Showing papers in "Frontiers of Earth Science in China in 2009"
TL;DR: A comprehensive review of the progress in remote sensing of soil moisture, with focus on technique approaches for soil moisture estimation from optical, thermal, passive microwave, and active microwave measurements is presented in this paper.
Abstract: Surface soil moisture is one of the crucial variables in hydrological processes, which influences the exchange of water and energy fluxes at the land surface/atmosphere interface. Accurate estimate of the spatial and temporal variations of soil moisture is critical for numerous environmental studies. Recent technological advances in satellite remote sensing have shown that soil moisture can be measured by a variety of remote sensing techniques, each with its own strengths and weaknesses. This paper presents a comprehensive review of the progress in remote sensing of soil moisture, with focus on technique approaches for soil moisture estimation from optical, thermal, passive microwave, and active microwave measurements. The physical principles and the status of current retrieval methods are summarized. Limitations existing in current soil moisture estimation algorithms and key issues that have to be addressed in the near future are also discussed.
390 citations
TL;DR: In this article, the authors analyzed surface air temperature variations during the last 100 years (1901-2003) in mid-latitude central Asia were analyzed using empirical orthogonal functions (EOFs).
Abstract: Surface air temperature variations during the last 100 years (1901-2003) in mid-latitude central Asia were analyzed using Empirical Orthogonal Functions (EOFs). The results suggest that temperature variations in four major sub-regions, i.e. the eastern monsoonal area, central Asia, the Mongolian Plateau and the Tarim Basin, respectively, are coherent and characterized by a striking warming trend during the last 100 years. The annual mean temperature increasing rates at each sub-region (represen- tative station) are 0.19°C per decade, 0.16°C per decade, 0.23°C per decade and 0.15°C per decade, respectively. The average annual mean temperature increasing rate of the four sub-regions is 0.18°C per decade, with a greater increasing rate in winter (0.21°C per decade). In Asian mid-latitude areas, surface air temperature increased relatively slowly from the 1900s to 1970s, and it has increased rapidly since 1970s. This pattern of temperature variation differs from that in the other areas of China. Notably, there was no obvious warming between the 1920s and 1940s, with temperature fluctuating between warming and cooling trends (e.g. 1920s, 1940s, 1960s, 1980s, 1990s). However, the warming trends are of a greater magnitude and their durations are longer than that of the cooling periods, which leads to an overall warming. The amplitude of temperature variations in the study region is also larger than that in eastern China during different periods.
107 citations
TL;DR: In this article, the platform, payloads, and ground segment designs of the Fengyun 3 series are introduced, and some typical images during the on-orbit commission test are rendered.
Abstract: Fengyun 3 series are the second-generation polar-orbiting meteorological satellites of China. The first satellite of Fengyun 3 series, FY-3A, is a research and development satellite with 11 payloads onboard. FY-3A was launched successfully at 11 a.m. on May 27, 2008. Since the launch, FY-3A data have been applied to the services on the flood season and the Beijing 2008 Olympic Games. In this paper, the platform, payloads, and ground segment designs are introduced. Some typical images during the on-orbit commission test are rendered. Improvements of FY-3A on Earth observations are summarized at the end by comparing them with FY-1D, the last satellite of Fengyun 1 series.
51 citations
TL;DR: Wang et al. as discussed by the authors showed that the carbon preference index (CPI) of higher plant-derived long-chain n-alkanes extracted from 62 surface soil samples in eastern China exhibited a specific pattern of variations, namely gradual increase with the increasing latitudes.
Abstract: Carbon Preference Index (CPI values) of higher plant-derived long-chain n-alkanes extracted from 62 surface soil samples in eastern China exhibited a specific pattern of variations, namely gradual increase with the increasing latitudes. Such regular variations existed in both forest soil and grassland soil. Our data implied that CPI values of higher plant-derived long-chain n-alkanes had a certain connection with climatic conditions, and such a connection was not influenced by vegetation types. Together with previous data from marine sediments, loess/paleosol sequences, tertiary red clay and modern plants, our observation made us conclude that CPI values of higher plant-derived long-chain n-alkanes may be used as an excellent proxy for paleoclimatic studies.
47 citations
TL;DR: In this article, the results show that there were one or several PAEs in all the samples, and the concentrations of total PAEs ranged from 80.12 to 1882.18 ng/L.
Abstract: Samples of groundwater were collected from 17 sites in the Jianghan plain in July 2007. Sixteen phthalate esters (PAEs) were detected in samples collected by using solid-phase extraction (SPE)-gas chromatography (GC). The results show that there were one or several PAEs in all the samples, and the concentrations of total PAEs ranged from 80.12 to 1882.18 ng/L. Four PAEs, i.e. di-isobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), bis (2-ethoxyethyl) phthalate (BEEP) and di (2-ethylhexyl) phthalate DEHP) were the dominant species. Among these, DIBP, DBP and DEHP concentrations were closely related to the water supply from the Yangtze River, Hanjiang River and Honghu Lake. However, the distribution of BEEP was irregular, which may be due to the application of some kind of products containing BEEP in the related areas. PAE distribution was irrelevant to the electrical conductivity and sample depth.
45 citations
TL;DR: In this paper, a comparative study on the erosion/depositional pattern between the two sections in relation to different hydrodynamic parameters prevailing in these two sections was made, and a plane table mapping was carried out to demarcate the different geomorphic units.
Abstract: Coastal erosion at Sagar Island of Sunderban delta, India, has been critically studied. The area is in the subtropical humid region. There are mainly three seasons viz: winter, summer and the monsoon. Different wave dynamic parameters were measured from theodolite observations with leveling staff and measuring gauges during lunar days at two sections of the western and eastern parts of the coastal zone during post-and pre-monsoons. A comparative study was made on the erosion/depositional pattern between the two sections in relation to different hydrodynamic parameters prevailing in these two sections. Plane table mapping was carried out to demarcate the different geomorphic units. The marine coastal landforms show dune ridges with intervening flats bordered by gently sloping beach on one side and a flat beach on the other side. The western part of the beach is mainly sandy; whereas the eastern part is silty and clayey with mud bank remnants. Actual field measurements indicate that the coastal dune belt has retreated to the order by about 20 m since 1985. The eastern part of the beach has lowered by about 2 m since 1985 and the western part was raised almost to the same tune. It is observed that accretion in the western and central parts of the beach took place; whereas severe erosion in the eastern part made the beach very narrow with remnants of mud banks and tree roots. Frequent embankment failures, submergence and flooding, beach erosion and siltation at jetties and navigational channels, cyclones and storm surges made this area increasingly vulnerable.
42 citations
TL;DR: In this article, the authors focused on the methodology of estimating the winter wheat biomass based on hyperspectral field data, including the LANDSAT TM and EOS MODIS images.
Abstract: Biomass can indicate plant growth status, so it is an important index for plant growth monitoring. This paper focused on the methodology of estimating the winter wheat biomass based on hyperspectral field data, including the LANDSAT TM and EOS MODIS images. In order to develop the method of retrieving the wheat biomass from remote sensed data, routine field measurements were initiated during periods when the LANDSAT satellite passed over the study region. In the course of the experiment, five LANDSAT TM images were acquired respectively at early erecting stage, jointing stage, earring stage, flowering stage and grain-filling stage of the winter wheat, and the wheat biomass was measured at each stage. Based on the TM and MODIS images, spectral indices such as NDVI, RDVI, EVI, MSAVI, SIPI and NDWI were calculated. At the same time, the hyperspectral field data was used to compute the normalized difference in spectral indices, red-edge parameters, spectral absorption, and reflection feature parameters. Then the correlation coefficients between the wheat biomass and spectral parameters of the experiment sites were computed. According to the correlation coefficients, the optimal spectral parameters for estimating the wheat biomass were determined. The bestfitting method was employed to build the relationship models between the wheat biomass and the optimal spectral parameters. Finally, the models were used to estimate the wheat biomass based on the TM and MODIS data. The maximum RMSE of estimated biomass was 66.403 g/m2.
31 citations
TL;DR: In this paper, the authors studied the environmental geochemistry of high arsenic groundwater at Hetao plain and a core sediment and found that arsenic is present in the solution predominantly as As(III), while particulate arsenic constitutes about 10% of the total arsenic.
Abstract: Environmental geochemistry of high arsenic groundwater at Hetao plain was studied on the basis of geochemical survey of the groundwater and a core sediment. Arsenic concentration in groundwater samples varies from 76 to 1093 μg/L. The high arsenic groundwater mostly appears to be weakly alkaline. The concentrations of NO3− and SO42− are relatively low, while the concentrations of DOC, NH4+, dissolved Fe and sulfide are relatively great. Analysis of arsenic speciation in 21 samples shows that arsenic is present in the solution predominantly as As(III), while particulate arsenic constitutes about 10% of the total arsenic. Methane is detected in five samples with the greatest content being 5107 μg/L. The shallow aquifer in Hangjinhouqi of western Hetao plain is of strongly reducing condition. The arsenic content in 23 core sediment samples varies from 7.7 to 34.6 mg/kg, with great value in clay and mild clay layer. The obvious positive relationship in content between Fe2O3, Mn, Sb, B, V and As indicates that the distribution of arsenic in the sediments may be related to Fe and Mn oxides, and the mobilization of Sb, B and V may be affected by similar geochemical processes as that of As.
27 citations
TL;DR: Wang et al. as discussed by the authors tested the performance of the SWAT model and the feasibility of using this model as a simulator of water flow and nitrogen and phosphorus yields over the Dongjiang River basin in South China.
Abstract: Population growth, urbanization, and intensified agriculture have resulted in mobilization of nitrogen and phosphorus, which is the main cause of river water quality deterioration. Environmental regulation has expedited the necessity for agricultural producers to design and implement more environmentally suitable practices. Therefore, there is a need to identify critical nutrients and their loss/transport potential. Watershed model can be used to better understand the relationship between land use activities/management and hydrologic processes/water quality changes that occur within a watershed. The objective of the study is to test the performance of the SWAT model and the feasibility of using this model as a simulator of water flow and nitrogen and phosphorus yields over the Dongjiang River basin in South China. Spatial data layers of land slope, soil type, and land use were combined with geographic information system (GIS) to aid in creating model inputs. The observed streamflow and sediment at Boluo station in the Dongjiang River basin were used to calibrate and validate the model. Time series plots and statistical measures were used to verify model predictions. Predicted values generally matched well with the observed values during calibration and validation (R
2≥0.6 and Nash-Suttcliffe Efficiency ≥0.5) except for underestimation of sediment peaks and overestimation of sediment valleys at Boluo. This study shows that SWAT is able to predict streamflow, sediment generation, and nutrients transport with satisfactory results.
22 citations
TL;DR: In this paper, the authors investigated the concentration and mass loadings of heavy metals adsorbed on sediment from an urban road surface in Beijing and found that Cd, Cr, Cu, and Ni were more likely to attach to smaller sediments than bigger ones, compared to Pb and Zn.
Abstract: Concentration and mass loadings of heavy metals adsorbed on sediment from an urban road surface in Beijing were investigated. The buildup and washoff processes are discussed. Results showed that masses of sediments smaller than 500 μm in diameter varied from 11.2 to 25.5 g/m 2 . On average, sediments smaller than 125 μm accounted for 42.9% of sediments smaller than 500 μm in mass. Cd, Cr, Cu, and Ni were more likely to attach to smaller sediments than bigger ones, compared to Pb and Zn. Mass loading of the sediments generally increased with antecedent dry periods, but the linear relationship was better for smaller sediments than for bigger ones. Heavy metal concentrations adsorbed on sediments with diameter less than 40 μm generally decreased more obviously than those adsorbed on bigger ones after rainfall events.
22 citations
TL;DR: Wang et al. as discussed by the authors made a comprehensive assessment of the environmental and socio-economic issues to affect Taihu Lake ecosystem health and identified pollution as the most serious environmental concern, and proposed some further policy options to mitigate environmental problems, including improving the fishery management; strengthening cross- provincial collaboration; making efforts to reduce flood disaster and increasing investment to new environmental protection technologies.
Abstract: Taihu Lake is located at the densely populated region of the eastern coast of China. Taihu Basin is one of the most developed regions of China. Over the past decades, especially since the reforming and opening-up of China in 1980s, the lake has received more and more pressure from a variety of interlinked human activities, including industrial pollution, fertilizer and pesticide application, eutrophication, overfishing, etc. Water quality has been deteriorating sharply in the lake. In this paper, we made a comprehensive assessment of the environmental and socio-economic issues to affect Taihu Lake ecosystem health. Pollution was identified as the most serious environmental concern. The root causes of these environmental problems are recognized to be diverse, including dense population, high urbanization, heavy industrialization, fast economic development, insufficient sewage treatment, weak public awareness of environment conservation, and lack of institutional capacity and insufficient enforcement through regulations and legislation. On the policy part, past and current policies and measures are reviewed, especially the “Zero” discharge action and phosphate ban in detergents in Taihu Basin. In order to mitigate environmental problems, some further policy options have been proposed, including: improving the fishery management; strengthening cross- provincial collaboration; making efforts to reduce flood disaster and increasing investment to new environmental protection technologies. It is important to assess the economic, social and environmental values of natural resources (soil, water and organisms) in order to allocate them efficiently and fairly between the present and future generations.
TL;DR: Wang et al. as mentioned in this paper showed that pollutant concentrations in Fu River and pollution load entering Wetland Baiyangdian generally increased during 2001-2005, on average, the concentrations of CODMn and BOD5 increased by 46.5% and 50% from 2001 to 2005, respectively.
Abstract: Fu River is the only river that has perennial flow into Wetland Baiyangdian and is mainly composed of living sewage and industrial wastewater from Baoding city. Pollutant concentrations were monitored at three sections in the upstream, midstream, and downstream of Fu River and water quality in Wetland Baiyangdian was monitored at seven monitoring sites from 2001 to 2005. Results show that pollutant concentrations in Fu River and pollution load entering Wetland Baiyangdian generally increased during 2001–2005. On average, the concentrations of CODMn and BOD5 increased by 46.5% and 50% from 2001 to 2005 in Fu River and CODMn increased by 17% in Wetland Baiyangdian. The total amount of CODMn and BOD5 entering Wetland Baiyangdian increased from 1630 and 997 t/a to 2243 and 1583 t/a from 2001 to 2005, respectively. Total amount of water within the wetland and non-point source pollution input from surrounding areas also influenced the water quality in the wetland.
TL;DR: In this paper, an ensemble is developed from the four schemes, whose relative contributions or weights are optimized locally to yield overall minimum root-mean-square errors from observed daily precipitation.
Abstract: RegCM3 (REGional Climate Model) simulations of precipitation in China in 1991 and 1998 are very sensitive to the cumulus parameterization. Among the four schemes available, none has superior skills over the whole of China, but each captures certain observed signals in distinct regions. The Grell scheme with the Fritsch-Chappell closure produces the smallest biases over the North; the Grell scheme with the Arakawa-Schubert closure performs the best over the southeast of 100°E; the Anthes-Kuo scheme is superior over the northeast; and the Emanuel scheme is more realistic over the southwest of 100°E and along the Yangtze River Basin. These differences indicate a strong degree of independence and complementarity between the parameterizations. As such, an ensemble is developed from the four schemes, whose relative contributions or weights are optimized locally to yield overall minimum root-mean-square errors from observed daily precipitation. The skill gain is evaluated by applying the identical distribution of the weights in a different period. It is shown that the ensemble always produces gross biases that are smaller than the individual schemes in both 1991 and 1998. The ensemble, however, cannot eliminate the large rainfall deficits over the southwest of 100°E and along the Yangtze River Basin that are systematic across all schemes. Further improve-ments can be made by a super-ensemble based on more cumulus schemes and/or multiple models.
TL;DR: In this article, the response of geochemical records in lacustrine sediments to climate and human activity in Mengjin, Henan Province of China during the middle Holocene was examined.
Abstract: In this paper, we examined the response of geochemical records in lacustrine sediments to climate and human activity in Mengjin, Henan Province of China during the middle Holocene. Indices used in this study include K, Na, Mn, Ba, Sr, Al, Ti, cation ratios, and Gramineae pollen in lacustrine sediments. Results indicate a drought event in this area around 5660 cal a BP, which weakened soil leaching and changed the element composition of surface soil runoff entering the paelo-lake and lacustrine sediments. Human activity appearing from 4695 cal a BP to 4000 cal a BP also affected the chemical composition of lake sediments. Human activities led to enhanced soil erosion and destroyed soil leaching horizons. Therefore, the substance of soil illuvial layer exposed to the surface and entering the paleo-lake were substantially altered by human activities.
TL;DR: In this paper, the authors studied the relationship between the δ13C value in modern surface soil organic matter and standing vegetation in arid areas in China, Australia and the United States.
Abstract: The stable carbon isotope composition in surface soil organic matter (δ13Csoil) contains integrative information on the carbon isotope composition of the standing terrestrial plants (δ13Cleaf). In order to obtain valuable vegetation information from the δ13C of terrestrial sediment, it is necessary to understand the relationship between the δ13C value in modern surface soil and the standing vegetation. In this paper, we studied the δ13C value in modern surface soil organic matter and standing vegetation in arid areas in China, Australia and the United States. The isotopic discrepancy between δ13Csoil and δ13Cleaf of the standing dominant vegetation was examined in those different arid regions. The results show that the δ13Csoil values were consistently enriched compared to the δ13Cleaf. The δ13Cleaf values were positively correlated with δ13Csoil, which suggests that the interference of microorganisms and hydrophytes on the isotopic composition of surface soil organic matter during soil organic matter formation could be ignored in arid regions. The averaged discrepancy between δ13Csoil and δ13Cleaf is about 1.71%in Tamarix L. in the Tarim Basin in China, 1.50% in Eucalytus near Orange in Australia and 1.22% in Artemisia in Saratoga in the United States, which are different from the results of other studies. The results indicate that the discrepancies in the δ13C value between surface soil organic matter and standing vegetation were highly influenced by the differences in geophysical location and the dominant species of the studied ecosystems. We suggest that caution should be taken when organic matter δ13C in terrestrial sediment is used to extract paleovegetation information (C3/C4 vegetation composition), as the δ13C in soil organic matter is not only determined by the ratio of C3/C4 species, but also profoundly affected by climate change induced variation in the δ13C in dominant species.
TL;DR: In this article, high resolution records of long chain n-alkanol biomarkers were obtained from a peat-lacustrine core from the Dingnan profile in southern China.
Abstract: High resolution records of long chain n-alkanol biomarkers were obtained from a peat-lacustrine core from the Dingnan profile in southern China. The n-alkanol distributions are characterized by the predominance of even-over-odd carbon number and maximize at C24 or C26. On the basis of the reported n-alkanol records in the literature and the n-alkane record in our samples, we concluded that the n-alkanol ratio of C26/C30 varying from 1.25 to 6.48, together with the n-alkanol ratio C22/C24 less than unity, is indicative of the presence of a dominant forest paleovegetation. A 2000-year cycling in the variation of the n-alkanol ratio C26/C30 is identifiable in our profile, and probably results from the change in the abundance of the grass relative to trees induced by a cyclic paleoclimate. The n-alkanol ratio C24/C26 appears to be more sensitive to change in precipitation than in temperature, and may be a potential indicator of precipitation/humidity, with increased values being associated with relatively dry conditions. The paleovegetation and the paleoclimate reconstructed on the basis of the n-alkanol records for the recent 18000 cal a BP in general accord with the pollen data and other lipid evidence recorded in the Dingnan region in southern China. In particular, both the n-alkanol records and the pollen data infer the different paleoclimate conditions for the two peat sequences, with a cool and wet climate dominating in the lower peat deposition formed during the latest Pleistocene and a change to a drier and cooler climate occurring in the upper peat sequence in mid-Holocene.
TL;DR: A review of the available information relevant to the effects of UV radiation and other climate change factors on the terrestrial carbon balance in an effort to highlight current gaps in knowledge and future research directions for UV radiation research can be found in this paper.
Abstract: One of the most documented effects of human activity on our environment is the reduction of stratospheric ozone resulting in an increase of biologically harmful ultraviolet (UV) radiation. In a less predictable manner, UV radiation incident at the surface of the earth is expected to be further modified in the future as a result of altered cloud condition, atmospheric aerosol concentration, and snow cover. Although UV radiation comprises only a small fraction of the total solar radiation that is incident at the earth’s surface, it has the greatest energy per unit wavelength and, thus, the greatest potential to damage the biosphere. Recent investigations have highlighted numerous ways that UV radiation could potentially affect a variety of ecological processes, including nutrient cycling and the terrestrial carbon cycle. The objectives of the following literature review are to summarize and synthesize the available information relevant to the effects of UV radiation and other climate change factors on the terrestrial carbon balance in an effort to highlight current gaps in knowledge and future research directions for UV radiation research.
TL;DR: In this paper, the authors used high resolution seismic data using boomer sound source to reveal a wide distribution of large-scale bedforms (sandwaves) on the Southeast Vietnam continental shelf.
Abstract: The application of high resolution seismic data using boomer sound source has revealed a wide distribution of large-scale bedforms (sandwaves) on the Southeast Vietnam continental shelf. Bedforms that are a few meters high in wave height and hundreds of meters long in wavelength are primarily developed in the inner shelf (20–40 m) and considered to be formed under the present-day marine hydrodynamic conditions. Those bedforms developed in the deeper water (120 m) of the northernmost part of the continent can be interpreted as the relict morphological features formed during the latest sea-level lowstand of the late Pleistocene period. Two sediment transport paths have been identified on the basis of the bedform’s leeward orientation: northeast-southwest (along-shore) and north-south (cross-shore). A quantitative bottom current map is constructed from sandwave dimensions, surface sediments and measurement data. The strongest current velocities that gradually decrease toward the southwest are indicated by large sandwaves in the north (field B). Water depth, surficial sediment composition and bottom current are three factors that control the development of bedforms.
TL;DR: In this article, the authors designed an evaluation system of ecosystem services in Poyang Lake area based on the Millennium Ecosystem Assessment (MA) framework and employed factor analysis to extract a number of factors which characterize the ecosystem services.
Abstract: According to the ecosystem assessment framework developed by the Millennium Ecosystem Assessment (MA), this paper designs an evaluation system of ecosystem services in Poyang Lake area. On the basis of relevant variables disaggregated to 1 km grid using the gridded 1 km, this paper employs factor analysis to extract a number of factors which characterize the ecosystem services of Poyang Lake area. The extracted principal component are then represented onto 1 km×1 km grids by spatial clustering analysis to recognize and identify the minimal but consistent mapping units for ecosystem services which can be used to delimit the boundaries of ecological service zones. The research identifies ten ecosystem service zones in Poyang Lake area according to the consistent principle of core ecosystem service unit. Four kinds of core ecosystem services including supporting function, provisioning function, regulating function and cultural function are identified and represented. The research results could provide both spatially and temporally valuable decision-making information for sustainable ecosystem management in the targeted area.
TL;DR: The result shows that the genetic algorithm is feasible in optimizing parameters of the DHSVM model, and devising the genetic operators, selecting the arithmetic parameters and identifying the arithmetic termination conditions.
Abstract: Due to the multiplicity of factors including weather, the underlying surface and human activities, the complexity of parameter optimization for a distributed hydrological model of a watershed land surface goes far beyond the capability of traditional optimization methods. The genetic algorithm is a new attempt to find a solution to this problem. A genetic algorithm design on the Distributed-Hydrology-Soil-Vegetation model (DHSVM) parameter optimization is illustrated in this paper by defining the encoding method, designing the fitness value function, devising the genetic operators, selecting the arithmetic parameters and identifying the arithmetic termination conditions. Finally, a case study of the optimization method is implemented on the Lushi Watershed of the Yellow River Basin and achieves satisfactory results of parameter estimation. The result shows that the genetic algorithm is feasible in optimizing parameters of the DHSVM model.
TL;DR: In this article, a set of environmental magnetic parameters (χlf, χfd%, χARM, SIRM, HIRM and SOFT) of 331 top-soil samples from Xinjiang Uygur Autonomous Region of China were systematically measured.
Abstract: In this study, a set of environmental magnetic parameters (χlf, χfd%, χARM, SIRM, HIRM, SOFT and SIRM/χlf, χARM/SIRM and χARM/χlf) of 331 top-soil samples from Xinjiang Uygur Autonomous Region of China were systematically measured and the magnetic characteristics and its environmental significance were discussed. Our results indicate that the main magnetic minerals of these top-soils are single-domain magnetite. The content of magnetic minerals in top-soils from north Xinjiang is higher than that from south Xinjiang; however, the content of hard magnetic minerals is higher in the top- soils from south Xinjiang. The top-soils from Yili region contain similar magnetic minerals as that from south Xinjiang, but with much stronger magnetic SP content due to higher pedogenic processes. The differences in magnetic characteristics among top-soils from different regions of Xinjiang might reflect the differences of regional climatic factors, especially the precipitation.
TL;DR: Li et al. as discussed by the authors presented an empirical analysis on Chinese local government rural eco-environment public expenditure performance in 2003-2006 with the method of nonparametric data envelope analysis-DEA-Malmquist.
Abstract: This paper presents an empirical analysis on Chinese local government rural eco-environment public expenditure performance in 2003–2006 with the method of non-parametric data envelope analysis-malmquist (DEA-Malmquist). The basic conclusion is: first of all, Inner Mongolia, Jiangsu, Zhejiang, Hainan, Tibet, Shanxi, Ningxia and Shanxi, Heilongjiang, Shandong and Gansu are the benchmark units, while Guangdong, Jilin, Liaoning, Guangxi, and Guizhou provinces are far from the frontier and inefficient in fund allocation and management. Secondly, in the entire Chinese local government, the technical efficiency of fiscal support to rural eco-environment investment during 2003/2004 and 2005/2006 was improved and stable, while it degenerated in 2004/2005. Finally, there are 23 provinces in China that have growing and stable technical efficiencies in rural eco-environment public expenditure.
TL;DR: Wang et al. as discussed by the authors analyzed the statistical properties of water level extremes in the Pearl River Delta using five probability distribution functions, and goodness-of-fit was done based on Kolmogorov-Smirnov's statistic D (K-S D).
Abstract: We analyzed the statistical properties of water level extremes in the Pearl River Delta using five probability distribution functions. Estimation of parameters was performed using the L-moment technique. Goodness-of-fit was done based on Kolmogorov-Smirnov’s statistic D (K-S D). The research results indicate that Wakeby distribution is the best statistical model for description of statistical behaviors of water level extremes in the study region. Statistical analysis indicates that water levels corresponding to different return periods and associated variability tend to be larger in the landward side of the Pearl River Delta and vice versa. A ridge characterized by higher water level can be identified expanding along the West River and the Modaomen channel, showing the impacts of the hydrologic process of the West River basin. Trough and higher grades of water level changes can be detected in the region drained by Xi’nanyong channel, Dongping channel, and mainstream of Pearl River. The Pearl River Delta region is characterized by low-lying topography and a highly-advanced socio-economy, and is heavily populated, being prone to flood hazards and flood inundation due to rising sea level and typhoons. Therefore, sound and effective countermeasures should be made for human mitigation to natural hazards such as floods and typhoons.
TL;DR: In this paper, the authors reveal the nature of flood-season discharge and the associated impact on the upper and middle Yangtze river basin, on the basis of a historical database of daily discharges recorded at the Yichang (1865-1985) and Hankou (1878-1988) hydrological stations.
Abstract: This paper reveals the nature of flood-season discharge and the associated impact on the upper and middle Yangtze river basin, on the basis of a historical database of daily discharges recorded at the Yichang (1865–1985) and Hankou (1878–1988) hydrological stations Results show the period of discharge fluctuations of 2–6a, which is significant during 1878–1900 and 1915–1975 at Yichang station and the period of 2–7a during 1865–1905 and 1925–1975 at Hankou station Within these periods, a major period of 29–35a and two secondary periods of 7–8a and 139–165a can be further identified from both stations Our observation verifies that the fluctuations of streamflows of the upper and middle Yangtze River are fairly consistent with the periodicities of the Asia monsoon precipitation and ENSO event, reflecting coupling effect on the fluctuations of discharges in the Yangtze basin In the 1920s–1960s, intensified variability of streamflows of the upper and middle Yangtze River was closely associated with warming temperature in the basin and in China as well In 1975–1988, insignificant discharge fluctuations recorded at both stations can be chiefly attributed to human activities, ie, the large number of reservoirs constructed and associated increasing capacity of water storage, which has largely weakened the discharge fluctuations throughout the basin
TL;DR: In this paper, a series of new indicators termed as total system throughput water use intensity (TSTUI), TSTP, and environmental flow indicator (EFI) are set up by incorporating parameters of GDP, population, and Environmental flow.
Abstract: Sustainable water use of the Haihe River Basin is studied by using the ecological network analysis (ENA) approach. Two related aspects including socioeconomic and environmental water uses sustainability and network organization inherent in system structures are analyzed. For the study of sustainable water use from each single aspect including water use intensity, water use pressure, and environmental protection, a series of new indicators termed as total system throughput water use intensity (TSTUI), total system throughput pressure (TSTP), and environmental flow indicator (EFI) are set up by incorporating parameters of GDP, population, and environmental flow. Based on these three indices, a new integrated index, intensity-pressure-environment (IPE) is established for synthesized measure of sustainable socioeconomic and environmental water uses. The indices of ascendency and overhead are applied for analyzing and characterizing water use network organization. The four subbasins of the Haihe River during 1999–2002 and 2005–2007 are studied. The results show that (i) the water use intensity in subbasin II is the best, while that in subbasins I and III are the worst; (ii) subbasin II and subbasins I and III suffer the highest and lowest water use pressure, respectively; (iii) the environmental flow situations in subbasins II and III are the worst and that of subbasin I is the best; (iv) as for the integrated socioeconomic and environmental water uses sustainability, subbasin III is the best, and subbasins I and IV are the worst; (v) the organization level of subbasin I is better than the others’, in which that of subbasin IV is the worst. It can be concluded that the application of ENA in sustainable water use study can provide new angles for water resources management to address the challenges of assessing and optimizing options to obtain more sustainable water use.
TL;DR: The dominant C31 αβ-22R hopane in young sediments, without any thermal maturation, might be formed through microbial epimerization under acidic conditions in the peatland as suggested before, or directly from aerobic bacteria.
Abstract: Based on gas chromatography and gas chromatography-mass spectrometry analyses, an amazing amount of hopanoids was detected in the peat deposits in the Dajiuhu National Wetland Park in central China. The hopanoids identified included hopanes (C27-C31 αβ, C27-C32 ββ, C29 βα), hopenes (hop-22(29)-ene, 22,29,30-trinorhop-17(21)-ene, hop-17(21)-ene, hop-13(18)-ene, etc.), hopanoic acids (C31-C34 ββ, C32-C33 βα, C32 αβ), hopanols (C32 ββ and αβ) and hopanone (22,29,30-trinorhop-21-one). C31 αβ-22R hopane was found to be the dominant hopanoid, more abundant than individual nalkanes derived from higher plants. These hopanoids, exclusive of some hopenes, are proposed to be primarily from bacteria. The dominant C31 αβ-22R hopane in young sediments, without any thermal maturation, might be formed through microbial epimerization under acidic conditions in the peatland as suggested before, or directly from aerobic bacteria. This finding highlights the importance of microbes in the formation of peatland as well as in the reconstruction of paleoenvironments.
TL;DR: In this paper, the authors made a comparison of major similarities and differences of extreme cold events between the cold and warm periods for recent 50 years, in order to gain a better insight into the impact of the global warming on Extreme cold events in China.
Abstract: The present paper has made a comparison of major similarities and differences of extreme cold events between the cold and warm periods for recent 50 years, in order to gain a better insight into the impact of the global warming on extreme cold events in China. Two typical events of low temperature, ice freezing and snow disasters that occurred in January 2008 and in the winter of 1954/1955, respectively, are selected as representative cases for the cold period (1950’s–1970’s) and the warm period (1980’s-present). The contrasting study has revealed that these two events both occurred under long-persistent blocking circulation over Eurasian continent, with continuous invasions of strong cold air into China mainland. They nearly brought about similar weather disasters such as extensive low temperature, record-breaking freezing rains and exceptionally heavy snowfalls. However, due to active northward transport of warm and moist air from Bay of Bengal and Indo-China Peninsula in the warm period, the January 2008 case had longer freezing rain days and heavier snowstorms in South China, thus leading to much more severe damage to electric grids and transportations. The case of the 1954/1955 winter was a stronger, extreme cold event than the case of January 2008, in terms of magnitudes of temperature drop and severity of impact on river icing. It was gradually recovered to normal condition while the case of January 2008 had a very rapid recovery to warming condition due to impact of the global warming.
TL;DR: In this article, a practical simulation approach was used to analyze domestic water demand and its future uncertainty in water scarce areas through a case study of Beijing, China. Analytic models and a forecasting model were constructed using statistic and econometric regression approaches.
Abstract: This paper demonstrates a practical simulation approach to analyze domestic water demand and its future uncertainty in water scarce areas through a case study of Beijing, China. Analytic models and a forecasting model were constructed using statistic and econometric regression approaches. The analytic models were used to analyze the interrelationships between domestic water demand and some socio-economic factors of Beijing. The forecasting model was applied to predict domestic water demand from 2009 to 2015, and this model was validated by comparing the prediction values with the observations. Scenario analysis was applied to simulate uncertainty and risks in domestic water demand in the future. The simulation results proved that domestic water demand will increase from 13.9×108 m3 to 16.7×108 m3 from 2009 to 2015. Three more sustainable strategies were also found through scenario analysis. The simulation and modeling approaches and results would be very supportive for water decision makers in allocating water efficiently and making sustainable water strategies.
TL;DR: In this paper, the credibility and predictability of sediment flux of the Changjiang River that has discharged into the seas on the basis of historical database was examined and a newly established sediment rating curve was proposed to simulate the sediment flux/load into the sea by using those suspended sediment concentration (SSC) only under discharge of 60000 m3/s at the Datong station.
Abstract: This paper examines the credibility and predictability of sediment flux of the Changjiang River that has discharged into the seas on the basis of historical database. The assumption of the study stands on the lack of sufficient observation data of suspended sediment concentration (SSC) during peaking flood period, which most likely results in the application of an inappropriate method to the downstream-most Datong hydrological gauging station in the Changjiang basin. This insufficient method (only 30–50 times of SSC observation per year), that obviously did not cover the peaking SSC during peaking floods, would lead to an inaccuracy in estimating the Changjiang sediment load by 4.7×108 t/a (multiyearly) into the seas. Also, sediment depletion that often takes place upstream of the Changjiang basin has, to some extent, lowered the credibility of traditional sediment rating curve that has been used for estimating sediment budget. A newly-established sediment rating curve of the present study is proposed to simulate the sediment flux/load into the seas by using those SSC only under discharge of 60000 m3/s at the Datong station-the threshold to significantly correlate to SSC. Since discharge of 60000–80000 m3/s is often linked to extreme flood events and associated sediment depletion in the basin, unincorporating SSC of 60000–80000 m3/s into the sediment rating curve will increase the credibility for sediment load estimation. Using this approach of the present study would indicate the sediment load of 3.3×108–6.6×108 t/a to the seas in the past decades. Also, our analytical result shows a lower sediment flux pattern in the 1950 s, but higher pattern in the 1960 s–1980 s, reflecting the changes in landuse in the upstream of Changjiang basin, including widely devastated deforestation during the middle 20th century.
TL;DR: In this paper, the authors focus on pollution from agricultural sources which share in global pollution, which is high and growing due to both intensification of agricultural activities and ignoring Agricultural Good Practice Code rules by farmers.
Abstract: Poland, like other EU countries, is obliged to implement the Water Framework Directive (2000/60/WE) by the end of 2015. The main objective of the Directive is to provide normative quality of all water resources (surface, underground and coastal sea waters). To reach this goal, reduction of water pollutant emission to the environment is needed. Our project focuses on pollution from agricultural sources which share in global pollution, which is high and growing. This is due to both intensification of agricultural activities and ignoring Agricultural Good Practice Code rules by farmers. In view of the above, this project is expected to provide analysis of selected catchments; especially those exposed to agricultural pollution risk, and propose adjustment strategies for new trends, still keeping in mind environment protection.