Search Results (10,134)

Cultural heritage sites in arid regions are often underestimated in terms of flood risk; however, the increasing frequency and intensity of extreme precipitation events under climate change have significantly amplified threats to these fragile environments. Taking the Xixia Imperial Tombs in China as a case study, this research investigates strategies for flood hazard prevention and control for cultural heritage in arid areas. By situating the study within the broader context of climate change and global heritage conservation, the paper examines the impacts of flooding on heritage sites and the historical evolution of flood control measures. It further integrates an analysis of the site’s geographical characteristics, traditional flood management structures, and contemporary conservation practices. The study systematically elucidates the compound risks of “drought–desertification–sudden flooding” faced by cultural heritage in arid landscapes. The findings suggest that heritage protection should transition from reactive, post-disaster restoration toward proactive preventive conservation. This shift requires the integration of both engineering and non-engineering measures, supported by technology-based systems such as environmental monitoring and early warning platforms, to establish a comprehensive risk management framework. The research highlights that overcoming the prevailing misconception that “arid regions are free from flood risks,” embedding heritage flood management into regional planning, and ensuring legal, financial, and interdisciplinary cooperation are essential for the long-term safeguarding of cultural heritage in arid environments. This study offers practical insights and a transferable reference for the protection of heritage sites in similar climatic and geographical contexts worldwide. Full article

Groundwater level (GWL) variations in the arid regions of Northwest China are driven by both natural processes and human activities. Identifying causal links between hydrological variables is fundamental to understanding groundwater evolution and conducting dynamic simulations. This study integrates the Mann–Kendall test, Seasonal-Trend decomposition using Loess, and the Peter and Clark Momentum-threshold and Momentary Conditional Independence (PCMCI) causal inference to analyze GWL variation characteristics and causal response processes across seven sub-basins in the Tarim Basin using multi-source remote sensing data. Results show an overall decline in GWL, primarily in the north-central part of the basin, with the Kaidu–Konqi River Basin reaching a maximum rate of 0.51 m/year. The trend components reveal localized depletion alongside broad stability, while seasonal components exhibit three types of temporal shifts in fluctuations. A mismatch exists between the prevalence of environmental influences and their causal strength. Daytime land surface temperature (LST_D), surface runoff (RO), and evapotranspiration (ET) show the highest detection frequencies, yet volumetric soil water in layers 2 (SWVL₂) and RO exhibit the largest ranges in strength and drive variations at specific sites. Response times are asymmetric. Negative effects from ET on GWL transmit quickly, while positive recovery is slow. Conversely, positive recharge from volumetric soil water in layer 1 (SWVL₁) is faster than its negative lag. At the basin scale, surface processes recharge GWL while mediating indirect influences from other variables. Climate and agricultural irrigation act as direct sinks. Depending on local conditions, three regional patterns emerge: direct climate-driven depletion, obstructed shallow water retention, and indirect compensation from agricultural water use. Causal networks indicate that RO and SWVL₁ have the highest centrality and dominate water output, whereas SWVL₂ acts as a passive receiver. Pathways from the surface to GWL are also asymmetric. The most frequent path involves step-by-step infiltration along RO → ET → SWVL₁ → SWVL₂ → GWL. In contrast, the paths with the highest cumulative strength are shorter and faster, specifically RO → ET → GWL and RO → SWVL₁ → GWL. The identified pathways and lag parameters provide a direct basis for groundwater dynamic modeling and water resource management in the basin. Full article

Understanding how land-use dynamics and carbon balance respond to socio-economic development and future climate change is essential. It supports the refinement of ecological management strategies in environmentally fragile regions and the achievement of China’s dual-carbon goals. This study aims to (i) analyze historical land-use evolution in Xinjiang from 2000 to 2020 and simulate its future dynamics from 2021 to 2060 under multiple SSP-RCP scenarios; (ii) quantify land-use carbon emissions and carbon storage using the coupled SD-PLUS-InVEST model; and (iii) evaluate the carbon balance through the carbon emission to storage ratio (CESR). This study coupled the system dynamics (SD) model, Patch-generating Land Use Simulation (PLUS) model, and InVEST model by integrating socio-economic statistics, IPCC climate data, and land-use datasets. The integrated model was used to simulate land-use evolution in Xinjiang from 2000 to 2060 and to quantify the spatiotemporal variation in land-use carbon emissions, carbon storage, and the CESR. Results indicated that carbon emission increased continuously from 2000 to 2020. Carbon emission showed an inverted U-shaped pattern from 2020 to 2060, with the peak occurring in approximately 2030 under the SSP1–2.6 and SSP2–4.5 scenarios, while it continued to rise from 2020 to 2060 under SSP585. Carbon storage exhibited an “initial increase followed by decline” from 2000 to 2020 but increased consistently from 2020 to 2060 under all scenarios. Xinjiang is a carbon-contributing area with the CESR less than 1 from 2000 to 2060. The CESR increased first and then decreased from 2020 to 2060 under SSP126 and SSP245, while it increased significantly under SSP585. The carbon contribution capacity in Xinjiang decreased under SSP585. These findings indicated that Xinjiang is a carbon contribution area, but its contribution function may be weakened by the expansion of energy-related land use and reduction in forest areas. Hence, it is necessity to uphold Xinjiang’s role within the national carbon balance framework by enhancing spatially differentiated land management, promoting the low-carbon transformation of the energy structure, and strengthening ecological restoration efforts to improve regional carbon sink capacity. Full article

Climate-driven heat and water stress are increasingly compromising rainfed maize yields in transition zones, with significant implications for global food security. While continental-scale models of crop suitability exist, they often fail to capture the high-resolution heterogeneity of agricultural landscapes or distinguish between irrigated and rainfed systems in semi-arid regions. This study models the current and future suitability of rainfed maize in Kansas, USA, using a Maximum Entropy (MaxEnt) approach. To accurately isolate biophysical constraints, we employed a novel data-filtering workflow using the USDA Cropland Data Layer (CDL) and Landsat-based Annual Irrigated Datasets (LANID) to train the model exclusively on rainfed occurrences. We projected suitability shifts for the mid- (2041–2070) and end-of-century (2071–2100) periods under two CMIP6 Shared Socioeconomic Pathways (SSP3-7.0 and SSP5-8.5), using high-resolution CHELSA bioclimatic variables. The model, achieving an Area Under the Curve (AUC) of 0.73 and validated against 30 years of historical USDA production records, reveals a distinct spatial contraction of areas climatically suitable for growing maize. Projections indicate a significant decline in suitability across Western and Central Kansas driven by rising temperatures and precipitation variability, with the most highly suitable optimal habitats projected to decline by approximately 90% by mid-century. These findings quantify mounting climate impacts on maize-growing areas of the Great Plains and provide spatially explicit baselines for the development of regional adaptation strategies and groundwater conservation policies. Full article

Relief is an important driver in the spatial differentiation of river runoff and its regime both in the mountains and on the plains, which is most evident in arid and semi-arid regions of the Earth’s land. Based on 22 small and medium-sized rivers of the zones of forest–steppe and steppe in the temperate climate zone of the eastern part of the East European (Russian) Plain, within the Middle Volga region and the eastern part of the Don River basin, the role of this factor in the spatiotemporal changes in various key runoff parameters (annual average runoff (Q), annual maximum runoff (Q_max), and annual minimum runoff for both cold (Q_min-CP) and warm (Q_min-WP) seasons) between two baseline climatic periods of the Anthropocene (1961–1990 and 1991–2020) is considered using the average elevation of river basin (H) as its quantitative indicator and statistical procedures of regression and correlation analysis. It is found that in the interperiod trends of the Anthropocene, the H factor was the leading (and statistically significant) cause of spatial variability in the changes in Q_max in the forest–steppe zone, through its inverse relationship with H (with a 70% contribution of influence), Q_min-CP in the forest–steppe and steppe zones (with a 55–75% contribution of influence), and Q_min-WP in the steppe zone (with a 64% contribution of influence), through their direct relationships with H. It is also shown that H acted as an important factor (with a 47% contribution of influence) of statistically significant strengthening of the spatiotemporal coherence of Q and Q_max values between the studied periods, but only in the river basins of the Middle Volga region: during the period of the most active climate warming (1991–2020), the region’s upland rivers turned out to be more coherent in these two runoffs than the lowland ones. An ambiguous influence of H on the mutual correlation of all the examined runoff parameters over the baseline periods was revealed. The identified patterns are a consequence of the reaction of the complex altitudinal zoning of the plain’s landscapes mainly to climate changes, especially during the cold season (frequent thaws, decreasing soil freezing depth, etc.). The achieved results are intended to contribute to the understanding of the role of so-called “passive” driving forces in contemporary regional changes in river runoff. Full article

Accurate quantification of ecohydrological processes is essential for effective water and carbon management in terrestrial ecosystems. Traditional simulations mainly rely on mechanistic models, yet their accuracy is often limited by inconsistencies in representing physical processes and uncertainties in parameterization. Integrating remote sensing signals offers a promising way to reduce these uncertainties and enhance model applicability. In this study, in-situ observations from a wheat cropland in the Guanzhong Plain were used to simulate gross primary productivity (GPP) and latent heat flux (LE) by comparing a forward model (STEMMUS-SCOPE) with a remote sensing-driven inverse model (STEMMUS-MLR). We further examined the role of solar-induced chlorophyll fluorescence (SIF), an emerging proxy for photosynthesis, as an input to improve mechanistic modeling of GPP and LE. Results show that STEMMUS-MLR outperformed STEMMUS-SCOPE in estimating water and carbon fluxes, demonstrating that incorporating SIF effectively reduces bias associated with uncertainties in parameters and forcing data. The contribution of SIF was quantified using Random Forest regression and Shapley additive explanations (SHAP), revealing that SIF markedly reduced the dependence of GPP and LE simulations on shortwave radiation (SW), air temperature (Ta), and leaf area index (LAI). These findings highlight the critical role of SIF in ecohydrological modeling of semi-arid cropland ecosystems and provide a scientific basis for advancing process understanding and improving the precision management of water and carbon budgets in terrestrial ecosystems. Full article

Outdoor thermal comfort in university courtyards is a key factor influencing students’ environmental experience and the usability of outdoor spaces in hot-arid climates. Courtyard design may also affect the environmental conditions of adjacent classrooms by modifying solar exposure, shading, air movement, and surface heat gain. Accordingly, this study aims to develop optimized design scenarios for improving outdoor thermal comfort in university courtyards through hybrid passive strategies, including vegetation, shading systems, and cool pavements. To achieve this goal, the research adopted a combined field-based and simulation-based methodology. Field measurements and student questionnaires for 292 students were conducted in courtyards and classrooms of three university buildings in Luxor, Egypt. These buildings represent different urban morphologies, courtyard aspect ratios, geometric configurations, and student densities. In parallel, simulation models were developed using ENVI-met V5.6.1 and Rhinoceros V8 with Grasshopper, to test and compare various design scenarios. Field monitoring revealed that wider courtyards with low aspect ratios (0.28–0.38), lacking trees and finished with concrete paving, recorded lower CO₂ concentrations (around 800 ppm), but experienced higher surface and air temperatures. These elevated temperatures negatively affected outdoor thermal comfort and increased heat gain in classrooms overlooking the courtyards. In contrast, courtyards with higher aspect ratios (0.63–0.82) demonstrated better microclimatic moderation and improved comfort conditions. Simulation results indicate that integrating a belt vegetation pattern of Cassia leptophylla, combined with textile shading and cool pavements with an albedo of 0.5, can reduce the Universal Thermal Climate Index (UTCI) by up to 14.7 °C, shifting conditions toward moderate heat stress. The findings provide practical design guidance for upgrading existing university courtyards and designing future educational buildings in hot-arid climates to enhance student comfort and environmental performance. Full article

Increasing total soil porosity and optimizing pore distribution improve soil water-holding capacity, thereby alleviating drought impacts on crop yields in semi-arid regions. A three year split-plot field experiment was conducted, with organic fertilizer (sheep manure) rates as main plots and water-retaining agent (WRA) rates as subplots. Four organic fertilizer (0, 45, 60, and 75 Mg hm⁻²) and four WRA rates (0, 0.3, 0.6, and 0.9 Mg hm⁻²) were set, resulting in 16 combined treatments. Undisturbed soil samples were collected to analyze pore distribution and water availability using the soil water retention curve. The results showed significant variations in ameliorative effects with soil depth. Individual applications of either organic fertilizer or WRA significantly improved topsoil pore distribution and water availability but exerted negative effects on the subsoil. Combined application enhanced both soil layers, with a stronger synergistic effect in the subsoil. The combination of 45 Mg ha⁻² organic fertilizer + 0.9 Mg ha⁻² WRA achieved optimal soil improvement in the 0–20 cm layer, increasing aeration porosity by 21.89% compared to organic fertilizer alone; this improvement led to 14.99% and 15.65% increases in plant available water (PAW) and readily available water (RAW), respectively. For the 20–40 cm layer, the combination of 60 Mg ha⁻² organic fertilizer + 0.9 Mg ha⁻² WRA was optimal, increasing total, aeration, and capillary porosity by 24.18%, 183.50%, and 56.73%, respectively, compared to organic fertilizer alone. Consequently, subsoil water availability was enhanced, resulting in 57.53% and 61.18% higher PAW and RAW than the control without WRA. These findings highlight the necessity of layer-specific regulation and differentiated management. The optimal combinations (OF45+W0.9 for 0–20 cm and OF60+W0.9 for 20–40 cm) effectively optimize pore distribution and increase water availability through the complementary synergistic effects of organic fertilizer and WRA. Consequently, this strategy alleviates drought stress on crop yields in semi-arid regions. Full article

Mycorrhizae utilization is an integral part of the strategy for adapting to climate change in semi-arid regions. A controlled experiment was conducted at the University of Limpopo, South Africa, to determine the effects of arbuscular mycorrhiza fungi (AMF) and soil type on crop growth and root colonization of Jew’s mallow. Treatments comprised two levels of mycorrhiza (with and without), two soil sources (Ofcolaco and Syferkuil), and three Jew’s mallow cultivars (“Amugbadu”, “Oniyaya”, and a landrace). The results revealed that the Amugbadu cultivar produced the highest Mycorrhizal growth response (MGR) in Syferkuil soil, whereas the Oniyaya cultivar was the highest in Ofcolaco soil. MGR in Ofcolaco soil was six times higher than in Syferkuil soil. AMF-inoculated Amugbadu consistently resulted in the highest crop growth rate (CGR) in Ofcolaco soil. The inoculated landrace was superior in CGR, compared to the uninoculated landrace in Syferkuil soil. Approximately 71.23–75.86% of the Jew’s mallow roots were colonized by AMF in both soil sources, with inoculated “Amugbadu” producing the highest root colonization. The landrace root colonization was inferior in both soil sources. Our results indicate that incorporating AMF in Jew’s mallow could improve root colonization, growth rate, and productivity in the semi-arid regions of South Africa, depending on soil type. Full article

Pre-sowing tillage under irrigated agriculture is associated with high energy demand and increased risk of soil structural degradation, particularly in heterogeneous loam soils of arid and semi-arid regions. This study presents the engineering optimization and field validation of a combined implement for single-pass rotary strip tillage and precision seeding developed for irrigated sierozem soils of Southern Kazakhstan. The research integrates analytical modeling of soil–blade interaction, optimization of rotary blade geometry, and comparative field experiments using an experimental prototype (FS-2.1). Analytical optimization identified an optimal blade installation angle of 54–56°, resulting in an approximately 22% reduction in specific cutting area. Field results demonstrated that the single-pass system formed a high-quality seedbed, with 85.2% of soil aggregates smaller than 25 mm and a surface leveling deviation below 5 mm. Compared with a conventional multi-pass technology, traction load, fuel consumption, and total energy input were reduced by 38%, 43%, and 54.5%, respectively. The results confirm that combining optimized rotary blade geometry with strip-based soil disturbance enables substantial energy savings without compromising agronomic performance. The proposed engineering solution provides a reproducible framework for low-traction, resource-efficient tillage–seeding systems suitable for irrigated agriculture in Southern Kazakhstan and comparable agroecological regions. Full article

Assessing the construction suitability and sediment reduction potential of dry-farming wide terraces is critical for improving soil and water conservation in semi-arid and semi-humid regions, yet these aspects are seldom evaluated within an integrated framework. Focusing on the Loess Plateau, this study delineates potential construction areas based on precipitation constraints, quantifies soil erosion using the Revised Universal Soil Loss Equation, and develops a multidimensional framework to jointly evaluate construction suitability and sediment reduction potential on sloping farmland. Results indicate that slope, transportation accessibility, and soil erosion intensity are the primary determinants of suitability. Highly suitable, suitable, and marginally suitable areas account for 7.5%, 7.2%, and 4.3% of the study area, respectively, with Shanxi, Shaanxi, and Gansu provinces—and particularly Yulin, Yan’an, and Qingyang—emerging as priority regions for implementation. Scenario analysis suggests that targeting (i) highly suitable and suitable areas or (ii) all suitable classes would reclaim approximately 59.89 × 10³ km² and 77.19 × 10³ km² of sloping farmland, respectively, leading to reductions in mean soil erosion modulus of 16.6% and 22%. These findings provide a quantitative basis for optimizing terrace deployment and advancing regionally targeted soil erosion mitigation strategies on the Loess Plateau. Full article

Effective management of reservoir water for irrigation is crucial in arid regions prone to drought and water shortages. However, evaporation losses from reservoirs remain poorly understood. Direct measurements typically quantify evaporation only at the measurement site rather than across the entire reservoir. This study introduces the Turbulent Exchange Approach for Reservoir Evaporation Estimation (TEAREE). The TEAREE is a simple model that integrates a bulk aerodynamic formulation with Landsat 8–9 satellite water-surface temperature data and meteorological observations to estimate spatially distributed daily reservoir evaporation. The TEAREE model was first evaluated at Elephant Butte and Caballo reservoirs in NM, USA, and subsequently applied across multiple reservoirs with diverse climatic conditions to demonstrate its applicability for estimating open-water evaporation. Daily evaporation was obtained by upscaling satellite overpass-time evaporation estimates using the daily-to-instantaneous vapor pressure deficit ratio (k_e) and wind speed. The model performed strongly across 12 lakes (R² = 0.91–0.99; RMSE = 0.27–0.85 mm/day) compared with the bulk aerodynamic (B_AER) method. Comparison with eddy covariance (EC) evaporation also showed good agreement. Monte Carlo analysis indicated moderate uncertainty associated with k_e variability, supporting the operational use of a constant k_e = 0.95 for daily upscaling. Full article

Understanding long-term hydroclimatic variability in arid and semi-arid regions is essential for sustainable water resource management in the context of accelerating climate change. This study examines historical trends (1950–2024) and data-driven extrapolations to 2040 for precipitation and temperature across 30 secondary river basins in Iran using ERA5 reanalysis dataset and the Light Gradient Boosting Machine (LightGBM) model. Results reveal pronounced spatial heterogeneity in precipitation, with more than two-thirds of basins showing median values of 0 mm, reflecting extreme rainfall intermittency. Long-term analysis indicates significant precipitation increases in northern basins, whereas decadal trends show widespread drying since the early 2000s, particularly in eastern regions (30–60 mm per decade). Mean, maximum, and minimum temperatures exhibit significant upward trends (0.015–0.045 °C yr⁻¹), with stronger warming in northern and northwestern basins; however, minimum temperatures increased faster than maximum temperatures, reducing the diurnal temperature range and indicating a shift in regional thermal dynamics. Maximum temperature is negatively correlated with precipitation (R ≈ −0.27 to −0.34), suggesting enhanced evapotranspiration under warming conditions. LightGBM extrapolations to 2040 indicate continued warming (1–3 °C) and precipitation declines across more than 80% of Iran, underscoring intensifying hydroclimatic stress and increasing challenges for water resource management in dryland environments. Full article

The Earth–Air Heat Exchanger (EAHE), also referred to as an air–soil heat exchanger, represents an effective passive cooling technology that exploits the thermal inertia of the ground. This study presents a combined experimental and analytical investigation of an EAHE system installed at the Faculty of Sciences of Agadir (Morocco). A steady-state analytical model based on convective heat transfer between the airflow within a buried duct and the surrounding soil is developed to describe the axial evolution of air temperature along the exchanger. The model is formulated under a sensible heat transfer framework, where the influence of humidity is accounted for through its effect on the thermophysical properties of moist air, while latent heat transfer and condensation phenomena are neglected. An instrumented experimental setup was implemented to perform continuous measurements of air temperature and relative humidity over a seven-month monitoring period. The experimental results indicate that the outlet air temperature remains stabilized within the range of 23.5–23.8 °C, despite significant variations in ambient temperature (13–38 °C). A parametric analysis is conducted to assess the influence of duct diameter, airflow velocity, and humidity through its effect on moist air properties on the thermal performance of the system. The close agreement between experimental observations and analytical predictions demonstrates the validity and predictive capability of the proposed model. These findings highlight the potential of EAHE systems as an effective passive cooling solution for greenhouse applications in semi-arid climatic conditions. Full article

Rainfed wheat (Triticum aestivum L.) production in semi-arid regions is strongly influenced by precipitation variability, soil water availability, and crop management practices. This study evaluated the effects of nutrient management under uniform weed control on soil water dynamics, weed density, and grain yield of winter wheat grown under rainfed no-till conditions in southern Kazakhstan. Field experiments were conducted during the 2018–2021 growing seasons on gray soils characterized by low organic matter and limited nitrogen and phosphorus availability. Eight fertilization treatments, including phosphorus and nitrogen combinations and a micronutrient treatment, were arranged in a randomized complete block design. Soil moisture reserves, weed density, and grain yield were analyzed in relation to precipitation variability. Productive soil moisture reserves in the 0–100 cm layer at tillering (BBCH 21–25) ranged from 155 to 178.8 mm and were closely associated with overwinter precipitation. Balanced nitrogen–phosphorus fertilization reduced weed density from 38 plants m⁻² in the control to 16 plants m⁻² under the P₄₅N₇₀ treatment. Yield stability varied across dry, normal, and wet years, reflecting the influence of precipitation conditions on crop performance. Overall, the results suggest balanced fertilization in no-till systems contributes to improved resource use and more stable wheat production under variable precipitation. Full article