Vegetation Dynamics Revealed by Remote Sensing and Its Feedback to Regional and Global Climate

This book focuses on some significant progress in vegetation dynamics and their response to climate change revealed by remote sensing data. The development of satellite remote sensing and its derived products offer fantastic opportunities to investigate vegetation changes and their feedback to regional and global climate systems. Special attention is given in the book to vegetation changes and their drivers, the effects of extreme climate events on vegetation, land surface albedo associated with vegetation changes, plant fingerprints, and vegetation dynamics in climate modeling

Remote sensing technology applications in forestry and REDD+

Advances in close-range and remote sensing technologies are driving innovations in forest resource assessments and monitoring on varying scales. Data acquired with airborne and spaceborne platforms provide high(er) spatial resolution, more frequent coverage, and more spectral information. Recent developments in ground-based sensors have advanced 3D measurements, low-cost permanent systems, and community-based monitoring of forests. The UNFCCC REDD+ mechanism has advanced the remote sensing community and the development of forest geospatial products that can be used by countries for the international reporting and national forest monitoring. However, an urgent need remains to better understand the options and limitations of remote and close-range sensing techniques in the field of forest degradation and forest change. Therefore, we invite scientists working on remote sensing technologies, close-range sensing, and field data to contribute to this Special Issue. Topics of interest include: (1) novel remote sensing applications that can meet the needs of forest resource information and REDD+ MRV, (2) case studies of applying remote sensing data for REDD+ MRV, (3) timeseries algorithms and methodologies for forest resource assessment on different spatial scales varying from the tree to the national level, and (4) novel close-range sensing applications that can support sustainable forestry and REDD+ MRV. We particularly welcome submissions on data fusion

CHARACTERISTICS OF TEMPORAL AND SPATIAL VARIATION OF NDVI IN BEIJING AND THE RELATIONSHIP WITH URBAN HEAT ISLAND EFFECT

Vegetation is an important part of ecosystems, and the use of vegetation coverage as an indicator to study the spatio-temporal dynamics of regional vegetation is necessary for ecosystem health evaluation. The urban heat island effect can change the structure and functions of urban ecosystems, and affect the climate, hydrology, atmospheric environment, and energy metabolism of cities, as well as the health of residents. Using Beijing as a case study, this research generates vegetation coverage maps using remote sensing imagery from 1998, 2003, 2008, 2013 and 2018. This study indirectly analyzes the urban heat island effect through spatio-temporal changes in vegetation cover. These analyses offer three key findings. First, vegetation coverage in Beijing from 1998 to 2018 experienced an oscillating upward trend, indicating that the urban heat island effect was weakening. Second, the vegetation coverage in Beijing exhibited a concentric structure, which increased from the central area to the surrounding area, indicating that the urban heat island effect gradually weakens from the inside to the outside of the city. Third, from 1998 to 2008, the normalized difference vegetation index (NDVI) of the areas outside the Sixth Ring Road and inside the Third Ring Road was increasing, therefore the urban heat island effect in these areas was weakening. Conversely, NDVI was decreasing between Sixth Ring Road and Third Ring Road; these areas experienced an increase in the urban heat island effect

The Effect of Hydrology on Soil Erosion

This Special Issue includes manuscripts about soil erosion and degradation processes and the accelerated rates due to hydrological processes and climate change. The new research included in this issue focuses on measurements, modeling, and experiments in field or laboratory conditions developed at different scales (pedon, hillslope, and catchment). This Special Issue received investigations from different parts of the world such as Ethiopia, Morocco, China, Iran, Italy, Portugal, Greece, and Spain, among others. We are happy to see that all papers presented findings characterized as unconventional, provocative, innovative, and methodologically new. We hope that the readers of the journal Water can enjoy and learn about hydrology and soil erosion using the published material, and share the results with the scientific community, policymakers, and stakeholders to continue this amazing adventure, facing plenty of issues and challenges

Land Degradation Assessment with Earth Observation

This Special Issue (SI) on “Land Degradation Assessment with Earth Observation” comprises 17 original research papers with a focus on land degradation in arid, semiarid and dry-subhumid areas (i.e., desertification) in addition to temperate rangelands, grasslands, woodlands and the humid tropics. The studies cover different spatial, spectral and temporal scales and employ a wealth of different optical and radar sensors. Some studies incorporate time-series analysis techniques that assess the general trend of vegetation or the timing and duration of the reduction in biological productivity caused by land degradation. As anticipated from the latest trend in Earth Observation (EO) literature, some studies utilize the cloud-computing infrastructure of Google Earth Engine to cope with the unprecedented volume of data involved in current methodological approaches. This SI clearly demonstrates the ever-increasing relevance of EO technologies when it comes to assessing and monitoring land degradation. With the recently published IPCC Reports informing us of the severe impacts and risks to terrestrial and freshwater ecosystems and the ecosystem services they provide, the EO scientific community has a clear obligation to increase its efforts to address any remaining gaps—some of which have been identified in this SI—and produce highly accurate and relevant land-degradation assessment and monitoring tools

Applied Geochemistry with Case Studies on Geological Formations, Exploration Techniques and Environmental Issues

Geochemistry has become an essential subject to understand our origins and face the challenges that humanity will meet in the near future. This book presents several studies that have geochemistry as their central theme, from the description of different geological formations, through its use for the characterization of contaminated sites and their possible impact on ecosystems and human health, as well as the importance of geochemical techniques as a complement to other current scientific disciplines. Through the different chapters, the reader will be able to approach the world of geochemistry in several of its subfields (e.g. environmental, isotope, or biogeochemistry) and learn through practical cases

Satellite imagery for land use change and ecosystem services assessment in the Greater Limpopo Trans-frontier Region

M.A. (Sustainable Urban Planning and Development)Abstract: Land use change can result in variations in ecosystem services (ESs) and their relationships. Understanding the spatiotemporal changes in land use and land cover change helps understand ESs management Studying the temporal dynamics of ESs and their relationships can support scenario analyses that provide the theoretical basis for policy decisions and regional ecosystem management in any context. This can be achieved by utilizing remote sensing techniques which are an efficient tool in conducting spatio-temporal analysis of phenomena on earth, in particular in data scarce regions of southern Africa. Consequently, this study is aimed at using Landsat imagery to assess land use land cover change dynamics from 2007 to 2018 in the Greater Limpopo Trans-frontier Region, as well as assess its impacts on ecosystem services during the stipulated time. Furthermore, to assess the drivers of land cover change in the study area over time. The specific objectives are as follows; (i) to spatially map the change in land cover within the given period, (ii) to assess performance of random forest classification scheme, and (iii) to use InVEST Carbon Model to quantify the amount of carbon storage in the study area, (iv) to use Scenario-based model to model future projections of carbon sequestration and vegetation change and (v) to utilize the carbon sequestration and vegetation change data to inform planning for ecosystem services. Landsat imagery acquired in 2007 and 2018 was used to derive land cover classes. The derived maps (classified) were compared graphically and statistically. To achieve this, the study spatially mapped the change in land cover using the Random Forest Classification Scheme with an overall accuracy of 76%. Results of the quantified spatial changes showed that in 2007, Agricultural areas occupied 2% of the total area, Bareland 29%, built up area 25%, dense vegetation 6%, grassland 22%, water 3% and shrubland a total of 7%. While in 2018, Agricultural areas occupied 3% of the area, bareland 13%, built up area 24%, dense vegetation 5%, water at 1% and shrubland a total of 13%. Overall, results showed a slight decrease in built-up areas and an increase in agricultural land over time. Drivers of land cover change in the area were identified mainly as migration, climatic conditions, agricultural drivers and deforestation. Carbon storage also shows that there was a decrease in carbon storage from 2007 to 2018. With the scenario-based model, the results showed an increase in agricultural areas and corresponding carbon storage. The results were used to inform policy and recommend effective land use management practices

Assessing soil redistribution and sediment apportationment from different land uses: geospatial analysis and modelling in a mountain agroecosystem

Los agroecosistemas Mediterráneos de montaña han experimentado secularmente intervenciones de la actividad humana como la eliminación de bosques y la cubierta vegetal para el desarrollo y la expansión de la agricultura de secano destinada a la subsistencia de las comunidades locales. Su principal impacto ha sido el incremento de las superficies de terreno proclives a la erosión junto con el aumento de la exportación de sedimentos a los cauces acentuada en las últimas décadas con la mecanización agraria. Sin embargo, este proceso se invirtió a mediados del siglo XX debido a diversos cambios socioeconómicos y posteriormente a la política agraria común que provocaron un éxodo rural y el abandono de estos sistemas. Este abandono permitió la recuperación de la vegetación y la consiguiente variación en la cobertera vegetal. Estos factores junto con la intensificación agrícola y la repoblación forestal han afectado de manera significativa al comportamiento hidrológico, las propiedades del suelo y las tasas de exportación de sedimentos en los agroecosistemas de montaña mediterráneos. El objetivo principal de esta investigación es analizar el efecto de los cambios en los usos del suelo junto con el impacto de las diferentes prácticas agrícolas en la conectividad hidráulica, la redistribución del suelo, sus propiedades fisicoquímicas, así como en la procedencia de los sedimentos exportados a los cursos de agua. Para conseguir este objetivo, se seleccionó una cuenca de tamaño medio (23 km2) localizada en la parte central de la cuenca del Ebro (NE España), representativa de los agroecosistemas de las montañas mediterráneas. El área de estudio ha permanecido cultivada casi en su totalidad hasta principios del siglo pasado. Sin embargo, después del abandono acaecido en la década de los 60 sólo el 16.5% de la cuenca se ha mantenido cultivado mientras que las áreas forestales bien de repoblación o de revegetación han pasado a ocupar el 83.5% de la superficie de la cuenca.En esta investigación se han implementado diferentes técnicas y metodologías, las cuales se han agrupado en dos líneas principales. Por un lado aquellas que analizan la variación en la conectividad hidráulica, las propiedades del suelo, los cambios en la cubierta vegetal y las tasas de redistribución del suelo. Por otro, las englobadas en la técnica de fingerprinting para el rastreo de la procedencia de los sedimentos que llegan a los cursos de agua. En el primer grupo cabe destacar la creación de un índice de conectividad hidráulica y su análisis antes y después del abandono de tierras en la cuenca. Además, mediante el uso del radioisótopo 137Cs se han cuantificado las tasas de redistribución del suelo en los distintos usos y se han comparado con propiedades del suelo como el tamaño de partícula o la cantidad de materia orgánica. En tercer lugar, se llevó a cabo un análisis de la distribución espacial de las propiedades fisicoquímicas del suelo junto con algunos nutrientes como el carbono orgánico de suelo o el nitrógeno total. Finalmente, mediante el uso de imágenes de satélite se monitorizó el cambio que la cubierta vegetal ha experimentado en las últimas décadas, correlacionando a su vez estas imágenes con datos del contenido de carbono y nitrógeno.Por otro lado, para obtener la información acerca de cuáles son las áreas que exportan sedimentos a los cursos de agua se han aplicado métodos de vanguardia como la técnica de fingerprinting junto a modelos de desmezcla. Para ello se ha desarrollado un modelo de desmezcla como paquete de R denominado FingerPro. Además, ya que la técnica requiere de diferentes métodos estadísticos para la selección de los trazadores, aquellos más utilizados por la comunidad científica se han incluido en este paquete como funciones adicionales. Sin embargo, los métodos estadísticos clásicos presentan varias limitaciones, siendo la principal que el uso de un método u otro puede dar lugar a la selección de diferentes trazadores, resultando así diferentes resultados de los modelos. Para superar la limitación de los métodos estadísticos clásicos, se ha desarrollado un nuevo método de selección de trazadores que previene la inclusión de trazadores no conservativos y discordantes, mejorando las capacidades de los métodos previos. Finalmente, mediante el uso de estas técnicas con distintos tipos de trazadores tales como radionucleidos, geoquímica elemental, propiedades magnéticas e isótopos estables ha sido posible cuantificar el efecto de eventos extremos de tormenta, las prácticas agrícolas y la tala en los bosques de repoblación, así como su impacto en la variación de los aportes de sedimento y su procedencia.Las diferentes técnicas implementadas para cuantificar y modelar el efecto del abandono de tierras, la distribución espacial de usos del suelo y las prácticas asociadas a estos han dado lugar a conclusiones similares. Una de las principales conclusiones es que son las tierras de cultivo las que presentan menor contenido en nutrientes, experimentan mayores tasas de redistribución de suelo y las que producen una mayor exportación de sedimento a los cursos de agua. Además, se ha comprobado que las prácticas agrícolas son uno de los mayores desencadenantes del aumento en las exportaciones de sedimento y contaminantes a los cauces. También se observó que durante las tareas de clareo de los pinares de repoblación las áreas afectadas producen una mayor contribución de sedimentos a los cauces lo cual se pudo monitorizar gracias al uso pionero de los trazadores CSSI en ambientes Mediterráneos. Por otro lado, los resultados de esta investigación han evidenciado el gran impacto de eventos extremos de tormenta en términos de erosión en toda la cuenca, produciendo además una gran exportación de sedimentos constituyendo uno de los procesos de mayor afectación en los agroecosistemas mediterráneos de montaña.Los resultados obtenidos han permitido comprender el impacto de los cambios de l uso de la tierra en las propiedades del suelo y su redistribución, lo que es esencial para la gestión de la tierra en los frágiles agroecosistemas mediterráneos. La creación de un paquete de software libre junto con un método mejorado de selección de trazadores ha permitido rastrear con éxito la procedencia de los sedimentos exportados, lo cual no podría haberse logrado con los métodos convencionales. Además los resultados de la técnica de fingerprinting, resaltan los peligros de las tormentas excepcionales al incrementar en gran medida la exportación de partículas finas y modificar la contribución de las distintas fuentes de sedimento respaldando así la protección de las tierras de cultivo, especialmente en períodos de ausencia de cobertura vegetal y mayor ocurrencia de tormentas convectivas para evitar la pérdida de suelo fértil y la exportación de contaminantes a los cursos y cuerpos de agua aguas abajo.<br /

A spatiotemporal epidemiological investigation of the impact of environmental change on the transmission dynamics of Echinococcus spp. in Ningxia Hui Autonomous Region, China

Background: Human echinococcoses are zoonotic parasitic diseases of major public health importance globally. According to recent estimates, the geographical distribution of echinococcosis is expanding and becoming an emerging and re-emerging problem in several regions of the world. Echinococcosis endemicity is geographically heterogeneous and might be affected by global environmental change over time. The aims of my research were: 1) to assess and quantify the spatiotemporal variation in land cover and climate change in Ningxia Hui Autonomous Region (NHAR); 2) to identify highly endemic areas for human echinococcoses in NHAR, and to determine the environmental covariates that have shaped the local geographical distribution of the disease; 3) to develop spatial statistical models that explain and predict the spatiotemporal variation of human exposure to Echinococcus spp. in a highly endemic county of NHAR; and 4) to analyse associations between the environment and the spatiotemporal variation of human exposure to the parasites and dog infections with Echinococcus granulosus and Echinococcus multilocularis in four echinococcosis-endemic counties of NHAR. Methods: Data on echinococcosis infections and human exposure to E. granulosus and E. multilocularis were obtained from different sources: 1) A hospital-based retrospective survey of human echinococcosis cases in NHAR between 1992 and 2013; 2) three cross-sectional surveys of school children conducted in Xiji County in 2002–2003, 2006–2007 and 2012–2013; and 3) A cross-sectional survey of human exposure and dog infections with E. granulosus and E. multilocularis conducted in Xiji, Haiyuan, Guyuan and Tongxin Counties. Environmental data were derived from high-resolution (30 m) imagery from Landsat 4/5-TM and 8-OLI and meteorological reports provided by the Chinese Academy of Sciences. Image analysis techniques and a Bayesian statistical framework were used to conduct a land cover change detection analyses and to develop regression models that described and quantified climate trends and the environmental factors associated with echinococcosis risk at different spatial scales. Results: The land cover changes observed in NHAR from 1991 to 2015 concurred with the main goals of a national policy on payments for ecosystem services, implemented in the Autonomous Region, in increasing forest and herbaceous vegetation coverages and in regenerating bareland. Statistically significant positive trends were observed in annual, summer and winter temperatures in most of the region, and a small magnitude change was found in annual precipitation, in the same 25-year period. The south of NHAR was identified as a highly endemic area for cystic echinococcosis (CE; caused by E. granulosus) and alveolar echinococcosis (AE; caused by E. multilocularis). Selected environmental covariates explained most of the spatial variation in AE risk, while the risk of CE appeared to be less spatially variable at the township level. The risk of exposure to E. granulosus expanded across Xiji County from 2002–2013, while the risk of exposure to E. multilocularis became more confined in communities located in the south of this highly endemic area. In 2012–2013, the predicted seroprevalences of human exposure to E. granulosus and dog infection with this parasite were characterised by similar geographical patterns across Xiji, Haiyuan, Guyuan and Tongxin Counties. By contrast, the predicted high seroprevalence areas for human exposure and dog infection with E. multilocularis did not coincide spatially. Climate, land cover and landscape fragmentation played a key role in explaining some of the observed spatial variation in the risk of infection with Echinococcus spp. among schoolchildren and dogs in the south of NHAR at the village level. Conclusions: The findings of this research defined populations at a high risk of human exposure to E. granulosus and E. multilocularis in NHAR. The research provides evidence on the potential effects of landscape regeneration projects on the incidence of human echinococcoses due to the associations found between the infections and regenerated land. This information will be essential to track future requirements for scaling up and targeting the control strategies proposed by the National Action Plan for Echinococcosis Control in China and may facilitate the design of future ecosystem management and protection policies and a more effective response to emerging local environmental risks. The predictive models developed as part of this research can also be used to monitor echinococcosis infections and the emergence in Echinococcus spp. transmission in the most affected areas