Search Results (9,063)

Rapid urbanization has intensified two critical urban challenges: the urban heat island effect and stormwater runoff. This study evaluates the pilot-level field performance of a low-tortuosity permeable pavement (LTPP) system in potentially contributing to improved thermal regulation and hydraulic functionality. The system comprises a reduced-tortuosity upper block incorporated with bottom ash (BA) as a recycled fine aggregate and an underlying storage unit connected through an interlocking configuration, enabling direct infiltration while reducing clogging susceptibility and improving resistance to settlement and displacement. Field tests included thermal imaging, water-spraying infiltration-storage and vehicle-loading observations, and theoretical storage analysis. Initially, conventional permeable pavement (PP) dry surface temperature was measured at 44.2 °C, whereas the LTPP system already exhibited a lower temperature of 42.4 °C. During the evaporative stage after wetting, the LTPP system showed a lower temperature recovery rate, with a 2.91% increase between 90 and 120 min compared with 3.60% for conventional permeable pavement, indicating improved surface-temperature regulation. The storage calculations approximated that the LTPP system could theoretically buffer the simulated 15.63 mm/h rainfall by 6.65 to 7.32 h. It was also determined using historical rainfall data that the LTPP system, especially when provided with an outlet or drainage system, could effectively accommodate short- to medium-duration rainfall. Water-spraying tests confirmed rapid infiltration and subsurface storage, while vehicle-loading observations showed no noticeable displacement or settlement. These findings highlight the potential of a multifunctional permeable pavement design strategy that combines low-tortuosity flow paths, functional recycled aggregate selection, and subsurface storage for surface-temperature regulation and stormwater management. Full article

Land-cover-based ecosystem service valuation commonly assigns a uniform value coefficient to pixels within the same land-cover class, thereby overlooking ecological heterogeneity in mountainous protected areas. This study developed an improved remote sensing ecological index (IRSEI) and applied it as a spatial adjustment factor in the equivalent factor method to assess ecosystem service value (ESV) changes in the Qionglai Mountains section of Giant Panda National Park, China, between 2017 and 2022. IRSEI integrated the normalized difference vegetation index, wetness, normalized difference built-up and soil index, land surface temperature, and cumulative dynamic habitat index derived from the fraction of absorbed photosynthetically active radiation. DHI-cum was included as a proxy for annual cumulative vegetation productivity and habitat energy availability rather than a direct measure of biodiversity or giant panda habitat quality. Total ESV increased from 3.27 × 10⁸ CNY in 2017 to 4.25 × 10⁸ CNY in 2022, representing an increase of 9.79 × 10⁷ CNY, or 29.98%. Water bodies contributed the largest absolute increase, rising by 4.79 × 10⁷ CNY, or 42.45%, whereas farmland showed the highest relative increase of 45.35%. Woodland remained the dominant contributor to total ESV. Spatially, ESV was higher in the northern and southern parts and lower in the central region. All corrected sensitivity coefficients were below one, indicating that total ESV responded inelastically to ±50% perturbations of individual land-cover value coefficients. The framework improves within-class spatial differentiation of ESV and may support targeted management of mountainous protected areas, although field-based habitat and biodiversity data are needed for further validation. Full article

Non-grain production of cultivated land has increasingly affected regional food security and the stability of agricultural ecosystems. In traditional rice-producing regions, changes associated with non-rice cultivation, fallow land, rice-fishery integrated farming, and intensive agricultural management are reshaping the spatial structure of paddy landscapes. To identify the long-term spatiotemporal evolution of paddy systems, this study investigated Northern Jiangxi, China, using Landsat surface reflectance imagery from 2000, 2005, 2010, 2015, and 2020 on the Google Earth Engine (GEE) platform. The Enhanced Vegetation Index (EVI) and Land Surface Water Index (LSWI) were used to construct a phenology-based Flooding Frequency (FF) indicator. Based on the annual frequency with which pixels satisfied the condition LSWI > EVI, cultivated land was classified into three categories: non-flooded cropland, standard rice paddy, and high-frequency flooded cropland. In this study, non-flooded cropland was used as an indicator of potential non-rice cultivation rather than as direct evidence of confirmed non-grain production. Landscape metrics, transition matrices, gravity center migration, standard deviation ellipses, and geographically weighted regression (GWR) were then used to examine paddy landscape dynamics, fragmentation patterns, and county-level spatial associations with socioeconomic factors. The results suggest that the paddy system in Northern Jiangxi experienced marked stage-based fluctuations between 2000 and 2020. Standard rice paddy recovered during 2005–2010, whereas non-flooded cropland expanded considerably during 2010–2015, accompanied by intensified paddy landscape fragmentation. Non-flooded cropland was mainly distributed around urban fringes, transport corridors, and some hilly margins. Standard rice paddy was concentrated in traditional grain-producing areas, including the Poyang Lake Plain and the Gan-Fu Plain. High-frequency flooded cropland was primarily located in low-lying lake areas, where its dynamics were likely associated with rice-fishery integrated farming, continuous irrigation, and hydrological fluctuations. Landscape metrics showed that the largest patch index and mean patch size of standard rice paddy declined after 2010, indicating reduced spatial continuity of core paddy fields. The GWR analysis provided auxiliary evidence that total population, per capita gross domestic product (GDP), and urbanization rate were spatially associated with changes in non-flooded cropland at the county level; however, the results should be interpreted as exploratory associations rather than causal mechanisms. Overall, paddy landscape change in Northern Jiangxi was expressed not only through changes in cultivated land area, but also through the reorganization of paddy function, spatial continuity, and land-use intensity. Future cropland protection should therefore move beyond area-based control toward integrated management of quantity, quality, function, and spatial configuration. Future research should further verify these findings using dynamic cropland boundaries, higher-resolution imagery, and more detailed socioeconomic data. Full article

Accurate modeling and partitioning of forest evapotranspiration (ET) are essential for understanding water cycle processes in forest ecosystems. This study develops an improved three-source ET model by integrating a physically based canopy interception evaporation (Ei) scheme into the Shuttleworth–Wallace–Hu (SWH) model. A Monte Carlo stochastic parameterization scheme was applied to optimize model parameters. The proposed framework disaggregates the total ET flux into three distinct components: vegetation transpiration, soil evaporation, and Ei, thereby reducing uncertainties associated with the original SWH model in humid forest regions. The new model’s performance was assessed using flux observations from two subtropical forest sites and compared to the SWH model. The verification results indicate that the three-source model provided reliable estimates of daily ET. At the QYZ station (2004–2007) and the DHS station (2005–2007), the fitting slopes for simulating daily ET were 0.97 and 1.01, respectively, with corresponding coefficients of determination of 0.92 and 0.81. The root mean square errors (RMSE) for the three-source model were 0.38 mm day⁻¹ and 0.52 mm day⁻¹, respectively, with a reduction of 4.33% and 3.10% in RMSE compared to the SWH model. Additionally, the new model simulated the annual T/ET ratio more accurately, with values closer to site-measured data than the SWH model’s estimates. At both sites, the T/ET ratios simulated by the new model were closer to the observed values than those simulated by the SWH model, indicating an improved representation of ecohydrological processes. Furthermore, environmental analysis revealed that vapor pressure deficit and precipitation primarily govern the T/ET ratio, exerting the strongest positive and negative effects, respectively. Importantly, it requires only one additional precipitation parameter compared to the SWH model, yet achieves higher simulation accuracy and a more realistic representation of hydrological processes. Overall, the three-source model provides an improved framework for estimating ET in humid forest ecosystems. Ultimately, these results offer deeper insights into the coupled water and energy fluxes within forest ecosystems, thereby facilitating more effective water management and guiding sustainable forestry under a shifting climate. Full article

Terrestrial water storage in semi-arid basins is increasingly affected by the combined pressures of climate variability, land use change and intensive human activities. However, how landscape composition and configuration interact with climatic forcing to shape basin-scale terrestrial water storage anomalies (TWSA) remains insufficiently understood, particularly in rapidly urbanising tributary basins of the Yellow River. This study integrates GRACE/GRACE-FO-derived TWSA, meteorological observations and multi-period land use data to examine the coupled relationships among climate variability, landscape patterns and water storage in the human-dominated Yiluo River Basin. The results show that basin-averaged TWSA experienced a significant long-term decline during the GRACE/GRACE-FO period (−4.47 mm yr⁻¹), with a statistically detectable transition around 2012 and stronger depletion in the northern and eastern parts of the basin. Precipitation exhibited a cumulative and delayed relationship with TWSA, with the strongest raw association occurring under a six-month accumulation and one-month lag (Pearson’s r = 0.44, p < 0.001, n = 134). After removing the seasonal cycle, the relationship remained significant but weaker (r = 0.30, p = 0.001, n = 129), indicating that precipitation explains part, but not all, of the interannual variability in water storage. Landscape composition showed stronger associations with TWSA than landscape configuration. Construction land was negatively associated with water storage, whereas cultivated land and grassland showed positive associations, suggesting that impervious surface expansion and the loss of permeable land may weaken the basin’s water retention capacity. These findings indicate that water storage change in the Yiluo River Basin is shaped by both climatic forcing and human-induced land surface transformation. Basin management should therefore prioritise the control of urban impervious surface expansion, the protection of permeable agricultural and ecological land, and the integration of land use planning with adaptive water resource regulation. Full article

Arid inland saline lakes are key components of basin ecosystems. As the largest saline lake in Xinjiang and a critical ecological barrier in northwest China, Ebinur Lake’s area dynamics are vital to regional sustainable development. This study integrates Landsat imagery (1992–2024) with meteorological and socio-economic data to investigate optimal water extraction methods, spatio-temporal lake area variations, and driving mechanisms. Multiple methods were employed, including water index comparison, Mann–Kendall test, Pearson correlation, and ridge regression. Results show that: (1) the Normalized Difference Water Index (NDWI) maintains high, stable classification accuracy across years and months, making it suitable for long-term monitoring; (2) from 1992 to 2024, lake area demonstrates a significant fluctuating downward trend without abrupt change points, indicating continuous degradation. During the growing season (April–October), it first decreases and then increases, with larger early-season areas, minima in August and September, coinciding with peak agricultural irrigation demand; (3) regarding driving mechanisms, socio-economic factors dominate (approximately 70%), while meteorological factors play a weakly regulatory role (about 30%). Population growth and increased water consumption are the primary drivers, with obvious seasonal differences. Meteorological changes, socio-economic development, and ecological measures jointly influence lake area. Although extreme events (e.g., anomalous precipitation) induce short-term fluctuations, they do not alter the long-term degradation trend dominated by human activities. This study provides methodological support for long-term monitoring of arid saline lakes and scientific evidence for ecological conservation and water resource management in the Ebinur Lake Basin. Full article

Coal mining in areas with high groundwater levels often induces land subsidence and water accumulation, leading to the formation of artificial secondary wetlands. Reclaimed wetlands may provide important opportunities for regional biodiversity recovery. Taking Shuoxi Lake Wetland in Huaibei City as a case study, this research aims to reveal the characteristics of waterbird diversity in artificial wetlands after ecological reclamation in a coal mining subsidence area and to identify their key environmental drivers, thereby providing a scientific basis for optimizing the habitat service functions of such wetlands. Based on habitat identification and classification of the reclaimed wetland, waterbird diversity was surveyed, and redundancy analysis (RDA), Mantel tests, and ridge regression models were used to identify the major environmental factors influencing the distribution of different waterbird groups and to quantify their relative contributions. The results showed that after ecological reclamation, a total of 28 waterbird species belonging to 7 families and 6 orders were recorded in the artificial wetland of the coal mining subsidence area. Redundancy analysis (RDA) indicated that wader assemblages were more sensitive to vegetation cover (VC), distance to water bodies (DTW), and distance to buildings (DTB), whereas waterfowl assemblages were mainly affected by distance to buildings (DTB), area (A), and distance to water bodies (DTW), and showed no significant response to vegetation heterogeneity. Mantel tests further confirmed significant spatial correlations between waterbird assemblages and area (A), distance to major roads (DTR), distance to buildings (DTB), water depth (WD), and distance to water bodies (DTW). Ridge regression analysis showed that, under conditions in which anthropogenic disturbance was minimized, vegetation cover (VC) and water depth (WD) were the main positive drivers of wader diversity, whereas perimeter to area ratio (PAR) was the main negative driver. Waterfowl diversity was mainly negatively affected by perimeter to area ratio (PAR) and distance to water bodies (DTW). These findings suggest that appropriately regulating water depth, increasing vegetation cover, and reducing patch fragmentation and anthropogenic disturbance are key measures for enhancing the habitat service functions of artificial secondary wetlands in mining areas. These management strategies provide an important reference for wetland rehabilitation in other coal mining subsidence areas. Full article

Water scarcity poses significant challenges to urban water management for long-term sustainability in hyper-arid regions. This study presents a longitudinal assessment of water demand and supply dynamics in Sharjah, United Arab Emirates, from 2016 to 2022 using operational data obtained from the Sharjah Electricity, Water and Gas Authority (SEWA). Temporal trends in water production, sectoral consumption, and source transitions were evaluated using descriptive statistics and operational performance metrics: Demand–Production Ratio (DPR), Operational Production Margin (OPM), Production Adequacy Index (PAI), Source Dependency Ratio (SDR), and Seasonal Variability Index (SVI). Results showed that Sharjah maintained a production capacity consistently exceeding billed consumption, with an average DPR of approximately 72% and a PAI of 1.0. Desalinated water became the dominant supply source (~90%), while groundwater reliance declined substantially to support aquifer conservation. The residential sector accounted for approximately 62% of total water demand, highlighting the importance of demand-side management strategies. Seasonal variability analysis indicated peak demand during summer months, while desalination capacity supported relatively stable supply conditions throughout the year. The findings provide localized empirical insights into urban water management, supply diversification, and long-term water security in a hyper-arid Gulf city. Full article

Reference evapotranspiration (ET_o) is essential for irrigation scheduling, water resources management, and climate-related applications, but the FAO Penman–Monteith (FAO-PM) method is often constrained by limited meteorological data availability. This study evaluated four machine learning (ML) algorithms, Kernel Approximation Regression (KAR), Multilayer Perceptron (MLP), Extreme Gradient Boosting (XGB), and Random Forest (RF), for reproducing FAO-PM ET_o under different levels of geographical and meteorological information availability in the Czech Republic. Daily observations from 59 meteorological stations (1980–2024) were used to develop eight input scenarios. Model performance was evaluated using a station-wise chronological train–test framework and station-based analyses. The results showed that predictor availability had a greater influence on model performance than model selection. The geographical-information scenario produced the lowest performance, whereas substantial improvements were achieved when meteorological variables were incorporated. Among the single-variable meteorological scenarios, relative humidity provided the greatest improvement in agreement with the FAO-PM ET_o benchmark. Across all input scenarios and ML algorithms, testing performance ranged from R² = 0.683 to 0.998 and RMSE = 0.076 to 0.939 mm d⁻¹, indicating progressively improved agreement with FAO-PM ET_o as additional meteorological information became available. The reduced-input scenarios therefore provide a practical approach for approximating FAO-PM ET_o at stations represented during model development when some meteorological inputs are unavailable. Full article

Film-mulched drip irrigation (FMDI) is used increasingly for cotton (Gossypium hirsutum L.) production in arid regions. However, salts often accumulate in the soil, eventually leading to soil salinization and crop failure when using FMDI with brackish water inappropriately. Evaluation of the leaching requirement (LR) for cotton under FMDI with brackish water that comprehensively considers cotton yield, water saving, soil conditions, and economic benefits needs to be investigated more completely. The present study compared the cotton growth for different leaching fractions (LF) under FMDI with brackish water and provides comprehensive analysis of LR for cotton and its relationships with soil conditions. A higher LF was related to a lower cotton yield when the LF was larger than 0.15. Moreover, a larger LF led to a lower ratio of reproductive growth and irrigation water productivity when the LF was larger than 0.2. A high soil water content (SWC) strip was observed in the 40–60 cm soil layers for all scenarios. Moreover, a higher SWC proportion in the deeper soil layers as for LF_0.15 or LF_0.2 may also be beneficial to cotton growth. Soil salinity decreased with decreases in irrigation water quantity when the LF was lower than 0.2, but increased when the LF was higher than 0.2. Either too much or too little irrigation water was not beneficial from an economic perspective. Our study indicated that the LR values between 0.05 and 0.15 were recommended for FMDI when the total dissolved solids for brackish water is within 1.61–3.21 g L⁻¹. Integrated strategies, including optimized irrigation-fertilizer management, groundwater depth monitoring, and halophyte intercropping, are required to sustain production while mitigating secondary salinization and groundwater pollution under FMDI with brackish water. Full article

Accurately acquiring soil moisture content (SMC) and its spatial distribution is of great significance for water-saving irrigation and sustainable agricultural development in arid regions. However, the complex soil background noise and weak moisture absorption features in the Xinjiang region severely restrict the accuracy and reliability of remote sensing inversion for SMC. To address the challenges of difficult feature capture and low estimation accuracy in soil moisture monitoring, this study utilized GF-5 satellite hyperspectral data and ground-measured SMC data. First, the effects of Fractional-Order Differentiation (FOD) at orders 0–2 (with a 0.2 step size) on spectral moisture response were systematically evaluated. Next, 60 dual-band spectral indices (DBIs) were constructed from full-band combinations under the optimal differentiation orders, and highly correlated indices were selected as candidate features. Finally, three variable screening methods were coupled with three machine learning models to construct nine SMC inversion schemes, and the optimal model combination was employed to map the spatial distribution of SMC in the study area. Results showed that FOD at orders 0.8–1.2 effectively enhanced spectral responses at soil moisture absorption bands, the introduction of DBI concentrated high-correlation band combinations in moisture-sensitive regions, and the optimal scheme (BSS-PLSR) demonstrated good predictive performance and stability. These findings provide data support for precision irrigation decision-making and soil moisture management in arid farmlands. Full article

To address the challenges of excessive water and fertilizer application, declining soil fertility, and suboptimal maize yields in the oasis irrigation areas of Northwest China, a two-year (2024–2025) field experiment was conducted. Three irrigation levels were implemented: a 30% reduction (W1: 3575 m³·ha⁻¹), a 15% reduction (W2: 4335 m³·ha⁻¹), and conventional irrigation (W3: 5100 m³·ha⁻¹). Nitrogen management comprised three strategies: 30% organic substitution (N3), 15% organic substitution (N2), and full chemical nitrogen fertilizer (N1). Statistical approaches, including correlation analysis and the CRITIC-AHP-VIKOR comprehensive evaluation model, were applied. The results indicated that ear length differed significantly among treatments, with the longest ears observed in W2N2 and W3N2 (17.39–17.68 cm) and the shortest in W1N1 (14.52 cm). Under W2 conditions, the kernel number per ear in N2 was 1.73% higher than that in N3, whereas under W1 conditions, N2 showed a 0.21% reduction compared to N3. The 100-kernel weight varied minimally, ranging from 32.04 to 40.70 g, with no significant difference between W2N2 and W3N3. Among all treatments, W2N2 produced the greatest yield, exceeding those of W3N3 and W2N3 by 6.07% and 5.96%, respectively. During the two experiments years, this treatment also promoted the accumulation of soil carbon and nitrogen in the 0–20 cm layer, increasing soil organic matter by 22.34–118.15% and total nitrogen by 5.62–40.45%. In contrast, grain quality parameters, including crude protein, crude starch, and crude fat contents, did not differ significantly between W2N2 and W3N3. Moreover, W2N2 achieved an irrigation water use efficiency of 4.41 kg·m⁻³, which was significantly greater than that under W1N2, while nitrogen use efficiency was improved by 42.57%. Correlation analysis revealed that maize yield is significantly positively correlated with soil carbon and nitrogen pools, grain quality indicators, and nitrogen fertilizer partial productivity, whereas quality parameters were positively correlated with irrigation water use efficiency, though not significantly. The CRITIC-AHP-VIKOR model identified that the comprehensive strategy of 15% irrigation reduction combined with 15% organic nitrogen substitution synergistically enhances maize yield, maintains soil carbon and nitrogen pools, and improves water–nitrogen use efficiency. These results provide a theoretical basis for promoting sustainable maize cultivation in arid irrigated areas characterized by limited water and nitrogen availability. Full article

Drought is a major climatic hazard affecting agricultural production and water resource management. This study investigates the spatiotemporal evolution of summer drought across nine major agricultural regions in China and quantifies associated uncertainties under historical (1981–2010) and future periods (2041–2070 and 2071–2100). Using multi-model simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6) under four SSP scenarios (SSP126, SSP245, SSP370, and SSP585), drought variations were characterized using the Standardized Precipitation Index at a 3-month timescale (SPI-3). Sen’s slope estimator combined with the Mann–Kendall test was applied to detect drought trends, and factorial analysis was used to quantify uncertainty contributions. Results show pronounced regional differences in historical drought conditions, with northern arid and semi-arid regions exhibiting stronger precipitation deficits (mean SPI-3 = −0.435), while the Yangtze River Plain and Northeast China Plain show wetter conditions. Historical trends indicate increasing drought conditions in South China, whereas humidification trends dominate several northern and eastern regions. Under future scenarios, most regions show overall wetting trends, but drying tendencies persist in South China. Factorial analysis reveals that regional differences (58.34%) and climate model uncertainty (31.15%) are the dominant contributors to drought variability. Overall, future summer drought in China is characterized by a general wetting tendency with localized intensification of drought conditions. Full article

Vertisols represent some of the most dynamic pedological systems due to the high content of smectitic clays and the intense shrinkage–swelling processes associated with seasonal variations in humidity. The present work analyzes the dynamics of pedoturbations and the rheological behavior of a smectitic Vertosol located in the Cheglevici experimental field (Aranca Plain, western Romania), continuously monitored for a period of over 50 years (1967–2020). In a stationary experiment, inert markers were buried at depths ranging from 25 to 150 cm to track the vertical displacement of the soil mass. Periodically collected samples were analyzed from a granulometric, mineralogical, chemical, and rheological point of view (plasticity limits, activity index, volumetric shrinkage, free swelling, deformation modulus, cohesion, conventional pressure). The results indicate a high smectite content (69–76%) and rheological indices specific to highly active soils (PI > 35%, A > 1.0, VS > 100%, FS > 140%). The progressive redistribution of the markers provides strong evidence of substantial profile-scale soil redistribution associated with long-term pedoturbation processes, supporting the hypothesis of a near-complete profile turnover over multidecadal timescales. A significant increase in apparent density and a tendency for granulometric homogenization across the profile, associated with structural reorganization, are also highlighted. The study provides long-term experimental evidence on the vertical dynamics of the soil mass in Smectitic Vertisols and reveals major implications for agricultural management, infrastructure stability, and water flow modeling in expansive soils. Full article

The tourism sector in the Sultanate of Oman is central to “Oman Vision 2040”, with a strategic focus of the government on its dynamic transformation. Coastal regions, vital to tourism, are affected by changes to the coastline due to flash floods, sea-water flooding, and erosion. Despite its implications for tourism and the economy, this topic remains relatively under-explored, especially as to use of Sentinel-1 satellite images. This study assesses water-level changes due to erosion in the urban coastal region of the Al-Batinah governorate via land cover classification. Using the Support Vector Machine (SVM) classification technique, the overall accuracy is found to be 97.7% and the Kappa coefficient value for the year 2018 is 1.0. Although, when using the Random Forest (RF) classification technique, the accuracy is nearly identical, there is varying precision for the water area. A critical observation is made, showing significant increase of the water area from 2.99% in the year 2017 to 12.36% in the year 2025, suggesting water encroachment. With fixed-effect and combined-effect size meta-analysis models, the confidence levels were identified as 95.0% and 0.37, respectively, indicating a consistent variation in water area that supports the outcomes of image classification. This study offers a valuable insight for policymakers as to managing coastal regions, along with providing assistance to vulnerable coastal communities. The study focuses on a particular governorate, given the satellite images, whereas a broader regional comparison would address the limitation of the generalizability of results. In the future, the research could integrate surveys from coastal communities and businesses for a comprehensive qualitative data perspective on the region’s tourism sector. Full article