Evaluating the spatial transferability and temporal repeatability of remote-sensing-based lake water quality retrieval algorithms at the European scale: a meta-analysis approach

Many studies have shown the considerable potential for the application of remote-sensing-based methods for deriving estimates of lake water quality. However, the reliable application of these methods across time and space is complicated by the diversity of lake types, sensor configuration, and the multitude of different algorithms proposed. This study tested one operational and 46 empirical algorithms sourced from the peer-reviewed literature that have individually shown potential for estimating lake water quality properties in the form of chlorophyll-a (algal biomass) and Secchi disc depth (SDD) (water transparency) in independent studies. Nearly half (19) of the algorithms were unsuitable for use with the remote-sensing data available for this study. The remaining 28 were assessed using the Terra/Aqua satellite archive to identify the best performing algorithms in terms of accuracy and transferability within the period 2001���2004 in four test lakes, namely V��nern, V��ttern, Geneva, and Balaton. These lakes represent the broad continuum of large European lake types, varying in terms of eco-region (latitude/longitude and altitude), morphology, mixing regime, and trophic status. All algorithms were tested for each lake separately and combined to assess the degree of their applicability in ecologically different sites. None of the algorithms assessed in this study exhibited promise when all four lakes were combined into a single data set and most algorithms performed poorly even for specific lake types. A chlorophyll-a retrieval algorithm originally developed for eutrophic lakes showed the most promising results (R2 = 0.59) in oligotrophic lakes. Two SDD retrieval algorithms, one originally developed for turbid lakes and the other for lakes with various characteristics, exhibited promising results in relatively less turbid lakes (R2 = 0.62 and 0.76, respectively). The results presented here highlight the complexity associated with remotely sensed lake water quality estimates and the high degree of uncertainty due to various limitations, including the lake water optical properties and the choice of methods.

Impact of protected forests on rural household fuel tree planting and deforestation: Chiro District, Ethiopia

This study aims at exploring the potential impact of forest protection intervention on rural households��� private fuel tree planting in Chiro district of eastern Ethiopia. The study results revealed a robust and significant positive impact of the intervention on farmers��� decisions to produce private household energy by growing fuel trees on their farm. As participation in private fuel tree planting is not random, the study confronts a methodological issue in investigating the causal effect of forest protection intervention on rural farm households��� private fuel tree planting through non-parametric propensity score matching (PSM) method. The protection intervention on average has increased fuel tree planting by 503 (580.6%) compared to open access areas and indirectly contributed to slowing down the loss of biodiversity in the area. Land cover/use is a dynamic phenomenon that changes with time and space due to anthropogenic pressure and development. Forest cover and land use changes in Chiro District, Ethiopia over a period of 40 years was studied using remotely sensed data. Multi temporal satellite data of Landsat was used to map and monitor forest cover and land use changes occurred during three point of time of 1972,1986 and 2012. A pixel base supervised image classification was used to map land use land cover classes for maps of both time set. The result of change detection analysis revealed that the area has shown a remarkable land cover/land use changes in general and forest cover change in particular. Specifically, the dense forest cover land declined from 235 ha in 1972 to 51 ha in 1986. However, government interventions in forest protection in 1989 have slowed down the drastic change of dense forest cover loss around the protected area through reclaiming 1,300 hectares of deforested land through reforestation program up to 2012.

Simulating Everglades National Park hydrology and phosphorus transport under existing and future scenarios using numerical modeling

The Florida Everglades has a long history of anthropogenic changes which have impacted the quantity and quality of water entering the system. Since the construction of Tamiami Trail in the 1920's, overland flow to the Florida Everglades has decreased significantly, impacting ecosystems from the wetlands to the estuary. The MIKE Marsh Model of Everglades National Park (M3ENP) is a numerical model, which simulates Everglades National Park (ENP) hydrology using MIKE SHE/MIKE 11software. This model has been developed to determine the parameters that effect Everglades hydrology and understand the impact of specific flow changes on the hydrology of the system. As part of the effort to return flows to the historical levels, several changes to the existing water management infrastructure have been implemented or are in the design phase. Bridge construction scenarios were programed into the M3ENP model to review the effect of these structural changes and evaluate the potential impacts on water levels and hydroperiods in the receiving Northeast Shark Slough ecosystem. These scenarios have shown critical water level increases in an area which has been in decline due to low water levels. Results from this work may help guide future decisions for restoration designs. Excess phosphorus entering Everglades National Park in South Florida may promote the growth of more phosphorus-opportunistic species and alter the food chain from the bottom up. Two phosphorus transport methods were developed into the M3ENP hydrodynamic model to determine the factors affecting phosphorus transport and the impact of bridge construction on water quality. Results showed that while phosphorus concentrations in surface waters decreased overall, some areas within ENP interior may experience an increase in phosphorus loading which the addition of bridges to Tamiami Trail. Finally, phosphorus data and modeled water level data was used to evaluate the spectral response of Everglades vegetation to increasing phosphorus availability using Landsat imagery.

Radiocarbon dating, carbon storage and soil properties of samples from Tulemalu Lake, central Canadian Arctic

We investigated total storage and landscape partitioning of soil organic carbon (SOC) in continuous permafrost terrain, central Canadian Arctic. The study is based on soil chemical analyses of pedons sampled to 1 m depth at 35 individual sites along three transects. Radiocarbon dating of cryoturbated soil pockets, basal peat and fossil wood shows that cryoturbation processes have been occurring since the Middle Holocene and that peat deposits started to accumulate in a forest-tundra environment where spruce was present (~6000 cal yrs BP). Detailed partitioning of SOC into surface organic horizons, cryoturbated soil pockets and non-cryoturbated mineral soil horizons is calculated (with storage in active layer and permafrost calculated separately) and explored using principal component analysis. The detailed partitioning and mean storage of SOC in the landscape are estimated from transect vegetation inventories and a land cover classification based on a Landsat satellite image. Mean SOC storage in the 0-100 cm depth interval is 33.8 kg C/m**2, of which 11.8 kg C/m**2 is in permafrost. Fifty-six per cent of the total SOC mass is stored in peatlands (mainly bogs), but cryoturbated soil pockets in Turbic Cryosols also contribute significantly (17%). Elemental C/N ratios indicate that this cryoturbated soil organic matter (SOM) decomposes more slowly than SOM in surface O-horizons.

Remote Sensing of Vegetation Change Across a Latitudinal Gradient in the Canadian Arctic

Global air surface temperatures and precipitation have increased over the last several decades resulting in a trend of greening across the Circumpolar Arctic. The spatial variability of warming and the inherent effects on plant communities has not proven to be uniform or homogeneous on global or local scales. We can apply remote sensing vegetation indices such as the Normalized Difference Vegetation Index (NDVI) to map and monitor vegetation change (e.g., phenology, greening, percent cover, and biomass) over time. It is important to document how Arctic vegetation is changing, as it will have large implications related to global carbon and surface energy budgets. The research reported here examined vegetation greening across different spatial and temporal scales at two disparate Arctic sites: Apex River Watershed (ARW), Baffin Island, and Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, NU. To characterize the vegetation in the ARW, high spatial resolution WorldView-2 data were processed to create a supervised land-cover classification and model percent vegetation cover (PVC) (a similar process had been completed in a previous study for the CBAWO). Meanwhile, NDVI data spanning the past 30 years were derived from intermediate resolution Landsat data at the two Arctic sites. The land-cover classifications at both sites were used to examine the Landsat NDVI time series by vegetation class. Climate variables (i.e., temperature, precipitation and growing season length (GSL) were examined to explore the potential relationships of NDVI to climate warming. PVC was successfully modeled using high resolution data in the ARW. PVC and plant communities appear to reside along a moisture and altitudinal gradient. The NDVI time series demonstrated an overall significant increase in greening at the CBAWO (High Arctic site), specifically in the dry and mesic vegetation type. However, similar overall greening was not observed for the ARW (Low Arctic site). The overall increase in NDVI at the CBAWO was attributed to a significant increase in July temperatures, precipitation and GSL.

Revisiting the Late Jurassic-Early Cretaceous of the NW South Iberian Basin: new ages and sedimentary environments

The study of the Upper Jurassic-Lower Cretaceous deposits (Higueruelas, Villar del Arzobispo and Aldea de Cort��s Formations) of the South Iberian Basin (NW Valencia, Spain) reveals new stratigraphic and sedimentological data, which have significant implications on the stratigraphic framework, depositional environments and age of these units. The Higueruelas Fm was deposited in a mid-inner carbonate platform where oncolitic bars migrated by the action of storms and where oncoid production progressively decreased towards the uppermost part of the unit. The overlying Villar del Arzobispo Fm has been traditionally interpreted as an inner platform-lagoon evolving into a tidal-flat. Here it is interpreted as an inner-carbonate platform affected by storms, where oolitic shoals protected a lagoon, which had siliciclastic inputs from the continent. The Aldea de Cort��s Fm has been previously interpreted as a lagoon surrounded by tidal-flats and fluvial-deltaic plains. Here it is reinterpreted as a coastal wetland where siliciclastic muddy deposits interacted with shallow fresh to marine water bodies, aeolian dunes and continental siliciclastic inputs. The contact between the Higueruelas and Villar del Arzobispo Fms, classically defined as gradual, is also interpreted here as rapid. More importantly, the contact between the Villar del Arzobispo and Aldea de Cort��s Fms, previously considered as unconformable, is here interpreted as gradual. The presence of Alveosepta in the Villar del Arzobispo Fm suggests that at least part of this unit is Kimmeridgian, unlike the previously assigned Late Tithonian-Middle Berriasian age. Consequently, the underlying Higueruelas Fm, previously considered Tithonian, should not be younger than Kimmeridgian. Accordingly, sedimentation of the Aldea de Cort��s Fm, previously considered Valangian-Hauterivian, probably started during the Tithonian and it may be considered part of the regressive trend of the Late Jurassic-Early Cretaceous cycle. This is consistent with the dinosaur faunas, typically Jurassic, described in the Villar del Arzobispo and Aldea de Cort��s Fms.

Patrons spatiaux d'une ��pid��mie de la tordeuse des bourgeons de l'��pinette sur la C��te-Nord : une approche de t��l��d��tection

La tordeuse des bourgeons de l�����pinette (Choristoneura fumiferana, TBE) est l���insecte ravageur le plus important de la for��t bor��ale de l���est de l���Am��rique du Nord. Depuis 2006, la r��gion de la C��te-Nord est affect��e par une ��pid��mie de TBE et les superficies foresti��res infest��es doublent annuellement. Des images satellitaires Landsat ont ��t�� utilis��es pour cartographier la s��v��rit�� de l�����pid��mie avec une approche de d��tection de changements, en utilisant une image pr��-��pid��mie (2004) et une image prise pendant l�����pid��mie (2013). Des relev��s terrains de la d��foliation par la TBE ont ��t�� utilis��s pour d��velopper (R2 = 0,50) une cartographie fiable (R2 de validation = 0,64) et non biais��e de la s��v��rit�� des infestations de la TBE sur une ��chelle continue de s��v��rit�� (0-100%) pour la r��gion d�����tude. Une analyse des facteurs environnementaux affectant la s��v��rit�� des infestations (extraite de la carte de d��foliation) a d��montr�� l���importance de la composition foresti��re en sapin baumier tant �� l�����chelle locale qu����� l�����chelle du paysage. De plus, une analyse de contexte spatial montre que dans les sites peu d��foli��s (d��foliation cumul��e < 50%), le meilleur pr��dicteur est plut��t son abondance �� l�����chelle du paysage (distance > 500 m). Ces r��sultats sugg��rent une interaction entre les ��chelles spatiales et temporelles lors des ��pid��mies de TBE.

Subfascial endoscopic perforator surgery (SEPS) in chronic venous insufficiency. A 14 years experience

Introduction. Subfascial Endoscopic Perforator Surgery (SEPS) enables the direct visualization and section of perforating veins. Morbidity and duration of hospitalization are both less than with conventional open surgery (Linton���s or Felder���s techniques). Patients and methods. A total of 322 legs from 285 patients with a mean age of 56 years (range 23-90) were treated at our Department from May 1996 to January 2010. In 309 cases, an endoscope (ETM Endoskopische Technik GmbH, Berlin, Germany) was introduced through a transverse incision approximately 1.5 cm in length and 10 cm from the tibial tuberosity, as with Linton���s technique. A spacemaker balloon dissector for SEPS, involving a second incision 6 cm from the first, was used in only 13 cases. Results. The procedure used in each case was decided on the basis of preoperative evaluation. SEPS and stripping were performed in 238 limbs (73.91%), SEPS and short stripping in 7 limbs (2.17%), SEPS and crossectomy in 51 limbs (15.84%), and SEPS alone in 26 limbs (8.07%). 103 patients presented a total of 158 trophic ulcers; the healing time was between 1 and 3 months, with a healing rate of 82.91% after 1 month and 98.73% after 3 months. Conclusion. Subfascial ligature of perforating veins is superior to sclerotherapy and minimally invasive suprafascial treatment for the treatment of CVI. It is easy to execute, minimally invasive and has few complications.

Comparaison des perceptions d'auto-efficacit�� chez des ��tudiants d'ordre coll��gial entre un enseignement th��orique magistral et un enseignement assist�� par ordinateur

Cette recherche de type pr��-exp��rimental a pour objectif de comparer les perceptions d���auto-efficacit�� chez des ��tudiants d'ordre coll��gial qui ont assist�� �� un cours th��orique sur un probl��me prioritaire de sant��, d'une part, en utilisant un enseignement th��orique magistral (ETM), et d'autre part, en utilisant un enseignement assist�� par ordinateur (EAO). L'hypoth��se de recherche sugg��re une augmentation significative des perceptions d'auto-efficacit�� chez les ��tudiants ayant re��u un EAO comparativement aux ��tudiants qui ont re��u un ETM. Dans cette ��tude, la th��orie de l'apprentissage social et des perceptions d'auto-efficacit�� de Bandura (1971,1986), est utilis��e comme cadre de r��f��rence. L'��chantillonnage des sujets de cette recherche est compos�� d'��tudiants de deuxi��me ann��e inscrits au programme de soins infirmiers du Coll��ge de Sherbrooke. Les donn��es ont ��t�� recueillies �� l'aide d'un instrument de mesure ��labor�� selon le Task-Associated Self-Perception Charting et d��velopp�� par Kingery, Ballard, Pruitt et Hurley (1992). Les r��sultats ont d��montr�� qu'il existait une diff��rence significative entre les perceptions d'autoefficacit�� suite �� un ETM et un EAO chez les m��mes sujets. Contrairement �� l'hypoth��se de cette ��tude, les ��tudiants ont exprim�� qu'ils consid��raient avoir une meilleure perception de leur auto-efficacit�� suite �� un ETM. Par contre, l'analyse des r��sultats de cette recherche nous fournit les ��l��ments qui laissent pr��sager la pertinence de l'utilisation de l'EAO comme strat��gie d'enseignement dans le but de motiver les ��tudiants en regard de leurs apprentissages.

Evaluation of vegetation recovery after fire: a case study in Calde, central region of Portugal

Remote Sensing has been used for decades, and more and more applications are added to its repertoire. With this study we aim to show the use of Remote Sensing in the field of vegetation recovery monitoring in burned areas and the added value of data with a high spatial resolution. This was done by analysing both Landsat 7 and 8 scenes, after the forest fire of summer 2012 in the parish of Calde, in the central region of Portugal, as well as an orthophoto produced with images acquired by an unmanned aerial vehicle.

Surface thermal analysis of North Brabant cities and neighbourhoods during heat waves

The urban heat island effect is often associated with large metropolises. However, in the Netherlands even small cities will be affected by the phenomenon in the future (Hove et al., 2011), due to the dispersed or mosaic urbanisation patterns in particularly the southern part of the country: the province of North Brabant. This study analyses the average night time land surface temperature (LST) of 21 North-Brabant urban areas through 22 satellite images retrieved by Modis 11A1 during the 2006 heat wave and uses Landsat 5 Thematic Mapper to map albedo and normalized difference temperature index (NDVI) values. Albedo, NDVI and imperviousness are found to play the most relevant role in the increase of nighttime LST. The surface cover cluster analysis of these three parameters reveals that the 12 ���urban living environment��� categories used in the region of North Brabant can actually be reduced to 7 categories, which simplifies the design guidelines to improve the surface thermal behaviour of the different neighbourhoods thus reducing the Urban Heat Island (UHI) effect in existing medium size cities and future developments adjacent to those cities.

Assessing the influence of abiotic factors and leaf-level properties on the stability of growing-season canopy greenness in a deciduous forest

Maps depicting spatial pattern in the stability of summer greenness could advance understanding of how forest ecosystems will respond to global changes such as a longer growing season. Declining summer greenness, or ���greendown���, is spectrally related to declining near-infrared reflectance and is observed in most remote sensing time series to begin shortly after peak greenness at the end of spring and extend until the beginning of leaf coloration in autumn,. Understanding spatial patterns in the strength of greendown has recently become possible with the advancement of Landsat phenology products, which show that greendown patterns vary at scales appropriate for linking these patterns to proposed environmental forcing factors. This study tested two non-mutually exclusive hypotheses for how leaf measurements and environmental factors correlate with greendown and decreasing NIR reflectance across sites. At the landscape scale, we used linear regression to test the effects of maximum greenness, elevation, slope, aspect, solar irradiance and canopy rugosity on greendown. Secondly, we used leaf chemical traits and reflectance observations to test the effect of nitrogen availability and intrinsic water use efficiency on leaf-level greendown, and landscape-level greendown measured from Landsat. The study was conducted using Quercus alba canopies across 21 sites of an eastern deciduous forest in North America between June and August 2014. Our linear model explained greendown variance with an R2=0.47 with maximum greenness as the greatest model effect. Subsequent models excluding one model effect revealed elevation and aspect were the two topographic factors that explained the greatest amount of greendown variance. Regression results also demonstrated important interactions between all three variables, with the greatest interaction showing that aspect had greater influence on greendown at sites with steeper slopes. Leaf-level reflectance was correlated with foliar ��13C (proxy for intrinsic water use efficiency), but foliar ��13C did not translate into correlations with landscape-level variation in greendown from Landsat. Therefore, we conclude that Landsat greendown is primarily indicative of landscape position, with a small effect of canopy structure, and no measureable effect of leaf reflectance. With this understanding of Landsat greendown we can better explain the effects of landscape factors on vegetation reflectance and perhaps on phenology, which would be very useful for studying phenology in the context of global climate change

Fenologia kwitnienia i produkcja py��ku w zr����nicowanych warunkach mikroklimatycznych du��ego miasta oraz ich wp��yw na przebieg sezonu py��kowego brzozy (Betula spp.) i bylicy (Artemisia spp.) w Poznaniu

Wydzia�� Biologii: Instytut Biologii ��rodowiska, Pracownia Aeropalinologii

Influ��ncia do uso e ocupa����o do solo na qualidade da ��gua e no processo erosivo da bacia de capta����o do Rio Barro Preto, Coronel Vivida-PR

This study was developed in objecting to investigate the use and occupation of land in 1999, 2005, 2011 e 2015 and estimate soil degradation by laminar erosion and the relation with water quality in 2015 in the catchment basin of the Barro Preto river, Coronel Vivida ��� PR. For multitemporal analysis of use and occupation of land in the basin used in the Landsat 5, 7 and 8 images and Geographic Information System. The laminar erosion was estimated by the Universal Soil Loss Equation through the systematization of calculations of the factors that compose the equation in SPRING/INPE. The water quality of the studied river section was evaluated according to the Water Quality Idex and the Resolution CONAMA n. 357/2005. The multitemporal analysis of the use and occupation of land has demonstrated that basin is predominantly agricultural in all years studied, as well as the permanent preservation area presents it not regularized during the period in accordance with the Brazilian Forest Code in force. In relation the quantification of laminar soil erosion in the study period, the rainfall and runoff factor was estimated considering the rainfall data from 1986 to 2014 and resulted in a value of 11.573,47 MJ/ha.mm/a. The Dystrophic Red Latosol, Dystrophic Red Nitisol, Fluvisol and Leptosol soil erodibility factor were 0,0138, 0,0137, 0,0207, 0,0196 t.ha.h/ha.MJ.mm/a, respectively. The topographical factor has demonstrated that the catchment basin has the rough terrain because the moderate and moderate strong classes are dominant in the study area. The cover and management and support practice factors were estimated according to the multitemporal analysis of the use and occupation of land in the basin and the values ranged from 0,0006 to 0,0688. The soil losses by laminar erosion were simulated with agriculture areas with corn and soybeans in no-till. The soil losses with maize crop in no-till in 1999, 2005, 2011 and 2015 were 9.782,75, 10.592,71, 9.636,61 e 11.058,26 t/year, respectively, and soybeans crops in no-till were 15.140,01, 16.645,20, 14.662,14 e 17.049,85 t/year, respectively. In relation with water quality of the section studied river, the average of Water Quality Index during the season were 55,47, 53,09 and 49,72, for the first, second and third sample point, respectively. Indication a decrease in water quality since the source to the last sample point. It is concluded that the use and occupation of land in the catchment basin interferes in the water quality, as well as in soil degradation.

Determina����o de cen��rios futuros de uso e cobertura do solo e sua influ��ncia na vulnerabilidade ambiental : o caso do munic��pio de Formosa ��� GO

Disserta����o (mestrado)���Universidade de Bras��lia, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, Programa de P��s-Gradua����o em Tecnologia Ambiental e Recursos H��dricos, 2015.