Search Results (151)

Coarse-grained soils serve as essential fill materials in earth–rock dam engineering, where their mechanical properties critically influence dam deformation and stability, directly impacting project safety. Artificial intelligence (AI) techniques are emerging as powerful tools for predicting the mechanical properties of coarse-grained soils. However, AI-based prediction models for these properties face persistent challenges, particularly in parameter tuning—a process requiring substantial computational resources, extensive time, and specialized expertise. To address these limitations, this study proposes a novel prediction model that integrates Adaptive Simulated Annealing (ASA) with an improved Particle Swarm Optimization (PSO) algorithm to optimize the Elman Neural Network (ENN). The methodology encompasses three key aspects: First, the standard PSO algorithm is enhanced by dynamically adjusting its inertial weight and learning factors. The ASA algorithm is then employed to optimize the Adaptive PSO (APSO), effectively mitigating premature convergence and local optima entrapment during training, thereby ensuring convergence to the global optimum. Second, the refined PSO algorithm optimizes the ENN, overcoming its inherent limitations of slow convergence and susceptibility to local minima. Finally, validation through real-world engineering case studies demonstrates that the ASA-PSO-optimized ENN model achieves high accuracy in predicting the mechanical properties of coarse-grained soils. This model provides reliable constitutive parameters for stress–strain analysis in earth–rock dam engineering applications. Full article

As a strategic replacement area for hydrocarbon exploration in the Tarim Basin, the Kuqa Depression has been the subject of relatively limited research on the sedimentary characteristics of the Triassic strata within its western Wushi Sag, which constrains exploration deployment in this region. This study focuses on the Wushi Sag, systematically analyzing the sedimentary facies types, the evolution of sedimentary systems, and the distribution patterns of the Triassic Kelamayi and Huangshanjie formations. This analysis integrates field outcrops, drilling cores, wireline logs, and 2D seismic data, employing methodologies grounded in foreland basin theory and clastic sedimentary petrology. The paleo-geomorphology preceding sedimentation was reconstructed through balanced section restoration to investigate the controlling influence of foreland tectonic movements on the distribution of sedimentary systems. By interpreting key seismic profiles and analyzing vertical facies successions, the study classifies and evaluates the petroleum accumulation elements and favorable source–reservoir-seal assemblages, culminating in the prediction of prospective exploration areas. The research shows that: (1) The Triassic in the Wushi Sag mainly develops fan-delta, braided-river-delta, and lacustrine–shallow lacustrine sedimentary systems, with strong planar distribution regularity. The exposed strata in the northern part are predominantly fan-delta and lacustrine systems, while the southern part is dominated by braided-river-delta and lacustrine systems. (2) The spatial distribution of sedimentary systems was demonstrably influenced by tectonic activity. Paleogeomorphological reconstructions indicate that fan-delta and braided-river-delta sedimentary bodies preferentially developed within zones encompassing fault-superposition belts, fault-transfer zones, and paleovalleys. Furthermore, Triassic foreland tectonic movements during its deposition significantly altered basin configuration, thereby driving lacustrine expansion. (3) The Wushi Sag exhibits favorable hydrocarbon accumulation configurations, featuring two principal source–reservoir assemblages: self-sourced structural-lithologic gas reservoirs with vertical migration pathways, and lower-source-upper-reservoir structural-lithologic gas reservoirs with lateral migration. This demonstrates substantial petroleum exploration potential. The results provide insights for identifying favorable exploration targets within the Triassic sequences of the Wushi Sag and western Kuqa Depression. Full article

Water resources have become a critical factor limiting agricultural development and ecological health in arid regions. The ecological efficiency of agricultural water use (EEAWU) serves as an indicator of the sustainable utilization of agricultural water resources, taking into account both economic output and environmental impact. This paper, grounded in the social–ecological system (SES) framework, integrates multidimensional variables related to social behavior, economic decision-making, and ecological constraints to construct an analytical system that examines the impact mechanism of farmers’ part-time employment on the EEAWU. Utilizing survey data from 448 farmers in the western Tarim River Basin, and employing the super-efficiency SBM model alongside Tobit regression for empirical analysis, the study reveals the following findings: (1) the degree of farmers’ part-time employment is significantly negatively correlated with EEAWU (β = −0.041, p < 0.05); (2) as the extent of part-time employment increases, farmers adversely affect EEAWU by altering agricultural labor allocation, adjusting crop structures, and inadequately adopting water-saving measures; (3) farm size plays a negative moderating role in the relationship between farmers’ part-time engagement and the EEAWU, where scale expansion can alleviate the EEAWU losses associated with part-time employment through cost-sharing and factor substitution mechanisms. Based on these findings, it is recommended to enhance the land transfer mechanism, promote agricultural social services, implement tiered water pricing and water-saving subsidy policies, optimize crop structures, and strengthen environmental regulations to improve EEAWU in arid regions. Full article

This study investigates the mechanisms of zooplankton community assembly and their relationship to environmental factors in high-latitude arid regions. We conducted seasonal sampling at four reservoirs in the upper Tarim River Basin from 2023 to 2024: Shangyou Reservoir (SY), Shengli Reservoir (SL), Duolang Reservoir (DL) and Xinjingzi Reservoir (XJZ). The zooplankton community was categorized into five functional groups based on the predominant species, with small crustacean filter feeders (SCF) in all reservoirs except XJZ, where a seasonal shift between rotifer collectors (RC) in the wet season and SCF in the dry season was observed. Pearson correlation and canonical correspondence analysis (CCA) revealed that interspecific competition, pH, conductivity (COND), and salinity (SALIN) were the main determinants of zooplankton community composition. Significant correlations (p < 0.05) were detected among functional groups RC (rotifers carnivora), RF (rotifers filter feeders), SCF (small copepods and claocera filter feeders), and MCC (middle copepods and claocera carnivora). Environmental factors showed significant spatial heterogeneity, while zooplankton biomass was positively correlated with pH and COND. Cluster similarity analyses indicated complex interactions between 29 zooplankton species, with RF identified as an important positive predictor for larger groups. The network of co-occurrences showed predominantly positive relationships, emphasizing the mutual facilitation between the species. Our results suggest that interspecific interactions have stronger effects on community structuring than environmental factors, with mutual facilitation emerging as an important survival strategy. This study provides important insights into the dynamics of zooplankton communities in dry reservoirs and establishes a framework for understanding ecological patterns and assembly mechanisms under drought conditions. Full article

Arid regions face multiple challenges such as population expansion, water scarcity, land degradation, and biodiversity reduction. Understanding temporal and spatial patterns of ecosystem service trade-offs and synergies is critical for sustainable development and effective ecosystem service management in arid regions under environmental stress. Taking the Tarim River Basin in China as an example, five ecosystem services (carbon sequestration, water yield, sediment delivery ratio, habitat quality, and food production) were studied at different scales in 1990, 2000, 2010, and 2020 in the inland arid region. Spearman correlation, geographical weighted regression, and self-organizing mapping were used to analyze the ecosystem service trade-offs and synergies. The results showed that the ecosystem services in the basin increased gradually; in particular, the water yield increased from 15.38 × 10⁹ m³ to 29.8 × 10 m³, and the food production increased from 11.03 × 10⁶ t to 29.26 × 10⁶ t. There was a significant positive correlation between carbon sequestration, water yield, and habitat quality, but a negative correlation between sediment delivery ratio and food production. The spatial distribution of trade-offs and synergies of ecosystem services varies in different years and on different scales. The area change in ecosystem service bundles at the pixel scale is relatively small, while the area change at the sub-basin scale is relatively large. This paper provides policy suggestions for the ecological management and sustainable development of the Tarim River Basin through the analysis of ecosystem service trade-offs and synergies. Full article

Ecosystem services (ESs) are a life-support system for human development that are also a strategic root for realizing global ecological security and sustainable development. In this study, the spatial distribution pattern of land-use and ESs under three scenarios (an ecological protection scenario (EPS), a natural development scenario (NDS), and a cropland protection scenario (CPS)) in the Tarim River Basin (TRB), Northwest China, is predicted for 2035 using the Future Land-Use Simulation (FLUS)–Integrated Valuation of ESs and Trade-Offs (InVEST) model. Land-use data from 2000 to 2023 are utilized as the basic data, and the spatial and temporal characteristics of land-use and multiple ESs under different scenarios are explored. The results show that (1) the land-use structure of the TRB is dominated by barren land (55.12%) and grassland (30.28%), and the dynamic evolution of the land-use pattern from 2000 to 2023 is characterized by the continuous shrinkage of the area of barren land and the expansion of impervious surfaces, cropland, water bodies, and other productive and living land and water. (2) According to the prediction results of the FLUS model, the different scenarios of land-use for 2020–2035 show various change trends. In the EPS, the proportion of ecological land jumps to 35.23%, while production land and living land show a systematic contraction. Under the NDS, water bodies, grassland, and impervious surfaces experience a decreasing trend, whereas cropland, forest land, and barren land increase in area. Under the CPS, the trend of shrinkage for ecological land accelerates, especially the fragmentation of forest patches (shrinking by 24 km²) and the expansion of cropland and barren land. (3) A comparison and an analysis of the ESs in several scenarios for 2035 show an increase in ESs under the EPS compared with those in 2020, along with a marked improvement in the TRB’s future ecological environment under this scenario. By adhering to the guidance of ecological priority through optimization of the national spatial pattern and the integration of ecological elements, the dynamic balance between ecological protection and economic development can be effectively coordinated, providing core support for the sustainable development of the region. (4) Ecosystem services are significantly impacted by changes in grassland in a variety of settings, particularly in the NDS. Contradictory trade-offs between ecological functions are revealed in the CPS, where cropland expansion promotes soil conservation but worsens the degradation of grassland. In the EPS, the synergistic expansion of grassland and water favorably regulates ecosystem services. A major way to increase the capacity of regional ecosystem services and accomplish sustainable development is to optimize the land-use for ecological preservation, with an emphasis on increasing the acreage of grassland, forest, and water while decreasing the area of cropland and barren. Full article

The Tarim River Basin is an important grain and cotton base in Xinjiang, China. Indeed, cotton production in this basin accounts for one-third of the total cotton production in China. The Tarim River Basin is characterized also by the presence of forestry activities and fruit plantations. However, frequent long-term droughts have seriously affected local agricultural productivity. In this paper, a new standardized precipitation evapotranspiration index (nSPEI), with an improved drought detection effect, was constructed based on the standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI). This drought index was subsequently employed as a hazard indicator of disaster-causing factors in the Tarim River Basin. In addition, a drought disaster risk assessment model was constructed using the natural disaster system theory. This model was applied to analyze the hazard of drought-disaster-causing factors, the exposure of disaster-affected bodies, the vulnerability of disaster-bearing environments, drought prevention/mitigation capabilities, and comprehensive drought disaster risks in the Tarim River Basin over the 2001–2021 period. The results demonstrated the applicability of the 12-month nSPEI (nSPEI-12) in the Tarim River Basin. Specifically, the nSPEI-12 values exhibited a decreasing trend, highlighting an aridification trend in the basin. In addition, a 25% increase in the vegetation cover of the Tarim River Basin was observed from 2000 to 2023 and remained unchanged at 4.5%. On the other hand, a decreasing trend of the vegetation cover was found in the remaining parts of the basin. The hazard level of the disaster-causing factors and the exposure of bearing bodies were high in the northeastern and northwestern parts of the Tarim River Basin, respectively. The disaster prevention/mitigation capacity was greater in the northern and southwestern parts, while the vulnerability level of disaster-bearing environments decreased from the northwestern part to the southeastern part. The western and northern parts of the Tarim River Basin exhibited the highest drought risk levels, followed by the northeastern and southeastern parts. Full article

As the process of agricultural modernization accelerates, exploring the impact of agricultural mechanization services on production technology efficiency has become a key issue for enhancing agricultural productivity and promoting sustainable agricultural development. The study focuses on cotton growers in the Tarim River Basin and systematically explores the impact and driving mechanisms of agricultural mechanization services (AMSs) on cotton production’s technical efficiency within the framework of the social–ecological system (SES). By employing a combination of stochastic frontier analysis (SFA) and propensity score matching (PSM), the research indicates that the adoption of AMSs significantly enhances the production technical efficiency of cotton farmers. Among the sample that adopted this service, as much as 53.04% of the farmers have their production efficiency within the range of [0.8, 0.9], demonstrating a high production capability. In contrast, the production efficiency values of the farmers who did not adopt such services are more dispersed, with inefficient samples accounting for 11.48%. Furthermore, while the technical efficiency levels across different regions are similar, there are significant efficiency differences within regions. A further analysis indicates that the age of the household head, their education level, the number of agricultural laborers in the family, the proportion of income from planting, and irrigation convenience have a positive impact on farmers’ adoption of AMSs, while the degree of land fragmentation has a negative impact. Therefore, AMSs are not only a core pathway to enhance cotton production’s technical efficiency but also an important support for promoting agricultural modernization in arid areas and strengthening farmers’ risk-resistance capabilities. Future policies should focus on optimizing service delivery, enhancing technical adaptability, and promoting regional collaboration to drive the high-quality development of the cotton industry and support sustainable rural revitalization. Full article

The flood–drought severity in arid regions such as Xinjiang is increasingly influenced by climate extremes. While prior studies have explored the relationship between climate extremes and flood–drought dynamics, few have analyzed these interactions at different time and spatial scales using different method combinations. This study addresses that gap by utilizing a gridded dataset (CN05.1) during 1961–2020, examining the China Z index (flood–drought index) and climate extremes. The analysis reveals significant increases in precipitation and heat extremes, while cold extremes have decreased. In addition to overall periodic changes with 2.5 and 8 years in the flood–drought severity, our results demonstrate a significant spatial shift between 1981 and 2000 and between 2001 and 2020. Previously flood-dominant regions, including portions of the Junggar Basin, Eastern Tianshan Mountains, and Tarim River Basin, transitioned to drought-dominant in 2001–2020. Conversely, drought-dominant regions became flood-dominant. Strong positive correlations (0.65–0.84) were found between the Z index and precipitation extremes, while temperature extremes showed weaker correlations. Furthermore, we applied six variable selection regression methods, with Random Forest variable selection + Random Forest regression (RF+RF) performing the best (mean R² = 0.71), highlighting their ability to manage non-linear relationships and multicollinearity between climate indices. RF+RF proved more effective at handling correlated variables, which were crucial in capturing the region’s flood–drought dynamics. The quantified spatial reversals and non-linear climate-flood/drought relationships provide actionable metrics for early warning systems, enabling targeted infrastructure upgrades and water allocation policies in arid regions. These findings establish a transferable framework linking climate extremes to hydrological risks, directly informing adaptive land management and disaster preparedness strategies for Xinjiang and analogous regions under intensifying climate variability. Full article

Snow cover variations significantly affect the stability of regional water supply and terrestrial ecosystems in arid northwest China. This study comprehensively evaluates snow resource changes since 2000 by integrating multisource remote sensing datasets and analyzing four key indicators: snow cover area (SCA), snow phenology (SP), snow depth (SD), and snow water equivalent (SWE). The results reveal a slight downtrend in SCA over the past two decades, with an annual decline rate of 7.13 × 10³ km². The maximum SCA (1.28 × 10⁶ km²) occurred in 2010, while the minimum (7.25 × 10⁵ km²) was recorded in 2014. Spatially, SCA peaked in December in the north and January in the south, with high-altitude subregions (Ili River Basin (IRB), Tarim River Region (TRR), North Kunlun Mountains (NKM), and Qaidam Basin (QDB)) maintaining stable summer snow cover due to low temperatures and high precipitation. Analysis of snow phenology indicates a significant shortening of snow cover duration (SCD), with 62.40% of the study area showing a declining trend, primarily driven by earlier snowmelt. Both SD and SWE exhibited widespread declines, affecting 75.09% and 84.85% of the study area, respectively. The most pronounced SD reductions occurred in TRR (94.44%), while SWE losses were particularly severe in North Tianshan Mountains (NTM, 94.61%). The total snow mass in northwest China was estimated at 108.95 million tons, with northern Xinjiang accounting for 66.24 million tons (60.8%), followed by southern Xinjiang (37.44 million tons) and the Hexi Inland Region (5.27 million tons). Consistency analysis revealed coherent declines across all indicators in 55.56% of the study area. Significant SD and SCD reductions occurred in TRR and Tuha Basin (THB), while SWE declines were widespread in NTM and IRB, driven by rising temperatures and decreased snowfall. The findings underscore the urgent need for adaptive strategies to address emerging challenges for water security and ecological stability in the region. Full article

The southwestern Tarim Basin, shaped by the far-field effects of the India-Eurasia collision, serves as a critical archive for reconstructing source-to-sink dynamics and tectonic evolution in a Cenozoic intracontinental foreland setting. This study presents detrital zircon U-Pb geochronology and trace element data from sands of the Yulongkash and Karakash Rivers, major tributaries of the Hotan River draining the West Kunlun Orogenic Belt. Our results reveal distinct provenance signatures between the two tributaries: Yulongkash river sands (HT1) exhibit dominant Triassic (~208 Ma) and Early Paleozoic (~418 Ma) zircon populations, sourced primarily from the South Kunlun and Tianshuihai terranes, whereas Karakash river sands (MY1) are characterized by Early Paleozoic (~460 Ma) and Precambrian zircons, reflecting predominant contributions from the North Kunlun Terrane. Integration with published datasets highlights systematic spatial variations in detrital zircon age spectra, controlled by bedrock heterogeneity, fluvial geomorphology, and sediment mixing efficiency. Furthermore, crustal thickness reconstructions based on zircon trace elements constrain the terminal closure of the Proto-Tethys Ocean to ~420–440 Ma (peak crustal thickness: ~80 km) and the Paleo-Tethys Ocean to the Late Triassic (~210 Ma). These findings not only refine the provenance framework of the Hotan River drainage system but also provide critical insights into the timing of Tethyan ocean closures and the tectonic evolution of the West Kunlun Orogenic Belt, emphasizing the utility of detrital zircon records in deciphering orogenic histories within complex intracontinental settings. Full article

Soil organic carbon (SOC) plays a crucial role in the terrestrial carbon cycle and climate regulation. Quantifying the sensitivity of SOC to climate change is essential for developing effective strategies to address climate change and optimizing agricultural production. This study compares the performance of four machine learning models in assessing SOC, ultimately selecting the optimal Extreme Gradient Boosting model for spatial predictions of surface SOC (0–30 cm) across the country. The results indicate that areas with higher organic carbon density are primarily concentrated in the Tibetan Plateau and northeastern regions. Notably, regions with high uncertainty in predictions correspond to areas of elevated organic carbon density. Average temperature, average precipitation, and the Normalized Difference Vegetation Index were identified as the most influential factors across all models. Based on the predictions from the optimal model and a bottom-up framework, various potential climate change scenarios were considered, allowing for the quantification of SOC sensitivity to climate change. Under scenarios of increased temperatures and decreased precipitation, SOC loss intensified, hindering SOC accumulation. When the average temperature rose by 1.45 °C and precipitation decreased by 14.67%, a loss of 10% in SOC was projected for most regions of China. These findings provide critical insights for the proactive formulation of climate adaptation strategies, soil health preservation, and the maintenance of ecosystem stability. Full article

In the western Tarim Basin, Carboniferous granular dolostones deposited on a carbonate platform contain a small amount of terrigenous materials of sand-size fraction, agglomerated clay minerals, or similar phases. However, the role of terrigenous materials on dolomitization is still unclear. The aim of this study was to reveal the dolomitization mechanism. The granular dolomites have small crystal size, earthy yellow color, and fabric-retentive texture, with relatively good order. These features indicate dolomites precipitated during early diagenesis. The ratio of rare earth elements (RREs) abundance of the stable isotopes ⁸⁷Sr/⁸⁶Sr relative to Post-Archean Australian Shale (PAAS) normalized patterns was used to study the source of the dolomitizing fluids. The composition of REEs is characterized by heavy rare earth (HREE) enrichment (average Nd_SN/Yb_SN = 0.83). There is a positive (La/La*)_SN anomaly and slightly positive (Gd/Gd*)_SN and (Y/Y*)_SN anomaly; δ¹⁸O of seawater in fractionation equilibrium with granular dolostones was from −2.8‰ to 1.7‰ PDB, implying the dolomitizing fluid was contemporary, slightly evaporated seawater. The granular dolostones on the relatively thick shoals were subject to subaerial exposure before pervasive dolomitization, with evidence that the input of detrital kaolinite predated the formation of dolomites. Higher ⁸⁷Sr/⁸⁶Sr values and ∑REE in granular dolostones than the values in equivalent limestones indicate that dolomitization was related to terrigenous materials. Within the terrigenous materials, the negative-charged clay minerals may have catalyzed the dolomitization, resulting in dramatically decreased induction time for precipitation of proto-dolomites. A greater amount of terrigenous materials occurred on the shoals at the sea level fall, resulting from enhanced river entrenchment and downcutting. As a result, after subaerial exposure, the penesaline water flow through the limy allochems sediments lead to dolomitization, with the catalysis of illite on relatively thick shoals. Full article

In order to cope with the ecological pressure caused by the uncontrolled expansion of cultivated land in arid areas and ensure regional food security, the implementation of a cultivated land fallowing system has become an effective way to restore the ecology, alleviate the pressure on cultivated land, and increase productivity. In view of this, this paper takes the Tarim River Basin, located in the arid zone of China’s agricultural continent, as the research object. Using a land use transfer matrix and a gravity center migration model, the paper analyzes the spatiotemporal characteristics of cultivated land expansion in the Tarim River Basin from 2000 to 2020. Through remote sensing and the integration of multi-source data, the paper constructs an arable land fallow urgency index (SILF) from multiple dimensions such as human activity intensity, ecological vulnerability, output value, water resources status, and terrain conditions. The research results show that (1) cultivated land in the Tarim River Basin expanded by 15,665.133 km² in general, which is manifested by spreading around based on existing cultivated land, mainly from the conversion of grassland and unused land; the center of gravity of cultivated land moved 37.833 km to the northeast and 7.257 km to the southwest first. (2) The area of not urgently fallow (NUF) in the watershed showed an overall downward trend, decreasing by 10%, while the area of very urgently fallow (VUF) increased by 16%. VUF is mainly distributed in the marginal areas of cultivated land close to the desert and is gradually expanding into the interior of cultivated land. (3) The overall ecological environment of cultivated land in the watershed is showing a deteriorating trend, and the deterioration is gradually spreading from the edge of the cultivated land to the interior. (4) There are significant differences in the SILF values of different land use types after conversion to cultivated land. The urgency of fallowing cultivated land converted from unused land is the highest, followed by grassland, forest land, water bodies, and construction land. The expanded cultivated land has a higher SILF value than the original cultivated land. The research results can provide insights into regional land resource management, the formulation of cultivated land protection policies, and the ecological restoration of cultivated land. Full article

It is of great significance to optimize water resource management and promote sustainable development in the Tarim River Basin (TRB) by using the water footprint (WF) evaluation method to evaluate the water shortage of fruit trees in the TRB and analyse its water-saving potential. This study aimed to elucidate the WF spatial–temporal distribution characteristics of fruit trees in the water-limited TRB from 2000 to 2020 and evaluate their water-saving potential capability. The WF was calculated using a combination of irrigation technology simulation and water usage assessments for four different fruit trees (apple, pear, date, and walnut). The results indicate that the green WF (WF_green) initially increased and then decreased, reaching its lowest value of only 175.09 m³/t in 2020, and decreased by 22.71% from 2000 to 2020. WF_blue decreased by 47.13% over the same period. In 2020, the WF_blue of date and walnut accounted for a higher percentage of WF_blue. WF_blue significantly exceeded WF_green, indicating their high water consumption and the limited adoption of water-saving technologies in the study area. Due to the increase in fruit tree planting area and fertilization, WF_grey exhibited an overall upward trend. Meanwhile, the total WF (WF_total) indicated a general downward trend, though the walnut tree had the highest WF_total at 2.21 × 10⁵ m³/t, indicating the popularization of water-saving technology. The results show that, taking 2020 as the baseline, the WF_blue of the four fruit trees in the TRB was 2.64 × 10⁵ m³/t (accounting for 89.1%), total WF_blue decreased by 0.73 × 10⁵ m³/t (a decrease of 48.38%) after drip irrigation, and the water-saving potential in the five prefectures of the TRB was in the range of 38.55–56.18%. Therefore, the promotion of drip irrigation technology plays a key role in alleviating the water pressure of fruit trees and promoting the sustainable utilization of water resources in the TRB. Full article