Qingshui River Research Articles

Space-Ground Remote Sensor Network for Monitoring Suspended Sediments in the Yellow River Basin.

The Yellow River, China's second-largest river, is renowned for its high sediment content. In response to the potential impacts of climate change on Yellow River water resources and water environmental management, an advanced monitoring and forecasting system for water and sediment throughout the entire Yellow River basin-from its source to the sea-is urgently needed. In this paper, based on the current status of water and sediment monitoring technologies, we proposed an integrated remote sensing monitoring network that combines satellite remote sensing, drone remote sensing, and ground-based wireless automatic monitoring networks, aiming to achieve the digital monitoring of water and sediment across the entire Yellow River basin, from its upper reaches to its estuary in the Bohai Sea. By utilizing ground-based in situ hyperspectral stations for sediment source areas in the upper reaches, such as the Qingshui River basin in Ningxia, and satellite remote sensing for midstream processes in the Xiaolangdi reservoir before the flood season in 2023, as well as downstream monitoring at the Yellow River estuary, this paper demonstrates the novelty and efficiency of the space-air-ground integrated remote sensing monitoring technology.

Numerical simulation of groundwater in hyporheic zone with coupled parameter stochastic scheme

Groundwater numerical modeling is a crucial scientific tool for understanding groundwater circulation and supporting regional water resource planning and management. The effectiveness of these models depends largely on the accuracy of hydrogeological parameters within aquifers, which are often spatially heterogeneous and randomly distributed due to complex geological and tectonic factors. Traditional modeling approaches frequently overlook this randomness, compromising the precision and resolution of groundwater simulations. This study focuses on a section of the Qingshui River in the Huaihe River Basin. Using field and laboratory data, probability distribution functions for key parameters like hydraulic conductivity, specific yield, and specific storage were developed. These functions were integrated into the groundwater model to reflect the inherent stochastic nature of aquifer properties. This integration significantly enhanced model accuracy, reducing the root mean square error of simulated water levels from 0.47–1.43 m to 0.13–0.16 m and improving the Nash-Sutcliffe efficiency coefficients (NSE) from −2.96–0.73 to 0.94–0.98. Additionally, the model facilitated analysis of the interactions between river and groundwater, particularly in the hyporheic zone, under various scenarios. It identified spatial and temporal variations in groundwater recharge dynamics and delay effects at different distances from the river channel. For instance, recharge rates at 50 m and 150 m from the river were 0.295 m/day and 0.015 m/day, respectively, indicating stronger recharge closer to the river. The study also assessed the impact of varying river flows, riverbed permeability, and irrigation practices on water exchanges between the river and groundwater. These factors were found to significantly influence the intensity of water exchange, seepage, and groundwater reserves. This research provides valuable insights for managing river-groundwater interactions and analyzing the ecological environment of surrounding groundwater systems, underscoring the importance of incorporating stochastic characteristics into groundwater modeling.

Integrated assessment of groundwater vulnerability in arid areas combining classical vulnerability index and AHP model.

Groundwater is the main source of water for agriculture, industry, and families in arid areas. At present, there is an urgent need to protect groundwater due to human activities. In this study, the Qingshui River Basin was selected as the study area. Based on the DRASTIC model, the DRASTIC-Land use type (DRASTICL) model and the analytic hierarchy process-DRASTICL (AHP-DRASTICL) model were constructed by optimizing the indicators and weights. And the three models were applied to calculate the groundwater vulnerability index (GVI), and the groundwater vulnerability map (GVM) was drawn. The validation results of Spearman correlation coefficient show that the DRASTICL model and the AHP-DRASTICL model have higher correlation, which indicates that the optimized model is more accurate. Among them, the AHP-DRASTICL model has the highest correlation coefficient (ρ = 0.92), which is more in line with the actual situation. The results of this study can provide scientific guidance for the protection and utilization of groundwater in the Qingshui River Basin. And it is of guiding significance for the study of groundwater vulnerability, especially for groundwater management in arid and semi-arid areas.

Analysis of spatiotemporal land use change characteristics in the upper watershed area of the Qingshui River basin from 1990 to 2020

Introduction: Land use land cover (LULC) change is an important factor driving global change, influenced by the interaction between human activities and natural ecosystems. The upper watershed of the Qingshui River is adversely affected due to anthropogenic activities. Therefore, analyzing the driving factors of land use changes in this area is crucial for ecological protection and sustainable development.Methods: Based on the long-term Landsat image data from 1990–2020, the spatiotemporal change characteristics of the LULC rate and its driving factors in the upper watershed of the Qingshui River basin were analyzed using the land use transfer matrix and dynamic degree of land use processes. The redundancy analysis was performed to investigate the links between LULC changes, socio-economic and climatic variables.Results: From 1990–2020, the area under waters and woodland decreased by −2.94 km2 and −451.44 km2, respectively. Meanwhile, grassland, arable land, construction land, and unused land area increased by 278.71 km2, 115.72 km2, 46.48 km2 and 13.49 km2. In terms of the proportion area to the total land (2334.10 km2), woodland accounted for 63.43–44.09% of the total land and was mainly distributed in the east; arable land was 17.00–21.96% and was largely distributed on both sides of the middle and lower parts of the basin; construction land comprised 1.03–3.02% and was generally found in flat areas near the downstream and water area was only 0.1–0.01% which primarily covered the Qingshui River and its tributaries from 1990–2020. Construction and unused lands showed the fastest rate of change, followed by water area and grasslands. Accelerated urbanization, rapid socio-economic development, and the farmland-to-forest policy were the main driving forces behind the change in LULC in the upper reaches of the Qingshui River.Discussion: The findings of this study can assist in planning strong management strategies for ecological protection and socio-economic sustainable development in the study area.

Coupled processes involving ammonium inputs, microbial nitrification, and calcite dissolution control riverine nitrate pollution in the piedmont zone (Qingshui River, China)

Rivers in agricultural countries widely suffer from diffuse nitrate (NO3−) pollution. Although pollution sources and fates of riverine NO3− have been reported worldwide, the driving mechanisms of riverine NO3− pollution associated with mineral dissolution in piedmont zones remain unclear. This study combined hydrogeochemical compositions, stable isotopes (δ18O–NO3−, δ15N–NO3−, δ18O–H2O, and δ2H–H2O), and molecular bioinformation to determine the pollution sources, biogeochemical evolution, and natural attenuation of riverine NO3− in a typical piedmont zone (Qingshui River). High NO3− concentration (37.5 ± 9.44 mg/L) was mainly observed in the agricultural reaches of the river, with ~15.38 % of the samples exceeding the acceptable limit for drinking purpose (44 mg/L as NO3−) set by the World Health Organization. Ammonium inputs, microbial nitrification, and HNO3-induced calcite dissolution were the dominant driving factors that control riverine NO3− contamination in the piedmont zone. Approximately 99.4 % of riverine NO3− contents were derived from NH4+-containing pollutants, consisted of manure & domestic sewage (74.0 % ± 13.0 %), NH4+-synthetic fertilizer (16.1 % ± 8.99 %), and soil organic nitrogen (9.35 % ± 4.49 %). These NH4+-containing pollutants were converted to HNO3 (37.2 ± 9.38 mg/L) by nitrifying bacteria, and then the produced HNO3 preferentially participated in the carbonate (mainly calcite) dissolution, which accounted for 40.0 % ± 12.1 % of the total riverine Ca2+ + Mg2+, also resulting in the rapid release of NO3− into the river water. Thus, microbial nitrification could be a new and non-negligible contributor of riverine NO3− pollution, whereas the involvement of HNO3 in calcite dissolution acted as an accelerator of riverine NO3− pollution. However, denitrification had lesser contribution to natural attenuation for high NO3− pollution. The obtained results indicated that the mitigation of riverine NO3− pollution should focus on the management of ammonium discharges, and the HNO3-induced carbonate dissolution needs to be considered in comprehensively understanding riverine NO3− pollution in piedmont zones.

Soil selenium enrichment in the Loess Plateau of China: Geogenic evidence, spatial distribution, and it's influence factors

The selenium (Se)-deficient soil belt in China has gained widespread attention. During large-scale soil surveys in China, Se-rich soils within low-Se belts have been identified. However, the sources of Se in those soils and the controlling factors for their enrichment remain unclear. Here we summarize Se concentrations and spatial distributions in the Yuanzhou district of the Loess Plateau. We evaluated Se variations in soil profiles, Se migration into water bodies, and considered soil indicators, topographic characteristics and the influence of land-use types on soil Se concentrations. The average Se concentration in the topsoil of the Yuanzhou district was 0.164 μg/g. High-Se soils (>0.222 μg/g) were found in the western valley plain and the southern red bed hilly area, as well as sporadically in higher elevation forestland and grassland areas in the east. Enrichment of Se in the topsoil in the eastern and southern areas was primarily due to Se adsorption and accumulation by soil organic matter as well as enrichment in gypsum, berlinite, and clay minerals during soil formation. Widespread enrichment in the southern area was linked to high Se concentrations in red Tertiary sedimentary rocks. In the western area, enrichment of Se in topsoil was found on both sides of the Qingshui River at low elevations with gentle slopes, with river water being the primary carrier of Se enrichment. These findings provide valuable insights into the epigenetic geochemical behavior of soil Se in China's low-Se belt that accounts for development of Se-rich soils in the region.

Spatial Variation Characteristics, Influencing Factors, and Sources of Hydrogeochemical of Surface Water and Groundwater in Mountainous Area of Hutuo River

Surface runoff has dropped sharply in the mountainous area of the Hutuo River, posing a huge challenge to the sustainable use of groundwater in the North China Plain (NCP). The Taihang Mountain area is the main recharge source area of groundwater in the NCP. An in-depth study of spatial variation characteristics, influencing factors, and sources of hydrogeochemical characteristics of surface water and groundwater in the mountainous area of the Hutuo River can facilitate a comprehensive understanding of regional water resource status and sustainable utilization of water resources. Based on isotopic, hydrogeochemical, and mathematical statistics methods, this study analyzed spatial variation of hydrochemical characteristics in surface water and groundwater and its sources and main controlling factors. The results showed that the river water, well water, and spring water were all recharged by atmospheric precipitation in the mountainous areas of the Hutuo River. Under the combined influence of natural factors and human factors, the hydrogeochemical characteristics of river, well, and spring water showed large spatial differences. On the whole, the hydrochemical types of mainstreams were relatively concentrated. In the upper and lower mining reach areas, the mainstream water chemical type was dominated by Ca·Mg-SO4·HCO3, whereas that in the natural vegetation area (middle reach:between Qingshui River and Longhua River) was dominated by Ca·Mg-HCO3·SO4. In the upper stream, the main hydrochemical type of the Yukou River and Ehe River tributaries was Ca·Mg-SO4·HCO3, which was consistent with that of the main stream. The main hydrochemical types of the Muma River and Qingshui River tributaries were Ca-HCO3, Ca·Mg-HCO3, and Ca·Mg-HCO3·SO4 in the midstream. The main hydrochemical types of the Mianhe River and Yehe River tributaries were Ca-SO4, Ca·Mg-SO4, and Ca·Mg-SO4·HCO3. Mineral dissolution was still the main controlling factor for the hydrochemical characteristics of surface water and groundwater in the mountainous area of the Hutuo River. The contribution rates were 69.86% and 18.84% for mineral dissolution and human activities, respectively. Therefore, in the future, water resource utilization in the upper reaches of the Hutuo River should not only consider the issue of water quantity but also a series of water environment problems such as nitrate pollution and mining pollution caused by human activities.

A distributed hydrological model for semi-humid watersheds with a thick unsaturated zone under strong anthropogenic impacts: A case study in Haihe River Basin

In the past decades, human activities, including hydraulic structure construction and operation, and groundwater overexploitation have largely changed the land surface conditions and correspondingly altered the natural rainfall-runoff processes. These changes make the traditional operational flood forecasting models without considering these anthropogenic impacts fail to capture these changes, leading to a downgraded forecasting capability. To improve the accuracy of flood forecasting in semi-humid watersheds under strong aboveground and underground anthropogenic impacts, the widely used operational flood forecasting model, the Xin’anjiang model, was chosen as a basis to build a new distributed hydrological model accounting for these anthropogenic impacts. To characterize the runoff generation process under the condition of a thick unsaturated zone caused by groundwater overexploitation, this study developed a runoff generation algorithm based on an idea that conceptualizes the soil free-water storage into two virtual reservoirs. To characterize the impacts of manmade reservoirs on the runoff concentration process, we modified the Muskingum method. In addition, we further developed a priori estimation method for deriving the spatial distribution of the tension water storage capacity by considering the anthropogenic impacts and geographical conditions. Based on the above work, a Grid Xin’anjiang-Haihe model (GXH) was developed. In this study, the Qingshui River, which is a tributary of the Haihe River Basin and a typical semi-humid medium-sized watershed in China with poor flood forecasting accuracy, was selected as the study area to test the effectiveness of the model. The results show that the GXH model can simulate the flood peak flow and peak time with higher accuracy than the current operational flood forecasting models and several other models. In addition, the parameter estimation method developed in this study has also proven to be superior in theory and practice.

Prediction and sensitivity analysis of chlorophyll a based on a support vector machine regression algorithm

Outbreaks of planktonic algae seriously affect the water quality of rivers and are difficult to control. Based on the analysis of the temporal and spatial variation characteristics of environmental factors, this study uses a support vector machine regression (SVR) algorithm to establish a chlorophyll a (Chl-a) prediction model and conduct Chl-a sensitivity analysis. In 2018, the average Chl-a content was 126.25 ug/L. The maximum total nitrogen (TN) content was 16.68mg/L and high year-round. The average NH4+-N and total phosphorous (TP) contents were only 0.78 and 0.18mg/L. The content of NH4+-N was higher in spring and increased significantly along the water flow, while TP decreased slightly along the water flow. We used a radial basis function kernel SVR model and tenfold cross-validation method to optimize parameters. The penalty parameter c was 1.4142, the kernel function parameter g was 1, and the training and verification errors were only 0.032 and 0.067, respectively, indicating a good model fit. Based on a sensitivity analysis of the SVR prediction model, the maximum sensitivity coefficients of Chl-a to TP and WT were 0.571 and 0.394, respectively, and the contributions were 33% and 22%, respectively. The next highest sensitivity coefficients were those of DO (0.28, 16%) and pH (0.243, 14%). The sensitivity coefficients of TN and NH4+-N were the lowest. According to the current water environment pollution conditions, TP is the limiting factor of Chl-a in the Qingshui River, and it is also the main prevention and control factor of phytoplankton outbreak.

Open ledger sustainability accounting for community forests: the case of Qingshui river society of southwest China in the 18th-19th centuries

PurposeThis article intends to explore the sustainability accounting practices that emerge from the business of artificial forestry in the Qingshui River society of southwest China in the 18th-19th centuries.Design/methodology/approachUsing a historical approach, we set out to discuss the systematic use of “folk contract” as a tool of tracing accountability in timber trading and in the collective management of community forests in this region, based on the archives of Qingshui River Manuscripts.FindingsThe findings indicate that active transactions of small forest plots facilitated by the prevalent use of folk contracts allow both the landlords and the tenants to easily acquire cashflow needed any time before the harvest, and in turn prevent premature logging and deforestation for crop farming. An “open ledger” bookkeeping system emerged from the extensive contracting practices guarantees the functioning of a dualistic accountability system, where both market value of timbers and “face” value of community members' reputation are preserved for long-term sustainability of local economy, society and ecological environment.Originality/valueFrom the perspective of economic anthropology, this study forms the link between the folk contract practice in sustainable forestry of the Qingshui River society and the emancipatory accounting literature.

Total Streamflow Variation for the Upper Catchment of Bosten Lake Basin in China Inferred from Tree-Ring Width Records

Bosten Lake Basin not only is a major source of drinking water for the residents of the surrounding area, but also maintains the ecological balance of the region. However, with the influence of climate change and human activities, the water level of Bosten Lake fluctuates sharply and has a great impact on the surrounding ecological environment. Therefore, the study of its historical water flow changes as a reference has become a focus of research. In this study, the radial growth of Schrenk spruces (Picea schrenkiana Fisch. et Mey.) significantly correlated with the tributary streamflow coming from the mountainous region near Bosten Lake Basin. On the basis of this good coherence, the tree-ring chronologies were used to reconstruct the streamflow for Huangshuigou River from the previous August to the present July (r = 0.766, p < 0.0001, n = 50). The reconstructed streamflow series matched observations well, explaining 63.3% of the variation in the observed streamflow of 1956–2005. Then, the sum of the streamflow reconstruction of Huangshuigou River and another two tree-ring-based streamflow reconstructions (Kaidu River and Qingshui River) was used to represent the hydrological variation of the upper catchment of Bosten Lake Basin, and the reconstruction sequence was 306 years. The 10.7, 5.5, and 2.1 year cycles of the power spectrum and wavelet analysis revealed that the runoff series reconstructed from tree-ring hydrometeorology was related to solar activity. Some dry and wet years in the reconstructed streamflow series of the upper catchment of Bosten Lake Basin corresponded to the historical record. During the wet years, the Indian Ocean was probably the main source of precipitation.

Structural Diversity of Bacterial Communities and Its Relation to Environmental Factors in the Surface Sediments from Main Stream of Qingshui River

This paper aims to preliminarily understand the structure and diversity of the bacterial community in the sediments of the Qingshui River, and analyze the differences of dominant bacteria in different river reaches, and identify the influence degree of environmental factors. In this study, surface sediments of the main stream of the Qingshui River were selected to analyze both bacterial community composition and a diversity index using the high-throughput sequencing analysis of bacterial 16S rDNA, further exploring their relationships with environmental factors. Results showed that 16,855 OTUs in the surface sediments belonged to 66 phyla, 164 classes, 274 orders, 317 families, and 501 genera of bacteria, while carbon/nitrogen-fixing bacteria were dominant at the class and genus level. There was a significant (p < 0.05) spatial difference between bacterial species composition and the diversity index in surface sediments. Proteobacteria was the most abundant phylum in the sediments of the main stream of the Qingshui River, with an average abundance of 48.15%, followed by Bacteroidetes (21.74%) and Firmicutes (5.71%). The abundance of Alphaproteobacteria in Proteobacteria was the highest (15.38%) and followed by Flavobacteriia in Bacteroidetes (11.57%). The most dominant bacteria genera were different at different areas. The most dominant genera were Phyllobacterium in Kaicheng, Qiying, Liwang, Tongxin and Changshantou, with relative abundances of 4.27%, 4.67%, 5.88%, 4.15% and 6.22%, respectively. Flavobacterium was the most dominant genus in both Dongjiao and Sanying, with a relative abundance of 5.03% and 5.84%, respectively. Rhodobacter was the most dominant genus in Hexi, with a relative abundance of 8.29%. Gillisia was the most dominant genus in Quanyanshan, with a relative abundance of 5.51%. Pearson correlation analysis further indicated that NH4+, pH, and Cr were the main factors affecting the bacterial community structure and diversity in surface sediments. Therefore, our findings suggest that both nutrient elements (i.e., N) and toxic heavy metalloids affect the abundance and diversity of bacteria in surface sediments from the main stream of the Qingshui River. Areas of the river sampled in this study provide the biggest microbial sampling coverage to date. The results provide a preliminary understanding of bacterial communities in sediments of different reaches of the Qingshui River, and provide a reference for further research on the application of functional bacteria in pollution control of the Qingshui River.

Nutrients retention of a series of small dam-impacted urban rivers in northern China

How a series of small rubber dams distributed within urban watersheds impact nutrients transport remains less investigated. To fill this research gap, this study assesses the composition of nitrogen (N) and phosphorus (P) and their retention in five urban river segments across the Qingshui-Yanghe rivers, China from March 2019 to September 2021. The upstream and downstream of the Qingshui river (QR-up and QR-city) were enriched with dissolved N and particulate P, suggesting a greater P contribution of agricultural origin. NH4-N concentrations were lower upstream but increased downstream of the Yanghe river due to the direct discharge of sewage and other human activities. N and P concentrations varied along the urban river and were relatively low at QR-city. A total of 159.2 and 8.4 metric tons/yr, corresponding to 63% and 70% of the TN and TP loading, were trapped within QR-up and QR-city, of which the dissolved N and particulate P load retention accounted for 58% and 78%. N and P retention rates within the river segments sharply decreased from 97 to –320% and were mainly sequestered in the upstream river segments (QR-up- QR-city). The retention rate of nitrate (78%) and dissolved reactive P (67%) were higher than that of TPN (9.75%) and TPP (78%) because of biological assimilation. Further, with retention rates of −320%, the upstream river segments were a net source of dissolved organic P. These results confirm that the small dams have an important nutrient retention function that is highly variable on a spatiotemporal scale similarly to large-scale reservoirs. Due to the cumulative influence of sewage discharge downstream of the Yanghe River, the nutrient load retention is significantly higher than that in the Qingshui river segments. The variations in hydrological regimes due to seasonal events and small dam regulation have a substantial impact on nutrient retention, resulting in higher loads retention in the flood period than in other periods. Overall, the results suggest that management plans must not only focus on decreasing nutrient export from the mountainous area of the Qingshui river basin but also on sewage outfalls and enhancing the hydrodynamic status of the dammed rivers with respect to eutrophication.

Coupling Effects of Precipitation and Vegetation on Sediment Yield from the Perspective of Spatiotemporal Heterogeneity across the Qingshui River Basin of the Upper Yellow River, China

Interactions between precipitation, vegetation, and erosion are crucial and not fully solved issues in the area of earth surface processes. The Qingshui River Basin (QRB), as the main sediment source tributary of the upper reaches of the Yellow River, is characterized by spatial heterogeneity of rainfall, vegetation, and soil erosion. In this study, we investigated the spatiotemporal variations of sediment yields within the QRB and further identified the coupling effects of precipitation and vegetation on soil erosion. We collected annual (1955 to 2016) and daily (2006 to 2016) hydrological and sediment series from six hydrological stations, which subdivided the whole basin into six different sub-basins with heterogeneity in climate and landscape. Variations in parameter a of the sediment rating curves among the six sub-basins continuously declined, showing the continuously increasing effect of vegetation coverage on reducing soil erosion. The unique combination of relationships between precipitation characteristics and vegetation patterns in six sub-basins and these coupling effects resulted in different precipitation–vegetation–erosion patterns in six sub-basins. Sediment yield followed bell-shaped relationships with vegetation and precipitation, with a clear critical threshold at normalized difference vegetation index (NDVI) = 0.36/precipitation = 100 mm at a monthly scale. Based on these thresholds, the non-linear relationships between precipitation, vegetation, and erosion were also explained. We also found that reducing the time lags in which vegetation follows precipitation may be effective in suppressing sediment yield. These findings could provide a quantitative approach to estimating the potential changes in sediment yield associated with proposed ecological rehabilitation schemes in this region.

The Impact of the Changes in Climate, Land Use and Direct Human Activity on the Discharge in Qingshui River Basin, China

Climate, land use and human activity have an impact on the Qingshui River in Chongli County. The Soil and Water Assessment Tool (SWAT) was used to separately analyze the contributions of climate, land use and direct human activity on the discharge variations. The results indicated that human activity had been the dominant factor for the discharge decrease, while climate and land use change had a positive influence on the discharge increase. The contributions of these three factors were −56.24%, 38.59% and 5.17%, respectively. Moreover, on the seasonal scale, the impact of those factors was consistent with their impact on the annual scale. Human activity was the main factor for discharge decrease in the summer, the contribution accounting for −77.13%. Due to the over-extraction of groundwater for irrigation and use in the mining industry, the discharge showed a decreasing tendency, which has the potential to place stress on sustainable water use in the future. The result of the study may contribute to the optimization of water resource allocation and management.

Assessment of Water Pollution Degree in Qingshui River Basin Based on Stochastic Forest Algorithm

Assessment of Water Pollution Degree in Qingshui River Basin Based on Stochastic Forest Algorithm

Effect of Check Dam on Phosphorus Transport and Retention in the Qingshui River, in Zhangjiakou City

The transport and retention of phosphorus is a key process in nutrient cycling in river ecosystems and one of the main indicators used to evaluate river health. To explore the effect of check dams on the transport and retention of phosphorus, water samples were collected from four representative monitoring sections of a check-dammed reach of the Qingshui River in Zhangjiakou City. Various forms of phosphorus and runoff process were monitored, and local real-time rainfall data were also collected. The results showed that:① The average concentration ratios of total phosphorus (TP), total dissolved phosphorus (TDP), total particulate phosphorus (TPP), and total suspended solids (TSS) downstream to upstream of the dam were 50%, 79%, 47%, and 58%, respectively, indicating that the check dam has a retention effect on phosphorus and sediment. ② During non-rainfall periods, TP, TDP, and TPP were retained in the check dam reach, while these forms of phosphorus were both retained and transported in the check dam reach during period of rainfall; the ratio of TP, TDP, and TPP retaining rainfall events to total rainfall events was 63.6%, 9%, and 81.8%, respectively, indicating that the transport-retention process was affected by the time interval, duration, and intensity of rainfall events. ③ When a single rainfall event or continuous event exceeded 56 mm, the retention effect of the check dam notably decreased.

Length‐weight and length‐length relationships of three fish species from the Qingshui River in Guizhou province, Southwest China

Length‐weight and length‐length relationships of three fish species from the Qingshui River in Guizhou province, Southwest China

A 475-year tree-ring-width record of streamflow for the Qingshui River originating in the southern slope of the central Tianshan Mountains, China

ABSTRACT We reconstructed the streamflow of the Qingshui River, which originates from the southern slopes of the central Tianshan Mountains in western China. The correlation between the hydrometeorological data and the tree-ring chronology indicated that the influences of temperature and precipitation on the radial growth of spruces were contrary in the different periods of the growth and non-growth seasons, while the highest correlation was found between the streamflow and the chronology. Based on the results of correlation analyses, a 475-year streamflow reconstruction from the previous August to the current July for the Qingshui River was reconstructed using the regional chronology. The reconstructed streamflow series matched observations well, with 43.1% of the variation in the observed streamflow. The streamflow reconstruction had a significantly positive correlation with a gridded PDSI dataset for an area closely corresponding to the Qingshui River watershed. The 50- and 2.0–3.0-year cycles of this reconstruction were consistent with other tree-ring based hydrometeorological reconstructions, and revealed the possible influences of the Gleissberg solar activity cycle and the interannual oscillations of land–atmospheric–ocean systems. The streamflow reconstruction for the Qingshui River captures some wet/drought years noted in historical documents and two turbulent periods after 1700 in Xinjiang, and agrees well with the streamflow reconstruction for the Kaidu River. Synoptic climatology analysis revealed a relationship between anomalous atmospheric circulation and wet/dry years for the Qingshui River watershed and its surrounding area. It is likely that the path of moisture in the wet years mainly originates from the Indian Ocean.

Variation and Trend Analysis of Rainfall in Qingshui River Basin of Ningxia in China

The study on the variation law and trend of rainfall characteristics of Qingshui River, a typical tributary of the upper Yellow River in China, is of great significance to reveal the cause of runoff and sediment change in the Yellow River. According to the daily rainfall data on 93 rainfall stations in the Qingshui River Basin from 1958 to 2015, the rainfall characteristics of the basin, such as annual rainfall, flood season rainfall, and main flood season rainfall were calculated. Using time-domain analogy, Mann-Kendall trend and abrupt change point test, coefficient of variation, etc., the variation and trend of rainfall characteristic values in the past 60 years were analyzed. The results showed that the distribution of rainfall during the periods from 1970 to 1979 and 2010 to 2015 was significantly different from other periods. There is no significant trend change in rainfall characteristic values from 1958 to 2015. From 1958 to 2015, the intensity of discrete changes in the rainfall characteristics of different series from small to large is the annual rainfall, flood season rainfall, and main flood season rainfall. The intensity of the discrete changes in main flood season rainfall gradually decreased with time.