Aedes aegypti and Aedes albopictus abundance, landscape coverage and spectral indices effects in a subtropical city of Argentina

The presence, abundance and distribution of Aedes (Stegomyia) aegypti (Linnaeus 1762) and Aedes (Stegomyia) albopictus (Skuse 1894) could be conditioned by different data obtained from satellite remote sensors. In this paper, we aim to estimate the effect of landscape coverage and spectral indices on the abundance of Ae. aegypti and Ae. albopictus from the use of satellite remote sensors in Eldorado, Misiones, Argentina. Larvae of Aedes aegypti and Ae. albopictus were collected monthly from June 2016 to April 2018, in four outdoor environments: tire repair shops, cemeteries, family dwellings, and an urban natural park. The proportion of each land cover class was determined by Sentinel-2 image classification. Furthermore spectral indices were calculated. Generalized Linear Mixed Models were developed to analyze the possible effects of landscape coverage and vegetation indices on the abundance of mosquitoes. The model's results showed the abundance of Ae. aegypti was better modeled by the minimum values of the NDVI index, the maximum values of the NDBI index and the interaction between both variables. In contrast, the abundance of Ae. albopictus has to be better explained by the model that includes the variables bare soil, low vegetation and the interaction between both variables.

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.

Assessment of the influence of the normalized vegetation index on the fire situation in the fire-hazardous period

The paper presents an analysis of the parameter obtained by remote sensing of the planet Earth, the normalized vegetation index (NDVI index). The results of assessing the impact of the index on the occurrence of fires in a certain area are presented. Using the example of statistical data for the Krasnoyarsk Territory, the index values for two periods of spring and summer were obtained, and the influence of NDVI values on the change in the probability of a forest fire was estimated. Static data on the index were selected from the «data lake» of the Ministry of Emergency Situations of Russia, data is collected from 2014 to the present, and data on thermal points from 2012. The consequences after wildfires will cause significant damage to forestry in Russia, and to the environment as a whole. Therefore, the allocation of previously known areas with a high probability of a natural fire will not only improve preventive measures for prevention, but will also make it possible to prevent most of the consequences. This article considers one of the parameters obtained by remote sensing of the Earth NDVI of its change before and after the event in question (natural fire).

Rule-based Classification of Airborne Laser Scanner Data for Automatic Extraction of 3D Objects in the Urban Area

LiDAR technology has been widely adopted as a proper method for land cover classification.Recently with the development of technology, LiDAR systems can now capture high-resolutionmultispectral bands images with high-density LiDAR point cloud simultaneously. Therefore, it opens newopportunities for more precise automatic land-use classification methods by utilizing LiDAR data. Thisarticle introduces a combining technique of point cloud classification algorithms. The algorithms includeground detection, building detection, and close point classification - the classification is based on pointclouds’ attributes. The main attributes are heigh, intensity, and NDVI index calculated from 4 bands ofcolors extracted from multispectral images for each point. Data of the Leica City Mapper LiDAR systemin an area of 80 ha in Quang Xuong town, Thanh Hoa province, Vietnam was used to deploy theclassification. The data is classified into eight different types of land use consist of asphalt road, otherground, low vegetation, medium vegetation, high vegetation, building, water, and other objects. Theclassification workflow was implemented in the TerraSolid suite, with the result of the automation processcame out with 97% overall accuracy of classification points. The

Long-Term Hydrological Regime Monitoring of a Mediterranean Agro-Ecological Wetland Using Landsat Imagery: Correlation with the Water Renewal Rate of a Shallow Lake

The Natural Park of Albufera (Valencia, Spain) is one of the Spanish Mediterranean wetlands where rice is cultivated intensively. The hydrology of the Albufera Lake, located in the center, combines natural contributions with complex human management. The aim of our study was to develop a new methodology to accurately detect the volume of flood water in complex natural environments which experience significant seasonal changes due to climate and agriculture. The study included 132 Landsat images, covering a 15-year period. The algorithm was adjusted using the NDWI index and simultaneous measurements of water levels in the rice fields. The NDVI index was applied to monitor the cultivated area during the summer. Lake inflows and residence times were also evaluated to quantify how the hydrodynamic of the lake is conditioned by the agricultural management. The algorithm developed is confirmed as a useful ecological tool to monitor the flood cycle of the wetland, being able to detect even the lowest water levels. The flood dynamics are consistent over the fifteen years, being in line with the rice cultivation cycle. Water renewal in Albufera lake is altered with respect to that expected according to the rainfall recorded in the study area, so an improvement in the water management of the hydrological basin is required to optimize the runoff during the rainiest months.

Time Series Analysis Using Digital Classification of Data on Land Use and Land Cover in Dohuk Governorate

This study deals with the analysis and detection of changes in land cover patterns and land uses, especially forests in Amadiya district in Dohuk Governorate. It carred out in northern of Iraq by area is (2775.21) km2 and the district is located astronomically between longitudes (01/04 ° 43), (17/08 ° 44), it extends between two circles of latitude, which are (16/50 ° 36) and ('30.'21 ° 37) north, during the periods (1999-2006-2013-2019). Application of the Supervised Classification and the detection of change over time in a comparative manner and by relying on the satellite images of the Land sat ETM satellite were used. The Landsat OLI satellite with a distinctive capacity of 30 meters in the Arc map 10.6.1 program, and one of the indicators of environmental degradation in the land cover patterns, which is the NDVI index for all study periods, was used to reveal the role of natural and human factors that lead to changes in the land cover patterns in the study area. The classification revealed the existence of five types of common land cover, which included dense forests, open forests, urban areas, bare soil and water, which showed clear changes in these land coverings during the period from 1999 to 2019, which were represented by a decrease in forests, bare soil and water by a percentage of (54.76601%), (5.212329%), (2.149469%) respectively, while the Dense and urban areas by (16.35919%) and (21.51301%) in 2019, respectively. The classification accuracy of the Spatial indication was estimated based on the error matrix from there we found that the accuracy was (93.29%) this indicates that the classification accuracy is very good It is acceptable and can relied upon and recommended for classification.

Is Climate or Direct Human Influence Responsible for Discharge Decrease in the Tunisian Merguellil Basin?

Climate change and direct anthropogenic impact are recognized as two major factors affecting catchment runoff. This study investigated the separate effect of each of these factors for runoff from the important Tunisian Merguellil catchment. For this purpose, more than forty years of hydrological data were used. The methodology was based on hydrological characterization, NDVI index to monitor land use dynamics, and the Budyko approach to specify origin of change. The results show that hydrological change is much more important upstream than downstream. The last three decades display a 40% reduction in runoff. This is associated with the direct influence of humans, who are responsible for about 78% of the variation in flow. It appears that climate change contributes to less than about 22%. The combination of increased cultivated land and decreased annual rainfall is the main reason for reduced catchment runoff. Consequently, these effects threaten the sustainable runoff, water in reservoirs, and future water supply in general. Ultimately, the available runoff remains an important parameter and a key indicator to guide the choices of decision-makers and practitioners in current and future climatic conditions. This contributes to supporting sustainable management of remaining water resources.

Relational Modelling of the Earth's Surface Topography Impact on Vegetation Density Using RS and GIS: Rawnduz as a Model

Through the analysis of the digital elevation model (DEM) of the search area, it was found that the search area is located within a mountainous region with a complex twisting, as the surface has been classified into five regions of elevations, among which the first region represents the lowest elevation lands, and extends an area of 118.7 km2 It equates to (22.6%) of the total area, while the largest region is the second region, occupying an area of (187.9) km2, 36% of the total area of the region, while the regression categories were divided into five levels depending on the classification of (Zink) It turns out that the Fifth Region is the most complex of the regions, and it includes the summit of Mount Hendrin, the summit of Mount Karukh. As for the characteristics of the direction of the slopes, nine slope directions of varying areas were found. As for the density of vegetation coverage according to (NDVI), we find that the NDVI index in the research area is divided into three levels of plant density, as the second level, i.e. average density, recorded the largest area at about (344.8) km2, equivalent to (66.1%) of the area the college. Which is characterized by the topological complexity of the surface, which makes it the most suitable areas for pastoral activity, while the higher density in relation to vegetation coverage was more widespread in the first and second steep categories by about (2.5, 9.8) km2, i.e. (21.6%, 24.3%) of the total area.

INFLUENCE OF CHEMICALS ON THE OPTICAL PROPERTIES OF AGROCENOSIS OF SPRING BARLEY WITH PERENNIAL GRASSES

The purpose of the research was to study the effect of mineral fertilizers and plant protection system on the vegetation index NDVI and its seasonal dynamics in agrocenoses of spring barley with overseeding of perennial grasses in the North-West of Russia. The data obtained indicate that against the background of the deficiency of the main elements of mineral nutrition in the second half of the growing season of spring barley, a significant phytomass of perennial grasses is formed in the crop, which account for 36.7%. This leads to a smaller decrease in the NDVI index (by 0.06) than in the fertilized variants (0.20). The value of NDVI index reflects not only the state of cultivated plants and weed infestation of crops, but also the level of development of crops, growing under vegetation. The influence of mineral nutrition developed during the period of maximum values of the index, which were recorded 6-8 weeks from the sowing date and 26-30 weeks from the beginning of the year. Under the influence of average doses of fertilizers, the NDVI index increased by 0.09...0.2 (on average 0.13), under the influence of high doses – by 0.13...0.26 (on average 0.18). The influence of plant protection system was expressed by a decrease in the phytomass of weeds (by 49.4...68.9%), at the same time the mass of spring barley and perennial grasses increased (by 1.7...18.5% and by 11.7...43.5% respectively). Carrying out the whole complex of protective measures led to a decrease in the NDVI index values by 0.01...0.06, depending on the phytosanitary situation in the agrocenosis. The most reliable forecast of the yield of spring barley can be implemented in the period from 5 to 7 weeks from the beginning of the emergence of barley shoots, especially against the background of the use of plant protection products that eliminate the influence of harmful organisms on the formation of the crop and the optical properties of crops