Unraveling the mechanisms underlying lake expansion from 2001 to 2020 and its impact on the ecological environment in a typical alpine basin on the Tibetan Plateau

Yanhu Lake basin(YHB)is a typical alpine lake on the northeastern Tibetan Plateau(TP).Its continuous expansion in recent years poses serious threats to downstream major projects.As a result,studies of the mechanisms underlying lake expansion are urgently needed.The elasticity method within the Budyko framework was used to calculate the water balance in the Yanhu Lake basin(YHB)and the neighboring Tuotuo River basin(TRB).Results show intensification of hydrological cycles and positive trends in the lake area,river runoff,precipitation,and potential evapotranspiration.Lake expansion was significant between 2001 and 2020 and accelerated between 2015 and 2020.Precipitation increase was the key factor underlying the hydrological changes,followed by glacier meltwater and groundwater.The overflow of Yanhu Lake was inevitable because it was connected to three other lakes and the water balance of all four lakes was positive.The high salinity lake water diverted downstream will greatly impact the water quality of the source area of the Yangtze River and the stability of the permafrost base of the traffic corridor.

Quantitative relationship between surface sedimentary diatoms and water depth in North-Central Bohai Bay,China

To study the quantitative relationship between surface sedimentary diatoms and water depth,67 surface samples were collected for diatom analysis on eight profiles with water depth variation from the muddy intertidal zone to the shallow sea area in North-Central Bohai Bay,China.The results showed that the distribution of diatoms changed significantly in response to the change in water depth.Furthermore,the quantitative relationship between the distribution of dominant diatom species,their assemblages,and the water depth was established.The water depth optima for seven dominant species such as Cyclotella striata/stylorum,Paralia sulcata,and Coscinodiscus perforatus and the water depth indication range of seven diatom assemblages were obtained in the study area above the water depth(elevation)of-10 m.The quantitative relationship between surface sedimentary diatoms and water depth provides a proxy index for diatom-paleo-water depth reconstruction in the strata in Bohai Bay,China.

Analysis on Residents’ Satisfaction and Its Influencing Factors with Water Environment Management: Based on the Data from Xiaoqing River

Xiaoqing River is one of the key rivers in the Yellow River Basin, and its management satisfaction is the content that the government should consider when formulating policies. This paper concentrates on residents’ satisfaction of water environment management in Jinan section of Xiaoqing River, using questionnaires to find out the problems and effects of Xiaoqing River management. Based on the correlation analysis of the questionnaire data, the results show that five factors including the impact of water pollution, understanding of Xiaoqing River governance, willingness to participate in Xiaoqing River governance, policy publicity, and government regulation have a positive impact on the satisfaction of Xiaoqing River water environment governance. Finally, the paper puts forward some countermeasures and suggestions to increase residents’ satisfaction from five aspects, such as increasing publicity efforts, paying attention to the cultivation of public participation consciousness, etc.

Epidemiological Survey and Analysis on an Outbreak of Gastroenteritis due to Water Contamination

Objective To document the investigation and control of an outbreak of gastroenteritis in City G, South China, and provide a reference for preventing future outbreaks. Methods An ambispective cohort study was designed. Attack rate （AR） and relative risks （RR） were calculated to identify the causes of gastroenteritis. Investigations using questionnaires included personal interviews with patients and doctors, reviews of medical records, laboratory examinations of fecal specimens and continuous hygiene monitoring of water samples from the waterworks. Results Overall, 427/71534 （AR=5.97%o） cases were identified between October 31 and November 12 2010. Geographic distribution was highly localized, with 80% of cases occurring in the areas supplied by waterworks-A. Consumption of water provided solely by waterworks-A was found to be associated with illness （RR=8.20, 95 C1%：6.12-10.99） compared with that from waterworks-B. Microbiological analyses confirmed the presence of Norovirus in six of eight fecal samples from symptomatic patients, two water samples from waterworks-A and two sewage samples. After taking effective measures, the hygienic indices of waterworks-A met health criteria again on November 9 and no cases were reported 3 days later.Conclusion The outbreak reported here was caused by drinking tap water contaminated with sewage at the source. Early identification of possible contamination sources and awareness of changes that might negatively impact water quality are important preventive measures to protect public health.

Topographic differentiation simulation of crop yield and soil and water loss on the Loess Plateau

De-farming slope farmland has been an effective measure in recent years for the improvement of the eco-environment and the mitigation of soil and water loss on the Loess Plateau. This paper, taking the Yangou Basin as a case study and using day-by-day mete- orological data of Yah＇an station in 2005, simulated and analyzed the quantitative relation between crop yield, soil and water loss and topographic condition with the aid of WIN-YIELD software. Results show that： 1） topographic gradient has important influence on crop yield. The bigger gradient is, the lower the crop yield. Yields of sorghum and corn decrease by 15.44% and 14.32% respectively at 25° in comparison to the case of 0°. In addition, yields of soya, bean and potato decrease slightly by 5.26%, 4.67% and 3.84%, respectively. The influences of topographic height and slope aspect on crop yield are slight. 2） Under the same topographic condition, different crops＇ runoff and soil loss show obvious disparity. Topographic gradient has important influence on soil and water loss. In general, the changing trend is that the soil and water loss aggregates with the increase of gradient, and the maximal amount occurs around 20°. The influence of topographic height is slight. Topographic aspect has a certain effect, and the fundamental characteristic is that values are higher at the aspect of south than north. 3） Topographic gradients of 5° and 15° are two important thresholds. The characteristic about soil and water loss with the variation of topographic gradients show that： the slope farmland with gradient less than 5° could remain unchanged, and the slope farmland more than 15° should be de-farmed as early as possible.

Survey and Protection for Geological Heritage Resources of Water Landscape in Yandangshan Global Geopark

The geological heritage resource of water landscape in Yandangshan Global Geopark consists of 5 subclasses and 9 types,which cover more than 20 geological heritage spots.Including Dalongqiu Waterfall that is one of the four most famous waterfalls in China,Yanhu Wetland and Baixi Stream, which are the core of the geopark,By investigating

Assessment of Domestic Water Sources Safety: Application of the Micro Biological Survey Method and Microbiological Profile of the Contaminating Bacteria

Water is essential for human life and it’s expected to be clean and safe. In Cameroon, government efforts to improve access to drinking water are mitigated. Many households are suffering from chronic water shortages leading to the majority of people using doubtful water sources. This study was carried out in accordance with guidelines produced by the STARBIOS2-EU funded project on Responsible Research and Innovation and aimed to assess the microbiological quality of water samples collected from domestic water sources in 3 divisions of the West region of Cameroon. 22 water samples from well water, stream, water pump and river were aseptically collected. At each sampling point, 50 mL of sample was taken aseptically and immediately transported to the laboratory for analysis. The detection of Coliforms bacteria was done using Micro Biological Survey (MBS) method. 1 mL of each sample was inoculated in the Coliforms MBS (Coli MBS) vial initially rehydrated with 10 mL of sterile distilled water. The Coli MBS vials were closed, shaken for homogenization, and then incubated at 37°C. From the initial red color of the Coli MBS vials, changes in color to yellow of the reaction vials were monitored at three different time intervals (12 h, 19 h and 24 h), corresponding to three levels of bacterial concentration. All positives samples on MBS method were selected to determine the presence of E. coli Loop full broths of Coli MBS vials were taken;streaked into the eosin methylene blue (EMB) agar plate and incubated at 37°C for 24 hours. E. coli was confirmed by observing green metallic sheen on EMB agar plate. The biochemical indole, methyl red, Voges-Proskauer and citrate (IMViC) test was performed to determine the complete microbiological profile of the water samples. Almost all the water samples were contaminated with Total Coliforms (TC). A high concentration of TC (>103 CFU/mL) was found in 8 samples (36.4%), a medium concentration (10 < x < 103 CFU/mL) was observed in 10 samples (45.5%) and 2 samples (9.1%) were low concentrated (1 < x < 10 CFU/mL). 8 samples were positive for the presence of E. coli by observing the green metallic sheen on EMB agar plates. The IMViC test confirmed the presences of 5 bacteria species: Enterobacter spp., Klebsiella spp., E. coli spp., Salmonella spp. and Shigella spp. We recommend integrating sanitary assessment in the design and implementation of water supply projects. Regular water purification using proper methods and maintenances of the water point. Regular microbiological quality assessment of water intended for human consumption should be planned and carried out.

Delineation of Groundwater and Soil Contamination Using EM Survey at an Industrial Abandoned Site

It is important to evaluate and monitor the environmental impacts by the activity in our hand with appropriate methods, and the geophysical techniques have often been used in the subsurface environmental monitoring and remediation processes. In the study an electromagnetic survey （EM） is performed to delineate deeply the extent of contamination at an industrial abandoned site, to detect the spread of groundwater and soil contamination, to locate possible pathways of leachate plumes. Based on the analysis of the geophysical anomaly of electrical conductivity, the survey area is delineated into three zones： original zone, transitional zone and contaminated zone. It was inferred that the high conductivity zones correspond to the contaminated zones of groundwater and soil. The survey demonstrates that EM method has the ability to measure small changes in subsurface properties involving ground water and is sensitive to the conductive layers. The measurement shows the behavior of groundwater and soil contamination and the position of groundwater pipelines, and it is beneficial to help waste management processes and to determine possible locations of monitoring wells so as to monitor the environment in the survey area in the future.

Exploration of Geotechnical Engineering Investigation under Complex Topographical and Geological Conditions

This paper will explore the geotechnical engineering investigation technology under the complex topographical and geological conditions,and introduce how to construct the water supply tube wells faster and better under the complex topographical and geological conditions by taking Inner Mongolia as an example,so as to provide reference for the relevant professionals.

Characteristics and sources of microplastic pollution in the water and sediments of the Jinjiang River Basin,Fujian Province,China

Microplastic pollution is widely distributed from surface water to sediments to groundwater vertically and from land to the ocean horizontally.This study collected samples from surface water,groundwater,and sediments from upper to lower reaches and then to the estuary in 16 typical areas in the Jinjiang River Basin,Fujian Province,China.Afterward,it determined the components and abundance of the microplastics and analyzed the possible microplastic sources through principal component analysis(PCA).As a result,seven main components of microplastics were detected,i.e.,polyethylene(PE),polypropylene(PP),polyvinyl chloride(PVC),polyethylene terephthalate(PET),polyformaldehyde(POM),nylon 6(PA6),and polystyrene(PS).Among them,PE and PP were found to have the highest proportion in the surface water and sediments and in the groundwater,respectively.The surface water,groundwater,and sediments had average microplastic abundance of 1.6 n/L,2.7 n/L and 33.8 n/kg,respectively.The microplastics in the sediments had the largest particle size,while those in the groundwater had the smallest particle size.Compared with water bodies and sediments in other areas,those in the study area generally have medium-low-level microplastic abundance.Three pollution sources were determined according to PCA,i.e.,the dominant agriculture-forestry-fishery source,domestic wastewater,and industrial production.This study can provide a scientific basis for the control of microplastics in rivers.

Topographic and geomorphological features and tectogenesis of the southern section of the Kyushu-Palau Ridge(KPR)and its adjacent areas

The Philippine Sea is the largest marginal sea in the Western Pacific Ocean and is divided into two parts by the Kyushu-Palau Ridge(KPR).The western part is the West Philippine Basin,and the eastern part consists of the Shikoku and Parece Vela basins.Based on surveyed data of massive high-resolution multibeam bathymetric data and sub-bottom profiles data collected from the southern section of the KPR from 2018 to 2021,this paper analyzes the topographic and geomorphological features,shallow sedimentary features,and tectonic genesis of the southern section of the KPR,obtaining the following conclusions.The southern section of the KPR has complex and rugged topography,with positive and negative topography alternatingly distributed and a maximum height difference of 4086 m.The slope of seamounts in this section generally exceeds 10°and is up to a maximum of 59°.All these contribute noticeably discontinuous topography.There are primarily nine geomorphological types in the southern section of the KPR,including seamounts,ridges,and intermontane valleys,etc.Among them,seven independent seamount groups are divided by five large troughs,forming an overall geomorphological pattern of seven abyssal seamount groups and five troughs.This reflects the geomorphological features of a deep oceanic ridge.Intramontane basins and intermontane valleys in the southern section of the KPR are covered by evenly thick sediments.In contrast,sediments in ridges and seamounts in this section are thin or even missing,with slumps developing locally.Therefore,the sediments are discontinuous and unevenly developed.The KPR formed under the control of tectonism such as volcanic activities and plate movements.In addition,exogenic forces such as underflow scouring and sedimentation also play a certain role in shaping seafloor landforms in the KPR.

Distribution and impacts on the geological environment of antiviral drugs in major waters of Wuhan,China

This study investigated water samples collected from the surface water and groundwater in Wuhan City,Hubei Province,China in different stages of the outbreak of the coronavirus disease 2019(hereinafter referred to as COVID-19)in the city,aiming to determine the distribution characteristics of antiviral drugs in the city’s waters.The results are as follows.The main hydrochemical type of surface water and groundwater in Wuhan was Ca-HCO3.The major chemical components in the groundwater had higher concentrations and spatial variability than those in the surface water.Two antiviral drugs and two glucocorticoids were detected in the surface water,groundwater,and sewage during the COVID-19 outbreak.Among them,chloroquine phosphate and cortisone had higher detection rates of 32.26%and 25.80%,respectively in all samples.The concentrations of residual drugs in East Lake were higher than those in other waters.The main drug detected in the waters in the later stage of the COVID-19 outbreak in Wuhan was chloroquine phosphate,whose detection rates in the surface water and the groundwater were 53.85%and 28.57%,respectively.Moreover,the detection rate and concentration of chloroquine phosphate were higher in East Lake than in Huangjia Lake.The groundwater containing chloroquine phosphate was mainly distributed along the river areas where the groundwater was highly vulnerable.The residual drugs in the surface water and the groundwater had lower concentrations in the late stage of the COVID-19 outbreak than in the middle of the outbreak,and they have not yet caused any negative impacts on the ecological environment.

Groundwater characteristics and climate and ecological evolution in the Badain Jaran Desert in the southwest Mongolian Plateau

The Badain Jaran Desert is the third largest desert in China,covering an area of 50000 km2.It lies in Northwest China,where the arid and rainless natural environment has a great impact on the climate,environment,and human living conditions.Based on the results of 1∶250000 regional hydrogeological surveys and previous researches,this study systematically investigates the circulation characteristics and resource properties of the groundwater as well as the evolution of the climate and ecological environment since the Quaternary in the Badain Jaran Desert by means of geophysical exploration,hydrogeological drilling,hydrogeochemistry,and isotopic tracing.The results are as follows.(1)The groundwater in the Badain Jaran Desert is mainly recharged through the infiltration of local precipitation and has poor renewability.The groundwater recharge in the desert was calculated to be 1.8684×10^(8)m^(3)/a using the water balance method.(2)The Badain Jaran Desert has experienced four humid stages since the Quaternary,namely MIS 13-15,MIS 5,MIS 3,and the Early‒Middle Holocene,but the climate in the desert has shown a trend towards aridity overall.The average annual temperature in the Badain Jaran Desert has significantly increased in the past 50 years.In detail,it has increased by about 2.5℃,with a higher rate in the south than in the north.Meanwhile,the precipitation amount has shown high spatial variability and the climate has shown a warming-drying trend in the past 50 years.(3)The lakes in the hinterland of the Badain Jaran Desert continuously shrank during 1973‒2015.However,the vegetation communities maintained a highly natural distribution during 2000‒2016,with the vegetation cover has increased overall.Accordingly,the Badain Jaran Desert did not show any notable expansion in that period.This study deepens the understanding of groundwater circulation and the climate and ecological evolution in the Badain Jaran Desert.It will provide a scientific basis for the rational exploitation of the groundwater resources and the ecological protection and restoration in the Badain Jaran Desert.

The hydrochemical characteristics and its significance of geothermal water in both sides of large fault: Taking northern section of the Liaokao fault in north China as an example

Based on comparative analysis on hydrochemical characteristics of geothermal water in the north part of Liaokao fault,this research focuses on studying the indicative significance of hydrochemical characteristics for the formation of geothermal water.The result shows that:(1)There is no obvious hydraulic connection between the karst geothermal water(occurred in the east part of the Liaokao fault)and the sandstone geothermal water(occurred in the west part of Liaokao fault).(2)In a close hydrological environment,caused by tectonic activities,geothermal water remains longer time in reservoir,hence the water-rock interaction is more complete,with high degree of concentrations,whereas the renewable capacity of the water is weaker.(3)There is no high temperature mantle source fluid mixed in the geothermal water.Karst geothermal water occurred deep circulatory convection along Liaokao fault and its secondary fault,therefore there is deep crust source fluid added into the geothermal water,closer to the Liaokao fault,the greater affected by the deep crust fluid.However,sandstone geothermal water has weak deep circulatory convection.

Soil water movement and deep drainage through thick vadose zones on the northern slope of the Tianshan Mountain: Croplands vs.natural lands

Regional aridity is increasing under global climate change,and therefore the sustainable use of water resources has drawn attention from scientists and the public.Land-use changes can have a significant impact on groundwater recharge in arid regions,and quantitative assessment of the impact is key to sustainable groundwater resources management.In this study,the changes of groundwater recharge after the conversion of natural lands to croplands were investigated and compared in inland and arid region,i.e.,the northern slope of the Tianshan Mountain.Stable isotopes suggest that soil water in topsoil(<2 m)has experienced stronger evaporation under natural lands than croplands,and then moves downward as a piston flow.Recharge was estimated by the tracer-based mass balance method,i.e.,chloride and sulfate.Recharge rates under natural conditions estimated by the chloride mass balance(CMB)method were estimated to be 0.07 mm/a in deserts and 0.4 mm/a in oases.In contrast,the estimated groundwater recharge ranged from 61.2 mm/a to 44.8 mm/a in croplands,indicating that groundwater recharge would increase significantly after land changes from natural lands to irrigated croplands in arid regions.Recharge estimated by the sulfate mass balance method is consistent with that from the CMB method,indicating that sulfate is also a good tracer capable of estimating groundwater recharge.

Applying a modified conduit flow process to understand conduit-matrix exchange of a karst aquifer

Due to the high heterogeneity and complexity of water flow movement for multiple karst water-bearing mediums,the evaluation,effective development,and utilization of karst water resources are significantly limited.Matrix flow is usually laminar,whereas conduit flow is usually turbulent.The driving mechanisms of water exchange that occur between the karst conduit and its adjacent matrix are not well understood.This paper investigates the hydrodynamic characteristics and the mechanism of flow exchange in dual water-bearing mediums(conduit and matrix)of karst aquifers through laboratory experimentation and numerical simulation.A karst aquifer consisting of a matrix network and a conduit was proposed,and the relationship between the water exchange flux and hydraulic head differences generated from the laboratory experiments was analyzed.Two modes of experimental tests were performed with different fixed water level boundaries in the laboratory karst aquifer.The results indicate that the water exchange capacity was proportional to the square root of hydraulic head differences.The linear exchange term in the conduit flow process(CFP)source program was modified according to experimental results.The modified CFP and the original CFP model experimental data results were compared,and it was found that the modified CFP model had better fitting effects.These results showed that the water exchange mechanism between conduit and matrix is very important for solid-liquid interface reaction,water resource evaluation,and understanding of karst hydrodynamic behavior.

Responses of phreatophyte transpiration to falling water table in hyper-arid and arid regions,Northwest China

Quantitative assessment of the impact of groundwater depletion on phreatophytes in(hyper-)arid regions is key to sustainable groundwater management.However,a parsimonious model for predicting the response of phreatophytes to a decrease of the water table is lacking.A variable saturated flow model,HYDRUS-1D,was used to numerically assess the influences of depth to the water table(DWT)and mean annual precipitation(MAP)on transpiration of groundwater-dependent vegetation in(hyper-)arid regions of northwest China.An exponential relationship is found for the normalized transpiration(a ratio of transpiration at a certain DWT to transpiration at 1 m depth,T_(a)^(*))with increasing DWT,while a positive linear relationship is identified between T_(a)^(*)and annual precipitation.Sensitivity analysis shows that the model is insensitive to parameters,such as saturated soil hydraulic conductivity and water stress parameters,indicated by an insignificant variation(less than 20%in most cases)under±50%changes of these parameters.Based on these two relationships,a universal model has been developed to predict the response of phreatophyte transpiration to groundwater drawdown for(hyper-)arid regions using MAP only.The estimated T_(a)^(*)from the model is reasonable by comparing with published measured values.

The Influence of Airflow Transport Pathways on Precipitation during the Rainy Season in the Liupan Mountains of Northwest China

This study investigates the influence of airflow transport pathways on seasonal rainfall in the mountainous region of the Liupan Mountains(LM) during the rainy seasons from 2020 to 2022, utilizing observational data from seven ground gradient stations located on the eastern slopes, western slopes, and mountaintops combined with backward trajectory cluster analysis. The results indicate 1) that the LM's rainy season, characterized by overcast and rainy days, is mainly influenced by cold and moist airflows(CMAs) from the westerly direction and warm and moist airflows(WMAs) from a slightly southern direction. The precipitation amounts under four airflow transport paths are ranked from largest to smallest as follows: WMAs, CMAs, warm dry airflows(WDAs), and cold dry airflows(CDAs). 2) WMAs contribute significantly more to the intensity of regional precipitation than the other three types of airflows. During localized precipitation events,warm airflows have higher precipitation intensities at night than cold airflows, while the opposite is true during the afternoon. 3) During regional precipitation events, water vapor content is the primary influencing factor. Precipitation characteristics under humid airflows are mainly affected by high water vapor content, whereas during dry airflow precipitation, dynamic and thermodynamic factors have a more pronounced impact. 4) During localized precipitation events, the influence of dynamic and thermodynamic factors is more complex than during regional precipitation, with the precipitation characteristics of the four airflows closely related to their water vapor content, air temperature and humidity attributes, and orographic lifting. 5) Compared to regional precipitation, the influence of topography is more prominent in localized precipitation processes.

Cash gifts,perception of social sphere and distribution of water resources for rural farmers in a typical oasis area in Northwest China

Face-to-face interviews(n=860) were conducted to determine cash-gift behavior, cognition and complexity of social relations, and family water consumption for agricultural production in a typical oasis area in Northwest China. The survey results revealed cash gifts to be the second-largest expenditure(1,330 Yuan) for rural households, far beyond the average spending on health(854.1 Yuan) or education(890.8 Yuan). The amount of cash-gift expenditures indirectly reflects a family's social relations level, and our developed Social Relations Extent Coefficient—based on cash-gift and food expenditures—can directly reflect the extent or level of these relationships. Different types of farmers or farming families have different coefficients. The coefficient also shows how social station affects a family's water resource utilization, and how water is distributed among different types of farmers. Despite the current inequities, however, promotion of better agricultural techniques and large-scale cultivation in this area could help distribute water resources more equitably and effectively.

Application of ERT Survey for Addressing the Issues of Urban Rain Storm Water Logging in the Qassim Province of Saudi Arabia

The Qassim province is one of the most arid regions of Saudi Arabia, however heavy rainfall events have led to water logging problems in the populated centers like Buraidah mainly as a consequence of construction in low lying areas and valleys. Urban rain storm water logging problem were reported at 4 localities in the Buraidah Municipal area after heavy rainfall in November 2008 and March 2009. The logged water from these sites were directed to 4 manmade lakes however the stagnant water in these lakes posed a serious environmental threat mainly in the form of water borne disease. Keeping this problem in mind, a detailed geophysical investigation in the form of Electrical Resistivity Tomography was carried out using the SYSCAL Pro Unit at these 4 locations with a dipole-dipole configuration. The survey was helpful in delineating the wet zones from the dry ones and based on the interpretations the optimum depth and sites of 4 injections bore-wells were determined at each locality. These injection bore-well would serve the dual propose of getting rid of the stagnant water in these lakes and also recharging the underlying aquifers.