Monitoring urban land cover and vegetation change by multi-temporal remote sensing information

In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a hierarchical classifier system that uses different feature inputs for specific classes and conducted a classification post-processing approach to improve its accuracy. From our statistical analysis of changes in urban land cover from 1987 to 2007, we conclude that built-up land areas have obviously increased, while farmland has seen in a continuous loss due to urban growth and human activities. A NDVI difference approach was used to extract information on changes in vegetation. A false change information elimination approach was developed based on prior knowledge and statistical analysis. The areas of vegetation cover have been in continuous decline over the past 20 years, although some measures have been adopted to protect and maintain urban vegetation. Given the stability of underground coal exploitation since 1990s, urban growth has become the major driving force in vegetation loss, which is different from the vegetation change driven by coal exploitation mainly before 1990.

Trend of <i>Cryptosporidium</i>Infection among Children below 24 Months in an Informal Urban Settlement, Kenya

Cryptosporidium infection is estimated to cause 2.9 million diarrheal cases yearly among children aged under 24 months in sub-Saharan Africa. Studies have shown long-term climatic variations can affect infectious diseases. The burden of cryptosporidiosis in rural areas of sub-Saharan Africa is well characterized. However, the trend of Cryptosporidium infection is not known, especially in informal urban settings. This study therefore sought to determine cryptosporidiosis trends, and further explore the association between year and Cryptosporidium infection among children below 24 months in Kibera urban informal settlement in Kenya. Data collected by the Kenya Medical Research Institute longitudinal study in Tabitha clinic in Kibera from 2009 to 2015 were used. At least 3000 children aged < 24 months receive free health care at the clinic. In the longitudinal study, children presenting with diarrhea were eligible for stool sample collection (n = 477), out of which 421 stool samples were tested using TaqMan™ Array Card (TAC) polymerase chain reaction panel that included a target for Cryptosporidium genus. Data for the 421 children were included in the analysis. Logistic regression was used to explore the difference between the seven years and cryptosporidiosis. Overall, the pooled data indicated that 23.5% of the children who were tested had Cryptosporidium infection, with the highest proportions of Cryptosporidium-positive cases observed in 2015 (45.2%). The logistic regression results also indicated that children who were tested in the year 2015 were more likely to have Cryptosporidium infection (OR = 3.39;95% CI: 1.44 - 7.96;p = 0.005) than those in 2009. Watery stool was also found to be an important symptom of cryptosporidiosis. There was a high prevalence of Cryptosporidium infection among young children, especially in the most recent year. Routine testing of Cryptosporidium infection using molecular methods, constant monitoring and identification of the infection sources is therefore necessary towards reducing the disease burden in the low resource settings.

Urban Settlement Spatial Analysis in Permanent Preservation Area of M’boicy Watershed River, Foz do Iguaçu City in Brazil

Irregular urban settlement increases environmental impacts, especially when these occupations occur in fragile location, as the environmental preservation areas. In these areas, also defined as Permanent Preservation Area (PPA), the presence of watersheds is common, which is the factor that increases the need of protecting them from anthropic actions. Those actions deteriorate the environment and mainly the watercourses. This research objective is to identify and estimate the environmental risks of M’Boyci watershed River PPA occupied areas by urban population. The risk analysis approach, at this PPA in Foz do Iguacu City in Brazil, is able to support public interventions in order to reestablish the PPA natural conditions. To reach this goal, it was necessary to use cartographical representation images, generated from digital orthophotos analyzed through free geographical information systems. The overlap and the contrast of geographical data related to preservation in urban areas show that urban occupation reaches almost 40% of the permanent preservation area. Complementarily, it is evidenced that the development of a risk map identifies PPA areas characterized by a greater concentration of irregular settlement, contributing to the planning process of residents, relocation actions and recovery of degraded areas.

Land Recycling,Food Security and Technosols

The world population will grow up to 9.8 billion by 2050.The intensification in urban growth will occur on all continents and in all sizes of cities,especially in developing countries,experiencing a greater rising in urban agglomerations of 300,000 to 500,000 people,those of 500,000 to 1 million and those of 1 to 5 million,by 2035.In this way,the demand of soil to host human activities(land take)will increase,mainly affecting soils with greater agricultural potential close to cities,at the same time as the need for food will increase.Land rehabilitation can contribute to human food security,to enhance ecosystem services and,if made by waste Technosols,those are viable as substrate for urban agroforestry systems.Although the references for brownfield reclamation for urban agriculture,adding constructed Technosols and de-sealed soils can recover its ecosystem functions even food supply services and would be the solution in urban areas.

Urbanization between compactness and dispersion:designing a spatial model for measuring 2D binary settlement landscape configurations

Measuring spatial patterns is a crucial task in spatial sciences.Multiple indicators have been developed to measure patterns in a quantitative manner.However,most comparative studies rely on relative comparisons,limiting their explanatory power to specific case studies.Motivated by advancements in earth observation providing unprecedented resolutions of settlement patterns,this paper suggests a measurement technique for spatial patterns to overcome the limits of relative comparisons.We design a model spanning a feature space based on two metrics-largest patch index and number of patches.The feature space is defined as‘dispersion index’and covers the entire spectrum of possible two-dimensional binary(settlement)patterns.The model configuration allows for an unambiguous ranking of each possible pattern with respect to spatial dispersion.As spatial resolutions of input data as well as selected areas of interest influence measurement results,we test dependencies within the model.Beyond,common other spatial metrics are selected for testing whether they allow unambiguous rankings.For scenarios,we apply the model to artificially generated patterns representing all possible configurations as well as to real-world settlement classifications differing in growth dynamics and patterns.

Uncertainty evaluation of the coordinated development of urban human settlement environment and economy in Changsha city

The coordinated development of human settlement environment and economy is of vital significance to urban sustainable development and urban ecosystem health. Urban human settlement and economic systems exist in urban ecosystems, which are a structural complexity. Therefore the research is being challenged by some uncertain factors between human settlements and economic systems. However most of the researches were focused on its determinate objective aspects and qualitative analyses while less concern on the quanti- tative evaluation of coordinated development of urban human settlement environment and economy, especially little on its uncertain aspect. At present, the urgent task is to study the coordinated development of urban settlement environment and economy in terms of the effect of uncertainty. This study analyzed the uncertain characteristics, which would be confronted at different stages, such as confirming the index categories, their bound values, and their construction rate, etc. According to the actual urban conditions, many construction principles based on uncertainties are put forward and an indicating system for human settlement and economic evaluation is established. Moreover, the application of fuzzy mathematics presents a new method and a calculation model for the comprehensive assessment of the coordinated development of urban human settlement environment and economy. The application of the method and model in Changsha city of China showed that the assessment results can reflect not only the overall coordination degree of the city, but also the mode of interactive mechanism between urban economic system and human settlement environment.

Does Tenure Security Reduce Disaster Risk? A Comparative Study of the Nairobi Settlements of Kibera and Kawangware

While scholarship suggests that improving tenure security and housing significantly reduces disaster risk at the household level within urban settings,this assertion has not been adequately tested.Tenure security can be conceived as being composed of three interrelated and overlapping forms:tenure security as determined by legal systems;de facto tenure security;and tenure security as perceived by residents.This article traces the relationship between tenure security,the quality of housing,and disaster risk on the basis of a mixed methods comparative case study of the settlements of Kawangware and Kibera in Nairobi.Although the findings suggest that owner-occupancy is associated with the structural integrity of dwellings to a greater extent than tenantship,no association was found between the length of occupancy by households and the structural integrity of the dwelling.Moreover,tenantship is not found to be closely associated with fires and flooding affecting the dwelling as extant scholarship would suggest.Formal ownership is linked with greater investment and upgrading of property with significant implications for disaster risk.Our findings highlight the complex relationship between tenure security and disaster risk in urban informal settlements and provide impetus for further investigation.

Overview and progress of Chinese geographical human settlement research

Increasing Chinese urbanization and industrialization has prompted greater attention to the study of human settlement and the human-land relationship in the fields of geography, architecture, and urban planning. We used bibliometric methods and statistical software to review 180 articles on human settlement in 16 Chinese geographical journals. We found that Chinese geographical human settlement research is characterized by the following：（1） Most research focuses on human settlement extension, valuation indicators, models for urban and rural settlements, theoretical exploration and the planning practices of single-factor, human settlement and complex, geographical livability in macro-scale, urban settlement differentiation and ideal patterns in medium scale, the comprehensive evaluation of settlement environment, and the planning of community units in micro-scale, community settlements; socio-cultural investigation and warnings about advancing human settlement.（2） No progress has been made in synthesizing and integrating method systems. PSR models and DPSIR models are used for targeting mechanisms, while the standard settlement evaluation system was composed of physical ＆ economic indicators by questionnaire surveys. On the other hand, spatial clustering based on GIS has been a frequent focus in recent years. Pioneering research on human settlement and theoretical systems within the context of China＇s urbanization and industrialization will provide guidance on the sustainability of Chinese cities and regions. The following five aspects require greater attention：（1） Natural suitability research on human settlement, and a survey of human settlement demands to reflect the range of different demands concerning ecologically suitable settlements in urban environments, the corresponding valuation indicators, systems, and evolution, and the impact of the residents＇ socio-economic attributes.（2） Spatial-temporal evaluation and sustainability research on urban and rural human settlement at various scales, focusing on evolution and spatial differen-tiation at various scales such as city clusters and comparisons between cities, within the cities and communities.（3） Development of theory and technology for human settlement evolution research, including detection technology and methods, data mining measures, and forecasting and emulation of regional and urban human settlement evolution processes, mechanisms and patterns.（4） Research on the control of human settlement that focuses on optimization, patterns, and policies for effective management and development.（5） Estimating the human settlement system service value and establishing suitable human settlement systems, including social, economic, cultural and ecological service values.