Assessment of Differential Forest Growth Following Disturbance in Minnesota, USA

We used LiDAR metrics and satellite imagery to examine regeneration on forested sites disturbed via harvest or natural means over a 44-year period. We tested the effectiveness of older low-density LiDAR elevation data in producing information related to existing levels of above ground biomass (AGB). To accomplish this, we paired the elevation data with a time series of wetness and greenness indices derived from Landsat satellite imagery to model changes in AGB for sites experiencing different agents of change. Current AGB was determined from high-density LiDAR acquired in northern Minnesota, USA. We then compared high-density LiDAR-based AGB and estimates modeled using Landsat and low-density LiDAR indices for 10,068 sites. Clear differences were found in standing AGB and accumulation rates between sites disturbed by different agents of change. Biomass accumulation following disturbance appears to decrease rapidly following an initial spike as stands 1asZX respond to newly opened growing space. Harvested sites experienced a roughly six-fold increase in the rate of biomass accumulation compared to sites subjected to stand replacing fire or insect and disease, and a 20% increase in productivity when compared to sites subjected to wind mediated canopy loss. Over time, this resulted in clear differences in standing AGB.

Spatial Analysis of Urban Thermal Island in Northern Iran (Case Study: Rasht City)

Land surface temperature (LST) is one of the key parameters in hydrology, meteorology, and the surface energy balance.The one-window algorithm of Kim et al. Uses Landsat satellite imagery to model the earth's surface temperature.These trends are validated using meteorological data. Two main and basic factors play a major role in the temporal and spatial trend of the thermal islands of Rasht. These two factors of climate change that have occurred in the last two decades in the region of Gilan province and the city of Rasht. The second factor that has greatly enhanced the effect of the first factor is the human factor that has greatly included other urban factors in Rasht, including urban management and proper urban planning in the province and the city of Rasht. These two factors in the temporal and spatial trend of urban thermal islands have caused thermal islands to rapidly increase the growth of the city and urban population from the urban center to the western and southwestern regions and have very negative effects on land use changes and human areas. It has caused the construction of Rasht city.

The Stability and Suitability of the Bhasan Char Island as an Accommodation for the Forcibly Displaced Myanmar Nationals (FDMN)

Assessing the dynamics of Bhasan Char is very crucial, as the Government of Bangladesh (GoB) has recently selected the island as the accommodation of the FDMN. This article critically evaluates the spatiotemporal morphological variations due to erosion, accretion, and subsurface deformation of the island through multi-temporal geospatial and geophysical data analysis, groundwater quality-quantity, and also determines the nature and rate of changes from 2003 to 2020. This is the first study in this island on which multi-temporal Landsat Satellite Imagery and seismic data have been used with geospatial techniques with Digital Shoreline Analysis System (DSAS) and petrel platform, respectively. The analysis of satellite images suggests that the island first appeared in 2003 in the Bay of Bengal, then progressively evolved to the present stable condition. Significant changes have taken place in the morphological and geographical conditions of the island since its inception. Since 2012, the island has been constantly accreted by insignificant erosion. It receives tidally influenced fluvial sediments from the Ganges-Brahmaputra-Meghna (GBM) river system and the sedimentary accretion, in this case, is higher than the erosion due to relatively weaker wave action and longshore currents. It has gained approximately 68 km2 area, mostly in the northern part and because of erosion in the south. Although the migration of the Bhasan Char was ubiquitous during 2003–2012, it has been concentrated in a small area to the east since 2018. The net shoreline movements (NSM) suggest that the length of the shoreline enlarged significantly by around 39 km in 2020 from its first appearance. Seismic and GPS data clearly indicate that the island is located on the crest of a slowly uplifting low-amplitude anticline, which may result in a stable landform around the island. Based on the analysis of historical data, it has been assessed that the current configuration of Bhasan Char would not be severely affected by 10–15-foot-high cyclone. Therefore, FDMN rehabilitation here might be safer that would be a good example for future geo-environmental assessment for any areas around the world for rehabilitation of human in remote and vulnerable island. The findings of this research will facilitate the government’s decision to rehabilitate FDMN refugees to the island and also contribute to future research in this area.

Spatiotemporal Evaluation of Eutrophication State in The Hammar Marsh Using A Satellite-Based Model

Water pollution is now a major threat to the existence of living beings. Accordingly, Water quality monitoring is an important activity toward restoring water quality. As wetland eutrophication is one of the essential ecosystem elements, devastation of this element is a significant issue. The Trophic State Index (TSI) provides information about trophic condition of water bodies. This paper aims to conduct spatiotemporal monitoring for the eutrophication of the west part of Al-Hammar Marsh for the period 2013-2020. To this end, a satellite-based TSI computation model was developed and implemented by using a series of OLI Landsat satellite images. The results showed that there was no improvement in the eutrophication state in the marsh, the percentage of the low class of TSI decreased in 2015 and 2018 to 7.9% and 2.6% and increased in 2017 and 2020 to 39.8%, and 56.3%. In general, the TSI was in the poor class in all the considered periods. Fluctuation of quantity and quality of the inflow prevents restoring the eutrophication of the marsh because this process requires stability in the levels of inundation above the critical limits for the water depth and periods. Therefore, it is necessary to find suitable alternatives to provide water drainage in quantities and quality that ensure the sustainability of the marsh ecosystem.

Estimation Des Concentrations Et Cartographie De La Dynamique Des Polluants Atmosperiques Particulaires Dans La Ville D’abidjan

En Côte d’Ivoire, la gestion et la sécurité sanitaire liée à la pollution atmosphérique revet un grand interêt . Dans ce même élan de gestion de la qualité de l’air l’OMS a fixé un seuil d’émission que les pays doivent intégrer dans leur mode de gestion. Cependant, dans les villes de grandes concentrations comme Abidjan il est parfois difficile de maitriser les paramètres d’émissions. L’objectif de cette étude est donc d’estimer les concentrations des polluants atmospreriques particulaires PM2.5 et ensuite cartographier la dynamique de ces polluants de 2015 à 2020. Pour atteindre cet objectif , les données de l’imagerie satellitaire LANDSAT ont été utilisées. Il a s’agit de calculer les réflectances de surfaces et les réflectances au sommet de l’atmosphère. Le but de ces calculs était de déduire les réflectances atmosphériques. En considérant la relation étroite existence entre les PM2.5 et la réflectance atmosphérique un modèle de régression linéaire a été conidéré pour déduire les PM2.5. Les résultats ont montré que les concentrations des PM2.5 sont de façon générale au-dessus du seuil de l’OMS. Ces valeurs sont de 31 μg/m3 en janvier 2015 , de 36 μg/m3 en janvier 2016 , de 32 μg/m3 en décembre 2016, de 33 μg/m3 en janvier 2019 et de 33 μg/m3 en janvier 2020. Cela donne une concentration moyenne de 33 μg/m3. Les communes de Yopougon Nord, Abobo Ouest, Cocody ouest et Port-Bouet Est sont les zones les plus pollués avec des concentrations allant de 26 à 49 μg/m3. In Côte d'Ivoire, management and health security related to air pollution are of great interest. In this same approach to air quality management, WHO has set an emission threshold that countries must integrate into their management method. However, in cities with a high concentration like Abidjan, it is sometimes difficult to control the emission parameters. The objective of this study is therefore to estimate the concentrations of particulate air pollutants PM2.5 and then to map the dynamics of these pollutants from 2015 to 2020. To achieve this objective, data from LANDSAT satellite imagery were used. . This involves calculating the surface reflectances and the reflectances at the top of the atmosphere. The purpose of these calculations was to deduce atmospheric reflectances. Given the close relationship between PM2.5 and atmospheric reflectance, a linear regression model was considered to derive PM2.5. The results showed that PM2.5 concentrations are generally above the WHO threshold. These values are 31μg /m3 in January 2015, 36 μg / m3 in January 2016, 32 μg / m3 in December 2016, 33 μg / m3 in January 2019 and 33 μg / m3 in January 2020. This gives an average concentration of 33 μg / m3. The cities of Yopougon noth part, Abobo west part, Cocody west part and Port-Bouet east part are the most polluted areas with concentrations ranging from 26 to 49 μg / m3.

Dynamic Relationship Study between the Observed Seismicity and Spatiotemporal Pattern of Lineament Changes in Palghar, North Maharashtra (India)

The Palghar region (north Maharashtra, India), located in the northwestern part of the stable continental region of India, experienced a low magnitude earthquake swarm, which was initiated in September 2018 and is continuing to date (as of October 2021). From December 2018 to December 2020, ~5000 earthquakes with magnitudes from M1.2 to M3.8 occurred in a small region of 20 × 10 km2. These earthquakes were probably triggered by fluid migration during seasonal rainfall. In this study, we have used multi-temporal Landsat satellite data of the year 2000, 2015, 2018, 2019, and 2020, extracted lineaments, and studied the changes in frequency and pattern of lineaments before and after the initiation of the swarm in the Palghar region. An increase in the lineament density and amount of rainfall are found to be associated with the increasing frequency of earthquakes.

Global land use extent and dispersion within natural land cover using Landsat data

The conversion of natural land cover into human-dominated land use systems has significant impacts on the environment. Global mapping and monitoring of human-dominated land use extent via satellites provides an empirical basis for assessing land use pressures. Here, we present a novel 2019 global land cover, land use, and ecozone map derived from Landsat satellite imagery and topographical data using derived image feature spaces and algorithms suited per theme. From the map, we estimate the spatial extent and dispersion of land use disaggregated by climate domain and ecozone, where dispersion is the mean distance of land use to all land within a subregion. We find that percent of area under land use and distance to land use follow a power law that depicts an increasingly random spatial distribution of land use as it extends across lands of comparable development potential. For highly developed climate/ecozones, such as temperate and sub-tropical terra firma vegetation on low slopes, area under land use is contiguous and remnant natural land cover have low areal extent and high fragmentation. The tropics generally have the greatest potential for land use expansion, particularly in South America. An exception is Asian humid tropical terra firma vegetated lowland, which has land use intensities comparable to that of temperate breadbaskets such as the United States’ corn belt. Wetland extent is inversely proportional to land use extent within climate domains, indicating historical wetland loss for temperate, sub-tropical, and dry tropical biomes. Results highlight the need for planning efforts to preserve natural systems and associated ecosystem services. The demonstrated methods will be implemented operationally in quantifying global land change, enabling a monitoring framework for systematic assessments of the appropriation and restoration of natural land cover.

Characteristics of changes in the moisture content of the tundra cover in the area of the Bovanenkovo field using Landsat satellite data

By the case of the area of a long-term technogenic load of the Bovanenkovo oil and gas condensate field, the possibility of monitoring the moisture content of the tundra cover near technical objects according to the Landsat 5 and Landsat 8 satellites is shown. The work used multispectral images from 1990, 1994, 2013 and 2020. The analysis was carried out on images characterizing the Earth’s surface temperature, surface moisture (NDWI index) and chlorophyll content in the canopy (NDVI index). Characterization and mapping of changes in the moisture content of the cover were carried out according to the difference between the images of 1990 and 2020. Variations in the NDVI index allow us to identify the reasons for these changes. The technogenic impact is shown to lead to an increase in the surface temperature and a decrease in the NDWI and NDVI values, which indicates the predominance of drainage processes and a decrease in the volume of living phytomass near technical objects. Such transformations are less dangerous for objects in comparison with waterlogging of the cover, however, they contribute to an increase in the emission of carbon-containing gases, since an increase in temperature and a decrease in surface moisture, as a rule, lead to degradation of the permafrost and an increase in the depth of the thawed layer.

Land area increase in Ukrainian part of the Danube delta

The quantitative indicators of land growth in the Ukrainian part of the Danube delta are considered. Comparison of Landsat satellite images in three key areas of the delta showed that for the period 1975-2020 the area of wetlands at the mouth of the Сhilia channel increased by 1448 hectares due to the accumulation of sediments between the Starostambul and Limba branches and their overgrowth with vegetation. In the area of the Bystroe channel, the area of new lands increased by 1037 hectares due to the artificial deepening of this channel for the Ukrainian ships passage into the Danube River and the deposition of sediments along the coast. A slightly smaller increase in land cover (797 ha) was found in the northern part of the coast of the Ukrainian part of the delta, where saline and carbonate soils are formed. In the future, active land growth is expected in the Musura bay between the mouths of the Starostambul and Sulina branches, ie at the contact of Ukraine and Romania. Some changes in these parameters are expected after a powerful flood in 2021, which will become known after the establishment of a relative equilibrium between the processes of accumulation and erosion after this extreme event.

Estimation of Suspended Sediment Concentration in Downstream of the Ba River Basin using Remote Sensing Images

Assessing the tendency of suspended sediment concentration (SSC) in the river watershedsenables a better understanding of the hydromorphological properties of its basins and the associatedprocesses. In addition, analyzing this trend is essential to address several important issues such as erosion,water pollution, human health risks, etc. Therefore, it is critical to determine a proper method to quantifyspatio-temporal variability in SSC. In recent years, remote sensing and GIS technologies are being widelyapplied to support scientists, researchers, and environmental resource investigators to quickly andsynchronously capture information on a large scale. The combination of remote sensing and GIS data willbecome the reliable and timely updated data source for the managers, researchers on many fields. Thereare several tools, software, algorithms being used in extracting information from satellites and support forthe analysis, image interpretation, data collection. The information from satellite images related to waterresources includes vegetational cover, flooding events on a large scale, rain forecast, populationdistribution, forest fire, landslide movements, sedimentation, etc., and especially information on waterquality, sediment concentration. This paper presents the initial result from LANDSAT satellite imageinterpretation to investigate the amount of sediment carried downstream of the Ba river basin.