24 research outputs found

    Ghost city extraction and rate estimation in China based on NPP-VIIRS night-time light data

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    The ghost city phenomenon is a serious problem resulting from the rapid urbanization process in China. Estimation of the ghost city rate (GCR) can provide information about vacant dwellings. This paper developed a methodology to quantitatively evaluate GCR values at the national scale using multi-resource remote sensing data. The Suomi National Polar-Orbiting Partnership–Visible Infrared Imaging Radiometer (NPP-VIIRS) night-time light data and moderate resolution imaging spectroradiometer (MODIS) land cover data were used in the evaluation of the GCR values in China. The average ghost city rate (AGCR) was 35.1% in China in 2013. Shanghai had the smallest AGCR of 21.7%, while Jilin has the largest AGCR of 47.27%. There is a significant negative correlation between both the provincial AGCR and the per capita disposable income of urban households (R

    Estimando indicadores socioeconômicos de pequenas bacias hidrográficas através de imagens noturnas de satélite no apoio à gestão dos recursos hídricos

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    Small watersheds lack socioeconomic data. These data are essential in land use decision-making and in water resources management, especially when determining its economic value. In order to contribute to filling this notable gap, this study presents an approach to estimate this type of information for small watersheds (from 5 to 100 km²), applying nighttime light (NTL) satellite images and available socioeconomic records from larger locale. Three socioeconomic indicators were chosen to test the method: Gross Domestic Product, population and jobs. The relationship between these three socioeconomic indicators and the radiance quantified from the NTL images was acquired through simple regression analysis applied at the 497 municipalities of the State of Rio Grande do Sul (RS), southern Brazil. The polynomial fit equations presented the best Coefficient of Determination, being further submitted to validation by using data from 50 municipalities of the neighboring State of Santa Catarina. The validation showed a very good estimation performance. The validated equations were used to estimate these socioeconomic indicators for small watersheds located in the municipality of Caxias do Sul, RS, in three different years: 2011, 2014 and 2018. Findings indicate that this novel application of NTL for estimating socioeconomic data can be a helpful tool towards land use and water resources management of small watersheds.Há falta de dados socioeconômicos para pequenas bacias hidrográficas. Esses dados são fundamentais para a tomada de decisões na gestão dos recursos hídricos, principalmente na determinação do seu valor econômico. Para contribuir em preencher essa lacuna, este estudo apresenta um método para estimar esse tipo de informação para pequenas bacias hidrográficas (de 5 a 100 km²), aplicando imagens noturnas de satélite e dados socioeconômicos disponíveis de regiões maiores. Três indicadores socioeconômicos foram selecionados para testar o método: Produto Interno Bruto (PIB), população e emprego. A relação entre esses três indicadores e a radiância quantificada nas imagens noturnas foi obtida por meio de análise de regressão simples aplicada nos 497 municípios do Estado do Rio Grande do Sul (RS). As equações do ajuste polinomial apresentaram o melhor Coeficiente de Determinação, sendo posteriormente submetidas à validação com dados de 50 municípios localizados no Estado de Santa Catarina. A validação mostrou um desempenho de estimação muito bom. As equações validadas foram usadas para estimar esses indicadores socioeconômicos para pequenas bacias hidrográficas localizadas no município de Caxias do Sul, RS, em três anos distintos: 2011, 2014 e 2018. Os resultados indicam que esta nova aplicação de imagens noturnas de satélite para estimar dados socioeconômicos pode ser uma ferramenta útil para a gestão do uso do solo e dos recursos hídricos de pequenas bacias hidrográficas

    Identifying Population Hollowing Out Regions and Their Dynamic Characteristics across Central China

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    Continuous urbanization and industrialization lead to plenty of rural residents migrating to cities for a living, which seriously accelerated the population hollowing issues. This generated series of social issues, including residential estate idle and numerous vigorous laborers migrating from undeveloped rural areas to wealthy cities and towns. Quantitatively determining the population hollowing characteristic is the priority task of realizing rural revitalization. However, the traditional field investigation methods have obvious deficiencies in describing socio-economic phenomena, especially population hollowing, due to weak efficiency and low accuracy. Here, this paper conceives a novel scheme for representing population hollowing levels and exploring the spatiotemporal dynamic of population hollowing. The nighttime light images were introduced to identify the potential hollowing areas by using the nightlight decreasing trend analysis. In addition, the entropy weight approach was adopted to construct an index for evaluating the population hollowing level based on statistical datasets at the political boundary scale. Moreover, we comprehensively incorporated physical and anthropic factors to simulate the population hollowing level via random forest (RF) at a grid-scale, and the validation was conducted to evaluate the simulation results. Some findings were achieved. The population hollowing phenomenon decreasing gradually was mainly distributed in rural areas, especially in the north of the study area. The RF model demonstrated the best accuracy with relatively higher R2 (Mean = 0.615) compared with the multiple linear regression (MLR) and the geographically weighted regression (GWR). The population hollowing degree of the grid-scale was consistent with the results of the township scale. The population hollowing degree represented an obvious trend that decreased in the north but increased in the south during 2016–2020 and exhibited a significant reduction trend across the entire study area during 2019–2020. The present study supplies a novel perspective for detecting population hollowing and provides scientific support and a first-hand dataset for rural revitalization

    A new evaluation of the role of urbanization to warming at various spatial scales: Evidence from the Guangdong‐Hong Kong‐Macao Region, China

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    The urbanization impacts on Surface Air Temperature (SAT) change in the Guangdong‐Hong Kong‐Macao region (GHMR) from 1979 to 2018 are examined using homogeneous surface observations, reanalysis, and remote sensing. Results show that the warming due to urbanization tends to be smaller or insignificant as the spatial scale increases. The urbanization contribution to the local warming can reach as high as 50% in the center of each metropolis, remains high (~25%) in the Greater Bay Area (GBA), and decreases to about 10% in the whole GHMR. The warming in GHMR is nearly uniform throughout the day, and therefore the observed trend of the Diurnal Temperature Range (DTR) is not statistically significant. However, the urbanization contribution exhibits distinct seasonal variations, large in summer and autumn while smaller in winter and spring

    Underload city conceptual approach extending ghost city studies

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    Global population growth and land development are highly imbalanced, marked by 43% of population increase but 150% of builtup area expansion from 1990 to 2018. This results in the widely concerned ghost city phenomenon and runs against the sustainable development goals. Existing studies identify ghost cities by population densities, but ignore the spatial heterogeneity of land carrying capacities (LCC). Accordingly, this study proposes a general concept termed underload city to define cities carrying fewer people and lower economic strength than their LCC. The underload city essentially describes imbalanced human-land relationship and is understood in a broader context than the usually applied ghost city. In this study, very high-resolution satellite images are analyzed to obtain land functional structures, and further combined with population and GDP data to derive LCC. We empirically identify eight underload cities among 81 major Chinese cities, differing from previous findings of ghost cities. Accordingly, the proposed underload city considers heterogeneous human-land relationships when assessing city loads and contributes to sustainable city developments

    The opportunity cost of watershed conservation : the decisions on urban water supply management

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    Land use intensification and the discharge of urban waste within the watershed have significantly contributed to the contamination of water sources. The growing concern over deteriorating source water quality has led to increasingly stringent drinking water standards over the years. Consequently, the demand for more advanced and expensive water treatment technologies has risen, resulting in an escalation of water tariffs. One alternative policy to mitigate the additional costs associated with water treatment is the implementation of land use restrictions within the watershed. By regulating land activities, it becomes possible to prevent further degradation of water quality. However, it is important to acknowledge that such conservation measures, aimed at maintaining or restoring watershed quality to ensure the production of raw water, impose financial burdens on landowners residing within the watershed. Decision makers should prioritize the careful consideration of costs and benefits when planning urban water management, even in the face of changing conditions. An efficient, equitable and sustainable approach to urban water management aims to benefit both city residents, who rely on the distribution of drinking water, and watershed landowners, who must preserve their properties to safeguard the water resources that supply the city. However, the decision-making process is complex and influenced by a myriad of uncertainties. Factors such as land use regulations, political interests, climate change, population growth, economic development, the costs of the chemicals used in water treatment plants and technological advancements all contribute to this complexity. Additionally, modest short-term gains in avoided water treatment costs can blur the perception of the outcomes in the long-term, potentially leading to decisions that are not truly efficient, equitable, or sustainable. In the dichotomous context between watershed conservation and low water treatment costs for urban water security in a world under deep uncertainties, it becomes imperative to engage in extensive analysis to identify trade-offs and comprehend the consequences associated with each chosen decision pathway. Consequently, the central question of this thesis emerges as the focal point: Which decisions regarding water treatment technologies, aimed at maintaining low tariffs, have the greatest impact on the opportunity cost of watershed conservation? Building upon this fundamental query, the overarching objective of this research is to ascertain a dynamic decision-making framework that can adapt over a specified timeframe, ensuring affordable water tariffs while simultaneously reducing the economic burden on landowners who contribute to watershed conservation. Nonetheless, there are additional secondary objectives that also need to be addressed. These include (1) identifying the extent to which treatment costs are influenced by the quality of the source water watershed, (2) estimating the additional water treatment costs when advanced technologies need to be incorporated into the existing treatment process due to watershed degradation, (3) quantifying the costs and benefits associated with watershed conservation and (4) developing an adaptive pathways map to facilitate robust decision-making in various future scenarios. To achieve these objectives, a methodological approach was employed and tested in a real-world case study: the municipality of Caxias do Sul, located in the State of Rio Grande do Sul, southern Brazil. This municipality supplies drinking water to over 500,000 inhabitants through five conventional treatment plants, which receive raw water from five small watersheds ranging from 5 to 100 km² in size. Detailed explanations of the applied methods, materials used, and the results obtained can be found in Chapters 4, 5, 6, and 7. Existing literature is limited in its comprehensive consideration of how water treatment costs are influenced by the quality of the watershed, particularly in the context of short and long-term planning. No references have been found that specifically associate this effect with planning considerations. Chapter 4 of the thesis sheds light on this aspect by illustrating how the short-term economic benefits derived from improved raw water quality can blur the perception of long-term treatment costs. The results indicate that, in the studied area, a one-unit improvement in the water quality index leads to a marginal reduction in treatment costs of only 0.0002 USD∙m-3. However, over the long-term, the cumulative effect of water quality degradation may result in an alarming increase of 242% in treatment costs. These findings underscore the importance of considering the long-term implications of watershed quality on treatment costs, emphasizing the need for holistic planning approaches that account for the interplay between raw water quality and treatment expenses. Obtaining socioeconomic data for small watersheds can be a challenging task, often resulting in a lack of available information. However, such data are crucial for making informed decisions regarding land use and water resources management, particularly when assessing their economic value. Recognizing the significance of addressing this knowledge gap, Chapter 5 of the thesis focuses on estimating key socioeconomic indicators, namely Gross Domestic Product (GDP), population, and jobs, for small areas. To overcome the data limitations, Chapter 5 employs nighttime light (NTL) satellite images and utilizes existing socioeconomic records from larger localities. By establishing a relationship between the radiance quantified from the NTL images and the three socioeconomic indicators, a simple regression analysis is conducted across the 497 municipalities in the State of Rio Grande do Sul. The findings are further validated using data from 50 municipalities in the neighboring State of Santa Catarina. The results demonstrate that this innovative application of NTL for estimating socioeconomic data can serve as a valuable tool in supporting land use and water resources management for small watersheds. In the context of the aforementioned dichotomy, it is often observed that those who bear the burden of watershed conservation rarely reap the direct benefits, because they live away from the water distribution network. Chapter 6 introduces a novel methodological framework, inspired by Data Envelopment Analysis, which explores the relationship between the opportunity cost of watershed conservation and changes in consumer surplus to quantify the benefits associated with such efforts. The results obtained from this analysis demonstrate that the economic benefits derived from watershed conservation outweigh the associated costs in all evaluated scenarios. These findings highlight that, when policies are oriented towards improving source water quality, there is a positive economic balance in the aggregate. This provides evidence that prioritizing conservation efforts has a beneficial outcome, both in economic and environmental terms. Urban water security is influenced by various factors, including the quantity and quality of raw water both in space and time. However, an often-overlooked aspect is the value of drinking water tariffs. Ensuring that tariffs remain affordable for users is crucial for achieving urban water security. In this regard, robust decision-making plays a significant role as it enables a thorough evaluation of the trade-offs between optimal land use practices within the watershed and optimal treatment costs. By considering potential future scenarios, decision-makers can make informed choices that are more likely to yield successful outcomes. Chapter 7 of this thesis focuses on the exploration of robust decisions in urban water supply. It employs the Dynamic Adaptive Policy Pathways methodology, coupled with a heuristic mathematical approach, which is a novel application in the field of watershed conservation and water treatment technology. The result is an adaptive decision map that presents various technological options, enabling decision-makers to understand the consequences associated with different alternatives. The purpose is not to determine the correct pathway, but to provide decision-makers with a comprehensive understanding of the potential outcomes associated with different decisions. This approach empowers decision-makers to make informed choices based on a deeper understanding of the implications of their actions within an adaptive context. The pursuit of low water treatment costs can come at a significant economic price. This "shadow price" of urban water must be acknowledged, and actions should be taken to compensate landowners for their role in preserving watersheds. Addressing this incongruence requires further investigation, and one potential solution could be the implementation of a payment for watershed services, similar to existing mechanisms of payment for environmental services. Throughout the thesis, it is recognized that urban water security is accompanied by inherent uncertainties. The research demonstrates that there is no singular optimal decision that perfectly balances costs and benefits in urban water management. Instead, a wide range of efficient alternatives exists, each involving tradeoffs. Decision-makers and stakeholders must be prepared to adapt their planning approaches to accommodate evolving future conditions. This allows for the exploration of diverse and efficient alternatives while considering the trade-offs inherent in each option.A intensificação do uso do solo e os resíduos urbanos na bacia têm contribuído para o aumento de contaminantes na água bruta. A preocupação com a baixa qualidade da água dos mananciais tem deixado os padrões de água potável mais rigorosos ao longo dos anos, o que exige um tratamento mais tecnológico e caro, culminando no aumento das tarifas de água. Para mitigar o aumento nesses custos, diversas ações devem ser planejadas e implementadas na bacia hidrográfica, que podem acabar por restringir alguns usos do solo e gerar a necessidade de melhores práticas de manejo. No entanto, essa conservação (ações para manter ou recuperar a qualidade da bacia hidrográfica para garantir a água ao abastecimento público) gera custos para os proprietários de terras nessas bacias. Os responsáveis pela tomada de decisão devem buscar avaliar custos e benefícios para as diversas partes envolvidas (por exemplo, os moradores de áreas ruais e urbanas, os produtores rurais e industriais) e identificar soluções que equilibrem esses custos e benefícios a longo prazo, para garantir segurança hídrica sob condições de incerteza futura. Aqui os responsáveis pela tomada de decisão incluem a administração pública municipal (prefeitos e secretarias), as empresas de saneamento, as entidades reguladoras e os comitês de bacia hidrográfica. Uma gestão eficiente, equânime e sustentável das águas favorece tanto os moradores das cidades, que recebem água potável nas suas casas, quanto os proprietários de terras na parte rural das bacias hidrográficas (por exemplo, os produtores agrícolas, as agroindústrias e os pequenos aglomerados e comunidades) cujos usos do solo e da água devem envolver ações e práticas de conservação para a salubridade dos recursos hídricos para abastecimento de todos. No entanto, a tomada de decisão é cercada por uma grande quantidade de incertezas, como a restrição do uso do solo, os interesses políticos, as mudanças climáticas, o crescimento populacional, o desenvolvimento econômico e o avanço tecnológico. Além disso, ganhos modestos de curto prazo com os custos evitados no tratamento de água podem ofuscar a percepção dos resultados de longo prazo, levando a decisões que não sejam eficientes, equânimes e sustentáveis. Nessa dicotomia entre conservação de bacias hidrográficas e baixos custos de tratamento de água para garantir a segurança hídrica urbana em um mundo sob profundas incertezas, identificar tradeoffs e mostrar as consequências de cada caminho escolhido é um procedimento que deve ser avaliado. Assim, a pergunta central desta tese vem à tona: quais decisões sobre tecnologias de tratamento de água para manter a tarifa baixa mais influenciam no custo de oportunidade da conservação de bacias hidrográficas destinada ao abastecimento público? Com base nessa pergunta, o objetivo geral desta pesquisa é identificar uma combinação de caminhos dinâmicos de decisão que possam se adaptar ao longo de um determinado período de tempo para garantir tarifas de água acessíveis e, ao mesmo tempo, reduzir as perdas econômicas que os proprietários de terras têm para a preservação da bacia hidrográfica. Essa tese possui ainda outros objetivos secundários, como (1) identificar até que ponto o custo do tratamento é influenciado pela qualidade da bacia hidrográfica, (2) estimar o custo adicional do tratamento da água quando uma tecnologia avançada deve ser adicionada àquela existente em um cenário de degradação da bacia, (3) quantificar o custo e o benefício da conservação de bacias hidrográficas e (4) desenvolver um mapa de caminhos adaptativos para produzir decisões robustas em diferentes cenários futuros. Para atingir todos esses objetivos, a abordagem metodológica foi testada em um caso real, o município de Caxias do Sul no Estado do Rio Grande do Sul. O município abastece mais de 500.000 habitantes por meio de cinco estações de tratamento convencionais cuja água é recebida de cinco pequenas bacias hidrográficas (de 5 a 100 km²). Os Capítulos 4, 5, 6 e 7 detalham os métodos aplicados, o material utilizado e os resultados obtidos. Existe uma literatura limitada que explica adequadamente como os custos de tratamento de água são impactados pela qualidade da bacia, nenhuma referência foi encontrada associando esse efeito ao planejamento de curto e longo prazo. O Capítulo 4 demonstra que muitas vezes o benefício econômico de curto prazo da qualidade da água bruta pode ofuscar a percepção dos custos de tratamento de longo prazo. Os resultados demonstram que há uma redução marginal no custo de tratamento de apenas 0,0002 USD∙m-3, dada a melhoria de uma unidade no índice de qualidade da água na área de estudo. No entanto, a longo prazo, o efeito cumulativo pode aumentar os custos do tratamento em 242%. Esses resultados ressaltam a importância de considerar as implicações de longo prazo da qualidade das áreas de mananciais nos custos de tratamento, enfatizando a necessidade de abordagens de planejamento holístico que levem em conta a interação entre a qualidade da água bruta e os custos de tratamento. Dados socioeconômicos para pequenas bacias são difíceis de encontrar, dependendo do tipo de informação requerida eles simplesmente não existem. No entanto, esses dados são essenciais na tomada de decisões sobre o uso do solo e na gestão dos recursos hídricos, principalmente na determinação do seu valor econômico. A fim de contribuir para preencher essa notável lacuna de conhecimento, o Capítulo 5 estima o Produto Interno Bruto (PIB), população e empregos para pequenas áreas, aplicando imagens de satélite de luz noturna (NTL) e registros socioeconômicos disponíveis de localidades maiores. A relação entre esses três indicadores socioeconômicos e a radiância quantificada nas imagens NTL foi obtida por meio de análise de regressão simples aplicada nos 497 municípios do Estado do Rio Grande do Sul e validada com 50 municípios do vizinho Estado de Santa Catarina. Os resultados indicam que esta nova aplicação da NTL para estimar dados socioeconômicos pode ser uma ferramenta útil para a gestão dos recursos hídricos e do uso do solo em pequenas bacias hidrográficas. Dentro da dicotomia supracitada, quem conserva costuma arcar com o ônus e não necessariamente compartilha todos os benefícios, pois habita região fora da cobertura da rede de distribuição de água. O Capítulo 6 apresenta uma nova estrutura metodológica, seguindo a Análise Envoltória de Dados, para abordar a relação entre o custo de oportunidade da conservação de bacias hidrográficas, enquanto segue as mudanças no excedente dos consumidores para calcular os benefícios de tal preservação. Os resultados demonstraram que o benefício econômico da conservação de bacias hidrográficas excede seu custo em todos os cenários avaliados. Essa descoberta revela que, no agregado, o saldo econômico é positivo quando as políticas são voltadas para a qualidade da água dos mananciais. Isso evidencia que priorizar os esforços de conservação tem um resultado benéfico, tanto em níveis econômicos quanto ambientais. A segurança hídrica urbana é influenciada por vários fatores, incluindo a quantidade e a qualidade da água bruta, tanto no espaço quanto no tempo. No entanto, um aspecto muitas vezes esquecido é o valor das tarifas de água potável. Garantir que as tarifas permaneçam acessíveis para os usuários é crucial para alcançar a segurança hídrica urbana. Decisões robustas são importantes para a segurança hídrica urbana, pois as compensações entre o uso ideal do solo na bacia e o custo ideal do tratamento são mais bem avaliadas e os resultados são propensos ao sucesso em possíveis cenários futuros. Ao considerar possíveis cenários futuros, os tomadores de decisão podem fazer escolhas propensas a gerar resultados bem sucedidos. O Capítulo 7 foca nas decisões robustas no abastecimento de água urbana, empregando a metodologia Dynamic Adaptive Policy Pathways, seguida de uma abordagem matemática heurística, em uma nova aplicação no campo da conservação de bacias hidrográficas e tecnologia de tratamento de água. O resultado é um mapa de decisão adaptativo que apresenta possíveis ações de tecnologia que permitem aos tomadores de decisão entender as consequências de diferentes alternativas, em vez de dizer qual é o caminho correto. Essa abordagem permite aos tomadores de decisão fazer escolhas com base em uma compreensão mais profunda das implicações de suas ações dentro de um contexto adaptativo. A busca por baixos custos de tratamento de água pode ter um preço econômico significativo. Esse preço sombra (shadow price) da água urbana precisa ser contabilizado e algum tipo de ação deve ser tomada para compensar os proprietários de terras devido ao seu papel na preservação das áreas de mananciais. A forma de ajustar tal incongruência deve ser melhor investigada, e uma possível solução poderia ser a implementação de um pagamento por serviços de conservação da bacia hidrográfica cuja água é destinada ao abastecimento público, semelhante aos mecanismos existentes de pagamento por serviços ambientais ou serviços ecossistêmicos. Esta tese reconhece que a segurança hídrica urbana é acompanhada de intrínsecas incertezas. A pesquisa demonstrou que não existe uma única decisão ótima capaz de equilibrar perfeitamente custos e benefícios na gestão da água urbana. Em vez disso, mostrou um conjunto de diversas alternativas eficientes, cada uma envolvendo trade-offs. Os tomadores de decisão e as partes interessadas devem estar preparados para adaptar o planejamento para condições futuras que vão surgindo. Isso permite a exploração de alternativas diversas e eficientes, considerando os trade-offs inerentes a cada opção

    Multisource Remote Sensing based Impervious Surface Mapping

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    Impervious surface (IS) not only serves as a key indicator of urbanization, but also affects the micro-ecosystem. Therefore, it is essential to monitor IS distribution timely and accurately. Remote sensing is an effective approach as it can provide straightforward and consistent information over large area with low cost. This thesis integrates multi-source remote sensing data to interpretate urban patterns and provide more reliable IS mapping results. Registration of optical daytime and nighttime lights (NTL) data is developed in the first contribution. An impervious surface based optical-to-NTL image registration algorithm with iterative blooming effect reduction (IS_iBER) algorithm is proposed. This coarse-to-fine procedure investigates the correlation between optical and NTL features. The iterative registration and blooming effect reduction method obtains precise matching results and reduce the spatial extension of NTL. Considering the spatial transitional nature of urban-rural fringes (URF) areas, the second study proposed approach for URF delineation, namely optical and nighttime lights (NTL) data based multi-scale URF (msON_URF).The landscape heterogeneity and development vitality derived from optical and NTL features are analyzed at a series of scales to illustrate the urban-URF-rural pattern. Results illustrate that msON_URF is effective and practical for not only concentric, but also polycentric urban patterns. The third study proposes a nighttime light adjusted impervious surface index (NAISI) to detect IS area. Parallel to baseline subtraction approaches, NAISI takes advantage of features, rather than spectral band information to map IS. NAISI makes the most of independence between NTL-ISS and pervious surface to address the high spectral similarity between IS and bare soil in optical image. An optical and NTL based spectral mixture analysis (ON_SMA) is proposed to achieve sub-pixel IS mapping result in the fourth study. It integrates characteristics of optical and NTL imagery to adaptively select local endmembers. Results illustrate the proposed method yields effective improvement and highlight the potential of NTL data in IS mapping. In the fifth study, GA-SVM IS mapping algorithm is investigated with introduction of the achieved urban-URF-rural spatial structure. The combination of optical, NTL and SAR imagery is discussed. GA is implemented for feature selection and parameter optimization in each urban scenario

    Land use change and climate variation in the Three Gorges Reservoir Catchment from 2000 to 2015 based on the Google Earth Engine

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    Possible environmental change and ecosystem degradation have received increasing attention since the construction of Three Gorges Reservoir Catchment (TGRC) in China. The advanced Google Earth Engine (GEE) cloud-based platform and the large number of Geosciences and Remote Sensing datasets archived in GEE were used to analyze the land use and land cover change (LULCC) and climate variation in TGRC. GlobeLand30 data were used to evaluate the spatial land dynamics from 2000 to 2010 and Landsat 8 Operational Land Imager (OLI) images were applied for land use in 2015. The interannual variations in the Land Surface Temperature (LST) and seasonally integrated normalized difference vegetation index (SINDVI) were estimated using Moderate Resolution Imaging Spectroradiometer (MODIS) products. The climate factors including air temperature, precipitation and evapotranspiration were investigated based on the data from the Global Land Data Assimilation System (GLDAS). The results indicated that from 2000 to 2015, the cultivated land and grassland decreased by 2.05% and 6.02%, while the forest, wetland, artificial surface, shrub land and waterbody increased by 3.64%, 0.94%, 0.87%, 1.17% and 1.45%, respectively. The SINDVI increased by 3.209 in the period of 2000-2015, while the LST decreased by 0.253 °C from 2001 to 2015. The LST showed an increasing trend primarily in urbanized area, with a decreasing trend mainly in forest area. In particular, Chongqing City had the highest LST during the research period. A marked decrease in SINDVI occurred primarily in urbanized areas. Good vegetation areas were primarily located in the eastern part of the TGRC, such as Wuxi County, Wushan County, and Xingshan County. During the 2000–2015 period, the air temperature, precipitation and evapotranspiration rose by 0.0678 °C/a, 1.0844 mm/a, and 0.4105 mm/a, respectively. The climate change in the TGRC was influenced by LULCC, but the effect was limited. What is more, the climate change was affected by regional climate change in Southwest China. Marked changes in land use have occurred in the TGRC, and they have resulted in changes in the LST and SINDVI. There was a significantly negative relationship between LST and SINDVI in most parts of the TGRC, especially in expanding urban areas and growing forest areas. Our study highlighted the importance of environmental protection, particularly proper management of land use, for sustainable development in the catchment
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