In estuarine regions, many iron/manganese (Fe/Mn) oxides linked to the phosphorus (P) cycling become rapidly deposited on the uppermost sediments. The impact of temperature fluctuations on Fe/Mn-related P remobilization in sediments remains poorly understood. Here, the characteristic mechanisms of P remobilization in sediments of the Jiaomen Channel were explored using sequential extraction method, diffusive gradients in thinfilms (DGT) device, and pore-water sampler. In the field, the labile P concentration was higher in summer, suggesting the great influence of temperature on P mobility. At river-outlet site, in contrast to other sites, the MnP relationship was superior to Fe-P relationship, accompanied by substantial increases in the DGT-labile Fe and Mn concentrations but only a minimal change in the DGT-labile P concentration during summer. This implied a need for the temperature-dependent experiment, the results of which confirmed that the reductive dissolution of Mn oxyhydroxides and the subsequent P release (R = 0.96-0.98) increased by 44% after warming. Intense organic matter mineralization removes dissolved Mn from pore water as carbonates, triggering an irreversible shift from Fe/Mn-P to Fe-P cycling in the short term. The labile P concentration therefore remains high in deep sediments, attributable to warming activation even after cooling. We present robust evidence indicating transformation of Mn-related P remobilization to an Fe-related mechanism. This explains well why Mn-P co-release was apparent only at river outlets exhibiting high sedimentation rates. Such seasonal variations should be considered by environmental managers, with a particular focus on the release of endogenous P from estuarine sediments during warm seasons.

ABSTRACT Establishing scientifically grounded soil erosion control targets and feasible vegetation restoration strategies is crucial for high quality development of the Chinese Loess Plateau which is severely affected by soil erosion. Currently, the commonly used tolerable soil loss (TSL) is inadequate for addressing the spatial heterogeneity in topography and temporal variability in climatic conditions attributed to its static characteristics. This study developed a dynamic assessment framework using the Revised Universal Soil Loss Equation (RUSLE) model to construct a monthly soil erosion rate raster dataset at a 500 m resolution for 2001–2024. Model validation was conducted through comparison with sediment yield data from 25 tributary hydrological stations. By analyzing the soil erosion rate and the prevailing climatic and land management factors, we established monthly erosion control targets (ECT) and the corresponding vegetation cover targets (VCT). Results showed that (1) the average erosion rate declined from 15.5 to 10.17 t ha −1 year −1 , with a mean of 10.53 t ha −1 year −1 , and peaks occurred in summer, especially July; (2) the estimated ECT values ranged from 13.4 to 8.9 t ha −1 year −1 , with a mean of 7.2 t ha −1 year −1 , peaking at 1.6 t ha −1 month −1 in July; (3) the estimated VCT ranged from 43.4% to 66.6%, averaging 59.8%. Overall, 51.6% of the Loess Plateau has already met the VCT requirements necessary to sustain the ECT. These findings provide scientific guidance for soil and water conservation and vegetation restoration tailored to local conditions, with potential applicability to other erosion‐prone regions.

Abstract. Protective forests play an important role in maintaining the stability of arid oasis agroecosystems; however, water exchange and competition between shelterbelts and cropland under limited water availability remain poorly quantified. This study used stable hydrogen and oxygen isotopes to investigate irrigation-water redistribution and water-use interactions in a maize (Zea mays L.)–poplar (Populus alba L.) shelterbelt system in the Minqin Oasis, Hexi Corridor. The results showed that irrigation water was transferred from cropland to shelterbelts through both soil lateral movement and root-mediated uptake. Across four irrigation events, modeled transpiration-related water exchange between farmland and shelterbelts reached 84.49 mm, accounting for 19.56 % of applied irrigation water. Irrigation-induced lateral transfer into shelterbelt soil averaged 13.26 % of irrigation depth, with the largest contribution occurring in the 20–60 cm soil layer (5.49 %). Maize and poplar exhibited substantial overlap in water-source use, with a mean proportional similarity index of 73.35 %, indicating strong potential competition for soil water resources. These findings reveal that irrigation water redistribution links cropland and shelterbelts through coupled hydrological processes and highlight the need to jointly consider crop water demand and shelterbelt water consumption in arid oasis management.

This study aimed to determine how submarine groundwater discharge (SGD) types influence bacterial community assembly in a mangrove subterranean estuary. Groundwater and seawater samples collected from Qi'ao Island (Pearl River Estuary, China) in March-April 2024 were analyzed for hydrochemistry and bacterial communities. SGD was classified into fresh SGD (FSGD; meteoric-dominated) and recirculated SGD (RSGD; tide-driven seawater) using a radon-222 (Rn-222) mixing model, with freshwater fractions calculated to distinguish SGD sources. Multivariate ordination and Mantel tests were used to assess community-environment relationships. FSGD occurred primarily at near-shore deeper sites (f >= 0.05), whereas RSGD dominated shallow offshore locations (f < 0.05). Although alpha diversity showed no significant differences among groups, beta diversity revealed distinct community structures. Proteobacteria were dominant overall, with group-specific enrichment of Campylobacterota and Alphaproteobacteria. Salinity-related ions and bicarbonate were key environmental drivers. These findings demonstrate that SGD types shape bacterial communities through environmental filtering and highlight their role in regulating coastal biogeochemical processes.

Dust activities on the Tibetan Plateau (TP) significantly impact on regional and global environmental change. As a direct record of past dust activity, TP loess has been accumulating since the early Quaternary. However, the processes and factors controlling TP dust accumulation remain poorly constrained. In this study, we present a high-resolution dust accumulation record spanning the last glacial cycle, derived from a newly established independent luminescence chronology of the well-preserved Ganzi loess-paleosol sequence. We further synthesize the spatial and temporal patterns of TP dust and explore the factors influencing its accumulation. Our results reveal that the TP dust accumulation is characterized by prominent glacial-interglacial fluctuations and rapid suborbital-scale variations throughout the last glacial cycle. TP dust activity is sensitive to global climate change, with significant expansion of loess coverage and enhanced dust activity occurring episodically since the late Quaternary. The dust mass accumulation rates reconstructed from TP loess are notably higher than those recorded in TP ice cores, indicating that dust activity in the plateau was more intense than previously recognized. Anthropogenic activities may have exerted a significant influence on TP dust flux since the late Holocene. Our study thus advances the current understanding of dust dynamics in the TP, indicating that dust activity across the region is substantially more intense than previously acknowledged.

The 26 August 2026 Gyirong cascade connected a high-mountain failure to developed downstream valleys. Event-bracketing observations delineate a preferred changed/source surface of 1.01 km^2, within alternative interpreted envelopes of 0.49-1.84 km^2, and a representative 21.8 km source-to-port route descending 3.40 km. Across two precipitation products, five antecedent windows and six fixed spatial supports, all 60 matched-year ranks remain below the 90th-percentile wet threshold. The source-nearest 7-day temperature mean of 9.43 degrees C exceeds all 25 matched years from 2001-2025. Positive temperature anomalies extend to every tested support, but ranks vary from the 88th percentile to above all historical values. Within the subsequently affected 37.354 km^2 UNOSAT footprint, modelled built-up surface increases from 0.036 to 0.441 km^2 between 1975 and 2020; its fraction of the fixed area rises from 0.096

The Northern South China Sea (NSCS) supports the livelihoods of hundreds of millions of people as one of the most important sea areas in China. However, research on the long-term evolution of nitrogen (N) and phosphorus (P) components in the surface water of NSCS and their ecological impacts and driving factors from a remote sensing perspective remains to be studied. To fill this research gap, we reconstructed the concentrations of dissolved inorganic nitrogen (DIN) and total phosphorus (TP), as well as their components nitrate nitrogen (NO3-) and reactive phosphate (PO43-) in surface water from 1987 to 2023. This was achieved by combining 4968 in-situ measurements from 623 stations with Landsat satellite data on the Google Earth Engine (GEE) platform using a Random Forest (RF) machine learning model. The model exhibited the idea simulation accuracy of four water quality parameters (WQPs) on the validation set (R2 > 0.82). The Pearl River Estuary (PRE) and the Huangmao Estuary (HM) had the highest degree of eutrophication. The satellite successfully captured the continuous increase in the mean concentration of N in the PRE and HM areas since 1987, with the mean concentration of N reached the highest in 2012 (about 1.19 mg/L) in PRE, and P showed a significant downward trend since 1999. N and P concentrations exhibited opposite seasonal patterns. The area of excellent water quality continued to increase in NSCS, but the area of excellent DIN water quality in PRE decreased from 22.5% to 9.5%. NO3- and PO43- contributed at least 50% and 17% of DIN and TP, respectively. The possible impact of the West Guangdong Coastal Current (WGCC) on the specific water quality concentration areas in the western NSCS was quantified for the first time, with an influence area of at least 3000 km2 and an expansion of the offshore up to 28 km. Additionally, the high N:P ratio may indirectly limited the growth of target marine fish. Moreover, agricultural production and fertilizer application dominated WQPs concentration in PRE in past two decades. The concentration and proportion of NO3- indicated a significant positive correlation with the area of algal bloom in NSCS. This research not only systematically reveals the spatio-temporal evolution of N and P and their components over a 40-year time scale for the first time, but also quantifies the possible impact of WGCC on the western area of the NSCS. This study offers scientific guidance for ecological environment assessment and provides a scientific basis for targeted nutrient management strategies.

Regional- and global-scale soil erosion assessments are essential tools for quantifying soil loss intensity and supporting soil conservation planning. At present, the most widely applied—and arguably the only models that are truly operational in practice—belong to the Universal Soil Loss Equation (USLE) family, including USLE, RUSLE, RUSLE2, MUSLE, CSLE, USPED, SWAT, WaTEM/SEDEM, SEDD, AGNPS, and EPIC. USLE is essentially a field-scale model, originally developed for field-level soil conservation planning, and its parameterization relies primarily on field surveys, supplemented by remote sensing interpretation. When applied at large regional or global scales, parameter acquisition becomes extremely labor-intensive and, in some cases, impractical; moreover, limitations remain in the effective use of remote sensing data. As a result, parameter misuse or misapplication has frequently occurred in previous studies. To address these issues, this study develops an open model framework designed for regional- and global-scale applications. Building upon a basic model structure, parameters can be flexibly added or simplified according to regional characteristics and data availability, thereby ensuring good generality and strong potential for broader application. The proposed model is conceptually rooted in the USLE framework. Based on the product of rainfall erosivity (R) and soil erodibility (K), the remaining factors are introduced as proportional coefficients under unit conditions; consequently, the model formulation is not restricted to the traditional form A = RKLSCP, but can be adjusted to A = RKLSBET or further extended as A = RKLSCnon-cropCcrop_iEjTk. This type of model offers two clear advantages: first, it enables more effective use of remote sensing data; second, it is better suited to the diverse soil conservation conditions across different countries and regions.

Accurate remote sensing retrieval of fractional vegetation cover (FVC) of photosynthetic vegetation (PV) and non-photosynthetic vegetation (NPV) is essential for assessing regional soil erosion. However, current linear spectral unmixing methods often ignore variability in endmember spectral indices, causing errors in FVC estimation. Using field-measured hyperspectral data and the derived indices of NDVI and the Cellulose Absorption Index (CAI), we analyzed the spectral properties of the endmembers across red, near-infrared, and shortwave infrared bands, examining their variability among different vegetation types and seasons. Furthermore, we identified optimal spectral indices and their combinations for retrieving PV, NPV, and bare soil (BS) fractions using MODIS imagery. Results showed that while endmember NDVI varied significantly with vegetation type (e.g., mean forest PV NDVI of 0.85 vs. 0.64 for grass) and season, the CAI demonstrated no significant variability under the same conditions. A three-component linear spectral unmixing model was developed and evaluated using MODIS-derived indices: NDVI, Enhanced VI (EVI), Kernel-NDVI (kNDVI), and two alternatives for CAI—Shortwave Infrared Ratio (SWIR32) and Dead Fuel Index (DFI). The kNDVI-SWIR32 and NDVI-SWIR32 combinations exhibited the highest predictive accuracy. Determination coefficients for FPV, FNPV, and FBS were 0.92, 0.74, and 0.70, respectively, with Nash-Sutcliffe efficiency coefficients of 0.90, 0.74, and 0.70, and RMSE values of 10.2 %, 16.6 %, and 13.5 %, respectively. This study provides a robust theoretical basis for high-precision retrieval of FPV and FNPV in the Loess Plateau and offers promising technical support for improving the accuracy of the cover and management factor in soil erosion models.

Water resources are the most critical influencing and limiting factor for ecosystem and socioeconomic development in arid zones. To mitigate ecological degradation in the lower reaches of inland rivers across arid regions, managed water redistribution has been widely implemented as a key anthropogenic intervention in drylands globally. The trade-off between water consumption and carbon sink benefits resulting from anthropogenic water resource allocation has then become an urgent scientific issue. The results showed that the trend of NPP increased from -1.5455 to 1.8611 gC/m2/a after the ecological water transfer. Among different vegetation types, forest land exhibited the highest carbon sequestration capacity, followed by farmland and grassland. Following the ecological water transfer, the total carbon stock in the input area increased from 21.97 in 2010 to 23.38 Tg in 2020. The implementation of ecological water diversion policies has markedly enhanced the carbon sink function in the lower reaches of the Shiyang River. However, the water cost per unit of carbon sequestration achieved was found to be substantially higher than the global average. Therefore, from the perspective of basin water-carbon balance, there is some room for discussion and optimization of the ecological water transfer policy in the arid zone.

The changes in salinity due to the saltwater intrusion can affect the geochemical cycling of phosphorus (P) in sediments. To determine whether salinization can stimulate the endogenous P release from sediment, a microcosm experiment was conducted, incorporating in-situ sampling techniques, solid-phase characterization, and microbial analysis. It was found that the salinization-induced P remobilization was tightly associated with iron (Fe) cycling (R2: 0.83–0.93). The enhanced P solubility contributed to greater upward diffusion flux across the sediment-water interface (11.5–25.2 μmol·cm−2·d−1) than the low-salinity period (−0.01 μmol·cm−2·d−1). As a result, P concentration in the overlying water increased within five days after salinization. However, it decreased rapidly, which was likely associated with the enrichment of manganese (Mn) oxides in the surface sediment. These Mn oxides functioned as “Mn curtain”, partially impeding P release and reducing P resupply capacity within the shallow sediment. In contrast, Fe oxides did not accumulate in the surface sediment, likely due to microbial activity. The relative abundance of sulfate-reducing bacteria increased significantly (p < 0.05) from 2.46 ± 0.36% to 3.06 ± 0.17% accompanied with salinization, promoting the generation of sulfides and suppressing the activity of iron-reducing bacteria. Consequently, the dissolution of Fe oxides was mainly accomplished through the chemical reduction induced by sulfate reduction, which resulted in the direct formation of Fe-S compounds. This research confirmed that salinization promoted P availability and underscored the potential role of “Mn curtain” in impeding the endogenous P release.

Atmospheric deposition of phosphorus (P) has multitudes of environmental implications, but quantifying and validating its spatial and temporal patterns remain highly challenging. Here, we integrated a detailed P emission inventory with atmospheric chemistry transport modeling and a temporally augmented mass-conserving downscaling approach to estimate terrestrial P deposition at 0.1° resolution during 2000-2019. The results reveal a 16.5% increase in global terrestrial P deposition, from 174.6 g ha-1 yr-1 (2.31 Tg yr-1) in 2000 to 202.6 g ha-1 yr-1 (2.69 Tg yr-1) in 2019. Among the natural sources, mineral dust predominated with emissions ranging from 1.31 to 1.50 Tg P yr-1, followed by primary biological aerosol particles (0.14-0.15 Tg P yr-1). Among anthropogenic sources, emissions were led by fossil fuel (1.12-1.62 Tg P yr-1) and biofuel combustion (0.39-0.52 Tg P yr-1), which significantly exceeded contributions from agricultural activities (0.07-0.10 Tg P yr-1). Spatially, the net global increase in P deposition was primarily driven by increased anthropogenic emissions in China (+4.09% per year) and India (+2.98% per year), which outpaced concurrent P emission reductions in the US (-0.40% per year) and Europe (-0.04% per year). Despite the implementation of a series of clean air policies in the two countries, anthropogenic P emissions continued to climb or level off, underscoring the need for systematic monitoring to mitigate potential environmental risks.

Establishing terraced hydropower stations in mountainous regions with abundant hydropower resources is a highly efficient approach to fostering socio-economic development. Nevertheless, the construction of hydropower stations would eventually cause substantial alterations in the hydrological cycle of a particular basin or region due to the artificial spatial distribution of water resources. This study examines the effects on the water cycle of stepped hydropower stations in the arid zone of Xiying River, in the northwestern of China. The study’s findings indicate that: (1) Hydropower stations rivers exceeded natural rivers in evaporation losses following the construction of these plants, leading to isotope enrichment in surface water. (2) Cascade hydropower station’s evaporative effect increases the proportion of recirculated water vapor within precipitation. (3) Increased surface and groundwater exchange through cascade hydropower stations. Consequently, when managing water resources in arid regions, it is imperative to consider the influence of artificial water conservancy structures, such as graded hydropower stations, on the local hydrologic cycle

Rapid industrialization is typically the primary cause for heavy metals [HMs: copper (Cu), zinc (Zn), cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pb)] contamination in urbanized river basins. In this study, sediment cores were collected from the Xizhi River (XZR) of the Pearl River Delta, South China, and its tributary, the Danshui River (DSR), to analyze the total concentrations and geochemical fractions of these HMs and to assess their potential hazards to the river ecosystem. By integrating a traditional geochemical model and multivariate statistical analysis into a positive matrix factorization (PMF) method, we quantitatively identified the possible sources of HM contamination in the sediments. The total concentrations of sediment HMs distinctly exceeded local background values and were higher in the DSR compared to the XZR. The enrichment levels of HMs were influenced not only by sediment properties, such as texture, but also, more critically, by the distribution of contamination sources. Sediment Cu, Zn, Cd, and Ni were dominated by acid-soluble fractions (31.4-56.2 %), exhibiting a great mobility potential; while reducible and oxidizable fractions were the predominant geochemical forms for Pb (45.0 +/- 12.8 %) and Cr (37.3 +/- 7.09 %). Based on the geo-accumulation index and enrichment factor of individual metals, contamination levels decreased in the order of Cd > Cu, Zn, and Ni > Cr and Pb. Sediment Cd was identified as the major contributor to the potential ecological risks posed to aquatic species. Across the entire watershed, the main sources of HM contamination were identified as industrial effluents (54 %), agrochemicals (16 %), domestic sewage (14 %), and weathering of parent rocks (16 %).

Migration characteristics and occurrence forms of redox-sensitive metal(loid)s such as arsenic (As), chromium (Cr), and vanadium (V) remained unclear in dynamic estuarine waters. In this work, size fractionation and chemical speciation of As, Cr, and V in the Jiaomen Waterway (JMW), a tidal river of the Pearl River estuary, were explored based on (ultra)filtration, the diffusive gradients in thin films (DGT) techniques and a thermodynamic chemical equilibrium model. The results showed that As was present mainly in soluble forms in the river water, and the suspended particulate matter (SPM) was identified the major carrier for Cr. The hosting phase of V converted from solid to liquid fractions during the transition from rainy to dry seasons. Decreasing Log Kd of Cr>V>As indicated particulate As presented greater potentials to be desorbed from the SPM and transferred into the liquid phase. Coagulation and flocculation of colloidal As was observed in rainy season, while changes in its partitioning behaviors between colloids and truly dissolved fractions were relatively weak in dry season. In contrast, Cr and V behaved a transfer from colloid to truly dissolved fraction along the JMW because of degradation of organic matter. During the migration to the estuary, AsO43- and CrO42- were transformed into H3AsO3 and Cr(III)-organic complexes, respectively, due to reduction of As(V) and Cr (VI) species. Meanwhile, proportions of V species decreased in order of HVO42->VO2+>V(IV)-organic complexes without obvious redox reactions of V(V) being taken place. The results were anticipated to provide a further supplement for geochemistry of redox-sensitive metal(loid)s in estuarine regions.

Graph-based multiview clustering (MVC) approaches have demonstrated impressive performance by leveraging the consistency properties of multiview data in an unsupervised manner. However, existing methods for graph learning heavily rely on either Euclidean structures or the manifold topological structures derived from fixed view-specific graphs. Unfortunately, these approaches may not accurately reflect the consensus topological structure in a multiview setting. To address this limitation and enhance the intrinsic graph learning process, an adaptive exploration of a more appropriate consistency topological structure is required. Toward this end, we propose a novel approach called collaborative topological graph learning (CTGL) for MVC. The key idea is to adaptively discover the consistent topological structure to guide intrinsic graph learning. We achieve this by introducing an auxiliary consistency graph that formulates the topological relevance learning function. However, estimating the auxiliary consistency graph is not straightforward, as it is based on the learned view-specific graphs and requires prior availability. To overcome this challenge, we develop a collaborative learning strategy that simultaneously learns both the auxiliary consistency graph and view-specific graphs using tensor learning techniques. This strategy enables the adaptive exploration of the consistency topological structure during graph learning, resulting in more accurate clustering outcomes. Extensive experiments are provided to show the effectiveness of the proposed method. The source code can be found at https://github.com/CLiu272/CTGL.

As an integral component of the global nitrogen cycle, nitrate are readily transferred from urban sewage discharge, agricultural activities, and atmospheric sedimentation to surface water. This paper introduces an innovative framework that combines multi-source remote sensing technology with stable nitrate nitrogen (δ15N-NO3−) and oxygen (δ18O-NO3−) isotopes mixing model, to identify nitrate sources quantitatively in surface water for the first time (R2 range from 0.50 to 0.99, RMSE range from 0.05‰ to 2.31‰, MAE range from 0.03‰ to 1.35‰). By reconstructing the historical nitrate isotopes from 2006 to 2023, we found that manure and sewage were the main contributing sources, followed by soil nitrogen, fertilizer and atmospheric deposition (contribution ratio of 3.5:2.5:2.5:1.5), wastewater discharge and fertilizer application in Xijiang river had a significant impact on this. This framework fills a gap in the research pertaining to remote sensing technology’s identification of surface nitrate sources, facilitating straightforward and user-friendly forecasting of nitrate source spatio-temporal sequences.

Study region: Yellow River Basin Study focus: The water resource patterns in the Yellow River Basin (YRB) have undergone significant changes. This study, based on multi-source data, retrieves and calculates Terrestrial Water Storage Anomalies (TWSA) and Water Scarcity Drought Index (WSDI) data to identify TWSA and hydrological drought events in the YRB,while comprehensively analyzing the natural and anthropogenic factors influencing TWS changes.Finally, the mechanisms leading to irreversible reductions in TWSA during drought periods are explored. New hydrological insights for the region: Both TWSA and Groundwater Storage anomalies (GWSA) in the YRB continue to decline at rates of -4.70 mm/a and -10.59 mm/a, respectively.Notably, 61.2 % of the water storage loss occurred during drought events.The groundwater overexploitation during droughts creates persistent deficits, leading the basin into long-term hydrological drought.Analysis using different drought indices reveals that hydrological drought has decoupled from meteorological drought since 2016,with human activities becoming the primary driver of hydrological drought.Regarding the factors influencing water storage, the correlation with human activity factors is significantly higher than with climatic factors.Moreover, a distinct ecological restoration paradox has emerged in the YRB: increases in ecological water use and NDVI have paradoxically exacerbated TWS loss.Trade-offs between anthropogenic water use, water resources, and ecology during droughts are crucial for the sustainable development of the YRB.

This study aimed to analyze the spatiotemporal trends of the non-agriculturalization of cultivated land (NACL) and evaluate the effectiveness of land management strategies in Shaanxi Province, China. First, geostatistical analysis was conducted to examine NACL dynamics, revealing that most areas remained in a mild early warning state from 2000 to 2010. However, warning levels escalated to severe or extreme in northern Shaanxi, parts of Guanzhong, and southern Shaanxi between 2010 and 2020. Subsequently, the Patch-Generated Land Use Simulation Model (PLUS) was employed to simulate NACL under different land management scenarios, using 2020 as the baseline and 2035 as the target year. The scenarios include natural growth (NG), cultivated land protection (CP), and ecological protection (EP), which were designed based on national and provincial land use planning objectives for 2035. The results indicated that, under the NG scenario, the overall NACL area is projected to decline by 2035, although northern and southern Shaanxi will remain highly susceptible to NACL. The CP scenario effectively mitigated NACL, reducing warning levels to moderate or mild in parts of Guanzhong and northern Shaanxi. Spatial clustering analysis further revealed that NACL in northern Shaanxi consistently exhibited high–high clustering in both historical periods and across different management scenarios. These findings establish a research framework for identifying and forecasting NACL while providing a scientific basis for optimizing land resource allocation and informing policy decisions.

Oasis agriculture is one of the main forms of agriculture in the world. Studying the impact of agricultural practices on soil organic carbon (SOC) within oases can provide valuable insights into the dynamics of carbon input and sequestration in oasis agriculture. It can contribute to the development of well-reasoned agricultural policies. This study focuses on the farmland in the typical inland river basin of the Shiyang River. We established an observation system and collected soil samples from different areas within the basin: upstream (mountainous farmland), midstream (oasis farmland), and downstream (farmland at the edge of the oasis). We analyzed the SOC content and compared the effects of various agricultural activities (abandoned land, forest land, grassland, and farmland abandoned for two years) on SOC levels. The findings suggest that: (1) In the same inland river basin, the organic carbon of farmland in the upper and middle reaches is significantly higher than that in the lower reaches, and the farmland in the core area of the oasis is higher than that in the marginal area; (2) Farmland in the inland river basin exhibits a higher SOC content compared to woodland and grassland areas. the process of agricultural leads to an increase in SOC content within the inland river basin; (3) The abandonment of cultivated land leads to a decrease in SOC, and plastic film mulching has no obvious effect on the content of SOC. The research clarifies the impact of agricultural activities on SOC in arid oasis areas, and quantified the impact of different agricultural activities on SOC. The research can provide new references for understanding the impact of agriculture in arid regions on carbon cycling.