Chemical weathering in Manas River Basin:Driven by sulfuric acid or carbonic acid?

Carbonic acid produced by the dissolution of atmospheric and soil CO_(2)in water is usually the most dominant catalyst for chemical weathering,but a sulfuric aciddriven phenomenon,different from usual,was found in the orogenic belt watersheds dominated by silicate bedrock.This study,rooted in comprehensive field investigations in the Manas River Basin(MRB)north of the Tianshan Mountains,delves into the mechanisms and impacts of sulfuric and carbonic acid as catalysts driving diff erent types of chemical weathering in the Central Asian Orogenic Belt.Quantitative analyses elucidate that carbonate weathering constitutes 52.4%of the total chemical weathering,while silicate and evaporite account for 18.6%and 25.3%,respectively,with anthropogenic activities and atmospheric precipitation having little eff ect.The estimated total chemical weathering rate in MRB is approximately 0.075×10^(6)mol/km^(2)/year.Quantitative findings further suggest that,preceding carbonate precipitation(<10^(4)year),chemical weathering can absorb CO_(2).Subsequently,and following carbonate precipitation(10^(4)-10^(7)year),it will release CO_(2).The release significantly surpasses the global average CO_(2)consumption,contributing to a noteworthy climate impact.This study underscores the distinctive weathering mechanisms,wherein sulfuric acid emerges as the predominant catalyst.The quantity of sulfuric acid as a catalyst is approximately three times that of carbonic acid.Sulfuric acid-driven carbonate rock weathering(SCW)is identified as the sole chemical weathering type with a net CO_(2)release eff ect.SCW CO_(2)release flux(5176 mol/km^(2)/year)is roughly 2.5 times the CO_(2)absorption by Ca-Mg silicate weathering,highlighting the pivotal role of chemical weathering in sourcing atmospheric CO_(2)over the timescales of carbonate precipitation and sulfate reduction.Lastly,this study posits that catalyst and transport limitations are the most plausible critical factors in MRB.The interplay between sulfuric acid and dissolved CO_(2)competitively shapes the types and rates of chemical weathering reactions.

Water Quality,Influential Factors,and Management Strategies from 2016 to 2020 in the Yangtze River Economic Belt,China

The Yangtze River economic belt(YREB),China is important to the Chinese economy and for supporting sustainable development.Clarifying the relationship between water quality indices and socioeconomic indicators could help improve aquatic environment management in the YREB and our understanding of the causes and effects of water quality variations in other large river basins.In this study,river water quality,factors affecting water quality,and management strategies,and correlations between water quality indices and socioeconomic indicators in the YREB during the 13th Five-Year Plan period(2016-2020)were assessed.The single-factor evaluation method,constant price for GDP,and correlation analyses were adopted.The results showed that:1)water quality in the YREB improved during the 13th Five-Year Plan period.The number of aquatic environment sections meeting GradeⅠ-Ⅲwater quality standards increased by 13.1%and the number below Grade V decreased by 2.9%.2)The values of 12 indicators in the YREB exceeded relevant standards.The indicators with highest concentreation were the total phosphorus,chemical oxygen demand,ammonia nitrogen,and permanganate index,which were relatively high in downstream regions in Anhui Province,Jiangsu Province,and Shanghai Municipality.3)Ammonia nitrogen,chemical oxygen demand,and total phosphorus emissions per unit area and water extraction per unit area are relatively high in the three downstream regions mentioned above.4)Increased domestic sewage discharges have increased total wastewater discharges in the YREB.5)River water quality in the YREB strongly correlated with population,economic,and water resource indices and less strongly correlated with government investment,agriculture,meteorology,energy,and forestry indices.This confirmed the need to decrease wastewater discharges and non-point-source pollutant emissions.The aquatic environment could be improved by taking reasonable measures to control population growth,adjusting the industrial structure to accelerate industrial transformation and increase the proportion of tertiary industries,and investing in technological innovations to protect the environment.

Geographical Indications and Regional Public Brands of the Whole Rice Industry Chain in the Yangtze River Economic Belt

The Yangtze River Economic Belt is the main rice producing area in China.The rice industry chain is the agricultural pillar industry chain of this economic belt and it is the key to ensuring national food security and promoting comprehensive rural revitalization.This study discusses the entire rice industry chain in the Yangtze River Economic Belt from the national rice production functional zones,agricultural product quality and safety,national famous and excellent new agricultural products,national specialty agricultural products,"China s good grain and oil"products,and national advantageous characteristic industrial clusters.Then,it discusses the geographical indications of rice and its products in this economic belt from geographical indication products,geographical indication trademarks,agricultural geographical indications,geographical indication standards,geographical indication special indications,national geographical indication product protection demonstration zones,and Chinese geographical indication products protected by the European Union.In addition,it analyzes the five main problems between geographical indications and public brands,such as the limited use of geographical indication specific signs and the imperfect intellectual property protection system for geographical indications.Finally,it proposes eight strategies,including promoting the high-quality development of the entire rice industry chain,creating a geographical indication regional public brand for rice and its products,and implementing geographical indication protection projects.

Changes in River Cross-section Morphology and Response to Streamflow and Sediment Processes in Middle Reaches of Yellow River,China

Changes in river cross-section morphology have decisive influences on the flood discharge and sand transport capacity of rivers;thus,these changes strongly reflect the vitality of a river.In this paper,based on the river cross-section and water and sediment data of two different periods(1974−1987 and 2007−2021),the trend analysis,change-point analysis and sediment rating curve method were used to analyze the change process of river cross-section morphology and its response to streamflow and sediment changes in the main river stream of the Yellow River at the Longmen hydrological station.From 1974 to 1987(except in 1977),the riverbed experi-enced siltation,and the riverbed elevation rose.Conversely,from 2007 to 2021,the riverbed experienced scouring,and the riverbed el-evation gradually decreased.The cross-section shape changed from rectangular to U-shaped(deeper on the right side)at the Longmen cross-section.The changes in streamflow and sediment processes significantly impacted the evolution of river cross-section.Stream-flow(P<0.05),sediment discharge(P<0.01),and the sediment load coefficients(P<0.01)decreased significantly.The relationship between the water depth and sediment load coefficients followed a power function.The decreasing trend in sediment discharge was sig-nificantly stronger than that in streamflow.Suspended sediment particles tended to become finer.The sediment rating curve indicates that the sediment supply from upstream decreased while the erosive power in the river channel increased,leading to a gradual decline in riverbed elevation at the Longmen cross-section from 2007 to 2021.These findings help us better understand the impacts of ecological restoration on changes in river streamflow and sediment during river evolution.

Dynamic Variation of Vegetation NPP and Its Driving Forces in the Yellow River Basin, China

The productivity of vegetation is influenced by both climate change and human activities.Understanding the specific contributions of these influencing factors is crucial for ecological conservation and regional sustainability.This study utilized a combination of multi-source data to examine the spatiotemporal patterns of Net Primary Productivity(NPP)in the Yellow River Basin(YRB),China from 1982 to 2020.Additionally,a scenario-based approach was employed to compare Potential NPP(PNPP)with Actual NPP(ANPP)to determine the relative roles of climatic and human factors in NPP changes.The PNPP was estimated using the Lund-Potsdam-Jena General Ecosystem Simulator(LPJ-GUESS)model,while ANPP was evaluated by the Carnegie-Ames-Stanford Approach(CASA)model using different NDVI data sources.Both model simulations revealed that significant greening occurring in the YRB,with a gradual decrease observed from southeast to northwest.According to the LPJ_GUESS model simulations,areas experiencing an increasing trend in NPP accounted for 86.82% of the YRB.When using GIMMS and MODIS NDVI data with CASA model simulations,areas showing an increasing trend in NPP accounted for 71.42% and 97.02%,respectively.Furthermore,both climatic conditions and human factors had positive effects on vegetation restoration;approximated 41.15% of restored vegetation areas were influenced by both climate variation and human activities,while around 31.93% were solely affected by climate variation.However,it was found that human activities served as the principal driving force of vegetation degradation within the YRB,impacting 26.35% of degraded areas solely due to human activities.Therefore,effective management strategies encompassing both human activities and climate change adaptation are imperative for facilitating vegetation restoration within this region.These findings will valuable for enhancing our understanding in NPP changes and its underlying factors,thereby contributing to improved ecological management and the pursuit of regional carbon neutrality in China.

Spatial Patterns and Controlling Factors of Soil Organic Carbon and Total Nitrogen in the Three River Headwaters Region,China

The alpine ecosystem has great potential for carbon sequestration.Soil organic carbon(SOC)and total nitrogen(TN)are highly sensitive to climate change,and their dynamics are crucial to revealing the effect of climate change on the structure,function,and services of the ecosystem.However,the spatial distribution and controlling factors of SOC and TN across various soil layers and vegetation types within this unique ecosystem remain inadequately understood.In this study,256 soil samples in 89 sites were collected from the Three River Headwaters Region(TRHR)in China to investigate SOC and TN and to explore the primary factors affecting their distribution,including soil,vegetation,climate,and geography factors.The results show that SOC and TN contents in 0-20,20-40,40-60,and 60-80 cm soil layers are 24.40,18.03,14.04,12.40 g/kg and 2.46,1.90,1.51,1.17 g/kg,respectively;with higher concentrations observed in the southeastern region compared to the northwest of the TRHR.One-way analysis of variance reveals that SOC and TN levels are elevated in the alpine meadow and the alpine shrub relative to the alpine steppe in the 0-60 cm soil layers.The structural equation model explores that soil water content is the main controlling factor affecting the variation of SOC and TN.Moreover,the geography,climate,and vegetation factors notably indirectly affect SOC and TN through soil factors.Therefore,it can effectively improve soil water and nutrient conditions through vegetation restoration,soil improvement,and grazing management,and the change of SOC and TN can be fully understood by establishing monitoring networks to better protect soil carbon and nitrogen.

Runoff simulation and hydropower resource prediction of the Kaidu River Basin in the Tianshan Mountains,China

The Tianshan Mountains of Central Asia,highly sensitive to climate change,has been comprehensively assessed for its ecosystem vulnerability across multiple aspects.However,studies on the region's main river systems and hydropower resources remain limited.Thus,examining the impact of climate change on the runoff and gross hydropower potential(GHP)of this region is essential for promoting sustainable development and effective management of water and hydropower resources.This study focused on the Kaidu River Basin that is situated above the Dashankou Hydropower Station on the southern slope of the Tianshan Mountains,China.By utilizing an ensemble of bias-corrected global climate models(GCMs)from Coupled Model Intercomparison Project Phase 6(CMIP6)and the Variable Infiltration Capacity(VIC)model coupled with a glacier module(VIC-Glacier),we examined the variations in future runoff and GHP during 2017-2070 under four shared socio-economic pathway(SSP)scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5)compared to the baseline period(1985-2016).The findings indicated that precipitation and temperature in the Kaidu River Basin exhibit a general upward trend under the four SSP scenarios,with the fastest rate of increase in precipitation under the SSP2-4.5 scenario and the most significant changes in mean,maximum,and minimum temperatures under the SSP5-8.5 scenario,compared to the baseline period(1980-2016).Future runoff in the basin is projected to decrease,with rates of decline under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios being 3.09,3.42,7.04,and 7.20 m^(3)/s per decade,respectively.The trends in GHP are consistent with runoff,with rates of decline in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios at 507.74,563.33,1158.44,and 1184.52 MW/10a,respectively.Compared to the baseline period(1985-2016),the rates of change in GHP under the SSP1-2.6,SSP2-4.5,SSP3-7.0,and SSP5-8.5 scenarios are-20.66%,-20.93%,-18.91%,and-17.49%,respectively.The Kaidu River Basin will face significant challenges in water and hydropower resources in the future,underscoring the need to adjust water resource management and hydropower planning within the basin.

基于River 2D模型的黄河花园口河段生态流量研究

针对目前生态流量研究方法难以充分考虑鱼类栖息地等生境因素的问题,以黄河花园口鲤鱼核心保护区为研究区域,选取黄河鲤鱼为研究物种,基于耦合水动力学模型和栖息地模型的River 2D模型确定黄河鲤鱼的生态流量,将水深和流速作为鱼类生存保护的限定性因子,采用栖息地模型模拟不同流量下对应的黄河鲤鱼的适宜栖息地面积。计算结果表明:花园口河段鲤鱼产卵期的最小生态流量为230 m^(3)/s,生长期的最小生态流量为430 m^(3)/s,越冬期的最小生态流量为150 m^(3)/s。计算结果可以为花园口核心鱼类保护区的鱼类保护以及黄河小浪底水库的生态调度提供参考。

Uphill or downhill?Cropland use change and its drivers from the perspective of slope spectrum

The continuous decrease of low-slope cropland resources caused by construction land crowding poses huge threat to regional sustainable development and food security.Slope spectrum analysis of topographic and geomorphic features is considered as a digital terrain analysis method which reflects the macro-topographic features by using micro-topographic factors.However,pieces of studies have extended the concept of slope spectrum in the field of geoscience to construction land to explore its expansion law,while research on the slope trend of cropland from that perspective remains rare.To address the gap,in virtue of spatial analysis and geographically weighted regression(GWR)model,the cropland use change in the Yangtze River Basin(YRB)from 2000 to 2020 was analyzed and the driving factors were explored from the perspective of slope spectrum.Results showed that the slope spectrum curves of cropland area-frequency in the YRB showed a first upward then a downward trend.The change curve of the slope spectrum of cropland in each province(municipality)exhibited various distribution patterns.Quantitative analysis of morphological parameters of cropland slope spectrum revealed that the further down the YRB,the stronger the flattening characteristics,the more obvious the concentration.The province experienced the greatest downhill cropland climbing(CLC)was Shannxi,while province experienced the highest uphill CLC was Zhejiang.The most common cropland use change type in the YRB was horizontal expansion type.The factors affecting average cropland climbing index(ACCI)were quite stable in different periods,while population density(POP)changed from negative to positive during the study period.This research is of practical significance for the rational utilization of cropland at the watershed scale.

Monitoring and evaluation of the water quality of the Lower Neches River, Texas, USA

Increasing bacteria levels in the Lower Neches River caused by Hurricane Harvey has been of a serious concern.This study is to analyze the historical water sampling measurements and real-time water quality data collected with wireless sensors to monitor and evaluate water quality under different hydrological and hydraulic conditions.The statistical and Pearson correlation analysis on historical water samples determines that alkalinity,chloride,hardness,conductivity,and pH are highly correlated,and they decrease with increasing flow rate due to dilution.The flow rate has positive correlations with Escherichia coli,total suspended solids,and turbidity,which demonstrates that runoff is one of the causes of the elevated bacteria and sediment loadings in the river.The correlation between E.coli and turbidity indicates that turbidity greater than 45 nephelometric turbidity units in the Neches River can serve as a proxy for E.coli to indicate the bacterial outbreak.A series of statistical tools and an innovative two-layer data smoothing filter are developed to detect outliers,fill missing values,and filter spikes of the sensor measurements.The correlation analysis on the sensor data illustrates that the elevated sediment/bacteria/algae in the river is either caused by the first flush rain and heavy rain events in December to March or practices of land use and land cover.Therefore,utilizing sensor measurements along with rainfall and discharge data is recommended to monitor and evaluate water quality,then in turn to provide early alerts on water resources management decisions.

Numerical study on local scour characteristics around submarine pipelines in the Yellow River Delta silty sandy soil under waves and currents

Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil around submarine pipelines is prone to local scour,severely affecting their operational safety.With the Yellow River Delta as the research area and based on the renormalized group(RNG)k-εturbulence model and Stokes fifth-order wave theory,this study solves the Navier-Stokes(N-S)equation using the finite difference method.The volume of fluid(VOF)method is used to describe the fluid-free surface,and a threedimensional numerical model of currents and waves-submarine pipeline-silty sandy seabed is established.The rationality of the numerical model is verified using a self-built waveflow flume.On this basis,in this study,the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed in the prototype environment are explored and the influence of the presence of pipelines on hydrodynamic features such as surrounding flow field,shear stress,and turbulence intensity is analyzed.The results indicate that(1)local scour around submarine pipelines can be divided into three stages:rapid scour,slow scour,and stable scour.The maximum scour depth occurs directly below the pipeline,and the shape of the scour pits is asymmetric.(2)As the water depth decreases and the pipeline suspension height increases,the scour becomes more intense.(3)When currents go through a pipeline,a clear stagnation point is formed in front of the pipeline,and the flow velocity is positively correlated with the depth of scour.This study can provide a valuable reference for the protection of submarine pipelines in this area.

Interdecadal variability of summer precipitation in the Three River Source Region: Influences of SST and zonal shifts of the East Asian subtropical westerly jet

Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the influence of the East Asian westerly jet(EAWJ)on TRSR rainfall.A strong correlation is found between TRSR summer precipitation and the Jet Zonal Position Index(JZPI)of the EAWJ from 1961 to 2019(R=0.619,p<0.01).During periods when a positive JZPI indicates a westward shift in the EAWJ,enhanced water vapor anomalies,warmer air,and low-level convergence anomalies contribute to increased TRSR summer precipitation.Using empirical orthogonal function and regression analyses,this research identifies the influence of large-scale circulation anomalies associated with the Atlantic–Eurasian teleconnection(AEA)from the North Atlantic(NA).The interdecadal variability between the NA and central tropical Pacific(CTP)significantly affects TRSR precipitation.This influence is mediated through the AEA via a Rossby wave train extending eastward along the EAWJ,and another south of 45°N.Moreover,the NA–CTP Opposite Phase Index(OPI),which quantifies the difference between the summer mean sea surface temperatures of the NA and the CTP,is identified as a critical factor in modulating the strength of this teleconnection and influencing the zonal position of the EAWJ.

Analysis of factors influencing carbon emissions in the Yangtze River Delta region and projections of carbon peak scenarios

Based on the supply-side perspective,the improved STIRPAT model is applied to reveal the mechanisms of supply-side factors such as human,capital,technology,industrial synergy,institutions and economic growth on carbon emissions in the Yangtze River Delta(YRD)through path analysis,and to forecast carbon emissions in the YRD from the baseline scenario,factor regulation scenario and integrated scenario to reach the peak.The results show that:(1)Jiangsu's high carbon emission pattern is the main reason for the YRD hindering the synergistic regulation of carbon emissions.(2)Human factors,institutional factors and economic growth factors can all contribute to carbon emissions in the YRD region,while technological and industrial factors can generally suppress carbon emissions in the YRD region.(3)Under the capital regulation scenario,the YRD region has the highest level of carbon emission synergy,with Jiangsu reaching its peak five years earlier.Under the balanced regulation scenario,the YRD region as a whole,Jiangsu,Zhejiang and Anhui reach the peak as scheduled.

Discovery and inspiration of large-and medium-sized glutenite-rich oil and gas fields in the eastern South China Sea:An example from Paleogene Enping Formation in Huizhou 26 subsag,Pearl River Mouth Basin

Based on the practice of oil and gas exploration in the Huizhou Sag of the Pearl River Mouth Basin,the geochemical indexes of source rocks were measured,the reservoir development morphology was restored,the rocks and minerals were characterized microscopically,the measured trap sealing indexes were compared,the biomarker compounds of crude oil were extracted,the genesis of condensate gas was identified,and the reservoir-forming conditions were examined.On this basis,the Paleogene Enping Formation in the Huizhou 26 subsag was systematically analyzed for the potential of oil and gas resources,the development characteristics of large-scale high-quality conglomerate reservoirs,the trapping effectiveness of faults,the hydrocarbon migration and accumulation model,and the formation conditions and exploration targets of large-and medium-sized glutenite-rich oil and gas fields.The research results were obtained in four aspects.First,the Paleogene Wenchang Formation in the Huizhou 26 subsag develops extensive and thick high-quality source rocks of semi-deep to deep lacustrine subfacies,which have typical hydrocarbon expulsion characteristics of"great oil generation in the early stage and huge gas expulsion in the late stage",providing a sufficient material basis for hydrocarbon accumulation in the Enping Formation.Second,under the joint control of the steep slope zone and transition zone of the fault within the sag,the large-scale near-source glutenite reservoirs are highly heterogeneous,with the development scale dominated hierarchically by three factors(favorable facies zone,particle component,and microfracture).The(subaqueous)distributary channels near the fault system,with equal grains,a low mud content(<5%),and a high content of feldspar composition,are conducive to the development of sweet spot reservoirs.Third,the strike-slip pressurization trap covered by stable lake flooding mudstone is a necessary condition for oil and gas preservation,and the NE and nearly EW faults obliquely to the principal stress have the best control on traps.Fourth,the spatiotemporal configuration of high-quality source rocks,fault transport/sealing,and glutenite reservoirs controls the degree of hydrocarbon enrichment.From top to bottom,three hydrocarbon accumulation units,i.e.low-fill zone,transition zone,and high-fill zone,are recognized.The main area of the channel in the nearly pressurized source-connecting fault zone is favorable for large-scale hydrocarbon enrichment.The research results suggest a new direction for the exploration of large-scale glutenite-rich reservoirs in the Enping Formation of the Pearl River Mouth Basin,and present a major breakthrough in oil and gas exploration.

Response of vegetation variation to climate change and human activities in the Shiyang River Basin of China during 2001-2022

Understanding the response of vegetation variation to climate change and human activities is critical for addressing future conflicts between humans and the environment,and maintaining ecosystem stability.Here,we aimed to identify the determining factors of vegetation variation and explore the sensitivity of vegetation to temperature(SVT)and the sensitivity of vegetation to precipitation(SVP)in the Shiyang River Basin(SYRB)of China during 2001-2022.The climate data from climatic research unit(CRU),vegetation index data from Moderate Resolution Imaging Spectroradiometer(MODIS),and land use data from Landsat images were used to analyze the spatial-temporal changes in vegetation indices,climate,and land use in the SYRB and its sub-basins(i.e.,upstream,midstream,and downstream basins)during 2001-2022.Linear regression analysis and correlation analysis were used to explore the SVT and SVP,revealing the driving factors of vegetation variation.Significant increasing trends(P<0.05)were detected for the enhanced vegetation index(EVI)and normalized difference vegetation index(NDVI)in the SYRB during 2001-2022,with most regions(84%)experiencing significant variation in vegetation,and land use change was determined as the dominant factor of vegetation variation.Non-significant decreasing trends were detected in the SVT and SVP of the SYRB during 2001-2022.There were spatial differences in vegetation variation,SVT,and SVP.Although NDVI and EVI exhibited increasing trends in the upstream,midstream,and downstream basins,the change slope in the downstream basin was lower than those in the upstream and midstream basins,the SVT in the upstream basin was higher than those in the midstream and downstream basins,and the SVP in the downstream basin was lower than those in the upstream and midstream basins.Temperature and precipitation changes controlled vegetation variation in the upstream and midstream basins while human activities(land use change)dominated vegetation variation in the downstream basin.We concluded that there is a spatial heterogeneity in the response of vegetation variation to climate change and human activities across different sub-basins of the SYRB.These findings can enhance our understanding of the relationship among vegetation variation,climate change,and human activities,and provide a reference for addressing future conflicts between humans and the environment in the arid inland river basins.

Restoration or Rehabilitation of the Faleme River Affected by Mining Activities: What Methods?

The Faleme River, a West Africa long transboundary stream (625 km) and abundant flow (>1100 million m3) is affected by severe erosion because of mining activities that takes place throughout the riverbed. To preserve this important watercourse and ensure the sustainability of its services, selecting and implementing appropriates restorations techniques is vital. In this context, the purpose of this paper was to present an overview of the actions and techniques that can be implemented for the restoration/rehabilitation of the Faleme. The methodological approach includes field investigation, water sampling, literature review with cases studies and SWOT analysis of the four methods presented: river dredging, constructed wetlands, floating treatment wetlands and chemical precipitation (coagulation and flocculation). The study confirmed the pollution of the river by suspended solids (TSS > 1100 mg/L) and heavy metals such as iron, zinc, aluminium, and arsenic. For the restoration methods, it was illustrated through description of their mode of operation and through some case studies presented, that all the four methods have proven their effectiveness in treating rivers but have differences in their costs, their sustainability (detrimental to living organisms or causing a second pollution) and social acceptance. They also have weaknesses and issues that must be addressed to ensure success of rehabilitation. For the case of the Faleme river, after analysis, floating treatment wetlands are highly recommended for their low cost, good removal efficiency if the vulnerability of the raft and buoyancy to strong waves and flow is under control.

Industrial Carbon Emission Distribution and Regional Joint Emission Reduction:A Case Study of Cities in the Pearl River Basin,China

China’s low-carbon development path will make significant contributions to achieving global sustainable development goals.Due to the diverse natural and economic conditions across different regions in China,there exists an imbalance in the distribution of car-bon emissions.Therefore,regional cooperation serves as an effective means to attain low-carbon development.This study examined the pattern of carbon emissions and proposed a potential joint emission reduction strategy by utilizing the industrial carbon emission intens-ity(ICEI)as a crucial factor.We utilized social network analysis and Local Indicators of Spatial Association(LISA)space-time trans-ition matrix to investigate the spatiotemporal connections and discrepancies of ICEI in the cities of the Pearl River Basin(PRB),China from 2010 to 2020.The primary drivers of the ICEI were determined through geographical detectors and multi-scale geographically weighted regression.The results were as follows:1)the overall ICEI in the Pearl River Basin is showing a downward trend,and there is a significant spatial imbalance.2)There are numerous network connections between cities regarding the ICEI,but the network structure is relatively fragile and unstable.3)Economically developed cities such as Guangzhou,Foshan,and Dongguan are in the center of the network while playing an intermediary role.4)Energy consumption,industrialization,per capita GDP,urbanization,science and techno-logy,and productivity are found to be the most influential variables in the spatial differentiation of ICEI,and their combination in-creased the explanatory power of the geographic variation of ICEI.Finally,through the analysis of differences and connections in urban carbon emissions under different economic levels and ICEI,the study suggests joint carbon reduction strategies,which are centered on carbon transfer,financial support,and technological assistance among cities.

Key changes across valley floors in mountain areas affected by different levels of human impact: a case study of the Ochotnica river catchment in the Polish Carpathians

The goal of this paper was to present knowledge on changes in the morphodynamic structure of the Ochotnica River(Polish Carpathians)and transformations within its active river zone since the end of the 19th century.The study used a set of archival and contemporary cartographic materials and the results of three-fold field mapping of the morphodynamic structure of the riverbed.Direct and indirect human interference with the natural environment of the catchment and the fluvial system was taken into account in the analysis.Analysis of changes in the morphodynamic structure of the Ochotnica and its active river zone since the end of the 19th century indicated significant changes in the development trend of the riverbed.The contemporary structure of the Ochotnica is more complex than in the 1980s.There has been a fragmentation of the riverbed into sections with different morphodynamic sections.The proportion of erosive sections has increased,which explains the reduced in the width of the active river zone of the Ochotnica.The average width of the active river zone of the river between 1861 and 2022 has changed from 80 m to 18 m.Human impact has been identified as the main reason for the changes in the morphodynamic structure of the riverbed and its active river zone.Currently,only the unregulated sect ion is characterised by free lateral migration of the riverbed and the widest active river zone(~28 m).

Spatio-temporal Pattern of the Coupling Relationship between the Regional Exhibition and Manufacturing Industries-Empirical Exploration Based on the Yellow River and Yangtze River Basins

The meetings,incentives,conventions and exhibitions(MICE)industry and manufacturing industry havea complex interaction and coupling relationship,and the correct understanding and handling of the relationshipbetween the industries is a prerequisite and foundation for high-quality regional development.Based on the provincial panel data from 2011 to 2020,the article establishes the evaluation index system of the manufacturing andexhibition industries in the Yellow River and Yangtze River basins and then analyzes the evolution characteristicsand influencing factors of the Yellow River and Yangtze River basins in time and space based on the coupling coordination degree model.The results show that the correlation between the manufacturing and exhibition industriesin each province(region)along the Yangtze River and Yellow River basins remained stable and the volatility increased linearly from 2011 to 2020,and the degree of coordination gradually increased from being on the verge ofbeing out of tune to be well coordinated;spatially,indicating a development pattern of high in the east,low in thewest,high in the south,and low in the north,and the provinces with a high level of coupled coordination are concentrated in the middle and lower reaches of the Yellow River and the lower reaches of the Yangtze River,and thedevelopment of manufacturing industry is generally better than the development of the exhibition industry.Thegovernment should play a leading role in guaranteeing the high-quality development of the exhibition and manufacturing industries.Second,the government should pay attention to the coordinated development of the region torealize the regional linkage of the integration of the two industries.Finally,the government should strengthen theinternal connection of each province to recognize the linkage development of the industry within the region.

Evaluation of Four Anthropogenic Activity Impacts on Heavy Metal Quality of the Kumba River in the South West Region of Cameroon

Anthropogenic activities have contributed to pollution of water bodies through deposition of diverse pollutants amongst which are heavy metals. These pollutants, which at times are above the maximum concentration levels recommended, are detrimental to the quality of the water, soil and crops (plant) with subsequent human health risks. The objective of the work was to evaluate the impacts of human-based activities on the heavy metal properties of surface water with focus on the Kumba River basin. Field observations, interviews, field measurements and laboratory analyses of different water samples enabled us to collect the different data. The results show four main human-based activities within the river basin (agriculture, livestock production, domestic waste disposal and carwash activities) that pollute surface water. Approximately 20.61 tons of nitrogen and phosphorus from agricultural activities, 156.48 tons of animal wastes, 2517.5 tons of domestic wastes and 1.52 tons of detergent from carwash activities were deposited into the river each year. A highly significant difference at 1% was observed between the upstream and downstream heavy metal loads in four of the five heavy metals tested except for copper that was not significant. Lead concentrations were highest in all the activities with an average of 2.4 mg∙L−1 representing 57.81%, followed by zinc with 1.596 mg∙L−1 (38.45%) and manganese with 0.155 mg∙L−1 (3.74%) for the different anthropogenic activities thus indicating that these activities highly lead to pollution of the Kumba River water. The level of zinc and manganese was significantly influenced at ρ 005 by anthropogenic activities though generally the variations were in the order: carwash (3.196 mg∙L−1) < domestic waste disposal (3.347 mg∙L−1) < agriculture (4.172 mg∙L−1) < livestock (4.886 mg∙L−1) respectively and leading to a total of 14.04 tons of heavy metal pollutants deposited each day.