on site observations. Sixty-two percent of the city residential units had gardens and those gardens were distributed unequally (21–100%) among city districts. Rural areas had higher garden densities (proportions) compared to that at the city center. Around 50% of the city gardens were utilitarian and were concentrated in the rural areas, while the aesthetically designed gardens represented 21% of the total gardens and were significantly concentrated near the core urban area of the city. Around 53% of the city domestic gardens were categorized as side yards. The districts’ domestic garden proportions and parcel sizes were positively correlated. The proportions of aesthetic gardens were positively correlated with districts’ median income while utilitarian garden proportions strongly and inversely correlated with districts income. This knowledge about the proportions of domestic gardens distribution, trends, garden attributes and other factors that interfere with the existence and shape of domestic gardens has implications for species composition and can serve as a basis for green infrastructure planning, sustainable environmental planning strategies, and land use policies.

Moving Urban Sculptures towards Sustainability: The Urban Sculpture Planning System in China

Following the continuous development characterized by large-scale constructions, Chinese urban development has shifted to the promotion of refined urban space quality. Urban sculpture, an important part of public arts, has been receiving increased attention in China as an important carrier for highlighting urban characteristics, culture, and history within cultural policies. As a type of cultural capital, it offers innovative methods to address the issues of economic, social, and environmental sustainability, in particular cultural sustainability. Interdisciplinary theories of urban planning are creatively applied to guide, coordinate, and improve the sustainable production of urban sculptures in China. This research was initiated to: (1) Illustrate how urban sculptures are produced through an urban planning system in the context of China; (2) explain what kind of influencing factors in relation to sustainability exist, mainly within the framework of planning strategies and cultural policies; and (3) put forward sustainable planning strategies to produce urban sculptures. To answer the above inquiries, we reviewed more than 100 articles, plans, and government documents, and we conducted several semi-structured interviews. The article argues that urban planning strategies and policies have been conceived as strategic instruments by the Chinese municipal governments to realize sustainable development of urban sculptures. Our findings would enrich knowledge on geographic studies of public art planning through the contextualized analysis of a Chinese urban sculpture planning system. It also fills the gap in the literature on the sustainability of urban sculptures by approaching the perspectives of planning strategies and cultural policies.

Urban sustainable transportation planning strategies for livable City's quality of life

Urban planning and its relevant transportation deploying have a particularly profound influence on the sustainability and livability of a city, and which also be crucial to the quality of life to urban residents at the same time. It was also suggested that the conception of livability should be extended to embrace the concerns associated with the sustainability. However, planning frameworks or assessment patterns that address the dynamics of urban planning and demand for transportation deploying are relatively rare; there also few public policies in related research fields have discussed the effects of the changes in various assessment indicators over time. Furthermore, following the rising advancements in social communication and computer technologies in modern society, the data collection, storage, and processing capabilities of people have improved substantially. And, the emergence of big data or extendible open data facilitates analysis and prediction availability, and enabled people to find immediate solutions to numerous dilemmas encountered. Therefore, based on the aforementioned intention, treating the city as a dynamic process with the trying of introducing the big data or extendible open data for facilitating urban sustainability and livability is undoubtedly worth to explore in further.The present study intends to initially examine the application of big data in sustainable and livable transportation strategies in Taipei City, Taiwan. Firstly, we investigate previous research on transportation sustainability in various countries to generalize our preliminary list of transportation sustainability indices that satisfy the principles of livable cities. And, key indices were then selected through the Fuzzy Delphi Method by administering a questionnaire to six experts from industrial, governmental, and academic sectors respectively. The research results were applied to develop decision-making strategies for responding to the environmental dynamics of Taipei City's transportation infrastructure system by using the analytic network process combined with a data-mining technique. Thus, big data pertaining to urban transportation were analyzed to predict the future dynamic trends of the key indices and prioritize the sustainable transportation strategies for a livable city under dynamic temporal and spatial changes. Ultimately, the policy implications of this study can not only offer a solution for current needs related to urban planning but also serve as a more transparent decision-making or well selection basis for developing sustainable and livable urban life in near future.

Applying the Kano two-dimensional model and quality function deployment to develop sustainable planning strategies for public housing in Taiwan

The worldwide issue of high housing prices has significantly affected the general population’s inhabitation right and their willingness to purchase homes. The governments of all countries have been actively promoting public housing policies to help satisfy daily living requirements for all social classes. However, many differences exist in the design requirements for public housing and typical housing design, and the lack of discussion on these differences has caused design outcomes to often fail in meeting users’ requirements. This study first adopts the Kano two-dimensional quality analysis method in an attempt to define the real needs of public housing users; subsequently, based on the quality function deployment method, it transforms the design requirements into a design strategy. The research findings indicate that future public housing must focus on multi-generational living arrangements, energy-efficient and barrier-free designs, flexible spaces, crime prevention, self-sufficient farming, and other such areas to satisfy the needs of different users. This study practically bases its case designs on a design strategy and obtained feedback from users to understand the expectations and cognitive differences between designers and residents.

Dasymetric mapping of urban population in China based on radiance corrected DMSP-OLS nighttime light and land cover data

High spatial resolution urban population dataset is increasingly required for sustainable urban planning and management. Dasymetric mapping is an effective approach to create such dataset. However, the created gridded total population datasets usually have limitation for urban analysis in developing countries as they usually underestimate urban population because of the strong urban-rural difference. In this study, we aimed to create a dataset of gridded urban population with 1 km resolution in China in year 2000 and 2010. We proposed an index of urban nighttime light (UNTL) by integrating radiance corrected DMSP nighttime light (RcNTL) and urban land, which is then used as weight to disaggregate county-level urban population. The validation using township population in Beijing as references shows reasonable accuracy with a mean relative error of 38% and a R2 of 68%. Using only two widely available datasets (RcNTL and urban land), the proposed method is simple and computing efficient compared with methods using multiple geospatial data (e.g., land use and land cover, distance to city center, slope) and that combined with remote sensing imagery. As the used two auxiliary datasets are accessible globally, the method has great potential to produce similar urban population dataset for other developing countries where fine scale census population datasets are scarce. The produced urban population dataset is valuable for enriching our understanding of the urbanization process and designing sustainable urban planning and management strategies in China.

Influencing Mechanism Analysis of Urban Form on Travel Energy Consumption—Evidence from Fukuoka City, Japan

The increasing threat of transportation energy insecurity, environmental issues and public health issues have led to a growing body of research that looks at the potential contribution of urban planning in reducing travel energy consumption. The sustainable planning strategies aimed at reducing travel energy consumption need to understand the relationships between urban form, travel behavior and energy consumption. This study provided additional insights into the relationships between urban form, travel mode choice and energy consumption via mode-wise (non-motorized, motorcycle, car, bus and rail) stratified models and travel energy consumption model by applying the multiple linear regression model based on 108 zones of Fukuoka city, Japan. This study suggests that urban form makes a major contribution towards conserving travel energy in cities. This study shows that the provision of bus stops and rail stations are essential alongside an increase in road connectivity, otherwise increasing only road connectivity encourages people to use private modes of transport, which is not good for travel energy conservation. The findings suggest that better transit accessibility promotes public mode use, and reduces private mode use and travel energy consumption even where travel distance is longer. Higher density with greater land use mix and better transit accessibility has a more profound influence on increasing use of the non-motorized mode.

Modelling the impact of urban growth on agriculture and natural land in Italy to 2030

The uncontrolled spread of towns and cities into their surrounding rural and natural land, and the consequent increasing demand for new natural resources are among the most important drivers of global climate and environmental change. This study investigated the loss of natural and agricultural land in Italy in the last decades, during which urban areas have undergone significant expansion. The study underlines the negative consequences of past uncoordinated urban and regional planning in Italy which often featured adaptive ex-post strategies favouring real estate market returns, rather than avoiding ex-ante the unsustainable threats. The aim is to show that only through a recalibration of priorities in planning, by adding policies that favour ecological conservation, it is possible to better foster sustainable land use practices. To this end, the research features a comparison of forecasts of land-use/cover changes (LUCC) corresponding to different policy-oriented scenarios, using a combination of multi criteria analysis and cellular automata modelling. In the planning literature there are many applications of land-use change modelling at the regional/local scale, however to the best of our knowledge, none does it at high resolution and at the full country scale. This sort of analysis is important for policy makers because it allows investigation of the combined relevance of local and global criteria in influencing urbanization for the future. Thus it couples locally relevant findings with a comprehensive vision of the phenomenon at a national scale. We conclude by discussing some critical socio-economic implications of the modelled scenarios in order to provide policy makers with useful tools and information to develop resilient and sustainable planning strategies.

Impact of urban land cover change on land surface temperature

The rapid growth in urban population is seen to create a need for the development of more urban infrastructures. In order to meet this need, natural surfaces such as vegetation are been replaced with non-vegetated surfaces such as asphalt and bricks which has the ability to absorb heat and release it later. This change in land cover is seen to increase the land surface temperature. Previous studies have tried to explain the impact of land cover changes on the land surface temperature. However, there is a growing need to spatially quantify the extent to which temperature has increased so as to identify areas where immediate mitigation measures can be introduced. In view of this, this study has incorporated remotely sensed Landsat data with remote sensing techniques in order to effectively quantify the spatial extent of urban growth and its impact on the land surface temperature in Lagos, Nigeria. The result shows that there have been changes in the land cover which has increased the land surface temperature between 2002 and 2013. Overall, there was an increase in the highly dense areas, moderately dense areas and less dense areas by 3.35% (2200.77 ha), 27.87% (13681.35 ha), 6.20% (3284.01 ha) and a corresponding increase in the mean land surface temperature of these urban areas by 3.8 oC, 4.2 oC and 2.2 oC. Hence, it was recommended that in order to reduce the land surface temperature of urban areas, sustainable urban planning strategies that include increasing the vegetated areas and embracing other green initiatives such as urban forestry should be adopted.

Integration of disaster management strategies with planning and designing public open spaces

Abstract Public open spaces (POS) are often used as a strategy to enhance cities’ sustainability while using it as a mode to improve the quality of life, aesthetic beauty, environmental health, economic growth and to increase the walkability, live ability and vitality of cities. However, sustainable development should comprise the improvements of disaster resilience. Moreover, past disaster events evidence that these POS have a significant potential to contribute to disaster management as a primary place to rescue and for shelters, as an agent of recovery, to provide essential life support and potential for adaptive response. Yet, lack of attempts have been made to harness this potential through the integration of disaster management strategies into planning and designing POS in cities. Accordingly, this ongoing research study aims to find out the innovative planning and designing methods, integrated with disaster management strategies to plan and design POS in cities. Accordingly, this research paper analyses the existing literature investigating the usage of POS in past disaster events and cross-compare the identified disaster management strategies with the sustainable planning and design strategies. Finally, the findings present five main approaches to integrate the disaster management strategies into planning and designing public open spaces.

The hysteresis effect on surface-air temperature relationship and its implications to urban planning: An examination in Phoenix, Arizona, USA

Urban areas, with massive built-up landscapes and manmade structures, have different patterns of local microclimate as compared to natural terrains. A better understanding of the surface-air temperature relationship in urban environments is of significant importance in interpreting urban climatic characteristics and solving related environmental problems via sustainable landscape planning strategies. In this study, we analyse the ground-based in-situ measurements as well as remotely sensed thermal dataset in Phoenix, AZ. Prominent hysteresis effect manifests in correlating diurnal cycles of surface and near-surface air temperatures. In particular, a peculiar pattern of “8-shaped” surface-air temperature hysteresis is observed over concrete pavement especially in winters. Pearson’s r values, measuring the strength of surface-air temperature coupling, show strong correlation with incoming solar radiation and wind speed, but are relatively insensitive to humidity. The hysteresis effect diminishes at climatic scale, such that the remotely sensed surface temperature can be approximated as linearly correlated to the near-surface air temperature.

Sustainable Land-Use Planning to Improve the Coastal Resilience of the Social-Ecological Landscape

The dynamics of land-use transitions decrease the coastal resilience of the social-ecological landscape (SEL), particularly in light of the fact that it is necessary to analyze the causal relationship between the two systems because operations of the social system and the ecological system are correlated. The purpose of this study is to analyze the dynamics of the coastal SEL and create a sustainable land-use planning (SLUP) strategy to enhance coastal resilience. The selected study site was Shindu-ri, South Korea, where land-use transitions are increasing and coastal resilience is therefore decreasing. Systems thinking was used to analyze the study, which was performed in four steps. First, the issues affecting the coastal area in Shindu-ri were defined as coastal landscape management, the agricultural structure, and the tourism industry structure. Second, the main variables for each issue were defined, and causal relationships between the main variables were created. Third, a holistic causal loop diagram was built based on both dynamic thinking and causal thinking. Fourth, five land-uses, including those of the coastal forest, the coastal grassland, the coastal dune, the agricultural area, and developed sites, were selected as leverage points for developing SLUP strategies to increase coastal resilience. The results show that “decrease in the size of the coastal forest”, “decrease in the size of the coastal dune”, and “increase in the size of the coastal grasslands” were considered parts of a land-use plan to enhance the resilience of the Shindu-ri SEL. This study developed integrated coastal land-use planning strategies that may provide effective solutions for complex and dynamic issues in the coastal SEL. Additionally, the results may be utilized as basic data to build and implement coastal land-use planning strategies.

Is Reducing Car Use a Utopian Vision?

Abstract Most urban environments appear to marginalise alternative forms of transport e.g. walking or cycling. New planning strategies are required to promote a reduction in car use and low carbon travel. This paper aims to inform sustainable transport planning strategies examining the effect urban demographics might have towards car usage. Research involved questionnaire surveys distributed to a sample population in Birmingham, UK. Results suggested that individuals indicated a strong dependency upon car usage despite two thirds recognising the contribution of car use to climate change. Data indicated car use was linked to age and there was a willingness amongst participants to reduce car use.

Analysis and Sustainable Management of Urban Growth’s Impact on Land Surface Temperature in Lagos, Nigeria

The rapid growth in urban population is seen to create a need for the development of more urban infrastructures. In order to meet this need, natural surfaces such as vegetation are been replaced with non-vegetated surfaces such as asphalt and bricks which has the ability to absorb heat and release it later. This change in land cover is seen to increase the land surface temperature. Previous studies have tried to explain the impact of land cover changes on the land surface temperature. However, there is a growing need to spatially quantify the extent to which temperature has increased so as to identify areas where immediate mitigation measures can be applied. In view of this, this study has incorporated remotely sensed Landsat data with remote sensing techniques in order to effectively quantify the spatial extent of urban growth and its impact on the land surface temperature in Lagos, Nigeria. The result shows that there have been changes in the land cover which has increased the land surface temperature between 2002 and 2013. Overall, there was an increase in the highly dense areas, moderately dense areas and less dense areas by 3.35% (2200.77 ha), 27.87% (13681.35 ha), 6.20% (3284.01 ha) and a corresponding increase in the mean land surface temperature of these urban areas by 3.8°C, 4.2°C and 2.2°C. Hence, it was recommended that in order to reduce the temperature of the urban areas, sustainable urban planning strategies that include increasing the vegetated areas and embracing other green initiatives such as urban forestry should be adopted.

Study on the Planning Strategies of Urban Street Open Space Constrained by the Environment in Winter City

Street open space, as a necessary place for residents to conduct interpersonal interaction in the city, serves as an important space for people to exchange material, energy and information with nature. In Harbin, a winter city, Dasongbei area, as a newly built zone, leads the strategic forefront in promoting new urbanization, whose open space has drawn increasing attention in its environmental construction. This paper summarizes four planning modes of street open space and some existing problems through field investigation and interview for Dasongbei area, such as inadequate consideration on citizen demands, neglect of weather factors in winter cities, monotonous plant landscape, etc. Under regional environment context, combining with the influence of the cold climatic elements on the street open space construction, this paper puts forward suitable and sustainable planning strategies of street open space so as to guide the planning and design of street open space in other winter cities.

Integrating biophysical and socio-economic factors for land-use and land-cover change projection in agricultural economic regions

Land-use and land-cover change (LUCC) are shaped by society–nature interactions and processes. Therefore, a full study of LUCC dynamics needs explicitly to take account of both socio-economic and biophysical factors. Although some studies have addressed both these drivers, most are built as a package/black-box and consider individual types of land-use rather than land systems as a whole. Our research aims to develop a comprehensive and flexible framework that links socio-economic and biophysical driving factors to project LUCC. The framework combines System Dynamics and Geographic Information System (GIS) models, with System Dynamics used to examine the relationship between socio-economic driving factors of LUCC processes and land demand estimates. The GIS model is used to allocate land demand to the most suitable grid cells, according to the different biophysical characteristics of the cells. The study is based on the application of the framework in Dak Lak province, Vietnam, where economic development has resulted in rapid LUCC. The Kappa value of our study, compared with actual land-use in the province (2010), is 0.87. It proves that our model is reliable and can help land-use planners and policy makers develop sustainable land-use planning and management strategies. Working on the assumption that the trends indicated in Dak Lak’s 2020 land-use plan continue, we produced projected land-use/land-cover maps for 2020 and 2030.

Automated mapping of impervious surfaces in urban and suburban areas: Linear spectral unmixing of high spatial resolution imagery

Quantifying impervious surfaces in urban and suburban areas is a key step toward a sustainable urban planning and management strategy. With the availability of fine-scale remote sensing imagery, automated mapping of impervious surfaces has attracted growing attention. However, the vast majority of existing studies have selected pixel-based and object-based methods for impervious surface mapping, with few adopting sub-pixel analysis of high spatial resolution imagery. This research makes use of a vegetation-bright impervious-dark impervious linear spectral mixture model to characterize urban and suburban surface components. A WorldView-3 image acquired on May 9th, 2015 is analyzed for its potential in automated unmixing of meaningful surface materials for two urban subsets and one suburban subset in Toronto, ON, Canada. Given the wide distribution of shadows in urban areas, the linear spectral unmixing is implemented in non-shadowed and shadowed areas separately for the two urban subsets. The results indicate that the accuracy of impervious surface mapping in suburban areas reaches up to 86.99%, much higher than the accuracies in urban areas (80.03% and 79.67%). Despite its merits in mapping accuracy and automation, the application of our proposed vegetation-bright impervious-dark impervious model to map impervious surfaces is limited due to the absence of soil component. To further extend the operational transferability of our proposed method, especially for the areas where plenty of bare soils exist during urbanization or reclamation, it is still of great necessity to mask out bare soils by automated classification prior to the implementation of linear spectral unmixing.