Study Area Research Articles

Geological exploration of coal mine burnt rock and waterlogged area boundary based on transient electromagnetic and high-density electrical resistivity

The water-rich burnt rock may threaten the safe production of coal mines. Identifying the boundaries of burnt rock and the water-rich area is of great practical significance for the ensuring the safety of mining operations. Transient electromagnetic and high-density resistivity methods are commonly employed in geophysical exploration, such as for investigating the presence of groundwater or delineating boundaries of altered rocks. These methods are non-invasive and provide detailed information about subsurface conditions without the need for drilling or excavation. The Jiangjun Gobi No. 1 open-pit coal mine is situated in the Kalamaili fault zone and is characterized by a high groundwater content. In certain mining sites within the study area, the inflow of water reaches tens of thousands of cubic meters per day, which significantly impacts production and presents major risks. To accurately determine the boundaries of burnt rock and water accumulation areas in the Jiangjun Gobi No. 1 open-pit coal mine, this paper uses different geophysical prospecting methods based on the depth of the strata. The middle and deep parts are investigated using the high-resolution transient electromagnetic method, while the shallow parts are examined using the high-accuracy high-density electric method. Through analyzing the electrical characteristics of the study area, it is inferred that the low-resistivity area in the northwest represents a shallow surface water-rich region. This area extends continuously towards the northwest, is not trapped, and is supplied by surface water. The deep low-resistivity zone primarily consists of sandstone and coarse sandstone. It is inferred that the low-resistance area in the southern part of the study area is also a shallow surface water-rich region, extending towards the east and west sides, not trapped, and supplied by surface water. The deep low-resistivity zone mainly comprises a combination of sandstone, coarse sandstone, and burnt rock, with intermittent layers of mudstone and argillaceous sandstone. The boundary line of burnt rock (coal-bearing strata) is located in the south of the study area. The resistivity of burnt rock (coal-bearing strata) is higher than that of the surrounding rocks, and the resistivity of coal seams is slightly higher than that of sandstone with larger porosity. Estimating the boundaries of groundwater and altered rocks serves to prevent geological disasters and provides valuable information for mineral development and ecological protection.

Spatiotemporal analysis of meteorological drought in El Niño years over Oromia region, Ethiopia

Drought is one of the most common natural disasters globally, having major impacts on environmental, economic, and social conditions and Ethiopia is no exception particularly the Oromia region. In order to evaluate and characterize the meteorological droughts associated with El Niño years over the Oromia region, the satellite data CHIRPS was used. The monthly time series data for the period from 1991 to 2020 was used for temporal and spatial analysis of meteorological drought using standardized precipitation index (SPI) across SPI3, SPI6, SPI9 and SPI12 indices using GeoCLIM, GIS, and Python tools. The results of this study show that meteorological droughts during the El Niño years indicated an increment across weak, moderate, and strong El Niño events over the Oromia region. The dryness was visualized with frequency and duration in time-scale across short-term drought indices in time steps. The time-scale temporal meteorological drought indices in three to twelve months show that the drought indices varied in magnitude, duration, and frequency in meteorological droughts. In general, the meteorological drought severity of correlation for the remaining zones analysis between SPI3 and SPI6, SPI6 and SPI12, and SPI9 and SPI12 indices was dominated by an increment of the correlation values over short to long timescales over the study area.

Brackish water pre-treatment method: selection of the study area and water sample testing

Abstract Climate change significantly disrupts the global water cycle, impacting rainfall and social and economic development in countries like Morocco. This has led to the need for alternative solutions like desalinating sea and brackish water. However, the efficiency of water pre-treatment operations depends on the characteristics of the raw water to be treated and affects the overall system's performance in terms of water quality and cost. The final objective of this study is to design a solar-powered brackish pre-treatment technique before desalination for remote rural populations. The primary task is to select the most suitable geographical area in Morocco for sampling and analysis of water characteristics and their compliance with drinking water standards. The results help identify the most appropriate provinces for our case according to certain selection criteria (distance, annual solar radiation, rural population, access to drinking water) and analyse the water's characteristics and compliance with national or international drinking water health standards. This provides a solid foundation for the next stages of desalination method development.

Extensional exhumation of cratons: insights from the Early Cretaceous Rio Negro–Juruena belt (Amazonian Craton, Colombia)

Abstract. This study presents results from apatite fission track (AFT) thermochronology to investigate the thermal history and exhumation dynamics of the Rio Negro–Juruena basement, situated within the western Guiana Shield of the Amazonian Craton. AFT dating and associated thermal history modeling in South America has largely been restricted to the plate's margins (e.g., Andean active margin, Brazilian passive margin, and others). Our paper reports on low-temperature thermochronological data from the internal part of the western Guiana Shield for the first time. This area is part of a vast cratonic lithosphere that is generally thought to be stable and little influenced by Mesozoic and Cenozoic tectonics. Our data, however, show AFT central ages ranging from 79.1 ± 3.2 to 177.1 ± 14.8 Ma, with mean confined track lengths of ca. 12 µm. Contrary to what might be expected of stable cratonic shields, inverse thermal history modeling indicates a rapid basement cooling event in the early Cretaceous. This cooling is interpreted as a significant exhumation event of the basement that was likely driven by the coeval extensional tectonics associated with back-arc rifts in the Llanos and Putumayo–Oriente–Maranon basins. The extensional tectonics facilitated both basement uplift and subsidence of the adjoining basins, increasing erosional dynamics and consequent exhumation of the basement rocks. The tectonic setting shifted in the late Cretaceous from extensional to contractional, resulting in reduced subsidence of the basins and consequential diminishing cooling rates of the Guiana Shield basement. Throughout the Cenozoic, only gradual, slow subsidence occurred in the study area due to regional flexure linked to the Andean orogeny. Comparative analysis with low-temperature thermochronology data from other west Gondwana cratonic segments highlights that exhumation episodes are highly controlled by tectonic inheritance, lithospheric strength, and proximity to rift zones. This study underscores the complex interplay between tectonic events and the response of cratonic lithosphere over geological timescales and highlights extensional settings as an important geological context for craton exhumation.

Assessment of vegetation change using NDVI, LST, and carbon analyses in Çankırı Karatekin University, Turkey.

Due to a rising population and urbanization, the green areas have been decreasing in cities, with a negative impact on air pollution, human health, and ecosystem. As part of the urban environment, university campuses contribute to urban ecosystem with their vegetation. This study aims to (1) assess the change of vegetative land cover of the Çankırı Karatekin University in Turkey and (2) evaluate its benefits to the ecosystem in terms of carbon sequestration, storage, and improvement of air quality by means of a simulation. In the study, the density and vegetation change were assessed with NDVI and LST analyses in ArcGIS; carbon emissions and air pollution benefits were estimated in i-Tree Canopy tool. The study showed that the healthy vegetation consisting of trees/shrubs and grass/herbaceous, which was 32.2% (28ha) in 2000, increased to 85% (74ha) in 2020 NDVI maps, and the surface temperature also increased between 2000 and 2020 in LST maps.The rise in vegetation as grass/herbaceous areas instead of trees/shrubs and the use of impervious buildings/roads on the land surface increased the land surface temperature. As a result of the analyses in the i-Tree-Canopy tool, it was estimated that the trees/shrubs and grass/herbaceous vegetation canopy covering 31.42% of the study area removed a total of 512,845.65g of pollutant gas and particles from the air, 20.79 tonnes of carbon sequestered annually, and 522.01 tonnes of carbon stored by vegetative land cover. In the simulation, where 32.62% soil/bare ground areas were converted to trees/shrubs in order to improve vegetation cover in the area, it was determined that it contributed 5 times more to the ecosystem service value for removing pollutants from the air, carbon storage, and improving the ecosystem. It was revealed that the vegetative land cover formed by tree/shrub species should be increased in the campus in the future. The study method model serves as a tool for planning and designing eco-friendly urban environment.

Perceived impact of COVID-19 lockdown on access to healthcare services, food affordability and family income among married patients of a resource-limited primary care setting

Objective: To examine the perceived impact of COVID-19 lockdown on access to healthcare services, food affordability, and family income during the first phase of the pandemic among married people of a resource-limited primary care setting in Kano, Nigeria. Methods: This survey involved 432 married respondents systematically selected from attendees of a primary care clinic in Kano, Nigeria, using a structured questionnaire. Results: Over half (53.5%) of respondents or their family members fell ill during the lockdown; 67.1% felt it difficult to access hospital treatment, while 32.9% sick patients resorted to self-medication. Over half (57.2%) could afford food as they used to, 75.0% reported that food items were costly, while 35.9% received government assistance. Only 29.9% had employment, of which 49.6% received a salary, while 29.5% had their salaries reduced. Educational level was significantly associated with ease of accessing healthcare services (χ2 =8.528, P=0.014). Age (χ2=12.209, P<0.001), family type (χ2 =12.943, P<0.001), home location in Kano state (χ2= 15.397, P<0.001) and family headcount (χ2=3.968, P=0.044) were significantly associated with perceived food affordability. Conclusions: This study demonstrated the negative impact of the lockdown on healthcare access, food affordability, and family income among respondents’ families. This suggests the need for more investments in promoting and scaling up telemedicine services as platforms for accessing healthcare, which could be utilized in similar future events. More studies will be needed to ascertain the complete picture of the implementation of social assistance in the study area to enhance planning and distribution of future government social assistance.

UAV Thermal Mapping as a New Tool to Detect Subsurface Moisture and Document Baseline Environmental Conditions

AbstractThe California High‐Speed Rail is currently planning a rail corridor through the San Gabriel Mountains. The alignment will require tunnels up to approximately 600 m deep and crossing through the San Gabriel Mountains in the SR 14 area. This study utilized repeated optical and infrared unmanned aerial vehicle (UAV) aerial imagery to document the baseline environmental conditions overlying one of the future high‐speed rail tunnels. Images provide vegetation and soil moisture patterns along the surface route of the corridor for future comparison when the tunneling segments are bored. Analysis of reflectance data revealed subsurface water flow in the Bear Creek‐Sand Canyon Creek Study Area. Using UAVs is considered an effective new tool to detect large‐scale and discrete environmental conditions, perhaps undocumented or unobservable, via standard mapping tools. Setting detailed baseline conditions is important to identify changes that may occur because of future tunneling.

Telugu letters dataset and parallel deep convolutional neural network with a SGD optimizer model for TCR

<p>Because of the rapid growth in technology breakthroughs, including multimedia and cell phones, Telugu character recognition (TCR) has recently become a popular study area. It is still necessary to construct automated and intelligent online TCR models, even if many studies have focused on offline TCR models. The Telugu character dataset construction and validation using an Inception and ResNet-based model are presented. The collection of 645 letters in the dataset includes 18 Achus, 38 Hallus, 35 Othulu, 34×16 Guninthamulu, and 10 Ankelu. The proposed technique aims to efficiently recognize and identify distinctive Telugu characters online. This model's main pre-processing steps to achieve its goals include normalization, smoothing, and interpolation. Improved recognition performance can be attained by using stochastic gradient descent (SGD) to optimize the model's hyperparameters.</p>

Compound drought and hot events assessment in Australia using copula functions

The occurrence of compound drought and hot events has been shown to cause stronger socio-economic, environmental and health impacts than the isolated events. Moreover, the frequency of these compound events has increased unevenly throughout the world and is expected to keep increasing in several regions. In this work, an assessment of compound drought and hot events in the summer months in Australia was made, using copula functions. Drought and hot conditions were identified by the Standardized Precipitation Evapotranspiration Index (SPEI) and the indices Number of Hot Days (NHD) and Number of Hot Nights (NHN) for the summer months, respectively. We analysed drought conditions in the current and the previous 1 to 3 months and the periods 1950–1978 and 1979–2020. The results show that the conditional probability of the occurrence of hot events given drought conditions is very high for the concurrent month in most of the study area, reaching 0.9 in some cases. Considering previous drought conditions, the higher probabilities are obtained in the southeastern region in December and in the north in February but, in most of the study area, these values are higher than for the case of non-drought conditions, pointing to an effect of previous drought conditions on hot events of up to 3 months. Moreover, an increased frequency of compound drought and hot events from the first to the second period was identified in more than half of the study area for lags of 1 and 2 months. We show that, although the conditional probabilities are mostly higher when computed with NHD, NHN is also affected by drought conditions, and should also be considered in this analysis, since nights can have a relieving contribution when impacts in health and wildfires are being analysed.

URBAN CONTEXT ANALYSIS ACCORDING TO THE CONCEPT OF SPENCER'S BIOLOGICAL THEORY USING GIS: BALAD CITY CASE STUDY

Concepts of evolution theory (by Herbert Spencer) were analyzed using a Geographic Information System according to living notions in the context of an urban city. The idea of the theory was applied to the society within the context of Balad city to find out whether the concepts of contrast, integration, specialization, and exclusivity on which the theory is based have an impact on the services in the city and an effect on the structure of the social elements and the stages of its development. The research problem centered on the shortcomings of the theory in predicting and explaining the morphological and functional structure of the city, while the main objective is to analyze the concepts of biological theory according to the requirements of the context of the study area. The analysis results of the living context notions present in the city were compared with the urban housing standards using GIS to determine the extent to which the context conforms to the concept of Spencer's theory. The research found the inability of the biological side of the theory to explain the population concentration in residential neighborhoods, as well as the lack of reliance on the concepts of contrast and integration in predicting the reasons for the growth and expansion of the city, and that the city neighborhoods showed a variance in their services without showing integration and exclusivity in these services, that is, the lack of integration organic between the biological parts of the city.

Features of the educational strategy of school graduates when entering regional universities in Russia

Introduction. With the change of generations, changes in the socio-economic conditions of life, global processes affecting local levels, the previously habitual mechanisms for the functioning of social institutions, in particular, education, also change. Restrictions on entry into the higher education system generate competition for state-funded places, and the USE mechanism is a key way to select the most talented and capable applicants. School graduates find other ways to universities because of the competitiveness and complexity of the Unified State Exam, along with the traditional trajectory of entering a university. The purpose of the study is to identify and analyze the educational strategies that Russian school graduates choose, the factors that determine this choice, and the problems that give rise to the variety of educational trajectories of graduates. Materials and methods. The study was conducted using an online survey among first-year students of two Volgograd universities – Volgograd State University and Volgograd State Technical University in October 2022 (N=527), the task of representation by gender and age was not set. Methods: analysis of sources, online survey, scaling, mathematical statistics (calculation of arithmetic mean), analysis of frequency distributions, analysis of contingency tables. Results. The quality of preparation for the USE is provided not only by general education schools, but also by various forms of additional education, tutors, courses, online schools. The overall level of USE results in the Volgograd region, based on average values, fluctuates in the range of 45-55 points out of 100, while the average scores for admission to the studied Volgograd universities, which were included in the study area of the authors, are 66.4 and 68.7 points, and in the capital - much higher. However, as the analysis of empirical data shows, the decision to enter a university is made on the basis of a wider range of factors, including the territorial location of the university, family traditions, and the socioeconomic status of the family. A rational approach to the implementation of the educational strategy gives rise to the so-called. "transit" trajectory of entering the university after college graduation. Admission to an institution of secondary vocational education can be an intermediate stage (for example, the share of college graduates in full-time departments of universities in Volgograd is 13%, in Russia – about 21%), or be the ultimate goal of the educational trajectory. Conclusion. Admission to a university after the 11th grade brings to the fore the quality of education in schools and preparation for the Unified State Exam, as a tool for the competitive selection of applicants applying for state-funded places at a university. Entering a university after graduating from college is not the most popular strategy, but it avoids the procedure for passing the exam, since admission is based on the results of the university's internal exams. Entering college after the 11th grade is a forced measure and reflects the problems of limited access to higher education on a budgetary basis, competition among applicants, poor preparation for the Unified State Examination, low level of family well-being, etc.

Analyzing land use land cover (LULC) changes induced by the run-of river project and respondent survey: a case of Ghazi Barotha Hydropower Project on Indus River, Pakistan

Land use land cover (LULC) change determination caused by development projects is always mandatory as land is the major source of local livelihoods and regional economy. Worldwide, very limited studies have been conducted to determine LULC changes caused by run-of-the-river projects, which are generally considered safe due to their design. Present study used Google Earth Engine (GEE) to examine the LULC changes caused by Ghazi Barotha Hydropower Project (GBHP), which is a run-of-the-river project, built in 2002 on Indus River in Pakistan. The project diverts river water from Ghazi barrage, for a 6,600 GWh annual power production, through an open concrete power channel of 100 m width and 9 m depth. Field surveys were carried out to assess respondents’ opinions about LULC changes and their major causes. LULC determination was carried out from 1990–2020 through processing Landsat images in GEE, and Random Forest (RF) machine learning technique was used for supervised classification of the study area. 384 respondents were consulted during the field survey and their responses were collected using semi-structured self-administered proformas. Results showed that after functioning, GBHP caused major LULC changes in project downstream areas from 2002–2010, as there was a significant decrease in area under agriculture by 29.10% and 47%, during summer and winter seasons respectively. The trend was concurrent with a decrease in area under water and was also followed by a marked increase in area under vegetation and baresoil. However, from 2010–2020, agriculture area again increased by 75.61% and 84.53% in summer and winter seasons respectively, as compared to 2002–2010. Respondents during the field survey revealed that agriculture reduction from 2002–2010 was due to water scarcity caused by GBHP; also leading to vegetation and baresoil increase. Recovery of agriculture from 2010–2020 was attributed to groundwater development intervention, better seeds, and farmers’ capacity building.

Integrating monetary and non-monetary valuation for ecosystem services in Piatra Craiului national park, Southern Carpathians: a comprehensive approach to sustainability and conservation

The concept of ecosystem services and their valuation has gained significant attention in recent years due to the profound interdependence and interconnectedness between humans and ecosystems. As several studies on valuation of forest ecosystem services have stressed the human-nature interactions lately, in the research study area, the environmental conditions shows rapid changes while human pressures on forests intensify. Thus, the research questions are as follows: (i) what are the the monetary and non-monetary value of ecosystem services provided by forests in Piatra Craiului National Park and (ii) their relationship with other variables, focusing on identifying differences and resemblances between each approach. The R PASTECS package was utilized to analyze primary statistical indicators for both monetary and non-monetary values, revealing significant variability in the results (s% monetary 141% and s% non-monetary 62%). Both monetary and non-monetary assessments were computed at the management unit level and the data used was provided by the Forest Management plans and photograph analysis which have significant value as indicators of ecosystem services. The correlation between nature and culture was assessed through social-media based method, highly known to stimulate participant engagement while the quantitative data was assessed through forest data computation and PCA method for visualization. The research highlighted that, in monetary terms, the minimum value of identified ecosystem services was €34 and the maximum value exceeded €570,000 at management unit level and in non-monetary terms, the values ranged from 1 to 5 (kernel score). The research reveals a substantial variability in both types of valuations. Strong associations between certain variables (monetary value with carbon stock and stand volume), moderate connections (slope with stand productivity), and weaker relationships (non-monetary value with altitude, age with slope, type of flora with altitude, and altitude with stand productivity) were revealed. The findings provided valuable insights for policymakers, land managers, and stakeholders involved in natural resource management and conservation, emphasizing the importance of considering both economic and non-economic benefits in decision-making processes. The integrated approach of this study shows how we can better assess the mixed value of ecosystem services, contributing to the ongoing actions of raising awareness and social responsibility.

Application of nanosilica in the construction industry: A bibliometric analysis using Methodi Ordinatio

The number of publications related to the implementation of nanotechnology in the construction industry, and specifically to the application of nanosilica (SiO2), has had a constant increase in recent years. Based on this, in the present work, an analysis was carried out using bibliometric techniques, with the aim at characterizing the development of specialized literature and identifying the largest areas of growth in the field, maintaining hydrophobic nanosilica as the research guideline. This analysis acquired information from the Scopus and Web of Science (WoS) databases to compare bibliometric indicators of the publications. It should be noted that, even though bibliometric analysis is useful to identify the study areas of greatest interest, to complement this work, the implementation of a method that helped in the research process to obtain the most important bibliography was required. This study implemented Methodi Ordinatio, which helped to take a new direction. Therefore, based on this method, a list of articles cataloged and ranked is obtained, which is the basis for integrating the final bibliographic portfolio.•The study applies the Methodi Ordinatio to obtain a portfolio of the most relevant articles to guide the researchers’ work.•Insightful information can be obtained using VOSviewer to analyze and visualize metadata of the bibliographic portfolio.•The study demonstrates how the alpha value in the InOrdinatio formula modifies the resulting portfolio.

Ecosystem service valuation and multi-scenario simulation in the Ebinur Lake Basin using a coupled GMOP-PLUS model

The Ebinur Lake Basin is an ecologically sensitive area in an arid region. Investigating its land use and land cover (LULC) change and assessing and predicting its ecosystem service value (ESV) are of great importance for the stability of the basin's socioeconomic development and sustainable development of its ecological environment. Based on LULC data from 1990, 2000, 2010, and 2020, we assessed the ESV of the Ebinur Lake Basin and coupled the grey multi-objective optimization model with the patch generation land use simulation model to predict ESV changes in 2035 under four scenarios: business-as-usual (BAU) development, rapid economic development (RED), ecological protection (ELP), and ecological–economic balance (EEB). The results show that from 1990 to 2020, the basin was dominated by grassland (51.23%) and unused land (27.6%), with a continuous decrease in unused land and an increase in cultivated land. In thirty years, the total ESV of the study area increased from 18.62 billion to 67.28 billion yuan, with regulation and support services being the dominant functions. By 2035, cultivated land increased while unused land decreased in all four scenarios compared with that in 2020. The total ESV in 2035 under the BAU, RED, ELP, and EEB scenarios was 68.83 billion, 64.47 billion, 67.99 billion, and 66.79 billion yuan, respectively. In the RED and EEB scenarios, ESV decreased by 2.81 billion and 0.49 billion yuan, respectively. In the BAU scenario, provisioning and regulation services increased by 6.05% and 2.93%, respectively. The ELP scenario, focusing on ecological and environmental protection, saw an increase in ESV for all services. This paper can assist policymakers in optimizing land use allocation and provide scientific support for the formulation of land use strategies and sustainable ecological and environmental development in the inland river basins of arid regions.

Sustainable rice farming in Indonesia

Rice is the main food in Indonesia, so increase in rice production must be achieved in a sustainable manner to maintain food security. The research case study is rice farming in Pancur Batu sub-district. The research method uses mixed methods (quantitative and qualitative) with quantitative dominance. The Objective of this study was to determine the implementation of sustainable rice farming in the Pancur Batu sub-district. The research tools used to evaluate the Sustainability Model in rice farming are Multi-Dimensional Scaling Analysis (MDS) with Rapid Appraisal Technique for Fisheries (RAPFISH) program analysis. indicators and criteria for the sustainability of rice farming are divided into ecological, economic and social dimensions, then input into the Rapid Appraisal Technique for Fisheries (RAPFISH) program. The results of the research showed that the social dimension had the highest sustainability index, namely 75.13 which indicates that the social dimension in the research location is quite sustainable, the ecological dimension with a sustainability index of 54.44 indicates that the ecological dimension is quite sustainable, and the lowest dimension value was the economic dimension with a sustainability index value of 43.58. This sustainability index value indicates that economic dimension of rice farming in the research location is not sustainable. The sustainability status of rice farming in the study area is multidimensional with an index value of 72. This index value indicates that the sustainability of rice farming in the study area is quite sustainable. The conclusion from this study was that the most sensitive and influential attributes for rice farming in the study area were: first, the ecological dimensions: (a) water availability, (b) pest attack rate, (c) land conversion rate; the economic dimension: (a) The price level of production inputs (fertilizers and pesticides), (b) The level of labor wages, (c) The level of availability of production inputs and social dimension which is counseling. Key words: Sustainability, Rice Farming, Social Dimension, Economic Dimension, Ecological Dimensions, RAPFISHS

Sea turtle density surface models along the United States Atlantic coast

Spatially explicit estimates of marine species distribution and abundance are required to quantify potential impacts from human activities such as military training and testing, fisheries interactions, and offshore energy development. There are 4 protected species of sea turtle (loggerhead, green, Kemp’s ridley, and leatherback) commonly found along the east coast of the USA, our study area, and which require impact assessments. Data from 7 different survey organizations were used to create density surface models for the 4 sea turtle species utilizing 1.2 million km of line-transect surveys. A substantial portion (29.7%) of available sightings were not identified to the species level. Not including these sightings would underestimate density, so a conditional random forest model was used to assign unidentified sightings to species. Higher densities of loggerhead, green, and Kemp’s ridley sea turtles were predicted south of the Outer Banks in cool months, transitioning northwards in late spring to occupy seasonal neritic habitats. The highest leatherback densities were predicted off the coasts of Georgia and Florida. Leatherbacks were also predicted throughout offshore areas. The predicted distribution patterns generally matched satellite tracking and strandings data, indicating the models reproduced established seasonal movements. Surveys rarely detect sea turtles smaller than 40 cm, so these age classes are not represented. The models are the first for the study area to apply availability bias estimates developed in or near the study area and attempt to classify unidentified sightings to the species level, providing an updated, critical tool for conservation management along the eastern seaboard.

Cropland and Crop Type Classification with Sentinel-1 and Sentinel-2 Time Series Using Google Earth Engine for Agricultural Monitoring in Ethiopia

Cropland monitoring is important for ensuring food security in the context of global climate change and population growth. Freely available satellite data allow for the monitoring of large areas, while cloud-processing platforms enable a wide user community to apply remote sensing techniques. Remote sensing-based estimates of cropped area and crop types can thus assist sustainable land management in developing countries such as Ethiopia. In this study, we developed a method for cropland and crop type classification based on Sentinel-1 and Sentinel-2 time-series data using Google Earth Engine. Field data on 18 different crop types from three study areas in Ethiopia were available as reference for the years 2021 and 2022. First, a land use/land cover classification was performed to identify cropland areas. We then evaluated different input parameters derived from Sentinel-2 and Sentinel-1, and combinations thereof, for crop type classification. We assessed the accuracy and robustness of 33 supervised random forest models for classifying crop types for three study areas and two years. Our results showed that classification accuracies were highest when Sentinel-2 spectral bands were included. The addition of Sentinel-1 parameters only slightly improved the accuracy compared to Sentinel-2 parameters alone. The variant including S2 bands, EVI2, and NDRe2 from Sentinel-2 and VV, VH, and Diff from Sentinel-1 was finally applied for crop type classification. Investigation results of class-specific accuracies reinforced the importance of sufficient reference sample availability. The developed methods and classification results can assist regional experts in Ethiopia to support agricultural monitoring and land management.

Simultaneous removal of fluoride and arsenic from drinking groundwater using limestones from Bajío Guanajuatense, Mexico

Numerous groundwater wells in Mexico exceed the maximum allowable fluoride (F−) and arsenic (As) drinking water concentration requirements, posing an environmental and health risk to the population that relies solely on these wells for drinking water sources. Since encouraging results have been obtained utilizing native limestones to remove some toxic elements from contaminated water, the ability of the limestone rock outcrop to the south of the Sierra de Guanajuato in Mexico to remove As and F− from groundwater was assessed. A sampling campaign was conducted in the study area, focusing on wells exhibiting elevated concentrations of arsenic (As) and fluoride (F−) in compliance with international standards. This water was employed in the treatment experiment involving limestone rocks. The rock sampling process involved a reconnaissance campaign covering the study area and outcrop points of limestone rocks. Representative limestone samples were collected and subsequently subjected to mineralogical and geochemical characterization. Using rock samples, synthetic water, and groundwater from contaminated wells in the region, batch experiments were conducted to evaluate the As and F− removal capacity of limestone. The batch testing consisted of water–rock interactions at various times with different samples of limestone rocks, grain sizes, and water containing distinct concentrations of both elements, artificial and groundwater extracted close to the limestones outcrop. The results indicate that the rock with the highest calcium carbonate (CaCO3) content and the smallest grain size (< 0.05 mm) removes the highest concentrations of both As and F−, with As removal being superior. The removal mechanisms were studied using scanning electron microscopy with energy-dispersive spectroscopy (SEM–EDS) images, saturation index calculations, and Eh–pH diagrams,. Fluoride precipitation was favored when the pH of the solution was slightly acidic, whereas sorption was favored when the pH was higher. The results obtained are encouraging for the removal of high levels of As, and to a lesser extent for F−; consequently, the use of regional limestone rocks could be a viable option for improving the water quality ingested by rural inhabitants in the study area. Calcium carbonate (CaCO3) concentration can be used to identify limestone rocks with the potential to effectively remove As and F− in other locations.

Estimation of the Ecosystem Service Value of the Yellow River Delta-Laizhou Bay Coastal Zone Considering Regional Differences and Social Development.

With economic and societal development, the ecological environment of the Yellow River Delta-Laizhou Bay coastal zone has been seriously damaged. Exploring the changes in land use and ecosystem service value (ESV) is essential to ecological construction of the region. The random forest classification method was used for land cover interpretation of the four periods of remote sensing images in the study area from 1990 to 2020. Newly calculated regional difference coefficients and social development coefficients were used to construct a dynamic ESV assessment model and to study its changes from overall and sea‒land gradient perspectives. The results showed that construction land, salt pans, aquaculture ponds, and inland water masses expanded rapidly, while cropland, tidal flats, and shallow waters shrank sharply over the past 30 years. The ESV in the study area has continued to decrease from 34.47 billion yuan in 1990 to 25.23 billion yuan in 2020, a total decrease of 9.23 billion yuan. This is mostly due to the encroachment of construction land, salt pans, and aquaculture ponds, and the flow of ecosystem services from high-value land cover types (tidal flats, herbaceous wetlands, and cropland) to medium- and low-value land cover types. Moreover, the land cover transfer and ESVs exhibited a decreasing trend from sea to land, with significant sea-land gradient differences. Land conversion is most common in the 0-15 km coastal zone, mainly from natural wetlands to artificial wetlands, where the ESV also decreases rapidly. Considering the regional differences and social development in this paper, the ESV of small-scale areas can be reasonably evaluated to explore the characteristics and causes of changes in land use and ESVs, which can provide an important reference for ecological protection and land use management in the region.