Introduction Located in central China, the Yellow River Basin (Henan section) is a vital grain-producing region with extensive farmland. Its strategic central location also means its economic development is crucial for the stable growth of both Henan Province and the national economy. Nevertheless, persistent drought has long presented significant challenges to the region’s agriculture, ecology, and economic development. Methods Based on TVDI (Temperature Vegetation Dryness Index) data from 2003 to 2022, this study investigated historical drought dynamics through Theil–Sen Median and Mann–Kendall trend analyses. Future drought tendencies were assessed using R/S analysis. Spatiotemporal influencing factors were further examined using Geographic Detector. Results Research results indicated that most areas of the region were experiencing drought conditions. From 2003 to 2022, drought intensified in the northeastern counties of Yuanyang, Fengqiu, Changyuan, Puyang, Fanxian, and Taiqian within the Yellow River Basin (Henan section), while drought conditions eased in the southwestern counties of Lingbao, Lushi, Luoning, Shanzhou District, and Jiyuan. Future trends in drought variation indicated that the southwestern part of the region showed potential for improvement in drought conditions, while drought conditions in the western areas were likely to worsen. The primary factors influencing the spatiotemporal variation of drought in this region were evapotranspiration, temperature, and rainfall. Discussion This study aimed to provide an in-depth analysis of the drought situation in the Yellow River Basin (Henan section), offering a reference to assist stakeholders in implementing timely drought mitigation measures, thereby reducing the impact of drought on agricultural production and the ecological environment.

Demographic expansion together with fast-paced urbanization within hilly terrain of ecologically fragile areas such as Darjeeling in West Bengal complicated the process of managing municipal solid waste (MSW). A study develops a comprehensive geospatial method which combines remote sensing (RS) and geographic information systems (GIS) with multi-criteria decision analysis (MCDA) to locate sustainable zones for municipal solid waste disposal. The study examines the Darjeeling Municipality area alongside its 2-km surrounding zone which demonstrates steep topography and density as well as ecological risks. A spatial decision support system (SDSS) is developed using a multi-criteria RS-GIS framework to determine the suitable areas for municipal solid waste disposal site suitability (MSWDSS). The framework standardizes geospatial and urban planning criteria through quantitative evaluation of slope, elevation, land use/land cover, and areas around roads, water bodies, and settlements which are weighted using analytic hierarchy process (AHP). The weighted linear combination (WLC) technique is used to compute a composite suitability index, ensuring proportional influence from each criterion after normalization. For proximity-sensitive factors, a Gaussian decay function is applied to model nonlinear reductions in suitability near sensitive infrastructure. The parameters were weighted using AHP based on their influence on landfill site suitability, with land value (0.184), distance to settlement (0.135), and distance to road (0.123) receiving the highest weights. These reflect the prioritization of economic feasibility, public health, and operational efficiency. Spatial data layers were generated, reclassified, and overlaid in a GIS environment to produce a composite suitability map. The final map classified land into three suitability zones: high, moderate, and low, highlighting that high suitability zones are located in the southern and southwestern parts of Darjeeling Municipality, characterized by low population density, low land value, greater distance from sensitive sites, gentle slopes, and poor access to existing waste services. The composite MSWDSS index is classified using natural breaks (Jenks) into three suitability categories: high (≥ 0.66), moderate (0.33-0.65), and low (≤ 0.32), to support informed site selection under constrained urban conditions. Findings reveal that only a limited portion of the study area meets the environmental and infrastructural criteria for landfill development, owing to Darjeeling's challenging topography and dense urban fabric. Nevertheless, the model successfully identifies zones with optimal accessibility, minimal ecological disruption, and reduced risks of leachate contamination and landslides. The findings show that the analysis produced the best results when applied to the study area, optimizing the balance between environmental, infrastructural, and economic factors.

Anchote [Coccinia abyssinica (Lam.) Cogn.] is a neglected and underutilized root crop indigenous to Ethiopia. Despite its high-yielding potential, a lack of awareness of the nutritional importance, production practices, improved varieties, poor knowledge of methods of food preparation and consumption, product development, as well as its restricted production location, has limited the contribution of anchote to food and nutritional security. This article summarizes research output available on distribution, biology, genetic diversity, and agronomic practices, as well as its nutritional, cultural, and medicinal value, and brings anchote to the attention of researchers, growers, and policymakers. This review consolidates a wide range of both published and unpublished articles covering different domains of anchote research, observations, and experiences to illustrate how the crop is studied to date and highlights the gaps using a review of published literature and observational insights. The key articles published on anchote aspects were collected from the Google Scholar search engine. The article starts by introducing the importance, biology, propagation methods, and diversity of the anchote crop. It also highlights the nutritional and medicinal values of anchote. Moreover, it addresses how to cultivate, prepare, and consume anchote roots. As major anchote production is limited to the southwestern part of the country, this study provides information to other researchers and policymakers to promote the introduction and adaptation of the crop into new production areas and new cultural societies.

The recent proliferation of sizeable buildings in the rural areas of Southwest of Nigeria where economic yardstick may not be the primary aim for such developments has continued to catch the attention of researchers. Specialized developments are so categorized because they are special by nature, size, design, land coverage, opulence and they are hardly sold in the open market. The properties are custom - built, and their types are rare: they should not have been found in the locations where they are sited in the first instance. Being so distinguished makes their appraisal to come with problems because the market data upon which to base their comparison with others are scarce and insufficient. This has made Valuers opt for advance methods such as Hedonic, Contingent and Artificial Intelligence Property Valuation Methods in their appraisals. This study centered at investigating the sources of financing such developments in the rural areas of the Southwestern part of Nigeria with the objective to determine if there are differences in the sources employed by property owners across the States in the region. Southwestern States are made up of six States sharing the same Yoruba language and of the same culture. Due to the spread of the region, Ondo, Osun and Ekiti States were sampled in the research. It was found out that owners of specialized developments in the region sourced their funding mainly from Commercial Banks, followed by Merchant Banks, Mortgage Institutions, and Insurance Companies in order of importance. The research also revealed that every development still has an element of personal contribution inform of equity contribution and that this runs throughout the lifetime of the development. A major problem that stares the owners in the face is the loan duration. Long term loans were found to account for 50% of the burrowed money, 33.3% are intermediate loans while 16.7% are short time; this however indicates that there is ample time at the disposal of owners to pay back burrowed funds.

This study examines the deictic functions of demonstratives in Koorete, an Omotic language classified under the East Ometo sub-group and spoken in the southwestern part of Ethiopia. The paper provides a thorough description and analysis of the various functions of demonstratives in the language, with a focus on their role as spatial deixis. In this regard, demonstrative determiners and demonstrative pronouns that carry strong locational meaning are analyzed with illustrative examples. The findings show that the language has six demonstrative adjectives and their corresponding pronouns. Their usage is determined by parameters such as distance from the deictic center, reference point, visibility, and vertical axis. In addition to their usage patterns, the morphological structure of deictic expressions is examined in detail. Moreover, the study explores the ongoing grammaticalization process by which demonstratives develop into markers of definiteness, tracing a path of change from the lexical to the grammatical and from the concrete to the abstract. Finally, the chapter also addresses two additional elements in some detail: deictic expressions of location and direction, as well as demonstrative presentatives.

Intracratonic deformation in the southwestern part of the Laurentian block of Laurussia produced N-NW−trending, Precambrian-cored basement uplifts known as the Ancestral Rocky Mountains that were structurally offset from adjacent basins. A central debate concerns whether the Ancestral Rocky Mountains evolved as a coherent, synchronous orogen or through diachronous wrenching with various structural styles. Despite preserving well-dated Pennsylvanian−early Permian strata, the structural style of the Orogrande basin in southern New Mexico (USA) remains poorly documented. This study presents new detailed geologic mapping of structures and subsidence analysis from three stratigraphic sections along the basin’s eastern margin near the Pedernal uplift to reconstruct basin history. Subsidence results reveal a stairstep, convex-up pattern typical of fixed-load flexural basins. Subsidence was broadly synchronous, characterized by an initial pulse from late Morrowan to early Desmoinesian time followed by peak subsidence in the Late Pennsylvanian. In the Virgilian−early Wolfcampian, shelf strata were faulted, folded, uplifted, and eroded. Faulting in the northern part of the basin is best characterized as high-angle reverse faults. North-trending, west-vergent, asymmetric folding is consistent with folding atop a blind thrust. Cross-section restoration indicates shortening accommodated by these folds of ∼70−300 m, consistent with high-angle, basement-involved reverse faults observed elsewhere across the Ancestral Rocky Mountains. The Pennsylvanian subsidence and structural history of the Orogrande basin and adjacent Pedernal uplift mimics the rest of the Ancestral Rocky Mountains, suggesting a coherent, synchronous orogen. By mid-Wolfcampian time, Ancestral Rocky Mountains−related deformation had ceased, and the basin and former uplift subsided together in response to regional epeirogenic processes. This epeirogenic subsidence is observed along the southern realm of the orogen and may represent the geodynamic response to initiation of subduction along the southwestern margin of Laurentia, continued convergence from the amalgamation of Gondwana to Laurussia as deformation continued from the Marathon belt to the Sonora belt, or a combination of both.

This article examines research related to the use of fetishistic beliefs in the shamanism of the Kyrgyz people in the southwestern part of the Fergana Valley. Such beliefs have not been extensively and deeply studied within Kyrgyz ethnography, despite being an important issue. To study fetishistic beliefs and the sacrality of various fetish objects used in shamanic practices based on elements of fetishism. Currently, fetishistic ideas in shamanism continue to exist in syncretism with Islam and are widely applied by the population in Kyrgyz traditional culture. It has been found that reverence for fetish objects and respect for them constitute one of the most important rituals. The study primarily utilized theoretical and empirical research methods to investigate fetishistic beliefs in shamanism. Items used by the shamans (bakshi) - such as whips, prayer beads, and knives - are regarded as sacred and possessing special power. In their practices, they also use water, fire, salt, knots, graveyard soil, needles, holy sites for worship, as well as both “white” and “black” magic. Through analyzing the application of fetishistic beliefs in Kyrgyz shamanism in the southwestern Fergana Valley, the study revealed features of their ethnoculture.

ABSTRACT Water is essential for life and socio-economic development, yet increasing population pressure and climate change are intensifying freshwater demand. This study delineates groundwater potential zones (GWPZ) in the Baja sub-watershed by integrating geospatial techniques with gravity data to assess surface and subsurface controls on groundwater occurrence. Nine thematic layers: geology, slope, land use/land cover, geomorphology, elevation, soil texture, rainfall, lineament density, and drainage density were evaluated using Multi-Criteria Decision Analysis (MCDA) and the Analytical Hierarchy Process (AHP). The resulting GWPZ map classifies the area into high (12.35 km², 2.93%), moderate (316.80 km², 75.11%), low (92.58 km², 21.95%), and very low (0.06 km², 0.01%) potential zones. High-potential zones are concentrated in the southwestern, southern, and northern parts of the watershed, whereas rugged volcanic terrains in the east and northwest exhibit low potential. Gravity data reveal N–S-oriented subsurface structures acting as groundwater barriers, while NNE–SSW lineaments derived from satellite imagery indicate shallow aquifer systems associated with springs. Validation using 46 well data produced an AUC value of 0.74, confirming good predictive accuracy. This integrated approach supports sustainable groundwater management in climate-affected, water-scarce regions.

Many mustelids share a history of population decline in North America following European settlement, followed by a period of restoration and recovery. Relative to their historical distributions, mustelids are now perceived to be common and widespread. However, the local conservation status of many mustelids challenges this perception. Fishers ( Pekania pennanti ) in Connecticut were considered abundant prior to the initiation of an annual trapping season in 2005, but indices of relative abundance have decreased over the last 18 years, particularly in western Connecticut. We collected detection data from camera surveys conducted in winter (December–April) in 5 km 2 units (n = 59 units, 354 cameras) throughout Connecticut between 2018 and 2023 to verify management concerns and contribute to an updated conservation assessment of fisher in the state. We applied an occupancy modeling framework to the detection data, emphasizing regional comparisons in occupancy, detection rate, and model-based density. We detected fishers across Connecticut except in the southwestern part of the state, but the area occupied was small (176 km 2 ). The model-based density estimate (λ) was much lower in Connecticut compared to an abundant fisher population in southern Vermont, and lower in western Connecticut compared to the east. Region was the best-supported covariate on occupancy in our single-season model, and parameter estimates (ψ, p) from top models were greater in eastern Connecticut compared to the west. Fishers did not show spatial segregation from other carnivores in the study but did exhibit temporal separation in daily activity patterns from other carnivores. Our results support management concerns regarding the conservation status of fisher in Connecticut, particularly in the western part of the state. The relative abundance of fisher appears low based on all metrics, and a short-term closure or reduction in the length of the trapping season in western Connecticut could benefit fisher recovery. Harvest data and other sighting metrics may be insufficient to fully assess the conservation status of mustelids such as fisher. Therefore, we recommend implementing a long-term monitoring program to provide current distribution data for fisher. Future studies should focus on understanding the impacts of anticoagulant rodenticides and canine distemper on the current decline of fisher in Connecticut.

Songaksan, a volcano in the southwestern part of Jeju Island, has been a place of contention since Japanese colonial rule, through the US occupation (1945–48), the Korean War, and the postwar era. With its military airfield, forced mobilization of labor, war preparation, civilian massacre, militarized dispossession, and speculative property development, the violence imposed on the place has continued and has been reinforced throughout each of these historical eras. Land has been central from multiple perspectives throughout Songaksan's history. First, the land becomes a key site at which colonialism, militarism, developmentalism, and predatory capitalism operate altogether. Second, the land is a repository of the scars of colonial domination, coercive labor, civilian massacre, militarized dispossession, and speculative extraction. Third, since the land is a reminder of the painful memories and ongoing violence, it has potentials for decolonial reconciliation and community resilience. By acknowledging multiple temporalities of the land and listening to stories the land tells, Songaksan's land-based movement opens up room for self-determination and alternative possibilities. The powerful documentation of Songaksan's densely layered histories and local struggles guides readers to think about broader questions of colonialism, militarism, developmentalism, and predatory capitalism in Jeju and East Asia.

Abstract This study conducts numerical simulations using the Weather Research and Forecasting (WRF) Model to evaluate the impact of urbanization on precipitation in the Osaka metropolitan area, a megacity adjacent to the sea and mountains. The simulations were conducted for 320 events on which convective precipitation was likely to occur. The results of the control (CTRL) experiment, which uses real land-use data, are compared with those of the nonurban (NOURB) experiment, in which the urban grids of the Osaka metropolitan area and surrounding regions are replaced with broadleaf forest, to assess the influence of urbanization on precipitation. The model successfully reproduces the general spatial distribution of convective precipitation in the Osaka metropolitan area, with a correlation coefficient of 0.83. Urbanization leads to a 14.6% increase in precipitation in urban areas and a decrease in precipitation over the surrounding mountainous regions. Notably, the slight increase in precipitation east of central Osaka and the decrease in the northern and southwestern parts of Osaka are statistically significant at the 1% level. The increase in precipitation in the Osaka metropolitan area results from two key processes induced by the rise in surface sensible heat flux due to urbanization. The first is an increase in the mixed-layer height. The second is the enhanced horizontal convergence of water vapor flux in urban areas, resulting from changes in the sea breeze due to a decrease in surface pressure over Osaka.

Complementary foods are crucial for infants´ nutritional development and they play a vital role in bridging nutritional gaps during weaning after exclusive breastfeeding for six months. Numerous infants in developing countries particularly Nigeria, suffer from protein-energy malnutrition due to inadequate access to essential nutrients, including protein, fibre, iron, amino acids and calcium. This study was aimed at evaluating the proximate and functional properties of complementary foods made from malted sorghum, maize, and soybean blends. Materials for this study were obtained from Wazo Market in Ogbomosho, Oyo State, Southwestern part of Nigeria. Two kilograms each of sorghum, maize and soybeans were cleaned washed and soaked in water for 12 hours separately. The hydrated grains were then spread on a moist jute bag and allowed to germinate for four days, dried at 60°C in a cabinet dryer to achieve a moisture content of 10-12%. The dried, rootless grains were milled into flour, sieved, and packaged in an airtight container. The flours were subjected to proximate and some functional analyses. All analyses were done in triplicates, and the acquired data was subjected to analysis of variance using Statistical Package, SPSS version 20.0 (SPSS Inc.). The results revealed significant variations in water absorption capacity which ranged from 25.20% to 28.60% this improves the textural ability of the complimentary food samples. The value of foaming capacity ranged from 1.95 to 2.95%. Foaming capacity gives indication of increase in volume upon introduction of air or gas into slurry of a given food, this shows that the samples will give a fluffy texture. The bulk density of the samples ranged from 0.54 to 0.59g/cm3. Low bulk density enhances flowability and ease of food packaging. Dispersibility of the flours ranged from 85.25 to 90.95%. Dispersibility ensures uniform mixing and blending which enhances product stability, shelf life and texture consistency. The moisture content of the flours ranged from 6.66% to 13.52%. Lower moisture content, is a desirable quality because it indicates a better shelf life due to reduced water activity. Protein content ranged from 22.4% to 24.7%, highlighting the importance of soybean as a protein source. Carbohydrate content was highest in Sample A (60.7%) and lowest in Sample B (54.9%). There were significant differences (p ) in carbohydrate content of all the samples. Sensory evaluation showed that Sample A (60% sorghum, 20% maize, 20% soybean) was most preferred in terms of appearance (7.84), taste (7.28), aroma (7.48), and mouth feel (7.56) indicating its overall acceptability. A nutrient-rich complementary food has been developed by blending locally sourced food materials to enhance nutritional value with sensory satisfaction and potentially reducing the prevalence of protein-energy malnutrition.

The brown bear (Ursus arctos) occurs across several regions of Türkiye and occasionally damages beehives near rural settlements. This study examines temporal data and the spatial arrangement of beehive damage incidents recorded in the Ilgaz district of Çankırı, Türkiye during 2023–2024. The temporal data were evaluated across lunar phases. A chi-square test showed that incidents did not distribute evenly. A higher frequency was found during the Waxing Crescent phase. Spatial intensity was mapped using Kernel Density Estimation (KDE), where bandwidth selection followed a cross-validation procedure. KDE results showed clear concentrations of incidents in the southern and southwestern parts of the district, while other areas recorded few or none. A Decision Tree (DT) classifier based on eleven environmental variables was used to identify predictors of incident presence. The DT achieved an AUC of 0.808. It identified “distance to settlement” as the primary separating variable, followed by “distance to road”, “distance to forest”, and the “Human Footprint Index”. Beehive damage followed a non-random temporal pattern across lunar phases. It clustered near settlements. Conflict timing followed both environmental conditions and human activity. The findings provide an empirical basis for reducing apiary losses and improving coexistence measures between local communities and brown bears in the Ilgaz region.

Polycyclic metamorphism recorded in garnet from Palaeozoic micaschists of the southwestern part of the Tisia Mega-Unit (Slavonian Mts., Croatia)

Abstract Background Earthquakes are the deadliest natural disasters affecting the human environment. Global seismic risk and vulnerability to earthquakes are increasing steadily as urbanization occupy more areas that a prone to effects of strong earthquakes. Purpose Successful preventive measures and planning of post-earthquake activities are based on scenarios of expected damage, destruction and casualties from predicted strong seismic impacts. Methods The study presents the comprehensive and advanced earthquake hazard assessment for the city of Blagoevgrad. The earthquake hazard for the city is estimated using both probabilistic and deterministic methods. The ground-shaking representations for the city of Blagoevgrad are produced through a GIS, by combining: active faults capable of generating strong earthquakes; location and geometry of the scenario earthquake source with assigned magnitude; an appropriate GMPE’s, consistent with the seismotectonic features of the region; and account soil amplification effects using geological zonation of the considered urban area. Results The deterministic and probabilistic estimates of maximum acceleration vary across the city in the range of 0.26 g - 0.45 g for MW7.2 earthquake and from 0.23g to 30.40 g for the 475- year return period respectively. The highest acceleration and velocity values are in the central and south western parts of the Blagoevgrad city. Conclusion The results of the study show that most of the Blagoevgrad territory is classified at the highest seismic hazard level - PGA larger than 0.3 g and PGV more than 24 cm/s. The results from the study will assist decision-makers involved in local and state government to manage potential damage and loss of life from strong earthquakes occurred in and near the city of Blagoevgrad.

The South-western part of Maharashtra includes the Sangli, Satara, and Kolhapur districts. These three districts are agriculturally well-developed due to fertile land and substantial water resources such as the river Krishna and its tributaries. Several minor irrigation tanks, which was specially built for irrigation and drinking purposes. The Siddhewadi and Morna MI tanks are major water resources to the Tasgoan and Shirala tehsil community for drinking and irrigation, but these water bodies are under environmental stress due to anthropogenic activity, agricultural runoff and industrial waste. Therefore, to study the water quality status of Siddhewadi and Morna tanks during the year 2022 to 2023. The temperature ranged between 26 to 33 throughout the years. The pH remained alkaline throughout the year. Electrical conductivity ranged between 600 to 622 µS/cm in Siddhewadi, while 180 to 216 µS/cm in the Morna tank. The turbidity was 1 to 2 in Siddhewadi and 9 to 12 NTU in the Morna tank, and the total dissolved solids remained 300mg/lit in Siddhewadi tank, while the total dissolved solids remained below 100 mg/lit in Morna tank.

A bstract Context: Effective glycemic management is crucial for preventing long-term diabetes mellitus (DM)-related complications. Amid the rising global prevalence of diabetes, the impact of inadequate glycemic control is increasing significantly, especially in low-income countries. Aims: To assess the glycemic status in the southwestern part of Bangladesh. Materials and Methods: We enrolled 514 adults with type 2 DM through purposive sampling. Baseline clinical and laboratory parameters were collected after obtaining informed consent. Glycemic control was defined by HbA1c (<7% = good, ≥7% = poor). Data were analyzed in SPSS v25 using descriptive statistics, Chi-squared tests, Spearman correlation, and multivariable logistic regression, with no multicollinearity and good model fit (area under the curve = 0.88); results were deemed significant if P < 0.05. Glycemic control was poor in 84.8% (436/514) of participants. Participants with a diabetes duration of less than 5 years had significantly better glycemic control compared to those with a longer duration (55.1% vs. 36.0%, P = 0.006). Similarly, participants who took antidiabetic medication regularly demonstrated better glycemic control than those with irregular intake (67.9% vs. 46.5%, P = 0.001). In multivariable analysis, a longer duration of diabetes was associated with higher odds of inadequate control (odds ratio [OR] = 1.05, 95% confidence interval [CI]: 1.00–1.11, P = 0.03), while regular medication adherence provided significant protection, reducing the odds of poor glycemic control (OR = 0.40, 95% CI: 0.23–0.69, P = 0.001). Conclusion: The glycemic control among our study participants was notably poor. Therefore, immediate action is necessary to manage diabetes effectively and prevent potential DM-related sequelae.

Understanding how climate variability drives tropical vegetation is critical for sustainable land management and climate-change adaptation. This study aimed to characterize the spatiotemporal distribution and trends of vegetation using the Enhanced Vegetation Index (EVI), Land Surface Temperature (LST), CHIRPS rainfall, and MODIS-derived Evapotranspiration (ET) in Tanzania from 2000 to 2024 and quantify the relative influence of climatic drivers on observed vegetation dynamics. Datasets were accessed via Google Earth Engine and processed with Savitzky–Golay noise filtering and spatial harmonization to generate annual and seasonal time series. Long-term trends were assessed using Sen’s slope estimator and Mann–Kendall significance tests, while vegetation cover was quantified through Fractional Vegetation Cover (FVC). Results showed heterogeneous rainfall increase during DJFMA (December to April) and MAM (March to May), 9.6 mm/year and 5.2 mm/year respectively. EVI and FVC revealed mixed vegetation trajectories: central, southeastern, and western regions experienced degradation, whereas southwestern and northeastern highlands and parts of the northern coast showed greening. Correlation and lag analyses indicate LST exerts the strongest immediate suppressive effect (ρ = -0.78, p < 0.05), while rainfall and ET influence both instantaneous growth and multi-year recovery (rainfall: ρ = 0.64 at year 0, ρ = 0.54 at year 5; ET: ρ = 0.72 at year 0, ρ = 0.56 at year 5). These findings demonstrate that vegetation dynamics in Tanzania are governed by a dual climatic control system: the acute, immediate sensitivity of vegetation to surface thermal conditions and a protracted, multi-year recovery potential driven by antecedent rainfall. The study underscores the necessity of integrated management frameworks that combine immediate heat-mitigation strategies to counter LST-induced suppression with multi-year water-governance policies that leverage the five-year ecological memory of rainfall and ET. Such evidence-based interventions are critical for stabilizing vegetation trajectories and enhancing ecosystem resilience across Tanzania’s climate-vulnerable landscapes.

The Xiannüshan Fault Zone, located in the southwestern part of the Huangling Anticline within the Three Gorges Reservoir area of Hubei Province, is one of the largest and most complex faults in the region. The geological structures of its different segments vary significantly. Previous studies have primarily focused on the northern segment and often relied on single geophysical methods, which are insufficient for detailed characterization of the entire fault zone. Based on existing geological data, field reconnaissance results, and the geological characteristics of different segments of the fault zone, we employed multiple geophysical methods for a varied investigation: shallow seismic reflection in the northern segment; a combination of waterborne seismic exploration and microtremor survey in the middle segment; and high-density resistivity in the southern segment. The integrated approach revealed the spatial extent, fault geometry, and activity characteristics of each segment, confirming that the Xiannüshan Fault Zone is a pre-Quaternary structure dominated by thrusting. The findings provide a critical scientific basis for regional seismic hazard assessment and disaster mitigation planning, while also establishing a technical framework with significant practical application value for detailed fault characterization in geologically complex environments.

Abstract In-situ stress is a key parameter in applied rock mechanics and a governing factor in design of unlined pressure tunnels. In Norway and some other countries, Norwegian thumb rules are commonly applied for the design of unlined pressure tunnels, intended to ensure that internal water pressure remains below the minimum in-situ principal stress. In-situ stress can also be evaluated using geo-mechanical numerical models. However, constructing such models presents challenges, especially in defining representative boundary conditions that best-fit all measurement points. To address this, the authors present an automated two-step optimization approach for obtaining best-fit in-situ stress model. The method is first used in a synthetic model and then applied to Løkjelsvatn Hydropower Project, where in-situ stress measurements are available. Results show that best-fit in-situ stress model can be achieved by integrating two-step optimization approach. Analysis suggests that weakness zones traversing the tunnels hold potential of attenuating stress in the vicinity, requiring careful consideration while orienting unlined pressure tunnel. In current geological setting, stiffness contrast between host rock and weakness zones is about two, but a higher contrast could significantly increase risk of leakages due to hydraulic fracturing. The study recommends using thumb rules mainly for early planning purposes. The manuscript also emphasizes the need for a systematic study of the stress state around weakness zones, so that geological heterogeneity could be technically represented in the geo-mechanical numerical models. The devised method can potentially be applied in locations where hydropower projects are envisaged.