Land use, land cover changes and expansion of artificial reservoirs in Eastern Thailand: implications for agriculture and vegetation drought reduction.

Eastern Thailand and Rayong province face perennial drought and water scarcity due to natural characteristics of climate and geology. Therefore, increasing water surface by man-made reservoirs is one of the priorities in the regional development plan to provide water adequately for industrial purposes, domestic consumption, and agriculture. The large reservoir constructions may induce land use, land cover changes (LULCC), yet it also is expected to alleviate the drought harshness in the region. By delineating Landsat satellite images and spatial analysis, this study revealed the LULCC in Rayong from 1990 to 2020. The most prominent LULCC was surface water expansion, about 10.9% per year, yet the increase was the most substantial in the first decade rather than the last two decades. Vegetation expansion was observed, contributing to an increase in forests/plantations and intensified agriculture by 39.19% and 25.54%, respectively. The LULCC corresponded to a 3.64% increase in ecosystem service values (ESV), implying positive benefits from the LULCC. Vegetation drought conditions monitored by the vegetation health index (VHI) exhibited an improvement trend, especially in the eastern basins. The development of artificial reservoirs was proven to stimulate the expansion of intensive agriculture and vegetation drought mitigation with spatial heterogeneity, spreading mainly across areas of the basins rather than remote areas. The research findings inform the efficiency of the reservoirs and irrigation systems regarding the beneficial effects on drought mitigation and water scarcity for agricultural cultivation. They also provide spatial information on areas still hindered by water problems that should be addressed in future strategies.

Habitat quality outweighs the human footprint in driving spatial patterns of Cetartiodactyla in the Kunlun-Pamir Plateau.

The Human Footprint (HFP) and Habitat Quality (HQ) are critical factors influencing the species' distribution, yet their relation to biodiversity, particularly in mountainous regions, still remains inadequately understood. This study aims to identify the primary factor that affects the biodiversity by comparing the impact of the HFP and HQ on the species' richness of Cetartiodactyla in the Kunlun-Pamir Plateau and four protected areas: The Pamir Plateau Wetland Nature Reserve, Taxkorgan Wildlife Nature Reserve, Middle Kunlun Nature Reserve and Arjinshan Nature Reserve through multi-source satellite remote sensing product data. By integrating satellite data with the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST)HQ model and utilizing residual and linear regression analysis, we found that: (1) The Wildness Area (WA) predominantly underwent a transition to a Highly Modified Area (HMA) and Intact Area (IA), with a notable 12.02% rise in stable regions, while 58.51% rather experienced a negligible decrease. (2) From 1985 to 2020, the Kunlun-Pamir Plateau has seen increases in the forestland, water, cropland and shrubland, alongside declines in bare land and grassland, denoting considerable land cover changes. (3) The HQ degradation was significant, with 79.81% of the area showing degradation compared to a 10.65% improvement, varying across the nature reserves. (4) The species richness of Cetartiodactyla was better explained by HQ than by HFP on the Kunlun-Pamir Plateau (52.99% vs. 47.01%), as well as in the Arjinshan Nature Reserve (81.57%) and Middle Kunlun Nature Reserve (56.41%). In contrast, HFP was more explanatory in the Pamir Plateau Wetland Nature Reserve (88.89%) and the Taxkorgan Wildlife Nature Reserve (54.55%). Prioritizing the restoration of degraded habitats areas of the Kunlun Pamir Plateau could enhance Cetartiodactyla species richness. These findings provide valuable insights for the biodiversity management and conservation strategies in the mountainous regions.

Conversion of coastal marsh to aquaculture ponds decreased the potential of methane production by altering soil chemical properties and methanogenic archaea community structure.

Coastal wetlands are among the most productive and dynamic ecosystems globally, contributing significantly to atmospheric methane (CH4) emissions. The widespread conversion of these wetlands into aquaculture ponds degrades these ecosystems, yet its effects on CH4 production and associated microbial mechanisms are not well understood. This study aimed to assess the impact of land conversion on CH4 production potential, total and active soil organic C (SOC) content, and microbial communities. We conducted a comparative study on three brackish marshes and adjacent aquaculture ponds in southeastern China. Compared to costal marshes, aquaculture ponds exhibited significantly (P < 0.05) lower CH4 production potential (0.05 vs. 0.02 µg kg-1 h-1), SOC (17.64 vs. 6.97 g kg-1), total nitrogen (TN) content (1.62 vs. 1.24 g kg-1) and carbon/nitrogen (C/N) ratio (10.85 vs. 5.66). CH4 production potential in aquaculture ponds was influenced by both microbial and abiotic factors. Specifically, the relative abundance of Methanosarcina slightly decreased in aquaculture ponds, while the potential for CH4 production declined with lower SOC contents and C/N ratio. Overall, our findings demonstrate that converting natural coastal marshes into aquaculture ponds reduces CH4 production by altering key soil properties and the structure and diversity of methanogenic archaea communities. These results provide empirical evidence to enhance global carbon models, improving predictions of carbon feedback from wetland land conversion in the context of climate change.

Stingless Bee Foraging Activity Related to Environmental Aspects.

The environment where bee colonies are inserted must provide the necessary resources for their survival. Given this, any biotic and abiotic changes in the environment can affect the development and survival of the colonies. We evaluated the foraging activity of Plebeia droryana (Friese), Scaptotrigona bipunctata (Lepetelier), and Melipona quadrifasciata (Lepetelier) in areas with different land uses and land cover. These areas were classified as predominantly (i) urbanized/forest (CDA-Cidade das Abelhas), (ii) agricultural (FER-Fazenda Experimental da Ressacada), and (iii) with dense vegetation (SFB-Sitio Florbela). We correlated the morphometric characteristics of the bees with the pollen load transported. Four colonies from each species were installed in the three areas. We recorded light, wind speed, humidity, and temperature and counted the foragers returning with nectar, pollen, and resin. Plebeia droryana and S. bipunctata collected more resin and nectar in with dense vegetation area compared to agricultural area. Scaptotrigona bipunctata collected more pollen in urbanized/forest area and with dense vegetation area, and M. quadrifasciata did not show differences in foraging activity between areas. Plebeia droryana and M. quadrifasciata showed moderate and strong correlations between morphometric characteristics and pollen load. SFB had higher luminosity and wind speed. CDA had higher average temperature. FER had higher humidity. The three species showed positive and negative correlations between temperature and light and foraging in the different areas. Smaller species showed a higher gathering of resources in the area predominantly covered by dense vegetation. The reduction of vegetation cover can affect the resource collection activity of stingless bees.

Soil benzene emissions and inhalation health risks affected by various land covers.

Accurate quantification of soil volatile organic compounds (VOCs) flux is crucial for assessing inhalation environmental health risks and developing region-specific remediation strategies. However, land cover significantly influences VOCs emissions from soil. This study investigated benzene, a representative VOCs, using a laboratory flux chamber and numerical simulations to evaluate its release patterns under different surface covers, including bare soil (no cover), clay brick, cement, and grass. In the experiment, gaseous benzene was collected using an adsorption tube filled with Tenax-TA adsorbent. The collected samples were subsequently analyzed using thermal desorption coupled with gas chromatography-mass spectrometry. By integrating these findings with environmental health risk assessment methodologies, we developed a tailored approach for assessing inhalation health risks at benzene-contaminated sites with varying land covers. Additionally, we conducted application studies of this method across various scenarios. The results indicate that soil benzene emissions could be reduced by using low-permeability coverings such as clay brick and cement, as well as by planting vegetation. The average fluxes of benzene through covering materials were of the order of 1.22 × 10-2, 4.37 × 10-3, 2.47 × 10-3, and 9.88 × 10-4 mg m-2·s-1 for bare soil, clay brick, grass, and cement, respectively. The application of clay brick and cement coverings on the soil surface results in more pollutants remaining in the soil in liquid and adsorbed states, making them less likely to volatilize. The inhalation carcinogenic risk (CR) values for soil benzene at an abandoned oil refinery site in Northwestern China under bare soil, brick, and cement cover are 1.3 × 10-6, 1.22 × 10-6, and 9.73 × 10-7, respectively. Low-permeability covers such as clay brick and cement reduces the inhalation CR of gaseous benzene from the surface soil, and delays the growth trend of cumulative inhalation CR.

Impacts of land-use and land-cover changes on temperature-related mortality.

Background: Land-use and land-cover change (LULCC) can substantially affect climate through biogeochemical and biogeophysical effects. Here, we examine the future temperature-mortality impact for two contrasting LULCC scenarios in a background climate of low greenhouse gas concentrations. The first LULCC scenario implies a globally sustainable land use and socioeconomic development (sustainability). In the second LULCC scenario, sustainability is implemented only in the Organisation for Economic Cooperation and Development countries (inequality). Methods: Using the Multi-Country Multi-City (MCC) dataset on mortality from 823 locations in 52 countries and territories, we estimated the temperature-mortality exposure-response functions (ERFs). The LULCC and noLULCC scenarios were implemented in three fully coupled Earth system models (ESMs): Community Earth System Model, Max Planck Institute Earth System Model, and European Consortium Earth System Model. Next, using temperature from the ESMs' simulations and the estimated location-specific ERFs, we assessed the temperature-related impact on mortality for the LULCC and noLULCC scenarios around the mid and end century. Results: Under sustainability, the multimodel mean changes in excess mortality range from -1.1 to +0.6 percentage points by 2050-2059 across all locations and from -1.4 to +0.5 percentage points by 2090-2099. Under inequality, these vary from -0.7 to +0.9 percentage points by 2050-2059 and from -1.3 to +2 percentage points by 2090-2099. Conclusions: While an unequal socioeconomic development and unsustainable land use could increase the burden of heat-related mortality in most regions, globally sustainable land use has the potential to reduce it in some locations. However, the total (cold and heat) impact on mortality is very location specific and strongly depends on the underlying climate change scenario due to nonlinearity in the temperature-mortality relationship.

Projection of land use and land cover changes based on land change modeler and integrating both land use land cover and climate change on the hydrological response of Big Creek Lake Watershed, South Alabama.

Changing land use/land cover (LULC) and climate substantially affect the hydrological components of a watershed. This study explored the future impact of the hydrological responses due to the changing LULC and climate on the Big Creek Lake watershed in Alabama, USA, from 2021 to 2050 using the Soil and Water Assessment Tool (SWAT). Five climate model datasets were used under the moderate scenario (Representative Concentrative Pathways 4.5) and the extreme scenario (Representative Concentrative Pathways 8.5), and the datasets were downscaled and bias-corrected. In addition, changing the LULC of five categories was predicted by Cellular Automata Markov (CA- Markov). With these data combined with the elevation (Digital Elevation Model), soils, and weather data, the SWAT model was calibrated and validated for the studied watershed to quantify how climate change will affect streamflow, nitrogen, and phosphorus. Our results indicate streamflow will increase due to the 50-acre increase in urban LULC. As streamflow increases, the percolation, surface runoff, lateral flow, groundwater flow, and water yield will also increase because the streamflow impacts these hydrological components. Moreover, the increase rate in streamflow is the same for all the components for January, February, and March. Therefore, there is a strong correlation between these months. On the contrary, evaporation will be high in May, June, and July because of the increasing temperature and streamflow. However, the changes in the water hydrological parameters and total nitrogen and phosphorus will be more intense in RCP8.5 than in RCP4.5.

Forest cover influences fish mercury concentrations in national parks of the western U.S.

The global prevalence of mercury (Hg) contamination and its complex biogeochemical cycling has resulted in elevated Hg concentrations in biota in remote and pristine environments. However, there is uncertainty in the relative importance of Hg deposition and landscape factors that control Hg cycling and bioaccumulation. To address this, we measured total mercury (THg) concentrations in 1344 fish across 60 subalpine lakes from 12 national parks (NPs). These parks represent three distinct high-elevation regions across the western U.S.: Cascades and Olympic Peninsula, Sierra Nevada and Great Basin, and Rocky Mountains. Within these regions, three NPs (Mount Rainier, Yosemite, and Rocky Mountain) were intensively studied representatives of each region. This study aimed to (1) assess the magnitude of mercury contamination in a collection of remote, small catchment lakes; (2) quantify the variability of fish THg concentrations among and within parks; and (3) test the relative importance of Hg inputs in comparison to landscape characteristics on lake-specific fish THg concentrations. The spatial variability in fish THg concentrations was 2.6-fold higher than variation in deposition to watersheds, suggesting that factors other than Hg delivery are important determinants of Hg accumulation in these environments. Spatially, fish THg concentrations (ng/g ww ± standard error) were lower in the Rockies (46.2 ± 5.0) and Sierra (56.5 ± 5.8) compared to the Cascades (67.8 ± 6.1). Additionally, fish THg concentrations increased with increasing conifer forest cover (Intensive parks: P < 0.0001, R2 = 0.43; All parks: P = 0.0001, R2 = 0.23) but were not correlated with wet Hg deposition across the catchment. These findings suggest that forest composition is likely an important aspect of Hg delivery to lake food webs, and although the mechanisms are unclear, could be tied to some combination of forest influences on catchment organic carbon and increased surface area for dry Hg deposition.

Assessing the effectiveness of integrated watershed management practices and suggesting innovative strategies in southern Ethiopia.

Integrated watershed management plays a vital role in promoting sustainable water resource management and addressing environmental challenges. This study aims to analyze and assess the effectiveness of existing IWM practices and develop new strategies to improve watershed management. The data collection process encompassed comprehensive field observations, surveys, and consultations with the stakeholders. According to a hydrometer test, loam soil was the average dominant soil type in Elgo and Kola shell kebele. The assessment of existing soil water conservation initiatives adhered to the rigorous standards set by the Ministry of Agriculture. From 2016 to 2022, Elgo Kebele saw significant land use changes: agriculture expanded by 11.24 %, bare land by 2.05 %, water bodies by 1.79 %, and settlements by 0.54 %, while forests declined by 15.34 %. In Kola Shele, agriculture, water bodies, and settlements slightly increased by 0.5 %, 1.03 %, and 0.033 %, respectively, with decreases in bare land (1.82 %) and forest (0.05 %). Only 25 % of sampled plots met the criteria for effective soil water conservation systems, indicating challenges in current practices. For cultivated land with less than a 15 % slope and vertisol, recommended conservation practices include broad bed and furrow, conservation tillage, grass strips, grassland improvement, and mulching. For slopes greater than 50 %, hillside terracing, graded bunds, and trenches are advised. Additional measures, such as water harvesting, grass waterways, revegetation, and actions against illegal farming, were proposed. In summary, this study highlights the urgent need for improved IWM practices, and used to enhance watershed management, address environmental and socio-economic issues, and promote sustainable land use in the study.

Long-term changes of mangrove distribution and its response to anthropogenic impacts in the Vietnamese Southern Coastal Region.

Human activities related to land use and land cover (LULC) conversion have been the primary factor driving changes to mangrove distribution over recent decades. In order to quantify the anthropogenic influences associated with LULC changes on mangroves in the Vietnamese Southern Coast (VSC), we investigated the variations and trends in mangrove distribution between 1988 and 2023. We used a time-series of Landsat spectral indices from Google Earth Engine and applied hot spot analysis and machine learning algorithms to analyse mangrove variations and LULC classification, respectively. Our findings revealed that over the past 36 years, approximately half of the mangrove area has been lost due to LULC conversions. The most significant losses in mangrove cover occurred during the 1998-2011 period, with a decline of 46.79% in total area (an average of 3.6% per annum). The rate of mangrove deforestation more than halved to 17.49% (1.5% per annum) in the period between from 2011 to 2023. We attribute the reduction in mangrove loss to conservation efforts and natural regeneration processes. The emerging hot spot analysis indicated that the most significant restoration of new mangrove areas occurred between 1988 and 1998, totalling 1795 ha (1.4%), while the highest rate of mangrove deforestation was observed between 1998 and 2011, amounting to 2249 ha (2.0%). The primary causes of these variations in mangrove distribution were the conversion of mangrove areas to shrimp farming (38.91%), followed by other agricultural land use (5.82%) and the expansion of impervious surfaces (3.34%). In contrast, a result of enhanced conservation efforts and natural regeneration was associated with a 17.91% of mangrove area gain in the 2011-2023 period. Despite the regeneration potential of mangroves, our study highlighted the ongoing need to manage and protect mangrove forests to facilitate their expansion in the VSC. The analytical approach adopted in this study is applicable to other coastal areas when assessing changes in mangroves and land use practices.

Multi-Source Remote Sensing Data for Wetland Information Extraction: A Case Study of the Nanweng River National Wetland Reserve.

Wetlands play a vital role in regulating the global carbon cycle, providing biodiversity, and reducing flood risks. These functions maintain ecological balance and ensure human well-being. Timely, accurate monitoring of wetlands is essential, not only for conservation efforts, but also for achieving Sustainable Development Goals (SDGs). In this study, we combined Sentinel-1/2 images, terrain data, and field observation data collected in 2020 to better understand wetland distribution. A total of 22 feature variables were extracted from multi-source data, including spectral bands, spectral indices (especially red edge indices), terrain features, and radar features. To avoid high correlations between variables and reduce data redundancy, we selected a subset of features based on recursive feature elimination (RFE) and Pearson correlation analysis methods. We adopted the random forest (RF) method to construct six wetland delineation schemes and incorporated multiple types of characteristic variables. These variables were based on remote sensing image pixels and objects. Combining red-edge features, terrain data, and radar data significantly improved the accuracy of land cover information extracted in low-mountain and hilly areas. Moreover, the accuracy of object-oriented schemes surpassed that of pixel-level methods when applied to wetland classification. Among the three pixel-based schemes, the addition of terrain and radar data increased the overall classification accuracy by 7.26%. In the object-based schemes, the inclusion of radar and terrain data improved classification accuracy by 4.34%. The object-based classification method achieved the best results for swamps, water bodies, and built-up land, with relative accuracies of 96.00%, 90.91%, and 96.67%, respectively. Even higher accuracies were observed in the pixel-based schemes for marshes, forests, and bare land, with relative accuracies of 98.67%, 97.53%, and 80.00%, respectively. This study's methodology can provide valuable reference information for wetland data extraction research and can be applied to a wide range of future research studies.

Terrestrial land use signals on groundwater fauna beyond current protection buffers.

Terrestrial and aquatic ecosystems are tightly linked, with direct implications for applied resource management and conservation. It is well known that human land use change and intensification of terrestrial systems can have large impacts on surface freshwater ecosystems. Contrastingly, the study and understanding of such land use impacts on groundwater communities is lagging behind. Both the impact strength of land use on groundwater communities and the spatial extents at which such interlinkages are operating are largely unknown, despite our reliance on groundwater for drinking water extraction as a key ecosystem service. Here, we analyzed groundwater amphipod occurrence from several hundred shallow groundwater aquifers used for drinking water extraction across a region of varying agricultural intensity and human population density in Switzerland. Despite drinking water extraction sites being generally built at locations with expected minimal aboveground impacts on water quality, we found a direct correlation between land use type and intensity within the surrounding catchment area and the locally measured nitrate concentrations, which is a direct proxy for drinking water quality. Furthermore, groundwater amphipods were more likely to be found at sites with higher forest coverage than at sites with higher crop and intensive pasture coverages, clearly indicating a tight connection between aboveground land use and groundwater biodiversity. Our results indicate that land use type effects on groundwater communities are most relevant and pronounced to spatial scales of about 400-1000 m around the groundwater sampling site. Importantly, the here identified spatial scale is 1.2- to 3-fold exceeding the average extent of currently defined groundwater protection zones. We postulate that incorporating an ecosystem perspective into groundwater management strategies is needed for effective protection of groundwater quality and biodiversity.

Mapping and Identification of Ecosystem Services Hotspots in the Brazilian Pampa Biome.

The intensification and expansion of changes in land use and land cover (LULC) can reduce the availability and quality of natural habitats and ecosystem services (ES). These changes have generated environmental damage in different parts of the world, especially in biomes more susceptible to modifications, such as the Pampa biome in the extreme south of Brazil. The Pampa biome has been neglected by environmental protection laws, despite its broad ecosystem and social importance. In this study, we used InVEST models to map and quantify five ES provided (i.e., water supply, carbon stock, groundwater stock, sediment retention and habitat quality) by 14 watersheds distributed in the Brazilian Pampa biome as well as determine ES hotspots by summing the areas with high provision of ES. We identified low availability of water supply and groundwater stock in practically the entire study area. High sediment retention and carbon stock were reported in areas with the presence of native vegetation. In addition, despite the large degraded areas, we observed high habitat quality associated with native vegetation in all studied watersheds. The hotspots varied spatially in the study area according to the proposed scenarios, the supply and the overlap of ES. Scenario 1 (>50% of ES) presented a larger area of high provision of ES. In contrast, scenario 2 (>75% of ES) presented smaller patches of areas with high provision of ES distributed across different watershed. We observed that large territorial extensions with high and medium provision of ES are vulnerable to the negative effects of LULC. Our study presented scenarios that indicate areas of high provision of ES, contributing to a more practical application, being a simplified and useful tool that can assist conservation and sustainable policies.

Predicting land use dynamics, surface temperature and urban thermal field variance index in mild cold climate urban area of Pakistan.

Rapid urbanization attributed to population growth is affecting the built environment's thermal and landscape dynamics. Using Landsat satellite datasets, this study investigated the complex interplay between urban Land Cover (LC) modification, fluctuation in Land Surface Temperature (LST) and severity of Urban Heat Island (UHI) from 1990 to 2020 in Peshawar City, Pakistan. Thermal bands were used to calculate LST and severity of UHI using the Urban Thermal Field Variance Index (UTFVI). Furthermore, through Cellular Automata (CA), Logistic Regression (LR), and Artificial Neural Network (ANN), future predictions on thermal characteristics associated with land use changes were made. The results showed that the urban areas expanded by ∼25 % from 1990 to 2020, while a ∼10 % decrease occurred in urban vegetation. The city is projected to expand by ∼45 % and ∼56 % in 2035 and 2050, respectively. Notably, the results also demonstrated that urban hotspots were found the warmest with the strongest UHI severity (∼34 °C), followed by the barren land (∼32 °C), and vegetation. The results further predicted an increase of LST (∼55 % and ∼82 %) and UTFVI (∼62 % and ∼83 %) in 2035 and 2050, respectively. These findings provide useful insights for policymakers and city planners to mitigate heat stress and create a sustainable urban environment through the development of effective urban land use policies and urban greening.

The state of nitrogen in rivers and streams across sub-Saharan Africa.

The nutrient status of rivers and streams is less researched in sub-Saharan Africa than in many other inhabited regions of the world. Given the expected population growth, intensification of agriculture, increased pressure on natural ecosystems and projected climate change in sub-Saharan Africa, it is crucial to quantify and understand drivers behind spatiotemporal patterns of nitrogen concentrations and loads in rivers and streams. Such knowledge can support sustainable management of water resources with the goal to provide clean water, create and maintain healthy ecosystems and prevent excessive pollution of water resources with nitrogen compounds, as is found in large parts of North America, Europe and Asia. This review provides a synthesis of the current available data from peer-reviewed literature (n = 243) on particulate and dissolved nitrogen in rivers and streams in sub-Saharan Africa, looking into seasonal and land cover-related differences. The review shows that data on nitrogen concentrations in rivers and streams is available for 32 out of the 48 countries (67 %) in sub-Saharan Africa, highlighting large data gaps given the size of the region. Differences in nitrogen concentrations between land cover types are reported, with highest median total nitrogen (3.9 mg N L-1) and nitrate (1.2 mg N L-1) concentrations observed at sites characterised by settlement and industry. In contrast, natural land cover types, like forest, have higher median (N:P) ratios (> 14.6) than cropland and urban areas (< 12.0). The analysis of paired samples from dry and wet seasons reveals varying effects of seasonality on the concentration of different nitrogen compounds between land cover types. However, the processes driving these spatiotemporal differences are still poorly understood. These findings highlight the need for a targeted research agenda for Africa to advance our understanding of the role of rivers and streams in nitrogen cycling in different ecosystems and their interaction with anthropogenic and natural drivers of change.

The impacts of climate change, early agriculture and internal fluvial dynamics on paleo-flooding episodes in Central China.

Floods clustered in episodes are the most prevalent natural disaster worldwide, causing substantial economic and human losses. Although these events are often linked to time-periods of extreme rainstorms and unique atmospheric circulation patterns, the river basin characteristics affected by anthropogenic land use changes could exert a strong influence. However, the way and extent of how land use changes across different time scales affect flooding periods are still unclear, especially considering the historical land use changes. This study uses the Landlab landscape evolution model, coupled with an evapotranspiration model, to investigate the forcing factors for the paleo-flooding trends in the Wei River catchment over the last 5000 years. The results indicate that the flooding period from 4400 to 4000 BP was caused by an increase of 28 % in antecedent moisture content as well as a decrease of 28 % in its spatial variability, which are primarily due to climate change, and that the contribution of land-use change is less than 5 %. The increases of about 14 % and 8 % in main channel sedimentation rate play a leading role in flood generation during the time periods from 3400 to 2800 BP and 2000-1400 BP, respectively. These two periods of increased flooding are primarily caused by the erosional effects of increasing anthropogenic land use, whose contributions range from 33 % to 64 %. Furthermore, based on our modelling results, we suggest that the downstream propagation of the main flooding locations, from the Wei River to the lower reaches of the Yellow River, can be explained by the downstream migrating sediment wave. In conclusion, our simulation results give new insights into the causes of Holocene flooding periods in the middle Yellow River from the perspective of dynamic changes in catchment characteristics, which is helpful to improve regional flood risk management under future climate change and anthropogenic activities.

Land use & land cover dynamics and its relationship with nitrate pollution in groundwater around inactive mine areas using geospatial techniques, SW part of Cuddapah basin, Southern India.

Geospatial maps can show how the ineffective operations of inactive mines affect water and aquifer quality. As such, the purpose of this study is to assess the impact of mining and irrigation on the aquifer ecosystem through the evaluation of LULC and slope maps through the application of Landsat 8 OLI/TIRS and DEM data. A total of 50 groundwater samples were prepared from villages in the close proximity to inactive mines during pre and post monsoon periods in 2021. The results of the analysis revealed alarming statistics, that 14% of groundwater samples exceeded the WHO nitrate limit in pre & post monsoon season, indicating a high-risk in the study area. According to guidelines (USEPA, 2014), 34% in pre-monsoon and 26% post-monsoon of samples exceeded the THI levels for adults and children respectively, indicating non-carcinogenic health risks. In addition, 80% of the samples in both seasons exhibited high NPI values, indicating nitrate contamination associated with blue baby syndrome. From the Geospatial analysis the findings from the LULC classification indicate that there has been a significant increase in cropland area from 2016 to 2021 due to changes in forest land, fallow land, and water resources. These problems have been exacerbated by the expansion of cultivated land, which has increased from 71.1 square kilometers in 2016 to 118 square kilometers in 2021, accounting for 13.1% of the total area. This expansion, coupled with elevated water body resource availability, has compounded the nitrate pollution including in intensely irrigated regions. The slope map analysis revealed that the inactive mines occur at low slope, high rainfall areas and these are compounded by runoff from other sources such as domestic and agricultural wastes. For these matters, sealing and remediating these inactive mines is essential so as to prevent further nitrate leakage.

Using patterns of shared taxa to infer bacterial dispersal in human living environment in urban and rural areas.

Contact with environmental microbial communities primes the human immune system. Factors determining the distribution of microorganisms, such as dispersal, are thus important for human health. Here, we used the relative number of bacteria shared between environmental and human samples as a measure of bacterial dispersal and studied these associations with living environment and lifestyles. We analyzed amplicon sequence variants (ASVs) of the V4 region of 16S rDNA gene from 347 samples of doormat dust as well as samples of saliva, skin swabs, and feces from 53 elderly people in urban and rural areas in Finland at three timepoints. We first enumerated the ASVs shared between doormat and one of the human sample types (i.e., saliva, skin swab, or feces) of each individual subject and calculated the shared ASVs as a proportion of all ASVs in the given sample type of that individual. We observed that the patterns for the proportions of shared ASVs differed among seasons and human sample type. In skin samples, there was a negative association between the proportion of shared ASVs and the coverage of built environment (a proxy for degree of urbanization), whereas in saliva data, this association was positive. We discuss these findings in the context of differing species pools in urban and rural environments. IMPORTANCE: Understanding how environmental microorganisms reach and interact with humans is a key question when aiming to increase human contacts with natural microbiota. Few methods are suitable for studying microbial dispersal at relatively large spatial scales. Thus, we tested an indirect method and studied patterns of bacterial taxa that are shared between humans and their living environment.

Spatio-temporal assessment of landscape ecological risk using spatial statistical analysis in a basin of Turkiye.

Monitoring the land use/land cover (LU/LC) changes that have occurred with rapid population growth and urbanization since the Industrial Revolution is important for the optimal configuration of landscape patterns and ensuring the sustainability of ecological functions. Spatiotemporal dynamic pattern of LU/LC change using high-resolution land use data is an indicator to evaluate the landscape ecological risk through landscape pattern index analysis. In this study, the landscape ecological risk index (LERi) based on LU/LC change was calculated using remote sensing images of Landsat TM (Thematic Mapper) and OLI (Operational Land Imager) Rdata of a Gediz Mainstream Sub-basin in Turkiye between 1992 and 2022, and the spatial distribution regularity of LERi values was determined with spatial statistical analysis. According to the results, it was determined that the LERi values of the study area changed by 45% in 30 years. The highest change is in the very high-risk class, with an increase of 10.96%, and the least change occurred in the very low-risk class, with a decrease of 1.29%. According to the obtained statistical analysis results, it was determined that the global spatial autocorrelation values analyzed at different grain levels showed positive autocorrelation for both years and that the LERi values tended to have strong spatial clustering. As a result, it is emphasized that strict control measures should be taken for areas showing High-High (HH) autocorrelation type located in the southeast and north-southwest line of the study area at the local level, and ecological restoration applications should be given priority in these areas.

Assessment of water quality and identification of priority areas for intervention in Guanabara Bay basin, Rio de Janeiro, Brazil, using nonparametric and multivariate statistical methods.

The Guanabara Bay hydrographic region (GBHR) has served as a central hub for human settlement and resource utilization throughout Brazil's history. However, the region's high population density and intense industrial activity have come at a cost, leading to a significant decline in water quality. This work aimed to identify homogeneous regions in GBHR according to water quality parameters in dry and rainy periods. The following water quality monitoring variables were monitored at 49 gauge stations: total phosphorus (TP), nitrate (NO3-), dissolved oxygen (DO), hydrogenionic potential (pH), turbidity (Turb), thermotolerant coliforms (TCol), total dissolved solids (TDS), biochemical oxygen demand (BOD), water temperature (Tw), and air temperature (Ta). The statistical analysis consisted of determining principal components, cluster analysis, seasonal differences, and Spearman's correlation. The water quality parameter correlations were not expressively influenced by seasonality, but there are differences in the concentrations of these parameters in the dry and rainy periods. In the dry period, urban pressure on water quality is mainly due to fecal coliforms. The resulting clusters delimited areas under urban, agricultural, and forestry influence. Clusters located in areas with high demographic density showed high concentrations of TCol and TP, while clusters influenced by forestry and agriculture had better water quality. In the rainy season, clusters with urban influence showed problems with TCol and TP, in addition to some characteristics in each group, such as high TDS, NO3-, and BOD. Forested areas showed high DO, and clusters under agricultural influence had higher concentrations of TCol, BOD, and NO3- concerning forested regions. The troubling state of sanitation in GBHR occurs in metropolitan regions due to lack of a formal sanitation system.