Time-variable gravity data from the Gravity Recovery and Climate Experiment （GRACE） satellite mission are used to study terrestrial water storage （TWS） changes over the Pearl River Basin （PRB） for the period 200...Time-variable gravity data from the Gravity Recovery and Climate Experiment （GRACE） satellite mission are used to study terrestrial water storage （TWS） changes over the Pearl River Basin （PRB） for the period 2003-Nov. 2014. TWS estimates from GRACE generally show good agreement with those from two hydrological models GLDAS and WGHM. But they show different capability of detecting significant TWS changes over the PRB. Among them, WGHM is likely to underestimate the seasonal variability of TWS, while GRACE detects long- term water depletions over the upper PRB as was done by hydrological models, and observes significant water increases around the Longtan Reservoir （LTR） due to water impoundment. The heavy drought in 2011 caused by the persistent precipitation deficit has resulted in extreme low surface runoff and water level of the LTR. Moreover, large variability of summer and autumn precipitation may easily trigger floods and droughts in the rainy season in the PRB, especially for summer, as a high correlation of 0.89 was found between precipitation and surface runoff. Generally, the PRB TWS was negatively correlated with El Nifio-Southern Oscillation （ENSO） events. However, the modulation of the Pacific Decadal Oscillation （PDO） may impact this relationship, and the significant TWS anomaly was likely to occur in the peak of PDO phase as they agree well in both of the magnitude and timing of peaks. This indicates that GRACE-based TWS could be a valuable parameter for studying climatic in- fluences in the PRB.展开更多
The protection of drinking water sources is vital to urban development and public health.In this study,the current situation of the mandatory protection area for drinking water source in the Pearl River Delta region w...The protection of drinking water sources is vital to urban development and public health.In this study,the current situation of the mandatory protection area for drinking water source in the Pearl River Delta region was investigated using a method combining Google Earth with the field survey.The gaps between management practices and legislation requirements were analyzed.Finally,several countermeasures for water resource protection were proposed as follows:to promote delineation in a more scientific way,to safeguard the sanctity of the law,to make better plan on water saving,and to encourage public participation in supervision and management.展开更多
[Objective] The study aimed to predict the peak water level in Pearl River Estuary under the background of sea level rise. [Method] The changing trends of peak water level at Denglongshan station and Hengmen station w...[Objective] The study aimed to predict the peak water level in Pearl River Estuary under the background of sea level rise. [Method] The changing trends of peak water level at Denglongshan station and Hengmen station were analyzed firstly on the basis of regression models, and then sea level rise in Pearl River Estuary in 2050 was predicted to estimate the 1-in-50-year peak water level in the same year. [Result] Regression analyses showed that the increasing rate of peak water level over past years was 6.3 mm/a at Denglongshan station and 5.8 mm/a at Hengmen station. In addition, if sea level will rise by 20, 30 and 60 cm respectively in 2050, it was predicted that the 1-in-50-year peak water level will reach 3.04, 3.14 and 3.44 m at Denglongshan station, and 3.19, 3.29 and 3.59 m at Hengmen station separately. [Conclusion] The estimation of peak water level in Pearl River Estuary could provide theoretical references for water resources planning.展开更多
In order to evaluate the distribution and partitioning characteristics of heavy metals in the large anthropogenically impacted Pearl River Basin, the contents of ‘‘anthropophile'' elements(Cr, Ni, Cu, Zn, Cd...In order to evaluate the distribution and partitioning characteristics of heavy metals in the large anthropogenically impacted Pearl River Basin, the contents of ‘‘anthropophile'' elements(Cr, Ni, Cu, Zn, Cd and Pb,which are clearly influenced by human activities) were determined, and their partitioning coefficients(Kd) between water and sediments and enrichment factors(EF) were calculated for samples collected at different locations along the Pearl River main stream. The modified BCR sequential extraction procedure(proposed by the European Community Bureau of Reference in 1993), which involves the successive extraction of metals in a decreasing order of reactivity, was applied. Sediment samples from the upper,middle, and lower reaches were included in this study. The results showed that the content of most metals in water and sediment samples gradually increases from upstream to downstream, suggesting a possible input from human activities as shown by their increasing high EF, ranged from 1.4 to 3.9 for Cu, from 1.4 to 6.7 for Zn, from 2.5 to59.1 for Cd, and from 1.7 to 8.9 for Pb, respectively. Thehigher partition coefficients(Kd) for Cr, Zn, and Pb(10~5–10~6) indicated that they were mainly transported in solid phase, while parts of Ni, Cu, and Cd were transported in dissolved phase as they display relatively lower Kdin the range of 10~4–10~5. According to the results of the BCR leaching, the percentage of non-residual fraction of heavy metals in the sediments showed a decreasing order of Cd [ Pb [ Zn [ Cu [ Ni [ Cr, implying that Cd and Pb were more active and bioavailable compared to the other four metals, and thus would be potentially more harmful to the watershed ecosystem.展开更多
PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta （PRD）, South China, during winter and summer in 2002. Six water-soluble ions, Na^＋, NH4＋, K^＋, Cl^-, NO3^- and SO4^2- were measu...PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta （PRD）, South China, during winter and summer in 2002. Six water-soluble ions, Na^＋, NH4＋, K^＋, Cl^-, NO3^- and SO4^2- were measured using ion chromatography. On average, ionic species accounted for 53.3% and 40.5% for PM2.5 and PM10, respectively in winter and 39.4% and 35.2%, respectively in summer. Secondary ions such as sulfate, nitrate and ammonium accounted for the major part of the total ionic species. Sulfate was the most abundant species followed by nitrate. Overall, a regional pollution tendency was shown that there were higher concentrations of sulfate, nitrate and ammonium in Guangzhou City than those in the other PRD cities. Significant seasonal variations were also observed with higher levels of species in winter but lower in summer. The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well. NO3^-/SO4^2- ratio indicated that mobile sources have considerably contribution to the urban aerosol, and stationary sources should not be neglected. Besides the primary emissions, complex atmospheric reactions under favorable weather conditions should be paid more attention for the control of primary emission in the PRD region.展开更多
EDSS is a comprehensive software system for water quality management in tidal river networks in general and for the Pearl River Delta in particular. Its purpose is to provide a practical tool that could assist governm...EDSS is a comprehensive software system for water quality management in tidal river networks in general and for the Pearl River Delta in particular. Its purpose is to provide a practical tool that could assist government agencies in decision making for the efficient management of water resources in terms of both quantity and quality. By combining the capabilities of geographical information system (GIS), database management system (DBMS), model base management system (MBMS) and expert system, the aim is to improve the quality of decision making in what is becoming an increasingly complex area. This paper first outlines the basic concepts and philosophy adopted in developing EDSS, the system architecture, design features, implementation techniques and facilities provided. Thereafter, the core part of the system—the hydrodynamic and water quality models are described briefly. The final contribution in this paper describes the application of EDSS to the Pearl River Delta, which has the most complicated tidal river network patterns as well as the fastest economic development in the world. Examples are given of the real-world problems that can be addressed using the system, including cross-boundary water pollution analysis, regional drinking water take-up site selection, screening of important polluters, environmental impact assessment, and water quality zoning and planning. It is illustrated that EDSS can provide efficient and scientific analytical tools for planning and decision-making purposes in the information era.展开更多
基金supported by the National Natural Science Foundation of China (41174020, 41131067)the Fundamental Research Funds for the Central Universities (2014214020203)+1 种基金the open fund of Key Laboratory of Geospace Environment and Geodesy, Ministry of Education (14-02-011)the open fund of Guangxi Key Laboratory of Spatial Information and Geomatics (14-045-24-17)
文摘Time-variable gravity data from the Gravity Recovery and Climate Experiment （GRACE） satellite mission are used to study terrestrial water storage （TWS） changes over the Pearl River Basin （PRB） for the period 2003-Nov. 2014. TWS estimates from GRACE generally show good agreement with those from two hydrological models GLDAS and WGHM. But they show different capability of detecting significant TWS changes over the PRB. Among them, WGHM is likely to underestimate the seasonal variability of TWS, while GRACE detects long- term water depletions over the upper PRB as was done by hydrological models, and observes significant water increases around the Longtan Reservoir （LTR） due to water impoundment. The heavy drought in 2011 caused by the persistent precipitation deficit has resulted in extreme low surface runoff and water level of the LTR. Moreover, large variability of summer and autumn precipitation may easily trigger floods and droughts in the rainy season in the PRB, especially for summer, as a high correlation of 0.89 was found between precipitation and surface runoff. Generally, the PRB TWS was negatively correlated with El Nifio-Southern Oscillation （ENSO） events. However, the modulation of the Pacific Decadal Oscillation （PDO） may impact this relationship, and the significant TWS anomaly was likely to occur in the peak of PDO phase as they agree well in both of the magnitude and timing of peaks. This indicates that GRACE-based TWS could be a valuable parameter for studying climatic in- fluences in the PRB.
文摘The protection of drinking water sources is vital to urban development and public health.In this study,the current situation of the mandatory protection area for drinking water source in the Pearl River Delta region was investigated using a method combining Google Earth with the field survey.The gaps between management practices and legislation requirements were analyzed.Finally,several countermeasures for water resource protection were proposed as follows:to promote delineation in a more scientific way,to safeguard the sanctity of the law,to make better plan on water saving,and to encourage public participation in supervision and management.
基金Supported by National Natural Science Foundation of China (50839005)Major State Basic Research Development Program (973 Program)(2010CB428405)+1 种基金Scientific Research Project of Public Welfare Industry of the Ministry of Water Resources,China (201001022)Scientific Research Project of China Water Resources Pearl River Planning Surveying and Designing Co.Ltd.(2012)
文摘[Objective] The study aimed to predict the peak water level in Pearl River Estuary under the background of sea level rise. [Method] The changing trends of peak water level at Denglongshan station and Hengmen station were analyzed firstly on the basis of regression models, and then sea level rise in Pearl River Estuary in 2050 was predicted to estimate the 1-in-50-year peak water level in the same year. [Result] Regression analyses showed that the increasing rate of peak water level over past years was 6.3 mm/a at Denglongshan station and 5.8 mm/a at Hengmen station. In addition, if sea level will rise by 20, 30 and 60 cm respectively in 2050, it was predicted that the 1-in-50-year peak water level will reach 3.04, 3.14 and 3.44 m at Denglongshan station, and 3.19, 3.29 and 3.59 m at Hengmen station separately. [Conclusion] The estimation of peak water level in Pearl River Estuary could provide theoretical references for water resources planning.
基金financially supported by the Natural Science Foundation of China (41561134017, U1612442, 41625012, U1301231)
文摘In order to evaluate the distribution and partitioning characteristics of heavy metals in the large anthropogenically impacted Pearl River Basin, the contents of ‘‘anthropophile'' elements(Cr, Ni, Cu, Zn, Cd and Pb,which are clearly influenced by human activities) were determined, and their partitioning coefficients(Kd) between water and sediments and enrichment factors(EF) were calculated for samples collected at different locations along the Pearl River main stream. The modified BCR sequential extraction procedure(proposed by the European Community Bureau of Reference in 1993), which involves the successive extraction of metals in a decreasing order of reactivity, was applied. Sediment samples from the upper,middle, and lower reaches were included in this study. The results showed that the content of most metals in water and sediment samples gradually increases from upstream to downstream, suggesting a possible input from human activities as shown by their increasing high EF, ranged from 1.4 to 3.9 for Cu, from 1.4 to 6.7 for Zn, from 2.5 to59.1 for Cd, and from 1.7 to 8.9 for Pb, respectively. Thehigher partition coefficients(Kd) for Cr, Zn, and Pb(10~5–10~6) indicated that they were mainly transported in solid phase, while parts of Ni, Cu, and Cd were transported in dissolved phase as they display relatively lower Kdin the range of 10~4–10~5. According to the results of the BCR leaching, the percentage of non-residual fraction of heavy metals in the sediments showed a decreasing order of Cd [ Pb [ Zn [ Cu [ Ni [ Cr, implying that Cd and Pb were more active and bioavailable compared to the other four metals, and thus would be potentially more harmful to the watershed ecosystem.
基金Project supported by the National Natural Science Founding of China(No.20347003,40121303)the Research Grants Council of Hong Kong(No.PolyU5038/01E,PolyU5145/03E)the Area of Strategic Development on Atmospheric and Urban Air Pollution of The Hong Kong Polytechnic University(No.A516,A510).
文摘PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta （PRD）, South China, during winter and summer in 2002. Six water-soluble ions, Na^＋, NH4＋, K^＋, Cl^-, NO3^- and SO4^2- were measured using ion chromatography. On average, ionic species accounted for 53.3% and 40.5% for PM2.5 and PM10, respectively in winter and 39.4% and 35.2%, respectively in summer. Secondary ions such as sulfate, nitrate and ammonium accounted for the major part of the total ionic species. Sulfate was the most abundant species followed by nitrate. Overall, a regional pollution tendency was shown that there were higher concentrations of sulfate, nitrate and ammonium in Guangzhou City than those in the other PRD cities. Significant seasonal variations were also observed with higher levels of species in winter but lower in summer. The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well. NO3^-/SO4^2- ratio indicated that mobile sources have considerably contribution to the urban aerosol, and stationary sources should not be neglected. Besides the primary emissions, complex atmospheric reactions under favorable weather conditions should be paid more attention for the control of primary emission in the PRD region.
文摘EDSS is a comprehensive software system for water quality management in tidal river networks in general and for the Pearl River Delta in particular. Its purpose is to provide a practical tool that could assist government agencies in decision making for the efficient management of water resources in terms of both quantity and quality. By combining the capabilities of geographical information system (GIS), database management system (DBMS), model base management system (MBMS) and expert system, the aim is to improve the quality of decision making in what is becoming an increasingly complex area. This paper first outlines the basic concepts and philosophy adopted in developing EDSS, the system architecture, design features, implementation techniques and facilities provided. Thereafter, the core part of the system—the hydrodynamic and water quality models are described briefly. The final contribution in this paper describes the application of EDSS to the Pearl River Delta, which has the most complicated tidal river network patterns as well as the fastest economic development in the world. Examples are given of the real-world problems that can be addressed using the system, including cross-boundary water pollution analysis, regional drinking water take-up site selection, screening of important polluters, environmental impact assessment, and water quality zoning and planning. It is illustrated that EDSS can provide efficient and scientific analytical tools for planning and decision-making purposes in the information era.
