Long-term experimental watershed studies have significantly influenced our global understanding of hydrological processes. The discovery and characterization of how stream water quantity and quality respond to a changing environment (e.g., land use change and acidic deposition) has only been possible due to the establishment of catchments devoted to long-term study. One such catchment is the Fernow Experimental Forest (FEF) located in the headwaters of the Appalachian Mountains in West Virginia, a region that provides essential freshwater ecosystem services to eastern and mid-western USA communities. Established in 1934, the FEF is among the earliest experimental watershed studies in the Eastern USA that continues to address emergent challenges to forest ecosystems, including climate change and other threats to forest health. This data note summarizes some of the seminal findings from more than 50 years of hydrologic research in the FEF. During the first few decades, research at the FEF focused on the relationship between forest management and hydrological processes – especially those related to the overall water balance. Later, research efforts included the examination of interactions between hydrology and soil erosion, biogeochemistry, N-saturation, and acid deposition. Hydro-climatologic and water quality datasets from long-term measurements and data from short-duration studies are publicly available to provide new insights and foster collaborations that will continue to advance our understanding of hydrology in forested headwater catchments. As a result of its rich history of research and abundance of long-term data, the FEF is uniquely positioned to continue to advance understanding of forest ecosystems in a time of unprecedented change.
The relationships and seasonal-to-annual variations among evapotranspiration (ET), precipitation (P), and groundwater dynamics (total water storage anomaly, TWSA) are complex across the Amazon basin, especially the water and energy limitation mechanism for ET. To analyze how ET is controlled by P and TWSA, we used wavelet coherence analysis to investigate the effects of P and TWSA on ET at sub-basin, kilometer, regional, and whole basin scales in the Amazon basin. The Amazon-scale averaged ET has strong correlations with P and TWSA at the annual periodicity. The phase lag between ET and P (ϕ_(ET-P)) is ~1 to ~4 months, and between ET and TWSA (ϕ_(ET-TWSA)) is ~3 to ~7 months. The phase pattern has a south-north divide due to the significant variation in climatic conditions. The correlation between ϕ_(ET-P) and ϕ_(ET-TWSA) is affected by the aridity index, of each sub-basin, as determined using the Budyko framework at the sub-basin level. In the southeast Amazon during a drought year (e.g., 2010), both phases decreased, while in the subsequent years, ϕ_(ET-TWSA) increased. The area of places where ET is limited by water continues to decrease over time in the southern Amazon basin. These results suggest immediate strong groundwater subsidy to ET in the following dry years in the water-limited area of Amazon. The water storage has more control on ET in the southeast but little influence in the north and southwest after a drought. The areas of ET limited by energy or water are switched due to the variability in weather conditions.
Soil detachment is one of the most important processes of soil erosion, as it is of great significance for the prevention and treatment of soil erosion in areas subject to seasonal freeze-thaw. However, most previous studies on the effect of freeze-thaw on soil detachment capacity (SDC) of bare soil, little research on SDC under the effect of freeze-thaw and the root system. This study investigated the effects of freeze-thaw and the root system on soil detachment capacity through hydraulic flume experiments to simulate the soil detachment process of two soil types, sand soil and loessal soil, under four treatments, control, freeze-thaw, root system and freeze-thaw + root system. And a prediction model was developed to calculate SDC under the effect of freeze-thaw and the root system. The results illustrated that the SDC of sand soil was higher than that of loessal soil. The SDC of two soils was reduced and increased by the root system and freeze-thaw, respectively, although the former effect was significant (P < 0.05) whereas the latter was not. The effect of freeze-thaw in combination with the root system showed that the root system contributed the majority of SDC variability (99.95%); therefore, inhibition of SDC by the root system played a leading role. When comparing shear stress, unit energy of the water carrying section and unit stream power, stream power was found to be the hydraulic parameter that best predicted SDC (R2¬ > 0.84). The inclusion of root weight significantly improve the accuracy of the SDC prediction model developed by hydraulic parameters. A general model based on stream power and root weight was developed to quantify SDC and was shown to have a high SDC prediction accuracy for both soils treated by freeze-thaw and the root system [NSE = 0.88，R2 = 0.90].
It is widely recognized that multi-year drought can induce changes in catchment hydrological behaviors. However, at present, our understanding about multi-year, drought-induced changes in catchment hydrological behaviors and its driving factors at the process level is still very limited. This study proposed a new approach using a data assimilation technique with a process-based hydrological model to detect multi-year drought-induced changes in catchment hydrological behaviors and to identify driving factors for the changes in an unimpaired Australian catchment (Wee Jasper) which experienced prolonged drought from 1997 to 2009. Modelling experiments demonstrated that the multi-year drought caused a significant change in the catchment rainfall-runoff relationship, indicated by significant step changes in the estimated time-variant hydrological parameters SC (indicating catchment active water storage capacity) and C (reflecting catchment evapotranspiration dynamics), whose average values increased 23.4% and 10.2%, respectively, due to drought. The change in the rainfall-runoff relationship identified by the data assimilation method is consistent with that arrived at by a statistical examination. The proposed method provides insights about the drivers of the changes in the rainfall-runoff relationship at the processes level. Declining groundwater and deep soil moisture depleted by persistent evapotranspiration of deep-rooted woody vegetation during drought are the main driving factors for the catchment behaviors change in the Wee Jasper catchment. The new method proposed in this study was found to be an effective technique for detecting both the change of hydrological behaviors induced by prolonged drought and its driving factors at the process level.
Despite the importance of headwater basins for western United States’ water supply, these regions are often poorly understood, particularly with respect to quantitative understanding of evapotranspiration (ET) fluxes. Heterogeneity of land cover, topography, and atmospheric patterns in these high-elevation regions lead to difficulty in developing spatially distributed characterization of ET. As a significant fraction of the water budget, ET contributes to overall water and energy availability in the basin. Using an eddy covariance tower in the East River Basin, a Colorado River headwaters basin, this study improves the quantification of water and energy fluxes in high-elevation, complex systems to better constrain ET estimates and calculate overall water and energy budgets. The eddy covariance method estimates ET from years 2017 through 2019 at a saturated, riparian end-member site. During the late spring, summer, and early fall months, due to strong variations in lower atmospheric stability and evidenced by a less than 30% energy balance closure error in these months (within the range of closure error reported at other riparian locations) we conclude that the eddy covariance method is useful in high-elevation, complex areas such as the East River Basin and helps bound regional ET estimates. We also compared East River ET magnitudes and seasonality to two other eddy covariance towers (Niwot Ridge, CO and Valles Caldera, NM), with similar site characteristics, located in the Rocky Mountains. East River ET estimations are useful for constraining water budget estimates at this energy-limited site, which uses groundwater for up to 76% of ET in the summer months. This data is useful for constraining ET estimates in similar end-member locations; however, to better constrain ET estimates across the entire East River basin, additional sampling is needed. This study helps constrain both the energy and water budgets in locations that are underrepresented by observations and where indirect estimates of ET may perform poorly.
Desert pavements are the common features widespread in arid region, which are important for regulating the ecological and hydrologic processes. However, few studies focused on the role of water movement in maintaining ecologic function in desert pavement landscapes. This study determined the role of desert pavements in water infiltration on fluvial fans, which were reflected by characteristics of desert pavements and infiltration parameters in the middle reaches of Hexi Corridor. Six sites (i.e. one site in hill slope and other five sites in the piedmont) were selected for surveying soil properties within a 50-cm depth soil profile and measuring sorptivity (S), initial water infiltration (ii), steady-state infiltration rate (is) and infiltration time (T) in crust and scalped crust conditions under 5-cm pressure head. The results indicated that desert pavement surfaces were covered by a thin layer of protective crusts, which were primarily composed of fine earth (56.94%) and fine-medium gravel (40.46%). Although characterized by a big range of gravel coverage (19.48%- 97.63%), the crusts had small gravels (mean size: 0.58 cm) and extremely low soil moisture content (SMC; less than 1.30%), which two parameters did not significantly differ from each site in fluvial fans. The crusts were effective in restricting water infiltration capacity. When the crusts were scalped, the S, ii and is would improve 1.6, 1.7 and 1.6-fold, respectively. These three parameters significantly increased with gravel coverage and medium gravels, but significantly decreased with crust thickness and fine gravels. Desert pavements were closely with water regulation in arid systems, reflecting the vegetation distribution. This study highlights that desert pavements have a strong impact on water infiltration to function as regulating water resource and supplying water for vegetation growth.
Wildfires are a cause of soil water repellency (hydrophobicity), which reduces infiltration while increasing erosion and flooding from post-fire rainfall. Post-fire soil water repellency degrades over time, often in response to repeated wetting and drying of the soil. However, in mountainous fire-prone forests such as those in the Western USA, the fire season often terminates in a cold and wet winter, during which soils not only wet and dry, but also freeze and thaw. Little is know about the effect of repeated freezing and thawing of soil on the breakdown of post-fire hydrophobicity. This study characterized the changes in hydrophobicity of Sierra Nevada mountain soils exposed to different combinations of wet-dry and freeze-thaw cycling. Following each cycle, hydrophobicity was measured using the Molarity of Ethanol test. Hydrophobicity declined similarly across all experiments that included a wetting cycle. Repeated freezing and thawing of dry soil did not degrade soil water repellency. Total soil organic matter content was not different between soils of contrasting hydrophobicity. Macroscopic changes such as fissures and cracks were observed to form as soil hydrophobicity decayed. Microscopic changes revealed by scanning electron microscope imagery suggest different levels of soil aggregation occurred in samples with distinct hydrophobicities, although the size of aggregates was not clearly correlated to the change in water repellency due to wet-dry and freeze-thaw cycling. A nine year climate and soil moisture record from Providence Critical Zone Observatory was combined with the laboratory results to estimate that hydrophobicity would persist an average of 144 days post-fire at this well-characterized, typical mid-elevation Sierra Nevada site. Most of the breakdown in soil water repellency (79%) under these climate conditions would be attributable to freeze-thaw cycling, underscoring the importance of this process in soil recovery from fire in the Sierra Nevada.
How to get the discharge information of the river becomes a hot topic in global research. However, most river discharge measurement methods involve long cycles, low efficiency, and transdisciplinary expertise. This makes it impossible to assess river flows in ungauged basin rapidly. With the improvement of accuracy of hydrological parameters and variables, the data obtained by remote sensing method can not satisfy the hydrological calculation. This study presents a new method to rapidly assessing river discharge coupling remote sensing images and UAVs. We selected eight typical river-course cross-sections in Bortala river and Jing river to calculate river discharge. Construction of river cross-section shape by UAV data combined with groundwater level monitoring. Dividing the reach and generalizing the relationship of hydraulic geometry of the reach. By extracting the river width, the river discharge of river cross-section was estimated. The results showed that the calculated results were consistent with the measured data and the accuracy was above 90%. This paper discusses the application of this method in satellite remote sensing. The results compared with the measured daily data of hydrological station, and the accuracy of the calculated results can reach above 85%. The method used in this study for calculating river discharge based on a combination of UAV and satellite remote sensing can effectively promote research progress into basin river discharge, and provide an important reference for river discharge monitoring in ungauged basins.
High nitrogen (N) and phosphorus (P) levels are the main causes of eutrophication of water bodies, and the chemical oxygen demand (COD) is one of the indices of relative organic matter content. Several simulated rainfall experiments have been conducted to investigate the effects of a single controlling factor on soil and nutrient loss. However, the role of precipitation and vegetation coverage in quantifying soil and nutrient loss is still unclear. We monitored runoff, soil loss, and soil nutrient loss under natural rainfall conditions from 2004 to 2015 in runoff plots around Beijing. Soil erosion was significantly reduced when vegetation coverage reached 20 and 60%. At levels below 30%, nutrient loss did not differ among different vegetation cover levels. Minimum soil N and P losses were observed at cover levels above 60%. Irrespective of the management measure, soil nutrient losses were higher at high-intensity rainfall events compared to low-intensity events (p < 0.05). We applied structural equation modelling (SEM) to systematically analyze the relative effects of rainfall characteristics and environmental factors on runoff, soil loss, and soil nutrient loss. At high-intensity rainfall events, neither vegetation cover nor antecedent soil moisture content (ASMC) affected runoff and soil loss. After log-transformation, soil nutrient loss was significantly linearly correlated with runoff and soil loss (p < 0.01). In addition, we identified the direct and indirect relationships among the influencing factors of soil nutrient loss on runoff plots and constructed a structural diagram of these relationships. The factors positively impacting soil nutrient loss were runoff (44-48%), maximum rainfall intensity over a 30-min period (18-29%), rainfall depth (20-27%), and soil loss (10-14%). Studying the effects of rainfall and vegetation coverage factors on runoff, soil loss, and nutrient loss can improve our understanding of the underlying mechanism of slope non-point source pollution.
The source and hydrochemical makeup of a stream reflects the connectivity between rainfall, groundwater, the stream, and is reflected to water quantity and quality of the catchment. However, in a semi-arid, thick, loess covered catchment, temporal variation of stream source and event associated behaviors are lesser known. Thus, the isotopic and chemical hydrograph in a widely distributed, deep loess, semi-arid catchment of the northern Chinese Loess Plateau were characterized to determine the source and hydrochemical behaviors of the stream during intra-rainfall events. Rainfall and streamflow were sampled during six hydrologic events coupled with measurements of stream baseflow and groundwater. The deuterium isotope (2H), major ions (Cl-, SO42-, NO3-, Ca2+, K+, Mg2+, and Na+) were evaluated in water samples obtained during rainfall events. Temporal variation of 2H and Cl- measured in the groundwater and stream baseflow prior to rainfall was similar; however, the isotope compositions of the streamflow fluctuated significantly and responded quickly to rainfall events, likely due to an infiltration excess, overland dominated surface runoff during torrential rainfall events. Time source separation using 2H demonstrated greater than 72% on average, the stream composition was event water during torrential rainfall events, with the proportion increasing with rainfall intensity. Solute concentrations in the stream had loglinear relationships with stream discharge, with an outling anomaly during an intra-rainfall event on Oct. 24, 2015. Stream Cl- behaved nonconservative during rainfall events, temporal variation of Cl- indicated a flush and washout at the onset of small rainfall events, a dilution but still high concentration pattern in high discharge and old water dominated in regression flow period. This study indicated that streamflow responded to rainfall events quickly and composition was dominated by overland flow. Stream isotope and hydrochemistry controlled by infiltration excess, overland flow indicated that stored water in the thick, loess covered areas were less connected with stream runoff. Solute transport may threaten water quality in the area, requiring further analysis of the performance of the eco-restoration project.
Estimating snow water equivalent (SWE) and snowmelt in semi-arid mountain ranges is an important but challenging task, due to the large spatial variability of the seasonal snow cover and scarcity of field observations. Adding solar radiation as snowmelt predictor within empirical snow models is often done to account for topographically induced variations in melt rates, at the cost of increasing model complexity. This study examines the added value of including different treatments of solar radiation within empirical snowmelt equations. Three spatially-distributed, enhanced temperature index models that respectively include the potential clear-sky direct radiation (HTI), the incoming solar radiation (ETIA) and net solar radiation (ETIB) were compared with a classical temperature-index model (TI) to simulate SWE within the Rheraya basin in the Moroccan High Atlas Range. Extensive model validation of simulated snow cover area (SCA) was carried out using blended MODIS snow cover products over the 2003-2016 period. We found that models enhanced with a radiation term, particularly ETIB which includes net solar radiation, better explain the observed SCA variability compared to the TI model. However, differences in model performance were overall small, as were the differences in basin averaged simulated SWE and melt rates. SCA variability was found to be dominated by elevation, which is well captured by the TI model, while the ETIB model was found to best explain additional SCA variability. The small differences in model performance for predicting spatiotemporal SCA variations is interpreted to results from the averaging out of topographically-induced variations in melt rates simulated by the enhanced models, a situation favored by the rather uniform distribution of slope aspects in the basin. Moreover, the aggregation of simulated SCA from the 100 m model resolution towards the MODIS resolution (500 m) suppresses key spatial variability related to solar radiation, which attenuates the differences between the TI and the radiative models.
Monitoring of the fluctuations of groundwater storage is particularly important in arid and semi-arid regions where water scarcity brings about various challenges. Remote sensing data and techniques play a preponderant role in developing solutions to environmental problems. Emergence of GRACE satellites have eased the remote monitoring and evaluation of groundwater resources with an unprecedented precision over large scales. Within the scope of the current study, the latest release of GRACE Mascon’s dataset as well as GLDAS models of Noah and CLSM were integrated to extract groundwater storage anomalies (GWSA) over Turkey. The temporal interactions of the estimated GWSA with the climatic variables of precipitation and temperature (derived from the reanalysis datasets of CHELSA and FLDAS, respectively) were investigated statistically. The results suggest the there is a descending trend for TWSA and GWSA over Turkey with a total loss of 11 and 6 cm respectively. The statistical analysis results also indicate that the monthly variations of GWS over Turkey are highly correlated with precipitation and temperature at 2-month lag. The analysis of the climatology (long-term) values of monthly GWSA, precipitation and temperature also revealed high agreement between the variables.
Modeling and prediction of soil hydrologic processes require the identification of soil moisture spatial-temporal patterns and effective methods allowing the data observations to be used across different spatial and temporal scales. This work presents a methodology for the combination of spatially- and temporally-extensive soil moisture data obtained in the Shale Hills Critical Zone Observatory (CZO) from 2004 to 2010. The soil moisture data sets were decomposed into spatial Empirical Orthogonal Function (EOF) patterns, and their relationship with various geophysical parameters was examined to determine the dominant factors contributing to the profiled soil moisture variability. The EOF analyses indicated that one or two EOFs of soil moisture could explain 76-89% of data variation. The primary EOF pattern had high values clustered in the valley region, and conversely low values located in the sloped hills. We suggest a novel approach to integrate the spatially-extensive manually measured datasets with the temporally-extensive automated monitored datasets based on the EOF analyses. Given the data accessibility, the current data merging framework has provided the methodology for the coupling of the mapped and monitored soil moisture datasets, as well as the conceptual coupling of slow and fast pedologic and hydrologic functions. This successful coupling implies that a combination of different extensive moisture data has provided interesting insights into our understanding of hydrological processes at multiple scales.
In this study, we characterize the snowmelt hydrological response of nine nested headwater watersheds in southeast Wyoming by separating streamflow into three components using a combination of tracer and graphical approaches. First, continuous records of specific conductance (SC) from 2016 to 2018 were used to separate streamflow into direct runoff and baseflow components. Then, diurnal streamflow cycles occurring during the snowmelt season were used to graphically separate direct runoff into quickflow, representing water with the shortest residence time, and throughflow, representing water with longer residence time in the soil column and/or regolith layers before becoming streamflow. On average, annual streamflow was comprised of between 22% to 46% baseflow, 7% to 14% quickflow, and 46% to 55% throughflow across the watersheds. We then quantified hysteresis at both annual and daily timescales by plotting SC versus discharge. Annually, most watersheds showed negative, concave, anti-clockwise hysteretic direction suggesting faster flow pathways dominate streamflow on the rising limb of the annual hydrograph relative to the falling limb. At the daily timescale during snowmelt-induced diurnal streamflow cycles, hysteresis was negative, but with a clockwise direction implying that quickflow peaks generated from the concurrent daily snowmelt, with shorter residence times and lower specific conductance, arrive after throughflow peaks and preferentially contribute on the falling limb of diurnal cycles. Slope aspect and surficial geology were highly correlated with the partitioning of streamflow components. South-facing watersheds were more susceptible to early season snowmelt at slower rates, resulting in less direct runoff and more baseflow contribution. Conversely, north-facing watersheds had longer snow persistence and larger proportions of direct runoff and quickflow. Watersheds with surficial and bedrock geologies dominated by glacial deposits had a lower proportion of quickflow compared to watersheds with large percentages of metasedimentary rocks and glaciated bedrock.
The water agreements between Mexico and the United States have been crucial to restore and preserve the wetlands of the Colorado River Delta. Nowadays, the increase of water demand and climate change in the northwest of Mexico could threaten the conservation of the Cienega de Santa Clara, a coastal wetland composed of 4,709 ha of marsh area in the limits of the Sonoran Desert. This ecosystem was recognized internationally by the international Ramsar convention for playing vital ecological roles, including the habitat service for endemic, endangered and migratory species. Since the inflow reductions by the trial run of the Yuma Desalting Plant during 2010-2011, and earlier events, the hydrology of the wetland has not been completely understanding due to accessibility. Therefore this study was conducted to obtaining the hydrological elements to conserve the wetland, analyzing three scenarios: 1] normal inflow conditions of the Wellton-Mohawk canal; 2] inflow reductions, and; 3] an increase of temperature in consequence of global warming. Water and mass balances were conducted every month during one year; in-situ measurements of inflows were carried out on Wellton-Mohawk, Riíto Drain, groundwater, and precipitation; also were including evapotranspiration outputs estimated using local weather registers and Penman-Monteith formulations. The implications of the increase in temperature considered include the Intergovernmental Panel on Climate Change projections for the one hundred years. Finally, the results showed superficial water disconnections between the hydrological system of the wetland and the Gulf of California. This behavior was observed in the three scenarios, mainly in the summer months. A continuous disconnection reduced the wetland area and the water storage. Therefore, the hydrological functionality of the wetland depends on the water supply thru Wellton-Mohawk canal, which was determinate that at least a continuous discharge of 5.10 m3 s-1 during summer months is needed to maintain its functionality.
Particle selectivity plays an important role in clarifying sediment transport processes in vegetative filter strips (VFS). 10-m long grass strips at slopes of 5○ and 15○were subjected to a series of silt-laden inflows experiments with different particle sizes to investigate the sediment transport and its response to overland flow hydraulics. The inflow sediments came from local soil, river-bed sand, and mixed, with median particle size d50 of 39.9, 207.9, and 77.4 μm, respectively. Three independent repeated experiments were carried for each treatment. The results show that when the sediment trapping lasted for a certain length of time, the re-entrainment of some small-sized particles was greater than the deposition; that is, negative deposition occurred, which was not erosion of the original soil. Negative deposition of particles is mainly determined by the particle diameter. The coarser the inflow sediment particles and/or the steeper the slope, the coarser the particles can be negatively deposited. Deposited sediment causes the VFS bed surface to become smooth and hydraulic resistance decrease exponentially. Stream power P is more suitable than shear stress τ of overland flow to be used to describe the process of sediment particle transport in VFS. The relationship between P and d50 of outflow sediment is very consistent with the form of power function with a constant term. These results are helpful to understand the physical process of sediment transport on vegetation hillslopes.
In this study, we unveiled the lumped effects at the reach spatial scale over three decades in one of the braided rivers in the Qinghai-Tibet Plateau of China, the Upper Lancang River (ULR). Using Landsat images obtained in 13 years between 1989 and 2018, we extracted flowing and non-flowing channels, active channel widths (unvegetated bars and flowing channels), and calculated lateral shifting rates of the main channel for the 13 periods. We also developed an empirical equation between vegetation area (Av) calculated from the high-resolution ortho-photo derived from an Unmanned Aerial Vehicle survey and Normalized Difference Vegetation Index for pixels of the Landsat image obtained at the same time. This relationship allowed us to estimate Av for other 12 selected years. We found that (1) braiding intensity increases with low discharges, indicating that the ULR is a very well-connected braided system with groundwater providing a large set of aquatic habitats, (2) this braided system is very well-supplied and actively shifting in relation to peak flow and flood duration, and (3) The ULR supports a progressive vegetation encroachment, which seems to be linked to temperature rising. Our study showed several similar morphological patterns to those in other braided rivers, such as the ones observed in the European Alps but much more active, well-supplied and highly connected. These similarities suggest that similar morphodynamic processes might take effect in the braided rivers with very high elevations and potentially high spots of biodiversity, indicating the ULR may be a reference for this region similarly to the Tagliamento in the Alps, but it seems that this system can be very sensitive to global change due to vegetation encroachment following temperature rising and decreases of low flows.
With the increasing demand for water resources, the utilization of marginal water resources of poor-quality has become a focus of attention. The brackish water developed in the Loess Plateau is not only salty but also famous for its “bitterness”. In the present work, multi-isotope analysis (Sr, B) was combined with geochemical analysis to gain insight into the hydrogeochemical evolution and formation mechanisms of brackish water. These results demonstrate that groundwater in the headwater is influenced by carbonate weathering. After the confluence of several tributaries in the headwater, the total dissolved solids (TDS) of water is significantly increased. The dissolution of evaporates is shown to be the main source of salinity in brackish water, which also greatly affects the Sr isotopic composition of water. This includes the dissolution of Mg-rich minerals, which is the main cause of the bitterness. Furthermore, the release of calcium from the dissolution of gypsum may induce calcite precipitation and incongruent dissolution of dolomite, which also contributes to the enrichment of magnesium. The highly fractionated boron isotopic values observed in the upstream groundwater were explained by boron interacting with clays, illustrating the important role played by the cationic exchange reaction. The inflow of brackish groundwater is the source of the observed quality of the river water. River water with relatively enriched 11B contents reflects the occurrence of evaporation along the flow path of the river. This process further aggravates the salinization of river water, with water quality evolving to saline conditions in the lower reach. When the river reaches the valley plain, the 87Sr/86Sr ratios decreases significantly, which is primarily related to erosion of the riverbanks during runoff. These results indicate that water resource sustainability could be enhanced by directing focus to mitigating salinization in the source area of the catchment.