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Woody vegetation restoration projects are an important feature of landscape function in Indonesian karst savannas. Understanding the relationship between available moisture and vegetation condition can assist with the planning and implementation of revegetation efforts. Working at vegetation restoration sites in East Nusa Tenggara, Indonesia, we applied a windowed cross-correlation method to mean values of NDVI to examine the lag between moisture input and NDVI response for both rainfall and soil moisture between 1999 and 2018. To test for increasing or decreasing trends in NDVI and rainfall time series, we undertook Mann-Kendall trend analyses. We identified increasing trends in Landsat 7 NDVI at two of four restoration sites, with annual increases in NDVI of 2.7 and 3.74 × 10-4 respectively. We found that rainfall dependent sites had significant Pearson's correlations with NDVI ranging from 0.52 to 0.71, while NDVI was not correlated with rainfall at shallow groundwater sites. There was a clear negative effect of the very dry period on all sites, and this was less pronounced at shallow groundwater sites. Wet years resulted in a positive response to NDVI across all sites, while the response was lower in very wet years with annual rainfall above 1,200 mm. We found that between 2 and 4 months of antecedent rainfall gave the highest correlation with NDVI, while for soil moisture the closest relationship was found with no lag and 1 month lag. Through this study, we demonstrated the applicability of using NDVI, rainfall, and soil moisture trend analyses to identify groundwater-dependent vegetation patches and monitor the effectiveness of vegetation restoration. [ABSTRACT FROM AUTHOR]

The susceptibility of surface soil to drying when rainfall is scarce has prompted evaluation of deeper placement (20 cm) of fertilizers within the profile to where soil moisture is more likely to be stored. However, concerns arise regarding potential chemical challenges to P availability in the subsurface. This study examined differences in chemical conditions between the soil surface (0–10 cm) and subsurface (15–25 cm), and investigated the effect on the diffusion and extractability of banded P. Analysis of surface and subsurface samples from 15 sites revealed substantial differences in characteristics that influence P behavior between depths. The phosphorus buffering index (PBI) was largely explained by concentrations of amorphous Al and Fe (hydr)oxides and CaCO3. The measured diffusion distance of P from monoammonium phosphate (MAP) granules was found to be inversely related to PBI. Consequently, significant differences in diffusion distances were typically observed between soil layers characterized by marked PBI variations. The measured diffusion radii were used to calculate the mean P concentrations of surface-banded and deep-banded MAP in a field scenario, which were replicated in a 4-week laboratory incubation. The resulting lability of applied P was determined through isotopic exchange, and although significantly higher P recoveries were measured from the subsurface at two sites where large pH differences existed between depths, no significant differences were measured between depths at all other sites. Hence, the subsurface is not a more hostile zone for deep-placed P. [ABSTRACT FROM AUTHOR]

In drylands, grass germination occurs after a large rainfall event. However, trees influence the water requirements for germination either by decreasing the rate of evaporation from soil surface or by interception rainfall with their canopy. The aim of this work was to evaluate the role of Neltuma flexuosa tree on the germination of Leptochloa crinita and Pappophorum caespitosum grasses in response to precipitation events of different sizes. The experiment was conducted in two locations within the Monte desert, Argentina: a semi‐arid location with an average annual precipitation of 345 mm and an arid location with an average annual precipitation of 156 mm. Six microsites were established under N. flexuosa canopies and six microsites in open areas at both locations. Within each microsite, 35 seeds of each grass species were exposed to precipitation events of varying sizes. This procedure was repeated 14 times across two growing seasons. Germinated seeds were counted in the laboratory. Generalized linear mixed models were then applied to evaluate the effects of accumulated precipitation and the microsite on the grass germination in both locations. Results showed that N. flexuosa did not influence the germination of either grass species in the arid location. However, in the semi‐arid location, N. flexuosa facilitated the germination of P. caespitosum only. Large precipitation events would act as an environmental signal for these perennial grasses, allowing them to germinate in favorable years regardless of the microsite or the location. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Northwest A & F University - Natural Science Edition is the property of Editorial Department of Journal of Northwest A&F University (Natural Science Edition) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Blackgram, a protein-rich pulse crop (24%), is crucial for combating food insecurity, particularly in malnourished and economically weak countries. Enhancing blackgram production requires improved, input-saving management practices. Given the challenges of climate change and population growth, efficient water management is vital for increasing pulse productivity and water use efficiency with minimal investment. This study aimed to identify cost-effective irrigation methods to optimise blackgram yields. Experiments were conducted at the National Pulses Research Centre in Vamban, Pudukkottai, and the Agricultural College and Research Institute in Kumulur, Tiruchirappalli, during the kharif season of 2021 and 2022. The study compared different treatments of irrigation methods, such as check basin, raised bed, drip, sprinkler and rain hose irrigation. Results showed that the rain hose system maintained the highest soil moisture (23.93% at 10 cm depth and 19.71% at 20 cm depth). Even though drip irrigation resulted in a higher seed yield (1363 kg ha−1), the rain hose system proved to be more cost-effective, saving 27.09% in costs and achieving a 15.23% higher benefit–cost ratio. These findings suggest that the rain hose method, combined with current agronomic practices, is a viable low-cost technique for sustainable blackgram cultivation, optimising water use and maximising profits. This research provides valuable insights into water-saving irrigation methods for pulse crops. [ABSTRACT FROM AUTHOR]

Inland oil spill accidents pose a negative impact on the health of the soil ecological system and human beings. The oil infiltration process is the main behavior of spilled oil, and its infiltration is influenced by many environmental factors like root netting and rainfall. This study was conducted to investigate the impact of these two important factors on the infiltration process and reduce the pollution of inland oil spill accidents. For root nettings, they can change the soil permeability and pore volume distribution, which are important in liquid infiltration, while rainwater can change the soil water content, thereby affecting the pressure, capillary force, and buoyancy force of spilled oil in the infiltration process. In the present study, these two unique factors of oil infiltration were investigated by detecting the infiltration front head and concentration distribution of spilled oil in soil layers with various root netting structures as well as the rainfall modes. It is found that root netting and surface rainfall critically affect oil infiltration in soil. The nettings with a finer mesh size and denser plant roots show a more significant effect on the infiltration process, particularly when their pore size is smaller than that of the soil. The netting's position and soil particle size also play crucial roles, influencing where oil accumulates within soil layers. Rainfall timing and intensity further modify oil movement, with prior rainfall reducing infiltration, while subsequent rain can increase it. The findings can help better understand the transport of spilled oil transport and implement emergency response measures for inland oil spills. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to explore the temporal and spatial variation characteristics of soil moisture in Robinia pseudoacacia plantation and Quercus liaotungensis natural secondary forest in the loess hilly region and its response mechanism to rainfall events, and reveal the soil moisture characteristics and differences between two typical forest communities in this region, so as to provide scientific basis for the construction and management of forest vegetation in this area. [Methods] The mature forest communities of two typical tree species in the loess hilly region were taken as the objects. By monitoring the soil moisture content in the range of 0-300 cm in the experimental site for 10 years (2009-2019), combining with the change of precipitation in the same period, the temporal and spatial variation pattern of soil moisture in these two typical forest communities and its response to rainfall were analyzed. [Results] (1) At the end of the growing season in 2019, the average soil water contents of the two forest communities at 0-100 cm and 0- 300 cm were higher than the average values in 2009, and there was a significant difference between the two communities in the range of 0-100 cm, and the average soil water content of Quercus liaotungensis forest in 2019 was significantly higher than that of Robinia pseudoacacia forest. The average value in the range of 0-300 em was significantly different only in Quercus liaotungensis forest. (2) The spatial distribution of soil moisture in the two forest communities fluctuated obviously in the 0-200 cm soil layer. The temporal and spatial stability of soil moisture in Quercus liaotungensis forest in 200-300 cm soil layer was higher than that in Robinia pseudoacacia forest. (3) The monthly dynamic trend of soil moisture in the two forest communities was basically the same, which was roughly synchronized with the monthly dynamic trend of rainfall, but the soil moisture in Quercus liaotungensis forest was always higher than that in Robinia pseudoacacia forest. (4) On the interannual scale, the soil water content of the two forest communities at the end of the growing season was significantly positively correlated with the rainfall in that year. With the increase of rainfall, the Quercus liaotungensis forest offset the evapotranspiration water consumption and supplemented the soil water more than the Robinia pseudoacacia forest. The increment of soil water storage in the two forest communities showed a very significant exponential growth relationship with the secondary rainfall. The supplementary effect of soil moisture in Robinia pseudoacacia forest was greater than that in Quercus liaotungensis forest when the secondary rainfall was small (less than 22 mm), but it was more beneficial to supplement soil moisture in Quercus liaotungensis forest when the secondary rainfall was large (more than 22 mm). [Conclusion] There are significant differences in temporal and spatial variation characteristics of soil moisture between two forest communities, especially in deep soil. Compared with Robinia pseudoacacia forest, the response of soil moisture in Quercus liaotungensis forest to interannual rainfall is more obvious. The difference of soil water storage in two forest communities to rainfall event depends on the amount of rainfall. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to analyze the runoff and sediment under different land use types and slopes in the loess hilly area of western Henan, and to provide scientific basis for quantitative evaluation of soil erosion and comprehensive prevention of soil erosion. [Methods] Based on the observation data of 12 runoff plots from 2011 to 2020 at the monitoring site of soil and water conservation in Hugou small watershed, Songxian County, Henan Province, the pattern of runoff and sediment under different land use was revealed. Correlation analysis was used to detect the relationship between rainfall characteristics, slope, land use, runoff and sediment yield. [Results (1) Compared with bare land plot, grassland plot had the greatest effect on runoff and sediment reduction. The average annual runoff reduction effect of grassland was 78.6%~85.9%, and the maximum sediment reduction effect was 100%. The runoff reduction effect of forestland was 32.9%~51.3%, and the sediment reduction effect was 55.3%~78.9%. (2) Runoff and sediment in each runoff plot and the slope were closely related. There was no significant difference between the runoff and sediment on the slopes of 10° and 15°, however, it increased significantly on the slope of 25°. In addition, with the increase of slope gradient, the soil and water conservation effect of forestland and grassland also reduced. (3) The correlation between runoff depth and maximum 30-minute rainfall intensity (130) and soil loss and rainfall erosivity were the most significant. [Conclusion] In areas where runoff and sediment localization observation is lacking in the loess hilly region of western Henan Province, rainfall process information can be used to estimate the runoff and soil loss under certain slope and vegetation conditions. [ABSTRACT FROM AUTHOR]

Various factors influence biocrust effects on infiltration and soil moisture. On China's Loess Plateau, well‐developed moss‐dominated biocrusts reduce infiltration and suppress shrub growth, however, the interrelationships between rainfall conditions and disturbance management to alleviate these impacts are unknown. In a semiarid watershed on the Loess Plateau, we applied two forms of disturbance, scarification (controlled harrowing) and compaction (simulated grazing), at four intensity levels (control‐intact, light, moderate, and heavy) to well‐developed moss‐dominated biocrusts and a bare soil (BS) for comparisons to form eight treatments with three replications. Rainfall intensity and depth, soil moisture, run‐off, and sediment yield were measured during the rainy season (July–October). In total, well‐developed biocrusts did not significantly affect infiltration but reduced soil moisture at depths of 120–180 cm (p < 0.05), and disturbance increased infiltration and deep soil moisture beneath biocrusts (p < 0.05). Rainfall conditions changed the effects of biocrusts and disturbance. Under long, low‐intensity rainfall, moss‐dominated biocrust infiltration was slightly greater than BS, but scarification increased infiltration and compaction reduced it (p < 0.001). Under short, high‐intensity rainfall, biocrusts reduced infiltration, and disturbance intensity increased infiltration and sediment yields (p < 0.001). Light grazing or using light or moderate scarification improves well‐developed moss‐dominated biocrust infiltration in the pastures during May–June before the rainy season during July–October on the Loess Plateau, while avoiding increased soil erosion. [ABSTRACT FROM AUTHOR]

Unsaturated soils are the major component of both natural and artificial earth structures, and they exhibit less predictable behavior than saturated soils. Presently, the world is experiencing pronounced impacts from climate change. Sudden heavy rainfalls and droughts both result in fluctuating soil moisture levels, meaning that soil responds differently to infrastructure loads. Accordingly, a better understanding is needed of failure causes in unsaturated soils. This research was conducted to investigate the coupled behavior of unsaturated soil with varying degrees of compaction and moisture change. Samples were prepared at 81% and 88% degrees of compaction with moisture content ranging from 10 to 25% on both sides of optimum moisture content for silty soil. Different parameters such as suction, porewater pressure, and deformation were carefully measured at every stage of the triaxial test, from sample placing to the shearing phase. The results show that there is more compressive soil behavior when there is a lower degree of compaction, i.e., 81%, along with moisture content of 15–25%. Where there is a higher degree of compaction at 88%, dilative behavior is more evident, which changes to compressive behavior as the moisture content increases. Any change in moisture content (increase or decrease) during the lifecycle of any earthen structure necessitates a long time to stabilize its suction value (decrease or increase) if it compacted to a degree that still exhibits a compressive response. This slow recovery of suction, specifically from the wetting to the drying cycle, is not favorable for soil stability upon loading. [ABSTRACT FROM AUTHOR]

Embankment failures can be prevented by introducing geocomposites to act as drains. The effect of the geocomposite layer on the pore pressure distribution and surface displacements of an unsaturated embankment upon infiltration has been studied numerically using deterministic and probabilistic approaches. The inclusion of the geocomposite layer leads to an increase of suction below the interface and a decrease in suction above it by functioning both as a capillary barrier and a drainage layer, thereby reducing the surface displacements upon infiltration. The load in the form of rainfall and the resistance such as suction of the embankment material being variable leads to a variability in the displacements; therefore, reliability analysis has been carried out using hydraulic permeability and soil water characteristic curve (SWCC) parameters as random variables. To assess the probability of failure (Pf), a surrogate model based on augmented radial basis function has been used. Probabilistic analysis revealed that the embankment with geocomposite has less Pf compared to the embankment without geocomposite considering the rainfall infiltration. Moreover, sensitivity analysis predicted that SWCC parameters influence the Pf of embankment containing geosynthetics under infiltration to a larger extent. [ABSTRACT FROM AUTHOR]

Human-generated aerosol pollution gradually modifies the atmospheric chemical and physical attributes, resulting in significant changes in weather patterns and detrimental effects on agricultural yields. The current study assesses the loss in agricultural productivity due to weather and anthropogenic aerosol variations for rice and maize crops through the analysis of time series data of India spanning from 1998 to 2019. The average values of meteorological variables like maximum temperature (TMAX), minimum temperature (TMIN), rainfall, and relative humidity, as well as aerosol optical depth (AOD), have also shown an increasing tendency, while the average values of soil moisture and fraction of absorbed photosynthetically active radiation (FAPAR) have followed a decreasing trend over that period. This study's primary finding is that unusual variations in weather variables like maximum and minimum temperature, rainfall, relative humidity, soil moisture, and FAPAR resulted in a reduction in rice and maize yield of approximately (2.55%, 2.92%, 2.778%, 4.84%, 2.90%, and 2.82%) and (5.12%, 6.57%, 6.93%, 6.54%, 4.97%, and 5.84%), respectively. However, the increase in aerosol pollution is also responsible for the reduction of rice and maize yield by 7.9% and 8.8%, respectively. In summary, the study presents definitive proof of the detrimental effect of weather, FAPAR, and AOD variability on the yield of rice and maize in India during the study period. Meanwhile, a time series analysis of rice and maize yields revealed an increasing trend, with rates of 0.888 million tons/year and 0.561 million tons/year, respectively, due to the adoption of increasingly advanced agricultural techniques, the best fertilizer and irrigation, climate-resilient varieties, and other factors. Looking ahead, the ongoing challenge is to devise effective long-term strategies to combat air pollution caused by aerosols and to address its adverse effects on agricultural production and food security. [ABSTRACT FROM AUTHOR]

This study uses Multifractal Detrended Fluctuation Analysis to examine the scaling behavior and spatiotemporal variability of drought indicators. We employ two hybrid drought indicators—the GRACE Root Zone Soil Moisture Percentile (SMI) and Evaporative Demand Drought Index (EDDI)—to elucidate agricultural drought characteristics, and we quantify meteorological drought using the Standardized Precipitation Index (SPI). Our investigation was carried out in the United States in the California and Mississippi watersheds, each characterized by distinct agricultural climate conditions and planting systems. The changes in drought indicators exhibit multifractality primarily derived from the long-term memory embedded within the time series. Spatially, the increment sequence of SPI displays pronounced dependence in almost all areas. Specifically, the changes in SPI demonstrate persistence, as the Hurst exponents changed from 0.53 to 0.58 in California, revealing the possibility of a degree of trend continuation (albeit, not very strong) in the future. A regular summary cannot be obtained for Mississippi, since the Hurst exponent ranges from 0.46 to 0.51 for the increment sequence of SPI in that watershed. However, the increment sequences for the agricultural drought indicators exhibit obvious short-term persistence (anti-persistence), indicating that future drought trends may be discontinuous. The variations in the strength of anti-persistence among agricultural drought indicators can be attributed to geographical differences, diverse irrigation strategies, and varying cropping systems. No significant evolution pattern is evident for the scaling structure of drought processes due to minor variations in external controlling factors, such as rainfall and temperature, within the drought process. [ABSTRACT FROM AUTHOR]

Rainfall infiltration is the primary factor affecting slope stability, which may lead to geological hazards such as landslides, collapses, and debris flows. Thus, it is crucial to investigate the rainfall infiltration patterns of unsaturated soil slopes. During a natural rainstorm, the soil volumetric water content at various depths of a significant unsaturated soil slope model was monitored onsite. The soil-water characteristic curve parameters and saturated permeability coefficient of remolded soil were quantified, and the Van Genuchten (VG) model was utilized to forecast the unsaturated permeability coefficient. The numerical simulation method was used to simulate the field rainfall experiment. Based on the mutual verification of the field measurement and numerical simulation, rainfall simulation with different rainfall intensities was added, and its influence on rainfall infiltration depth, pore water pressure, and transient saturated zone was analyzed. The findings revealed that under the rainstorm intensity of the field rainfall test, the rainfall infiltration depth ranged from 0.2 to 0.4 m after a continuous 9-h rainfall period. As the rainfall intensity increased, the range of soil pore water pressure variations expanded, with a maximum value ranging from 9 to 140 kPa under the rainstorm rainfall intensity. By extending the duration of rainstorm rainfall intensity to 14 h, the depth of the transient saturated zone reached 0.2 m. With a duration of 20 h, it reached 0.4 m. The depth reached 0.6 m after 27 h and 1.5 m after 36 h. The research findings of this paper can provide scientific guidance for revealing the hydrological characteristics of slopes during rainfall and for the protection and reinforcement of slopes. [ABSTRACT FROM AUTHOR]

The impact of antecedent soil moisture content on soil erosion has been a contradictory issue in erosion research, as well as process-based soil loss estimation models. The objective of this study was to investigate the impact of antecedent soil moisture content on the loss of clay soil through two-year runoff plot experiments under natural rainfall. Volumetric soil moisture sensors were used to monitor soil moisture changes, and readings were used along with rainfall records to quantify the antecedent soil moisture conditions. The results of this study show that the impact of antecedent soil moisture on interrill erosion is conditional, and the impact only exists in erosion events with a low Rainfall–Runoff Erosivity Index. The coefficient of determination between antecedent soil moisture content and soil loss per the Rainfall–Runoff Erosivity Index (Soil Loss/EI30) varies from 0.222 to 0.758, depending on the rainfall duration and Rainfall–Runoff Erosivity. The results of this study also suggest that accumulative rainfall within 48 h (Pp48) prior to an effective erosion event is strongly correlated with Soil Loss/EI30, particularly when the duration of an effective erosion event is either 3~7 h or 10~30 h. Hence, Pp48 can be considered as a replacement for antecedent soil moisture in process-based soil loss simulation models. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil & Water Conservation (1009-2242) is the property of Institute of Soil & Water Conservation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Drought stress poses a significant risk to soybean production, as it relies on optimum rainfall under rainfed conditions. Exposure to brief dry periods during early vegetative growth impacts soybean growth and development. Choosing a genotype that can withstand stress with minimal impact on physiology and growth might help sustain biomass or yields under low rainfall conditions. Therefore, this study characterized 64 soybean genotypes for traits associated with drought tolerance during the early vegetative stage under two soil moisture treatments, 100% evapotranspiration (well-watered) and 50% evapotranspiration (drought), using the Soil–Plant–Atmosphere Research (SPAR) units. Eighteen morpho-physiological traits responses were assessed, and their relationship with the early vegetative drought tolerance was investigated. Drought stress significantly increased root weight, root volume, and root-to-shoot ratio but reduced shoot weight. Drought-stressed plants increased the canopy temperature by 3.1 °C. Shoot weight positively correlated with root surface area (r = 0.52, P < 0.001) and root weight (r = 0.65, P < 0.001). There was a strong negative correlation between shoot weight and root-to-shoot ratio (P < 0.01). Further, the combined drought response index was strongly associated with the root response index and weakly with the physiological response index. These findings suggest that genotypes (S55-Q3 and R2C4775) with high above-ground biomass with a balanced root-to-shoot ratio improves drought tolerance during the early vegetative. These genotypes could serve as valuable genetic resources to dissect the molecular networks underlying drought tolerance and ultimately be used in breeding programs to improve root ability at the early vegetative stage. [ABSTRACT FROM AUTHOR]

Most regional landslide susceptibility models do not consider the evolving soil hydrological conditions leading up to a multiple occurrence regional landslide event. This results in inaccurate predictions due to the non-linear behaviour of the terrain. To address this, we have developed a simple and efficient model that incorporates the mid-term evolution of soil hydrological conditions. The model combines a water balance model and a geotechnical model based on infinite slope theory. The analysis of 561 high-intensity rainfall events in a typhoon-prone region of the Philippines revealed that the percolation of water during the 5-month wet season is crucial in determining landslide susceptibility. Consequently, high-intensity rainfall events at the start of the wet season are less likely to trigger landslides, while later events are more hazardous. We analysed the change in landslide susceptibility during the 2018 rainy season by comparing the probability of failure (PoF) before and after three high-intensity rainfall events (July, August and September). Only the event in September caused a significant increase in the probability of failure (PoF). The model showed an accuracy of 0.63, with stable cells better represented than unstable cells. The antecedent hydrological conditions on the lower soil layers are responsible for changes in landslide susceptibility. Our findings support the hypothesis that new approaches to developing hydro-meteorological thresholds for landslide early warning systems should be evaluated, especially in regions with strong seasonality. [ABSTRACT FROM AUTHOR]

The middle and upper reaches of the Han river are involved in the South-to-North Water Diversion Project, and the change of runoff affects the amount of adjustable water. In order to investigate the change of runoff in the middle and upper reaches of the Han river basin under climate change, based on the SWAT (Soil & Water Assessment Tool, SWAT) model, we have developed a new model, which is based on the Soil & Water Assessment Tool (SWAT), five global climate models and four Shared Socioeconomic Pathways (SSPs) scenarios are simulated under future climate scenarios (2021-2021) in the upper and middle reaches of the Han river Basin. Based on the SWAT (Soil & Water Assessment Tool) model, we applied five global climate models and four Shared Socioeconomic Pathways (SSPs) scenarios from the latest 6th Coupled Model Intercomparison Project Phase 6 (CMIP6), and simulated the temporal and spatial changes of runoff in the middle and upper reaches of the Han river basin in the near term (2021-2040), middle term (2041-2060), and long term (2061-2080) under the future changes of climate scenarios. The results showed that: (1) compared with the baseline period (2000-2014), rainfall and temperature increased significantly under all model scenarios, and under the "two-carbon" scenario, the increase in temperature and precipitation was smaller than that of the high-carbon scenario, and the watershed was developing towards wetting and warming. (2) The future runoff in the study area showed a significant increasing trend under the SSP2-4.5 and SSP5-8.5 pathways, relative to the historical period, and the runoff decreased in some years in the upstream near, middle and far periods. 8.5 pathways show a significant increasing trend, relative to the historical period, and runoff decreases in some years in the upstream near-, mid-, and far-periods. (3) Intra-annual distribution was more even, and runoff increased during the dry period from November to June of the following year, which improved the drought-resistant capacity of the basin. (4) Spatially, the increase in runoff was dominated by the central and eastern parts of the country, and runoff decreased under the high-carbon scenario in the near future, but showed an increasing trend in the long term, with an increasing trend in future runoff at the source area of the South-to-North Water Diversion Project. [ABSTRACT FROM AUTHOR]

The summer of 2022 was particularly notable for the prolonged and extensive hot and dry conditions experienced across the UK. The resultant 2022 drought had widespread impacts and prompted much discussion about the continuing vulnerability of the UK to drought, particularly in the context of anthropogenic warming. Here, we briefly describe the evolution of the drought before focusing on the severity of rainfall, river flow, soil moisture and groundwater level deficits from summer 2022, placing the event into a historical context and addressing the impacts of the drought. We also consider whether the 2022 drought is part of a long‐term trend towards increasing drought severity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Hazards & Environment (JNHE) / Doğal Afetler ve Çevre Dergisi (DACD) is the property of Artvin Coruh University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rainfall partitioning by the vegetation canopy into stemflow (SF) and throughfall (TF) plays a crucial role in soil infiltration and the local water balance. This study aims to quantify the differences in SF and TF between two sand‐binding shrubs, Caragana liouana and Salix psammophila, in the desert steppe, clarify the effects of biotic and abiotic factors on them using the boosted regression trees (BRT) model, and compare soil moisture replenishment during the growing seasons of 2021 and 2022. Under identical rainfall conditions, the canopies of C. liouana and S. psammophila can lead to differences in rainfall partitioning. The SF percentage ranged from 0 to 23.70% for C. liouana and from 0% to 3.3% for S. psammophila, respectively, while the TF percentage ranged from 42.12% to 90.07% for C. liouana and from 52.39% to 94.87% for S. psammophila. The funnelling ratio for C. liouana (69.59) is 1.19 times higher than for S. psammophila (58.36). Rainfall amount is the primary variable affecting rainfall partitioning. The average soil moisture replenishment and soil moisture conversion efficiency under the C. liouana canopy are 11.02 mm and 58.39%, respectively, which are significantly higher than those for S. psammophila (4.84 mm and 24.33%, respectively). These findings suggest that C. liouana, with its relatively higher SF and soil moisture conversion capability compared to S. psammophila, plays a significant ecohydrological role in water‐limited ecosystems. This study provides a reference for species selection and ecological management in vegetation restoration efforts in desert steppes and similar regions. [ABSTRACT FROM AUTHOR]

Soil moisture response to rainfall is a key factor that dictates how well a landscape can support crop growth as well as its susceptibility to water runoff and leaching, however, few studies have investigated how agricultural management impacts this important soil function. This study compares two common agricultural soil treatments (cover crops and soil compaction) and their soil moisture response to rainfall in comparison to a control. In a humid temperate climate during March to November, individual rainfall events were delineated over two growing seasons and corresponding soil moisture responses were identified using in situ soil moisture sensors at four soil depths (20, 30, 40, and 60 cm). Results suggest that hydrological responses differed with both event type and management treatment. Not all rainfall events triggered a response: those that triggered responses at shallower soil depths were typically characterized by higher total event rainfall, and higher maximum and average rainfall intensity. In contrast, rainfall events triggering responses at deeper soil depths were characterized by longer event duration as well as higher 10‐day antecedent rainfall (AR). Soil moisture responses for the cover crop treatment were characterized by relatively lower initial and peak soil moisture at shallower depths but higher values at 60 cm depth, whereas soil moisture responses for the control and compacted soil treatments demonstrated the opposite. Matrix flow was most often generated for rainfall events with high magnitude and was not preferentially associated with any particular soil treatment. However, specific conditions were needed to generate vertical preferential flow, namely high total event rainfall for both horizons, or high AR for preferential flow in the Ap horizon, or high rainfall intensity for preferential flow in the Bt horizon. Our findings demonstrate the potential for detailed event‐based soil water process analysis using high‐frequency, multi‐depth soil moisture data. [ABSTRACT FROM AUTHOR]

Numerous studies focus on the impacts of ENSO diversity on tropical cyclone (TC) activities in the western North Pacific (WNP). In recent years, there is a growing threat of landfalling and northward-moving TCs in East Asia, accompanying an increase in central Pacific (CP) El Niño. Here, we aim to discover variations in landfalling TCs during various types of CP El Niño (CP-I and CP-II El Niño). It is found that significant changes in landfalling and going northward TCs over East Asia north 20°N are modulated by CP-I El Niño. During CP-I El Niño, TCs tend to landfall more often over the mainland of China with longer duration, moving distance, and stronger power dissipation index (PDI) after landfall and increased TC-induced rainfall, due to favorable conditions (beneficial steering flow, weak vertical wind shear, increased specific humidity, increased soil moisture, and temperature), especially significant over the northeastern part. The situation over the mainland of China is reversed during eastern Pacific (EP) El Niño and CP-II El Niño, with a significant decrease in the characteristics with corresponding unfavorable environments. Over the Korean Peninsula and Japan, the frequency of TC landfalls, as well as the duration and the moving distance after landfall, exhibits greater levels during CP-I and CP-II El Niño than during EP El Niño due to favorable steering flow, and thus, TC-induced rainfall enhances correspondingly. Regarding the PDI over the Korean Peninsula and Japan, it remains relatively consistent across all El Niño types. However, a notable increase in the PDI during EP El Niño could be attributed to the higher intensity of TCs prior to landfall. [ABSTRACT FROM AUTHOR]

Rainfall is the major component of the hydrologic cycle and it is the primary source of runoff. The main purpose of this study was to estimate daily discharge by employing an Adaptive Neuro-Fuzzy Inference System (ANFIS) model using rainfall and soil moisture data at three different depths (5 cm, 100 cm and bedrock) for the Damanganga basin. The length of the data for the study period 1983–2022 is 39 years. The model employed nine membership functions for each variable of soil moisture, rainfall, discharge and 30 rules were optimized. The results were compared considering a range of model performance indicators as correlation coefficient (R2) and Nash–Sutcliffe efficiency (NSE) coefficient. The model application results shows that soil moisture at bedrock gives more precise value of daily discharge with (R2) and NSE value as 0.9936 and 0.9981, respectively, as compared to the soil moisture at depths of 5 and 100 cm. The better results obtained for the measurement of soil moisture in the deeper soil layer are consistent with the hydrological behavior anticipated for the analyzed catchment, where the root-zone soil layer is the driver of the runoff response rather than the surface observations. This study can be helpful to hydrologists in selecting appropriate rainfall–runoff models. HIGHLIGHTS To estimate the daily discharge by employing an Adaptive Neuro-Fuzzy Inference System (ANFIS) model using rainfall and soil moisture data.; The model employed nine membership functions for each variable of soil moisture, rainfall, discharge and 30 rules were optimized.; The results were compared considering a range of model performance indicators such as correlation coefficient (R2) and Nash-Sutcliffe efficiency (NSE) coefficient.;

Impact of rainfall and slopes on soil organic carbon (SOC) dynamics was assessed under tea and coffee plantations, land covers, in Western Ghats Mountain (WGM). Severe water erosion in the western side of WGM by heavy rainfall and land sloppiness recorded less SOC (3.07%) compared to the eastern side (4.03%) in tea plantations. Similar trend in SOC was observed in coffee plantations, with 1.98% in western side and 3.25% in eastern side. Loss of soil organic carbon stock under tea plantations in western sides was 0.346 million tonnes and in coffee plantations it was 0.190 million tonnes. Hence, the total organic carbon loss was 0.536 million tonnes. Highest SOC content and stocks were recorded in steep slopes in tea and coffee plantations due to dense biomass cover and adoption of soil and water conservation measures. [ABSTRACT FROM AUTHOR]

The restoration of native vegetation like pines helps mitigate soil erosion, but the effects of pine needle litter on runoff, erosion, and hydrology in karst hillslopes are unclear. This study investigated these factors during the rainy season from June to August 2021 under six treatments (flat, gentle, and steep slopes with and without pine needle coverings). The results showed that pine needle litter significantly increased the soil water content, particularly on steeper slopes, by improving the water-holding capacity. It also substantially reduced runoff (by 23.8%) and soil erosion (by 92.5%). The critical rainfall threshold for generating runoff did not occur in the pine needle covering treatment, whereas it was 19.3 ± 8.8 mm in the bare soil treatment under wet conditions. These findings highlight the efficacy of pine needle cover in reducing runoff and erosion in karst areas, promoting it as a sustainable method for restoring degraded soil. [ABSTRACT FROM AUTHOR]

Hydrometeorological variables are sensitively regulated by atmospheric dynamics and variability. Weather research and forecasting (WRF) model is the cutting-edge tool for studying and investigating the dynamics of physical atmospheric conditions, but the configuration scheme of WRF parameters remains a research challenge for topical peatland situated in the maritime continent. Here, we evaluated WRF parametrization based on three kalibration configuration schemes, which influence rainfall, temperature, and soil moisture dynamics. We tested the WRF evaluation for Sebangau-Kahayan peatland for a wet-dry season in August 2020. The best configuration was determined based on three statistical metrics namely mean absolute error, percent bias, and coefficient of correlation. Our results showed that WRF forecasts were greatly depend on a bias correction to improve the model performance, in which it was consistently found in all configurations. Rainfall was barely predicted in station level with a low performance in term of weekly spatial distribution. Other findings revealed that all configurations showed a good performance for temperature and soil moisture forecasts. Further, our findings emphasize the important physical parameter of WRF that control rainfall formation and dynamics. Last, we highlight an urgent need of more ground stations in term of spatial distribution to validate the weather forecast. [ABSTRACT FROM AUTHOR]

This study addresses the impact of climate variability on latex yield. Field research was carried out in the Indonesian Rubber Research Institute Experimental Field, located in South Sumatra, Indonesia for 2020 to 2022. The study used mature IRR 118 clones of rubber (Hevea brasiliensis) planted in clay loam soil. Latex yields for dry and rainy seasons were compared to obtain the effects of climatic factors. A purposive sampling of latex clone IRR 118 was applied in the field. The results showed that declined rainfall and soil moisture content contributed to the low latex yield during dry season. A declined water availability acts as a limiting factor resulting in decreased latex yield. Latex yield consistently decreased when soil moisture content fell below 21.5%. Based on statistical analysis, the correlation between latex yield and climate factor was 0.36, 0.42, and 0.52 for rainfall, soil moisture content, and evapotranspiration, respectively. Our findings highlight the crucial influence of climatic factors, emphasizing the significance of optimal water availability for latex production. [ABSTRACT FROM AUTHOR]

Investigating the spatial distribution characteristics of the interaction between soil salinity and moisture is crucial in revealing moisture–salinity interaction in semi-arid farmland. The sampling of soil was performed on the second (S1), fifth (S2), eighth (S3), eleventh (S4), and fourteenth (S5) days after the erosive rainfall. The multifractal method was used to analyze spatial distribution parameters of soil moisture and salinity under the different stages. The findings showed that the soil moisture content decreased from 22.44% to 12.73%, while the salinity increased from 0.71 to 1.18 g kg–1 after the rainfall. As the amount of moisture in the soil decreased, the variability in the distribution of moisture initially increased from S1 to S3 and then decreased, while the salinity content also decreased. The spatial distribution of soil moisture and salinity content showed a strong correlation at S3 to S4 (with the relative water content of soil ranging from 0.52 to 0.75), indicating a significant coupling effect in these stages. However, the distribution of soil salinity was not uniform under high moisture content conditions (S1 to S2), as it was leached unevenly by rainfall, and under low moisture content conditions (S5), it precipitated, resulting in a low correlation between the spatial distribution of soil moisture and salinity content. This research has provided insight into the coupling dynamics of soil moisture and salinity content, revealing the mechanisms governing their spatial distribution in dryland agricultural regions. [ABSTRACT FROM AUTHOR]

Climate change scenarios of precipitation and temperature were divided into three time windows of 30 years each from 2011 to 2099. The new version of Soil and Water Assessment Tool (QSWAT v2.6.1) was used to simulate the hydrological response and it was first calibrated and validated using observed data as an input for assessing the hydrological responses. The results showed that the QSWAT calibration and validation reveals a good agreement (R²=0.77) during calibration and validation. Whereas nash and Sutcliffe simulation efficiency (NSE) was found to be 0.76 during calibration and 0.73 during validation. Based on changes of precipitation, maximum and minimum temperature, the monthly flow volume did not show systematic trends i.e. increases non-rainy months and decreases in the wet-months. Thus, the hydrology of Megech River is highly vulnerable to climate change which causes water stress for domestic use and environmental flow. [ABSTRACT FROM AUTHOR]

In recent decades, the Himalayas have seen increasing extreme precipitation events. Climate change has impacted the occurrence and distribution of extreme precipitation events across the Himalayas. Patterns of both western disturbances and the Indian summer monsoon are undergoing significant changes in nature due to climate change. However, the magnitude and intensity of flood in a stream are not always linearly dependent on the amount of precipitation. Other factors, such as topography, land use, soil characteristics, and antecedent hydrological conditions, play a pivotal role in modulating the response of a watershed to an extreme precipitation event. On July 07–11, 2023, several districts of Himachal Pradesh faced devastating floods resulting in loss of life, infrastructure, and environmental damage with significant economic consequences. Developing a resilient solution for managing such events and reducing damage requires an in-depth understanding of multiple causative factors of such extreme events. In this paper, we analyzed the meteorological and hydrological factors that caused the flooding situation in Himachal Pradesh during July 2023. Hydrometeorological data from several observation stations were analyzed along with reanalysis data from ERA5, SMAP-L4, and FLDAS-NOAH to understand the causative factors that lead to peak floods. The compounding of extremely heavy rainfall with near-saturation antecedent moisture content and snowmelt was found to be the leading factor in inflating and sustaining the flood peak. [ABSTRACT FROM AUTHOR]

A long-term experiment was conducted during kharif seasons of2013 to 2020 at AICRP on Agrometeorology, VNMKV, Parbhani, to study the crop-weather relationship of soybean grown under four environments (27th SMW, 28th SMW, 29th SMW and 30th SMW) with three soybean varieties (MAUS-158, MAUS-71, and JS-335). Results indicated that soybean yield was significantly highest in (1541.4 kg ha-1) in the early sown crop, and it decreased with delay in sowing with the lowest yield (803.8 kg ha-1). Among the cultivars, MAUS-158 produced significantly the highest yield (1321.3 kg ha-1). Correlation analysis between weather parameters during different phases with the yield revealed that the vegetative and grain formation period of soybean were found to be the most sensitive to weather parameters, as the correlation coefficients with most of the weather parameters. Rainfall, number of rainy days, humidity and soil moisture had favorable effects while temperatures and sunshine duration had negative effects on the yield of soybean in the Marathwada region. Individual weather parameters during 50% flowering to maturity period could explain 40 to 55% variation in the soybean yield while the multiple regression developed all weather parameters during grain formation to physiological maturity period could explain up to 82% variation which could be used the predict the soybean yield in Marathwada region. [ABSTRACT FROM AUTHOR]

Drought is expected to increase in temperate regions in the coming decades due to global climate change and will strongly affect nitrogen (N) transformation and balance. However, the underlying mechanisms (soil microenvironment vs. biotic community) of rainfall reduction induced changes in soil N transformation rates, and whether the responses of soil N transformation rates to rainfall reduction vary over time remains poorly understood. In this study, we experimentally examined rainfall reduction effects on soil N transformation rates over two (the second and third experimental years) growing‐seasons in a temperate meadow. We applied four treatments: ambient rainfall, 30%, 50%, and 70% reduction in rainfall. Our findings demonstrated that, 70% rainfall reduction significantly decreased the average net N mineralization and nitrification rates by 68.4% and 72.0%, respectively. Soil nitrous oxide emission was profoundly varied between the experimental years, with it was sensitive no only to changes in annual precipitation amount, but also to seasonal distribution, the highest emissions appeared at the early growing‐season. Moreover, plant diversity, microbial biomass, and soil NO3−‐N content mainly regulated soil N transformation rates in response to rainfall reduction in the greater annual precipitation year; but soil N transformation rates were mainly controlled by soil water content in the less annual precipitation year. We suggest that to accurately project future ecosystem functions and improving the prediction of N cycling responses to changing precipitation patterns, stronger focus should be allocated not only to changes in precipitation amounts, but also to inter‐ and intra‐annual differences in precipitation distribution. Plain Language Summary: The variation in precipitation regimes may have profound impacts on soil N cycling. To understand how the soil N transformation rates respond to different rainfall levels, we used rainout shelters to simulate reduced precipitation amount in a temperate meadow. We examined a suite of soil N transformations responses. Our results showed that soil N transformation rates decreased along the gradient of declining in rainfall amount over the two sampling years, with inter‐ and intra‐annual variation in precipitation distribution also played important roles in determining soil N transformation rates. The high values of each soil N transformation rates were appeared at different periods of the growing‐seasons. We also examined the pathways associated with the responses of soil N transformation rates to rainfall reduction in the two contrasting precipitation years. In summary, we conclude that rainfall reduction led to reductions in soil N transformation rates through a combination of plant, microbial, and soil factors during the greater annual precipitation. Nonetheless, in the less annual precipitation, the key factor determining N transformations was found to be soil water content. These findings offer valuable insights for forecasting interactions within the plant‐microbe‐soil N cycling system under forthcoming precipitation patterns within the context of climate change. Key Points: The high soil N transformation rates corresponded to a certain precipitation range at regional scaleRainfall reduction decreased soil N transformation rates via changing plant, microbial, and soil factors in greater precipitation yearSoil water content was the key factor determining soil N transformation rates, especially in less precipitation year [ABSTRACT FROM AUTHOR]

SNOSWAB (Snow, Soil Water and Water Balance) is a unique online deterministic model built using tipping-bucket approaches that allows for the daily estimation of (i) snowpack processes; (ii) soil water content; and (iii) soil water budget. SNOSWAB is most suitable for modeling field-scale processes for vertically and horizontally homogeneous soils, and its applicability is not limited to specific climate zones or geographical areas. The model is freely available, and its streamlined online interface integrates powerful calibration, visualization and data export routines. In this study, SNOSWAB development and a conceptual model, as well as an example of its application using data collected during a 12-year (2008–2019) field study conducted at the Agriculture and Agri-Food Canada Harrington Experimental Farm (HEF) on Prince Edward Island (PEI), Canada, are presented. Input data consisting of daily air temperature, total precipitation, rainfall and evapotranspiration were used in conjunction with soil properties and daily soil water content, snowpack thickness, surface runoff and groundwater recharge to calibrate (2010–2014) and validate (2015–2019) the model. For both the calibration and validation simulations, the statistical indicators used for evaluating model performance indicated, in most cases, high model fitness (i.e., R2 > 0.5, NRMSE < 50% and −25% < PBIAS < 25%) for the various time intervals and parameters analyzed. SNOSWAB fills an existing gap in the online environment and, due to its ease of use, robustness and flexibility, shows promise to be adopted as an alternative for more complex, standalone models that might require extensive resources and expertise. [ABSTRACT FROM AUTHOR]

Background: Peninsular India, being completely under the influence ofmonsoonal climate, suffers crop yield variability due to rainfall distribution-induced soil moisture constraints. Timely and appropriate assessment of this rainfall and soil moisture-induced crop yield variability serves as a key for exemplary relief assistance. Per cent available soil moisture (PASM) is one among several drought declaration indices followed by stakeholders in India for declaration of drought, needs re-evaluation as the existing criteria in unable to capture the yield loss due to ineffective classification of PASM categories. This study attempts to revise the agricultural drought classes by PASM based on relationships established between yield of major rainfed crops of the study region and PASM. Methods: Analysis of yield variability due to PASM was carried out based on long term observations in experiments conducted at five dry farming locations (Akola, Parbhani, Kovilpatti, Ananthapuramu and Bengaluru) of peninsular India. The average yield for each category of PASM was calculated and tabulated for regression analysis. The PASM versus yield in each group was correlated and regression equations were developed if significant positive correlations were established. Results: The range of available soil moisture to obtain at least 50 percent of optimum yield in cereals (maize: 26 and finger millet: 52.9 PASM), pulses (pigeon pea: 37.2 PASM), oilseeds (soybean: 26.8 to 30.5, groundnut: 53.8 to 61.7 PASM) and commercial crops (cotton: 26.3 PASM) was 26--61 percent. Conclusion: The revised PASM-based drought classes (0--50 severe; 51--75 mild and 76--100 no drought) would help in drought declaration and precise identification of drought-hit areas for meaningful relief assistance. However, there is further investigation is needed to include a soil component for further fine-tuning of the criteria. [ABSTRACT FROM AUTHOR]

The Tulancingo River basin is part of the upper Metztitlán River basin and has an aquifer deficiency that covers 87 % of its surface area; however, floods have occurred in the valley region. This disparity encouraged the current work, the goal of which was to estimate the spatio-temporal availability of water in the soil within the basin from the modeling of surface water balance elements. Sensitivity analysis of the model fit parameters was performed with the SWATCUP program and the SUFI2 algorithm. The runoff values were estimated with the SWAT program and were compared with the records of the Venados Hydrometric Station, obtaining values of the statistical indicators R² = 0.89 and Nash Sutcliffe (NS) = 0.86 for the calibration period (1982–2002); and R² = 0.77 and NS = 0.62 for the validation period (2003–2013). Of the nine sub-basins that make up the Tulancingo basin, the upper sub-basins of the Río Chico (11), Ventoquipa stream (12), and San Lorenzo River (13) showed values 2.2 times higher than the rainfall depth of the lower sub-basins (5, 6, 7, 8, 9, and 10). Surface runoff and infiltration reported maximum values from July to October and minimum values from April to May. The maximum final water availability in the soil occurred in September. Regarding the analysis by periods, the Generalized Additive Model provided a good fit for most of the variables (0.6 < R2 < 0.94); during the last period, higher values were observed than in the previous periods (p < 0.001), identifying a change in the hydrological state of the basin. This was mainly associated with a significant change in rainfall, which was reflected in the trend of surface runoff. [ABSTRACT FROM AUTHOR]

Investigating the effects of natural rainfall on the soil moisture for sloping farmland is extremely important for comprehending a variety of hydrological processes. Rainfall regimes can elicit different responses to soil moisture at the depth of soil layers, and the responses may differ depending on the landscape position of the sloping farmland. This paper utilized the surface runoff natural rainfall and soil moisture measured on sloping farmland with conventional tillage and contour tillage in the red soil area of China to investigate the influence of natural rainfall events on soil moisture content and to evaluate if the response results were consistent across the four rainfall regimes. Natural rainfall events were classified into different four regimes in line with rainfall duration, rainfall amount, and the maximum 30 min rainfall intensity (I30) by the k-means clustering method, including advanced, intermediate, uniform and delayed regimes. The result showed that the advanced regime was the predominant one in the study area, which represented 45.9% of the total rainfall events. The rainfall regimes influenced the surface runoff coefficient and runoff depth on sloping farmland for conventional and contour tillage, with the uniform regime generating the highest runoff coefficient (5.20% and 5.82%) and runoff depth (2.00% and 2.05%), respectively. For the conventional tillage, soil moisture at a depth of 0–20 cm increased appreciably when the rainfall amount was larger than 20 mm and larger than 30 mm for the advanced regime. For the contour tillage, soil moisture in 20–40 cm layer increased for the advanced regime when the rainfall amount was larger than 15 mm and 30 mm, while the values were modified with rainfall duration and the antecedent dry day (ADD). A longer rainfall duration had a more obvious effect on soil moisture increasing in deep soil. At a depth of 20 cm, the ADD showed an appreciably positive correlation with the increment in soil moisture, which means that a brief ADD produces a compounding effect for a natural rainfall event. The present results underline the complexity of the effect of the rainfall events on soil moisture under two tillage measures for different rainfall regimes and suggest that the advanced regime significantly affects the distinction of soil moisture and the contour tillage can effectively reduce soil water loss and enhance water storage on the sloping farmland with red soil, presenting a theoretical basis for local soil and water conservation research and sloping farmland conservation tillage management. [ABSTRACT FROM AUTHOR]

Flash flood early warning is a very effective way to reduce casualties induced by rainstorm flash flood in mountainous area. The forecasting of flash flooding remains challenging because of the short response time and inaccurate warning threshold. So far, the flash flood disaster defenses often adopt the critical rainfall amounts inducing the peak discharge or water level to establish an early warning threshold in China. However, the runoff peak discharge depends on rainfall patterns including rainfall intensity and accumulation, result in the critical rainfall threshold has a significant uncertainty. To reduce this uncertainty, herein we present a dual-threshold method for flash flood early warning with consideration of rainfall patterns based on above two-rainfall metrics. Moreover, applying this new method in the flash flood disasters occurred in the Zhongdu river basin, Sichuan province of China to evaluate the early warning reliability. Firstly, five most likely rainfall patterns of this basin were determined according to the timing of rain peak in historical rainfall events, and then, we determined the critical rainfall thresholds under different rainfall patterns and soil moisture conditions. The result showed that the rainfall thresholds uncertainty caused by rainfall pattern is more pronounced than soil moisture. Next, using the cumulative rainfall depth and maximum rainfall intensity corresponding to disaster discharge in different flood processes to establish the dual-thresholds. We found the dual-threshold method comprehensively considers the impacts of soil moisture, rainfall temporal distribution and flood rising property, which can achieve early warning for the four protected objects along the Zhongdu River, with an average lead duration of 46.2 min. Compared with the other three single-threshold methods, the critical rainfall and the critical rainstorm curve methods frequently created false or missing warnings, making it difficult to achieve the effect of early warning. Although reliability of flood water level rising rate method is high, the lead time is relatively short and only lasts for a few minutes in some cases. As a result, the new proposed dual-threshold method, accounting for both the reliability and long lead time, can be a potential candidate for the flash flood disaster early warning. [ABSTRACT FROM AUTHOR]

Soil moisture can be an important indicator of climate change in humid and semi-arid areas. This indicator can more efficiently propose different public policies related to climate change than just using precipitation and temperature data. Given the above, the objective of this study is to evaluate changes in soil moisture in the state of Pernambuco during the period 1961–2021, using the System of Hydrological Response Units for Pernambuco. In this study, two river basins in the state of Pernambuco that represent the different climatic conditions of the state were chosen. The results show that in the coastal region there is a tendency towards more saturated soils, and in the semi-arid region there is a tendency towards drier soils. With these results, it is possible to conclude that public policy decisions for the economy, environment, and society must consider this vital water balance variable. Leveraging soil moisture and precipitation data makes it possible to differentiate between flood risks and landslide vulnerabilities, particularly in regions characterized by higher levels of rainfall. Monitoring soil water content in humid and semi-arid areas can significantly enhance early warning systems, thereby preventing loss of life and minimizing the socio-economic impacts of such natural events. As such, this study provides a holistic understanding of the relationship between climatic patterns, soil moisture dynamics, and the occurrence of droughts and floods, ultimately contributing to more effective disaster preparedness and response measures in Pernambuco and similar regions. [ABSTRACT FROM AUTHOR]

Soil moisture patterns are crucial factors in gully bank erosion and may significantly vary depending on the water conditions before winter freezing. Rainfall events can evoke different moisture responses throughout the soil profile of gullies. However, the relative importance of prewinter conditions and rainfall events to the soil moisture responses of gully banks in seasonally frozen regions remains unclear. In this study, a field infiltration experiment of a gully bank with four prewinter soil moisture regimes and three replicates was conducted in October 2017 in the Mollisol region of China. We aimed to elucidate the temporal variations in moisture responses under different prewinter water treatments at various distances to the gully bank after three representative rainfall events in 2018. The response magnitude (Δs) varied widely and was largest in the intermediate layers (30-50 cm) for wetter prewinter regimes (i.e., HI and MED) but was larger in the upper soil layers (0-30 cm) for drier prewinter regimes (i.e., CK and LO). In contrast to the findings of other studies, we found that the relative influences of prewinter conditions and rainfall events on the soil moisture responses varied with soil depth and distance to the gully edge. The soil moisture response increased with rainfall depth, and the effect of prewinter conditions dominated until the end of the rainy season (August). The most important explanatory variables for the response magnitude (Δs) were rainfall events (46%), soil depth (10%), and prewinter conditions (7%). This study increases the understanding of the heterogeneity in soil moisture responses and the relationship to rainfall events under different prewinter conditions on gully banks in the Mollisol region. Understanding subsurface hydrological processes and identifying the relative importance of prewinter conditions and rainfall are beneficial for building gully bank erosion models for seasonally frozen regions. [ABSTRACT FROM AUTHOR]

The diversity of flood‐generating mechanisms superimposed on catchment physiographic features with non‐stationary meteorological drivers makes future flood hazard assessment a grand challenge. To date, many studies have examined patterns in rainfall and streamflow, but far fewer have investigated trends in the other drivers of flooding. The complex transfer function between precipitation and flooding makes it potentially misleading to simply look at the change in rainfall to express the hazard. Furthermore, there are very few studies that have directly used output from km‐scale climate models in flood modeling. Coarse resolution climate data sets may not credibly resolve local climate and weather extremes. Changes in rainfall distribution and antecedent moisture over extended time periods due to climate change have so far been ignored when assessing urban pluvial flood risk. In this paper, an urban flood hazard assessment framework using the latest 2.2 km resolution UK Climate Projections Local is proposed. Global warming induced changes in pluvial flood risks under RCP8.5 are projected, focusing on the impact of changing precipitation patterns and soil moisture dynamics on flood generation. Results indicate a strong increase in the frequency of occurrence of extreme floods, and the resultant future (2060–2080) annual flood volume is expected to increase up to 52.6% relative to 1980–2000 over a major UK urban region, and these patterns are likely to hold more generally elsewhere in the UK. Shifts to a later occurrence of extreme flooding is identified under global warming. Previous studies that have neglected soil moisture dynamics are unlikely to give accurate flood estimates. Plain Language Summary: The future flood hazard status over the major UK urban region of Bristol (domain size ∼746 km2) is evaluated using the latest 12‐member UK Climate Projections Local ensemble rainfall data set at the hourly and kilometer scale. A total of 30,098 rainfall events from an equivalent 720 years of climate data are identified and used for flood modeling. Impact of changing precipitation pattern and soil moisture dynamics on surface water floods are evaluated, and the interaction between precipitation, inundation, infiltration, and soil wetness are handled simultaneously at a spatial resolution of ∼30 m or less using an improved hydrodynamic model (LISFLOOD‐FP). Our findings highlight a shift toward a later seasonal occurrence of extreme flooding under global warming. Specifically, a large proportion of future extreme flood hazards is projected to manifest in December, contrasting with historical trends where most extreme events occurred in November. Extreme precipitation can be magnified in rainy seasons due to amplified moisture convergence, while in dry periods limited moisture availability may offset precipitation increases. Despite an overall increase in the total annual rainfall volume, the future summer is anticipated to be much drier due to limited rainfall availability, leading to a further reduction in soil moisture availability. Key Points: Shifts to a later seasonal occurrence of extreme flooding is identified under global warming in the UKIncrease in annual total rainfall leads to a disproportionate rise in the resultant flood volumeImpact of the antecedent soil moisture on flood generation shows seasonality [ABSTRACT FROM AUTHOR]

Understanding the dynamic response of soil moisture to rainfall is crucial for describing hydrological processes at the hillslope scale. However, because of sparse monitoring coupled with the complexity of water movement and steep topography, the findings of rainfall‐related soil moisture dynamics have not always been consistent, indicating a need for systematic investigations of soil moisture dynamics and infiltration patterns following rainfall inputs at multiple topographic positions along a hillslope. This study aimed to examine the nature of these responses by characterizing and quantifying the response amplitude, rate and time for 37 large rainfall events at 25 combinations of topographic positions and soil depths along a steep forested hillslope. Our results showed that soil moisture responses under different rainfall patterns could be attributed to one or the other rainfall characteristics, such as rainfall intensity and amount. However, soil moisture dynamics at different hillslope positions after rainfall varied widely due to the controls of soil properties, topography, and non‐equilibrium flow. Preferential flow was more evident under dry initial soil conditions than under wet initial soil conditions. Findings of this study reveal that the dynamic response patterns of soil moisture to rainfall do not always follow topographic controls, which can improve our understanding of water cycling related to the infiltration process at the hillslope scale, and support water resources management in subtropical mountain ecosystems. [ABSTRACT FROM AUTHOR]

Soil moisture is crucial to vegetation restoration in karst areas, and climate factors and vegetation restoration are key factors affecting changes in soil moisture. However, there is still much controversy over the long‐term changes in soil moisture during vegetation restoration. In order to reveal the changes in soil moisture during vegetation restoration, we conducted long‐term positioning monitoring of soil moisture at 0–10 and 10–20 cm on secondary forests sample plot (SF, tree land) and shrubs sample plot (SH, shrub land) in karst areas from 2013 to 2020. The results showed that the aboveground biomass of SF and SH increased by 50% and 240%, respectively, and the soil moisture of the SF and SH showed an increasing trend. When shrubs are restored to trees in karst areas, the soil moisture becomes more stable. However, the correlation coefficients (R2) between the annual rainfall and the annual average soil moisture of SF and SH are 0.84 and 0.55, respectively, indicating that soil moistures in tree land are more affected by rainfall. The soil moisture of shrubs and trees are relatively low during the months of alternating rainy and dry seasons. Rainfall has a very significant impact on the soil moisture of tree land, while air temperature and wind speed have a significant impact on the soil moisture of tree land, but the soil moistures of shrub land are very significantly affected by rainfall and relative humidity. Therefore, during the process of vegetation restoration from shrubs to trees, the main meteorological factors that affect soil moisture changes will change. The results are important for understanding the hydrological processes in the ecological restoration process of different vegetation types in karst areas. [ABSTRACT FROM AUTHOR]

Uneven rainfall, in the context of global warming, can cause soil moisture fluctuations (SMFs) that harm crop growth, and it is not yet known whether nitrogen (N) can mitigate the harm caused by a strong SMF. This paper uses okra as a test subject and sets three SMFs of 45–55% FC (W1), 35–65% FC (W2), and 25–75% FC (W3) and three N applications of 0 kg hm−2 (N0), 110 kg hm−2 (N1), and 330 kg hm−2 (N2) to investigate the effects of SMF and N application on the physiological and biochemical aspects of okra. The results demonstrated that okra exhibited the highest values in stem diameter, number of leaves, photosynthesis characteristics, antioxidant enzyme activity, and yield under the N1 treatment. The average yield in the N1 treatment was 149.8 g, significantly surpassing the average yields of the N0 (129.8 g) and N3 (84.0 g) treatments. Stomatal density, antioxidant enzyme activity, malondialdehyde content, and proline content in okra leaves were highest in the W3 treatment, indicating that plants experienced stress in the W3 treatment. However, the agronomic traits and yields of okra in the N1 treatment were higher than those in the N0 and N1 treatments, indicating that the crop damage caused by W3 could be mitigated by an appropriate amount of N application. The N1W1 treatment emerged as the most suitable combination for okra growth in this study, exhibiting the highest stem diameter, leaf count, photosynthetic characteristics, and yield (201.3 g). Notably, this yield was 67.8% higher than the lowest treatment (N2W3), signifying a significant improvement. [ABSTRACT FROM AUTHOR]

Rainwater is the main water source in arid and semiarid areas of the Loess Plateau, where rainfall is generally insufficient, ineffective and underutilized during the growing season. Thus, improving rainwater utilization efficiency is essential for sustainable agricultural development. A new system composed of rainwater harvesting, an infiltrator bucket with multiple holes and mulching (RHM), was designed to maintain soil moisture at a proper level in rain-fed orchards in arid and semiarid areas of the Loess Region of China. However, there is a lack of clarity on the effectiveness of RHM. In this study, changes in the soil environment and the growth and physiology of apricot trees were monitored via two treatments: (1) Rain-harvesting irrigation system (RHM) treatment and (2) traditional orchard treatment (CK) as a baseline. The results showed that (1) RHM could effectively improve soil water storage at depths of 0–45 cm and at a horizontal distance of 40 cm from the trunk. For the 1.4 mm light rain event, the soil water content increased by 6.3–12%, and for the two moderate rains, the soil water content increased by 12–25%. The change in the soil relative water content predicted by the LSTM model is consistent with the overall trend of the measured value and gradually decreases, and the prediction accuracy is high, with an error of 0.65. (2) The average soil temperatures at 5 cm, 20 cm and 40 cm under RHM were 17.0% (2.4 °C), 13.6% (1.9 °C) and 7.5% (1 °C) greater than those under CK, respectively. (3) Compared with the control treatment, RHM improved the growth and WUEL of apricot trees. The results highlighted the efficiency of the RHM system in enhancing the soil environment and regulating the growth and physiology of apricot trees, which has greater popularization value in arid and semiarid areas. [ABSTRACT FROM AUTHOR]

One of the alternative methods for managing irrigation water is deficit irrigation, particularly alternate furrow irrigation (AFI). This deficit in irrigation is affected by uncontrolled rainfall. In line with this, rainfall uncertainty causes a variation between the measured actual crop evapotranspiration and the theoretical crop evapotranspiration. Let us imagine that rain falls during the deficit irrigation research, and the soil moisture under the deficit experiment is then raised to the soil field capacity. It is incorrect to report the result as a deficit. Thus, there is a research gap on the effect of rainfall uncertainty on the quantity of theoretical and actual crop evapotranspiration under deficit irrigation. This study was carried out at the Arba Minch University demonstration site on onion crops. Using CROPWAT 8.0 software, the reference evapotranspiration (ETo) was calculated using the Penman-Monteith formula. The crop coefficient and ETo were used to calculate the theoretical crop evapotranspiration. In contrast, actual crop evapotranspiration was calculated using soil moisture measurements before and after each irrigation event after applying theoretical crop evapotranspiration. As a result, there is a significant difference between the calculated theoretical crop evapotranspiration and actual crop evapotranspiration from a deficit study. Thus, the calculated seasonal theoretical crop evapotranspiration was 201.72 mm. On the other hand, the actual crop evapotranspiration was 275.82 mm. This revealed that the actual crop evapotranspiration was greater than the calculated theoretical crop evapotranspiration by 36.7%. Uncontrolled rainfall was identified as the output's cause. This has an evident effect on the deficit in experimental research. Hence, conducting the deficit experiment in a greenhouse is more reasonable. In addition, it is possible to assess actual crop evapotranspiration based on daily soil moisture measurements and report the deficit level based on the measured amount. [ABSTRACT FROM AUTHOR]

Understanding the unstable evolution of railway slopes is the premise for preventing slope failure and ensuring the safe operation of trains. However, as two major factors affecting the stability of railway slopes, few scholars have explored the unstable evolution of railway slopes under the joint action of rainfall-vibration. Based on the model test of sandy soil slope, the unstable evolution process of slope under locomotive vibration, rainfall, and rainfall-vibration joint action conditions was simulated in this paper. By comparing and analyzing the variation trends of soil pressure and water content of slope under these conditions, the change laws of pore pressure under the influence of vibration and rainfall were explored. The main control factors affecting the stability of slope structure under the joint action conditions were further defined. Combined with the slope failure phenomena under these three conditions, the causes of slope instability resulting from each leading factor were clarified. Finally, according to the above conclusions, the unstable evolution of the slope under the rainfall-vibration joint action was determined. The test results show that the unstable evolution process of sandy soil slope, under the rainfall-vibration joint action, can be divided into: rainfall erosion cracking, vibration promotion penetrating, and slope instability sliding three stages. In the process of slope unstable evolution, rainfall and vibration play the roles of inducing and promoting slide respectively. In addition, the deep cracks, which are the premise for the formation of the sliding surface, and the violent irregular fluctuation of soil pressure, which reflects the near penetration of the sliding surface, constitute the instability characteristics of the railway slope together. This paper reveals the unstable evolution of sandy soil slopes under the joint action of rainfall-vibration, hoping to provide the theoretical basis for the early warning and prevention technology of railway slopes. [ABSTRACT FROM AUTHOR]

The Indian Summer Monsoon (ISM) can profoundly influence the summer precipitation patterns of the Tibetan Plateau (TP) and indirectly affect the TP's soil humidity. This study investigates the responses of TP's precipitation and soil moisture to the ISM in the monsoon season (June to September, JJAS) from 1979 to 2019. Precipitation in the TP and the ISM intensity generally exhibit a positive correlation in the west and a negative correlation in the east. The response of TP soil moisture to the ISM generally aligns with precipitation patterns, albeit with noted inconsistencies in certain TP regions. A region exhibiting these inconsistencies (30°–32°N, 80°–90°E) is selected as the study area, hereafter referred to as IRR. In periods of strong ISM, precipitation in IRR increases, yet soil moisture decreases. Conversely, in years with a weak ISM, the pattern is reversed. During strong ISM years, the rainfall increase in IRR is modest, and the soil remains drier compared to other TP regions. Under the combined effects of a marginal increase in precipitation and relatively rapid evaporation, soil moisture in the IRR decreased during years of strong ISM. During weak ISM years, the surface temperature in the IRR is higher compared to strong ISM years, potentially accelerating the melting of surface permafrost and snow in this region. Additionally, glacier meltwater, resulting from warmer temperatures in the northwest edge of the TP, may also result in the humidification of the soil in the IRR. [ABSTRACT FROM AUTHOR]