Land Use Variables Research Articles

Assessment of Soil Erosion within the Gayathripuzha River Basin Using RUSLE Model and GIS Tools

Soil erosion, a natural phenomenon accelerated by human activities, became a major problem for agricultural land use and for water quality concerns. Soil erosion by water is influenced by various factors like climate, nature of land surface, slope steepness, soil properties, land cover, and management practices. Estimation of soil erosion is essential to know the nature and quantity of soil loss and create specific strategies for soil conservation. This research paper thoroughly examines the susceptibility of soil erosion in the Gayathripuzha river basin in Kerala, India, which is encompassing a wide area of around 961 km². Employing the Revised Universal Soil Loss Equation (RUSLE), this investigation assesses the influential factors affecting soil erosion, which comprise rainfall (R Factor), soil erodibility (K Factor), topography (LS Factor), land usage (C Factor), and the impact of conservation measures (P Factor). The study was conducted using Geographic Information System (GIS) tools like ArcGIS 10.8 Desktop and integrating data on rainfall, soil properties, land topographic features, and land use. Rainfall erosivity is a major factor causing erosion in Gayathripuzha river basin and it ranges from 746.03 to 1222.35 MJ mm ha−1 h−1 y−1 in the river basin. Soil erodibility factor also varies widely within the region. Slope length and steepness factor showed that highland ecosystems are present only in a small area of the river basin. Variation in land use and land cover also influenced the soil erosion within the area. The estimated average annual soil erosion ranges from 0 to 133.18 t ha-1 yr-1 within the research site. The research found that soil erosion varied greatly across the study area. Regions with slopes over 50% had much higher erosion rates, while most of the study area had low erosion levels. Notably, the intensity of soil erosion demonstrated a positive correlation with slope percentage, with areas classified as bare ground demonstrating the highest erosion rates. These findings emphasize the necessity for targeted and comprehensive conservation strategies tailored to the diverse landscape of the region to effectively manage soil erosion and mitigate its adverse impacts.

Climate and land use changes impacts on streamflow in the Brazilian Cerrado basin

This study evaluated the effects of climate change and land use (LULC) on the discharge regime of a watershed located in the Brazilian Cerrado. The SWAT model was calibrated and validated in three different periods: period 1 (LULC of 1990 with meteorological data from 1980 to 1995), period 2 (LULC of 2000 with meteorological data from 1996 to 2005), and period 3 (LULC of 2015 with meteorological data from 2006 to 2015). The statistical coefficients of performance NSE, PBIAS and R² and the flow duration curves for each period of analysis showed that the model is suitable for use in simulations on a monthly scale in the hydrographic basin of the Correntina River. The results show that variations in land use and land cover affect surface flow more intensely than changes in climate, and that the reduction in discharge over the 36 years of the study is due to changes in land use and land cover, in particular the use of water for agriculture. The results of this study show that it is necessary to consider the implications of climate change and land use for decision making, providing information to guide the future management of water resources in a region of intense agricultural activity and with conflicts over water use.

Exploring the relationship between land use change patterns and variation in environmental factors within urban agglomeration

Sustainable Development Goal (SDG) 11 aims to promote a more livable urban environment for humanity. However, the rapid global urbanization process has exerted significant pressure on urban environment, posing challenges for many cities to achieve this target. The urbanization process within urban agglomeration is accompanied by rapid and diverse land use change. Exploring the relationship between land use change and environmental factors is crucial for achieving sustainable urban development. To address this issue, this study investigates the interactive relationship between pixel-scale land use change and environmental indicators (CO2, Land Surface Temperature, and PM2.5) in China's three major urban agglomerations from 2000 to 2020. This study aims to analyze major land use change patterns, explore intrinsic connections among environmental indicators, and assess the impact of land use change on these indicators. The findings show that cropland, forestland, and built-up land are the major types of land change in all three urban agglomerations. Regions characterized by high population density, heavy industry, and intense transportation exhibit more pollutant emissions. Rapid urban construction has resulted in different types of environmental degradation issues. This study provides a comprehensive examination of the relationship between urbanization and environmental issues.

Spatial and temporal differentiation and coupling analysis of land use change and ecosystem service value in Jiangsu Province

A detailed exploration of the nexus between land use change (LUC) and ecosystem service value (ESV) at the urban level is crucial for fostering high-quality urban economic growth alongside the sustainable management of land resources. This study focuses on Jiangsu Province, employing an enhanced and refined ESV assessment model to perform a dynamic examination of the spatial and temporal variations in land use and ESV across the region from 2000 to 2020. Additionally, it delves into the intricate coupled coordination dynamics between land use intensity and ESV by developing a coupled coordination model. Key findings include: (1) Jiangsu Province experienced notable land use transformations over the two decades, with a marked reduction in cropland and a significant expansion of construction sites being the most prominent shifts. (2) The ESV in Jiangsu Province has exhibited fluctuating trends over the past 20 years, with water bodies and agricultural lands serving as the cornerstone for the province's ESV. Areas with high ESV are predominantly located around the Yangtze River's water bodies, along the coastline, and around lakes and radiate outward from these aquatic centers. (3) The coupling between LUC and ESV in Jiangsu Province has been upward, albeit with pronounced city disparities. This coupling displays distinct spatial patterns, characterized by higher levels in the east and lower levels in the west, as well as higher levels in the north and lower levels in the south. The outcomes of this analysis offer valuable insights and policy recommendations for enhancing land use planning, refining land use configurations, and promoting the synergistic development of land use and ecosystem service functions in Jiangsu Province.

Are Transit-Oriented Development and Travel Characteristics Influencing Residential Dissonance? Analysis From a Developing Country’s Perspective

The success of transit-oriented development (TOD) could hinge on reduced residential dissonance among the people living in TOD neighborhoods. Understanding the factors that could be associated with residential dissonance would be crucial in different contexts. Therefore, this study focused on exploring the various factors, such as TOD indicators, travel, and socio-demographic characteristics, that could influence the level of dissatisfaction of people living in TODs in Hyderabad, India. An ordered logit model was developed, which used data collected from primary as well as secondary sources. Results showed negative impacts of gender (male) and income on levels of dissatisfaction about neighborhoods, prompting policy interventions to address the disparities in gender and income groups. Further, it outlined the need to fulfill the varying requirements of larger households to reduce the dissonance. The roles of density, horizontal land-use diversity, and proximity to transit are very significant in improving living-satisfaction levels among people in TODs. More findings suggested the need for well-designed and maintained public spaces to address concerns related to safety and security and improve levels of satisfaction with TOD neighborhoods. The study also suggested that travel distances for educational trips, trip frequencies for work and shopping, and the use of private vehicles for work trips have positive influences on residential dissonance. It would be important to look for ways to provide convenient and sustainable alternative modes along with compact and diverse development, even though a longer commute may be acceptable.

Exploring trade-offs between residential and industrial functions in rural areas and their ecological impacts across transitioning agricultural systems: Evidence from the metropolitan suburbs of China

The rapid transition of agricultural systems substantially affects residential and industrial land use systems in rural areas, often generating spatiotemporal trade-offs between residential and industrial functions and producing considerable ecological impacts, which has thus far not been well understood. We conduct an indicator-based assessment of transitioning agriculture systems, and then links the transitioning agricultural systems to trade-offs between residential and industrial functions from 2005 to 2020 by using a case study—the metropolitan suburbs of Beijing, China. Also, the associated ecological impacts of the trade-offs are characterized based on the calculation of the ecological quality index (EQI) and ecological contribution rate. The results show that trade-offs between residential and industrial functions in the metropolitan suburbs have gradually adapted to the different agricultural systems in transition, which can be characterized by increasing industrial function as well as declining residential function, together with the diversification of land use into a mixed pattern. Additionally, along with the transitioning process comes a U shape of the ecological quality curve, which indicates that relentless industrial sprawl into regions where the agricultural system has a low capacity for technology, as well as decay in rural areas attributed to a rural exodus and industrial decline in semi-subsistence agricultural areas, even cause ecological degradation. In general, trade-offs between residential and industrial functions (especially for the non-agricultural production function) in rural areas could partially and temporally generate unfavorable ecological impacts, but it seems to be a favorable phenomenon to promote ecological quality in the long term. Therefore, to achieve rural sustainable planning, it is necessary for land use management to observe the trade-offs between residential and industrial functions while avoiding negative impacts, such as low-density land use patterns, disordered land use functions, and eco-environmental deterioration. Such effective strategies can contribute to the feasible implementation of policies aiming to achieve the compatible development of liveable residences, highly efficient industrial production, and eco-friendly operations in rural areas.

Electrical Conductivity, Basic Cations and Organic Matter content of Soils under different Land use Practices in AkwaIbom State

Variation in electrical conductivity, basic cations and organic matter content of soils can be influenced by land use practices, and these parameters may be affected by another. The study was conducted to ascertain the electrical conductivity (EC), basic cations and organic matter content of soils under varying land use types and to assess the relationship between electrical conductivity and the other parameters. The land use types were intensively cultivated farmland (ICF), natural forest (NF), oil palm plantation (OPP) and gmelina plantation (GP). Stratified random sampling technic was used in the collection of soil samples from the land use types. Three (3) replicates of bulk soil were collected for each land use giving a total of twelve (12) observational units. Soil samples were prepared and analyzed in a laboratory and data generated were subjected to analysis of variance, regression analysis and descriptive statistics. There was significant (P≤0.05) variation in the measured parameter among soils of the land use types. Soils under ICF, OPP, and GP had similar electrical conductivity of 0.08 (dS/m), while NF had 0.10 (dS/m). Organic matter (OM) content of 13.3 g/kg, 19.0 g/kg, 15.3 g/kg and 18.7 g/kg were observed under ICF, NF, OPP and GP, respectively. Exchangeable calcium at ICL was 2.33 cmol/kg; at NF it was 2.50 cmol/kg; at OPP, it was 2.40cmol/kg, and 1.93cmol/kg at GP. Exchangeable magnesium (Mg) was highest (1.07 cmol/kg) at ICL but lowest (0.93cmol/kg) at GP. Similarly, ICF had highest (1.73cmol/kg) and NF had lowest (0.04 cmol/kg) for exchangeable sodium. Calcium and magnesium had significant (P≤0.05) positive relationships with electrical conductivity, while organic matter and sodium had negative but non-significant relationship with electrical conductivity. The soils do not have salt problem and may not be prone to salinity in the future, meanwhile, organic matter input should be increased at the soil under intensively cultivated farmland.

Quantifying spatiotemporal variations in tidal flats and coastal land use in Jiangsu Radial Sandbars through remote sensing

The Jiangsu Radial Sandbars in China have experienced significant changes due to extensive human activities in past decades. This study provides new insights by coupling multitemporal remote sensing analysis with landscape pattern assessment to comprehensively evaluate tidal flat evolution and land use suitability from 1984 to 2020. The integrated remote sensing approach enabled continuous high-resolution mapping of tidal flats, revealing a 25.9% area loss equaling 123.2 km2, driven mostly by land reclamation, while also quantifying coastline accretion patterns through shoreline position analysis. The coastal landscape analysis systematically assessed land use changes and human impacts through metrics such as diversity and fragmentation, which revealed intensified seaward expansion and increased fragmentation of unused land and underdeveloped nearshore sea areas. The suitability evaluation considered land resources, ecological factors and socioeconomics to assess four key land use types. The method of coupling with landscape analysis provided integrated insights, including 1) identifying ecologically sensitive zones for prioritized conservation based on landscape patterns; 2) quantifying the intensity and spatial pattern of human activities and their impacts; and 3) comprehensively evaluating land use suitability by integrating landscape analysis with other factors. Future research should explore management strategies, assess the impact of climate change, and make predictions to inform policy-making.

The Urban Environment and Cardiometabolic Health.

Urban environments contribute substantially to the rising burden of cardiometabolic diseases worldwide. Cities are complex adaptive systems that continually exchange resources, shaping exposures relevant to human health such as air pollution, noise, and chemical exposures. In addition, urban infrastructure and provisioning systems influence multiple domains of health risk, including behaviors, psychological stress, pollution, and nutrition through various pathways (eg, physical inactivity, air pollution, noise, heat stress, food systems, the availability of green space, and contaminant exposures). Beyond cardiometabolic health, city design may also affect climate change through energy and material consumption that share many of the same drivers with cardiometabolic diseases. Integrated spatial planning focusing on developing sustainable compact cities could simultaneously create heart-healthy and environmentally healthy city designs. This article reviews current evidence on the associations between the urban exposome (totality of exposures a person experiences, including environmental, occupational, lifestyle, social, and psychological factors) and cardiometabolic diseases within a systems science framework, and examines urban planning principles (eg, connectivity, density, diversity of land use, destination accessibility, and distance to transit). We highlight critical knowledge gaps regarding built-environment feature thresholds for optimizing cardiometabolic health outcomes. Last, we discuss emerging models and metrics to align urban development with the dual goals of mitigating cardiometabolic diseases while reducing climate change through cross-sector collaboration, governance, and community engagement. This review demonstrates that cities represent crucial settings for implementing policies and interventions to simultaneously tackle the global epidemics of cardiovascular disease and climate change.

A Very High-Resolution Urban Green Space from the Fusion of Microsatellite, SAR, and MSI Images

Jakarta holds the distinction of being the largest capital city among ASEAN countries and ranks as the second-largest metropolitan area in the world, following Tokyo. Despite numerous studies examining the diverse urban land use and land cover patterns within the city, the recent state of urban green spaces has not been adequately assessed and mapped precisely. Most previous studies have primarily focused on urban built-up areas and manmade structures. In this research, the first-ever detailed map of Jakarta’s urban green spaces as of 2023 was generated, with a resolution of three meters. This study employed a combination of supervised classification and evaluated two machine learning algorithms to achieve the highest accuracy possible. To achieve this, various satellite images were utilized, including VV and VH polarizations from Sentinel-1, multiple bands from Sentinel-2, and eight bands from Planet. The Planet data were subsequently transformed into the Red-Edge Triangulated Vegetation Index and Red-Edge Triangulated Wetness Index. The data training and testing samples for urban green spaces were obtained using the Street View images available on Google Maps. The results revealed that using the Random Forest classifier algorithm and only eight bands of Planet images achieved an accuracy rate of 84.9%, while a combination of multiple images achieved an impressive 95.9% accuracy rate. Jakarta’s urban areas cover approximately 33.2% of green spaces. This study provides unprecedented insights into the type, size, and spatial distribution of Jakarta’s urban green spaces, enabling urban residents and stakeholders to explore and promote healthier living and better manage these green areas. Additionally, a previously unexplored concept, Jakarta’s urban green belt, is introduced.

Design Strategies to Improve Metro Transit Station Walking Environments: Five Stations in Chongqing, China

While transit-oriented development (TOD) has been widely adopted in urban design alongside the expansion of urban metro transit, the creation of pedestrian-friendly environments has often been overlooked during implementation. This has resulted in a lower walking advantage around metro transit stations. To address this issue and encourage walking and public transport use in metro transit station areas, this study undertook a quantitative comparative analysis of the pedestrian environment in five Chongqing metro transit station areas. The analysis focused on three key dimensions: “comprehensive evaluation”, “basic scale”, and “structural quality”. The comprehensive evaluation considered factors such as the pedestrian catchment area ratio, POI kernel density distribution, and crowd agglomeration. The basic scale dimension comprised floor area ratio, building density, pedestrian road density, and the quantity of station entrances and exits. Finally, structural quality factors included land use type mixing degree, POI function mixing degree, intersection connectivity, median street length, pedestrian route directness, and green view index. Based on these analyses, this study proposes a series of pedestrian environment design strategies including land use and transportation. The strategies for land use advocate for “developing compact and diverse land use”, “strengthening attraction of station center”, “positioning large projects on the edge”, “restricting private transportation capabilities”. The strategies for transportation consist of “increasing pedestrian road density”, “traffic calming organization”, “subdivision of road types”, and “three-dimensional pedestrian traffic system”. These strategies aim to create a more humanized and environmentally friendly pedestrian environment, proactively rise to the challenge of climate change, thereby cultivating sustainable urban development.

Examining Soil Microplastics: Prevalence and Consequences Across Varied Land Use Contexts

In an extensive exploration of microplastics within soil environments, our study aims to investigate the presence, spread, and ecological impact of microplastics in soil, focusing on Makassar City, Indonesia. Using a Sinher binocular digital microscope, we visually examined soil samples in Petri dishes, measuring microplastic sizes with Image-J software. Fourier-transform infrared (FTIR) spectroscopy was also employed for additional identification and analysis of polymer compositions. Our research uncovered a widespread presence of microplastics across diverse soil types and land uses, including residential, fishpond, agricultural, landfill, coastal, and bareland areas. The concentration of these microplastics was found to be between 16.6 to 21.9 particles/gram, showing consistency across most land uses, with some variations in coastal areas. We noted a significant variety in microplastic forms, predominantly fragments and films, across the different land uses. A wide range of colors was observed, including blue, green, red, and transparent. Polyethylene (PE) and polypropylene (PP) were identified as the predominant polymers. Our study highlights the non-uniform distribution of microplastics in soil, suggesting potential significant impacts on soil organisms and the wider ecosystem. These findings underscore the critical need for more comprehensive research on the ecological implications of microplastics in soil environments. Doi: 10.28991/CEJ-2024-010-04-017 Full Text: PDF

SOC and TN fluctuations determine the variations in microbial enzymatic activities under diverse land use types in the Central Himalaya, India

Soil microbial enzymatic activities, often used as indicators of soil health and fertility, are vulnerable to changes in climate and anthropogenic activities. This study analyses the responses of specific soil enzymatic activities– dehydrogenase (DHA), acid phosphatase (APH), β-glucosidase (BG) and urease (URE)– in Nitosols/Luvisols of the subtropical zone of the Central Himalaya, India. We investigated how these enzymatic activities vary with different land uses: arable land (AL), kitchen garden (KG) and peach orchard (PO), across four villages– Niglat, Kainchidham, Majhera and Syalikhet. Considering associated management practices, we quantified cumulative average soil enzymatic activities for the rabi season (2017–2018). In general, catalytic activity of the selected enzymes was highest in Syalikhet and lowest in Majhera. However, for land use types, enzymatic activities were lower in AL and KG (75.56–90.17% and 39.41–61.72%, respectively) compared to PO values. MANOVA analysis evaluated significant spatial differences (P < 0.001) in enzymatic activities. Soil enzymatic mean values were highest in the surface layer (0–10 cm) and decreased gradually with increasing depth. Parameters such as soil moisture content (SMC) and pH, along with vegetation, management practices, and nutrients such as SOC, TN, K, AP, and N forms (NH4+–N and NO3––N) showed significant and strong correlations with all the soil enzyme activities (r = 0.40–0.97; P < 0.05). TN, SOC, K, SMC, pH, AP, NH4+- N, and clay content were key determining factors of soil enzymatic activities, explaining approximately 59% of the variation. These results suggest that using soil microbial enzymatic activities as soil quality indicators is a feasible approach to assess the impacts of vegetation, management practices, and soil profile depths in soils under different land use types/systems in selected impoverished villages of the fragile Central Himalaya, India.

Wintering raptor species distribution in a semiarid Mediterranean region: the relevance of lowlands and open habitats as stopover sites

As land-use cover types affect wintering birds’ strategies, studying their habitat suitability for species conservation is relevant. Predictive spatial models are considered excellent tools for conservation planning and improving our understanding of species distribution. Here we build models to predict the spatial distribution of raptor species that overwinter in SE Spain. We modelled the wintering raptor species distribution based on the presence-only data obtained between 2017 and 2019 and analysed their habitat preferences based on elevation and land-use cover variables. Our results show that altitude and distance to the coastline are the most important environmental factors to affect most species’ habitat suitability. Habitat type-related factors are other important predictors, and raptors subject of this study prefer lowlands and areas close to the coastline for overwintering by selecting open habitats, which include wetlands and irrigated and rainfed crops. This study highlights the importance of the habitat heterogeneity generated by wetlands and herbaceous crops within a low-altitude range as the optimal environment for wintering raptors. Such information should be considered for raptor conservation planning in human-altered landscapes.

Mycorrhizal Types Modulate Responses of Global Soil Microbial Biomass to Environments Across Varied Land Use Types

AbstractSoil microbial biomass (SMB) is a fundamental contributor to soil ecosystem services. Mycorrhizal fungi, a significant group of soil microbes, play essential roles in regulating carbon allocation and nutrient cycles. Acknowledging the profound importance of SMB and mycorrhizal symbiosis, our objective was to explore how mycorrhizal types modulate the global patterns of SMB across varied land use types (LUTs). Using data from 329 independent studies, we categorized vegetation species with defined mycorrhizal types into arbuscular mycorrhizal (AM) type (with 958 observations) or mixed AM and ectomycorrhizal (AM + ECM) type (with 481 observations). This categorization served as the foundation for our investigation into the impacts of various LUTs and environmental conditions (mean annual temperature, and mean annual precipitation, MAP) on global SMB patterns associated with specific mycorrhizal associations. The overall mean value of SMB was remarkably higher under AM + ECM type (92.23 ± 4.73 nmol/g) compared with that under AM type (49.45 ± 1.87 nmol/g) at a global scale. The primary factor contributing to this difference was the natural system. Additionally, the AM + ECM type (0.19 ± 0.01) exhibited a higher F:B ratio (Fungi‐to‐bacteria ratio) than the AM type (0.16 ± 0.001), attributed to the cumulative effects of different LUTs. Furthermore, SMB was markedly positively affected by aridity index under AM type and negatively influenced by temperature under AM + ECM type. Besides, MAP had a pronounced positive impact on SMB under AM type, while exhibiting a negative impact under AM + ECM type. Our study presented evidence affirming the essential role of mycorrhizal associations in shaping global patterns of SMB in response to environmental factors across varied LUTs.

Chemodiversity of Dissolved Soil Organic Matter from Amazon Rainforest as Influenced by Deforestation.

Many biogeochemical processes are modulated by dissolved organic matter (DOM), but the drivers influencing the chemodiversity of DOM compounds in Amazonian soils are poorly understood. It has also been theorized whether deforestation controls the decline of DOM. In this study, we collected soil samples from thirty sites across different regions of Brazil's Legal Amazon, and we investigated the trade-offs among soil physical-chemical properties and DOM chemodiversity. We employed optical spectroscopy, Fourier transform ion cyclotron resonance, and multivariate analysis. Our results indicated that, despite variations in land use and soil physical-chemical properties, factors such as the deforested site, geometric mean diameter, weighted average diameter, and soil organic carbon were the main influencers of DOM chemodiversity variation. These findings highlight the importance of considering DOM chemodiversity as closely related to land use and its potential use in developing deforestation models for predicting soil quality decline in Brazil's Legal Amazon.

Transport, dispersion, and degradation of nonpoint source contaminants during flood‐managed aquifer recharge

AbstractIn water‐stressed regions of the world, the inundation of working landscapes to replenish aquifers—known as flood‐managed aquifer recharge (flood‐MAR)—has become a valuable tool for sustainable groundwater management. Due to their diverse land use histories, however, many potential recharge sites host nonpoint source contaminants (such as salts, pesticides, and fertilizers) within the vadose zone that may flush to groundwater during recharge operations. To identify the controls on contaminant migration, we perform stochastic simulations of flood‐MAR through a heterogeneous alluvial aquifer and apply transient particle tracking to evaluate conservative and reactive contaminant transport over 80 years of recharge operations. With semi‐annual recharge events, the water table begins to rise 0.13–1.84 years after the first inundation event while solutes take much longer (11 to 80 years) to transit the 45‐m thick unsaturated zone. We derive a parametric expression for the ratio of celerity (or rate of pressure transmission) to velocity of the flood‐MAR wetting front and show that this simplified expression agrees with values calculated from heterogeneous model simulations. Slow solute velocities (0.25–1.75 m year−1) allow for significant contaminant removal through denitrification, but the contaminant plume experiences minimal dispersion or dilution over this time, reaching the water table as a sharp front. Our results suggest that minimizing groundwater velocity and maximizing groundwater celerity during flood‐MAR should optimize increases in water supply while limiting water quality degradation.

Organic Carbon Storage and Structural-Hydraulic Properties of Ultisol under Agricultural Land Use Systems at Umuahia

The extent and pattern of interaction among organic carbon, structural and hydraulic properties of soils under varying land use systems are of great concern in the overall management of soil fertility and productivity. This study was conducted to examine the relationship among soil organic carbon storage, structural and hydraulic properties of soils under different agricultural land use systems at Umuahia, Abia State. The treatments were the four (4) land use systems (continuously cultivated arable farmland, 3 – year fallow land, oil palm plantation, and forest land) in which nine (9) replicates each of disturbed and undisturbed soil samples were randomly collected to give thirty six observational units laid out in a randomized complete block design. The soil samples were prepared and analysed in the laboratory. Analyses of variance, regression and correlation analyses were conducted on the data collected using Genstat version 14 and SPSS version 20. Results show that organic carbon had significant positive relationship with saturated hydraulic conductivity, macro porosity and total porosity but significant negative relationship with bulk density at all the land use systems. However, the influence of organic carbon on the other parameters was greatest at continuously cultivated arable land followed by the 3 – year fallow land. There is need to increase organic matter input at the continuously cultivated arable land and 3 – year fallow land through increased organic manuring and extension of the fallow period, respectively.

Assessing Groundwater Resources Vulnerability with the New DRASTIC-LP: A Case Study in Chiang Mai Province, Thailand

Groundwater vulnerability has gained widespread attention, particularly in Chiang Mai Province, one of Thailand’s fastest-growing cities, which is experiencing rapid development in both economic and social sectors. The expansion of urban communities and the industrial, tourism, and agriculture sectors has resulted in the overutilization of available resources, notably water resources. This overuse, coupled with the adoption of modern technology to boost productivity and meet market demands, has led to an increased reliance on groundwater to supplement surface water sources, providing benefits across all sectors. However, the economic and social growth plays a pivotal role in shaping the diversity of land use, encompassing residential, commercial, industrial, and agricultural activities. These activities, in turn, directly contribute to environmental pollution, particularly in terms of the risk of groundwater contamination in Chiang Mai Province. This study aims to predict the future vulnerabilities of groundwater resources under an ensemble of climate change scenarios and changes in land-use patterns. Chiang Mai Province in northern Thailand is one of the fastest-growing cities and therefore is experiencing rapid urbanization, as well as land-use pattern changes, which was important for the case study. The new DRASTIC model, namely the DRASTIC-LP model, combined with GIS-based techniques and overlay techniques, was used to generate the map of groundwater resource vulnerabilities. A point pollution source (P)-related land-use pattern (L) that represents contamination impacts was considered an additional new DRASTIC parameter. The study’s findings reveal the high reliability and maximum effectiveness of the new DRASTIC-LP model in assessing groundwater vulnerability and contamination-risk areas under a climate change scenario (by MIROC-ESM-CHEM model under RCP.8.5 scenario) and land-use pattern changes (by CA_Markov Chian Model) for both the current year (2020) and the next 50-year period (2021–2070). Furthermore, the new DRASTIC-LP model is employed to trace the movement of pollutants from high- to very high-risk areas based on the groundwater vulnerability and contamination-risk maps. The results highlight that waste disposal dumping sites pose a more critical distribution and movement of pollutants when compared to industrial sites. Additionally, unconsolidated aquifers and cracked consolidated rock aquifers show a potentially higher occurrence of pollutant distribution and movement when compared to consolidated aquifers. Consequently, the study’s outcomes are applied to formulate guidelines for the management and control of groundwater resource contamination. These guidelines serve as valuable tools for decision makers, aiding in pollution prevention and the effective management of contamination risks in groundwater resources.

In vitro bioaccessibility round robin testing for arsenic and lead in standard reference materials and soil samples.

In this study, we assessed the suitability of using a standard reference material (SRM) other than National Institute of Standards and Technology (NIST) 2710a or NIST 2711a in USEPA Method 1340 to determine arsenic (As) and lead (Pb) in vitro bioaccessibility (IVBA) and the capabilities of Canadian-based laboratories to perform the method. Five laboratories participated in an initial round robin study and analyzed NIST 2710a, NIST 2711a, BGS119, and Enviromat SS-2. Intra- and inter-laboratory variability were generally acceptable with percentage relative standard deviations (RSD) of less than 20%. The mean total As and Pb concentrations obtained for BGS119 (332 and 936 mg/kg, respectively) and the mean IVBA values (As = 14.3% and Pb = 78.1%) suggested it may be a suitable and acceptable SRM, whereas the concentration of As in Enviromat SS-2 as received (3.2 mg/kg) was deemed too low. Ten soil samples from sites with varying land use were analyzed in a follow-up round robin study using the modified IVBA method that included BGS119 as SRM. The concentrations of As and Pb in the IVBA extracts reported by the participating laboratories were comparable. The mean As IVBA values for the field-collected samples ranged from 0.1% to 56.4%; for Pb, they ranged from 7.0% to 121%. The lowest IVBA values were measured in mine site samples; the highest values were associated with smelter-affected soils. The low IVBA values correlated with high iron content. Intra- and interlaboratory reproducibility were acceptable (RSD < 30%). Based on the findings of the study, laboratories can use the modified method to provide reproducible and comparable As and Pb IVBA data. The use of BGS119 as an alternative SRM to assess contaminated sites in the province of British Columbia for regulatory purposes is recommended, as it is representative of As and Pb concentrations in contaminated soils in British Columbia. Integr Environ Assess Manag 2024;20:1486-1495. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).