Nitrate pollution from agriculture in different hydrogeological zones of the regional groundwater flow system in the North China Plain   总被引：13，自引：2，他引：11  

Jianyao Chen  Changyuan Tang  Yasuo Sakura  Jingjie Yu  Yoshihiro Fukushima 《Hydrogeology Journal》2005,13(3):481-492

A survey of the quality of groundwater across a broad area of the North China Plain, undertaken in 1998 to 2000, indicates that nitrate pollution is a serious problem affecting the drinking water for a vast population. The use of nitrogen (N)-fertilizer in agriculture has greatly increased over the past 20 years to meet the food needs of the rapidly expanding population. During the study, 295 water samples were collected from wells and springs to determine the water chemistry and the extent of nitrate pollution. High concentrations of nitrate, especially in a recharge area along the western side, but also in the vicinity of Beijing and locally in other parts of the plain, pose a serious problem for the drinking water supply. In places, the nitrate concentration exceeds the maximum for safe drinking water of 45 mg/L. The intense use of N-fertilizer and the widespread use of untreated groundwater for crop irrigation contribute greatly to the problem, but no doubt the disposal of industrial and municipal waste into streams and infiltrating the aquifer also contribute to the problem; however, the lack of data prevents evaluation of those sources. In the recharge area, nitrate is found at depths of as much as 50 m. Near Beijing, relatively high concentrations of nitrate occur at depths of as much as 80 m. In the discharge area, in the vicinity of the Yellow River, high concentrations of nitrate occur at depths of <8 m.

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Electronic Supplementary Material Supplementary Material is available in the online version of this article at

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Resumen Contaminacíon de nitratos a causa de prácticas agrícolas en diferentes zonas hidrogeológicas del sistema de flujo regional de aguas subterráneas en la planice del norte de China. Un estudio de la calidad del agua subterránea en una zona amplia de la planice del norte de China se llevó a cabo entre 1998 y el año 2000. Este estudio indica que la contaminación de nitratos es un problema grave que afecta el agua potable de una vasta población. El uso de fertilizantes a base de nitratos en la agricultura ha aumentado considerablemente durante los últimos 20 años para satisfacer las necesidades alimentices de la creciente población. Durante el estudio, se tomaron 295 muestras de pozos de agua y manantiales para determinar la química de las aguas y el grado de contaminación por nitratos. Altas concentraciones de nitratos, especialmente en una zona de recarga a lo largo del lado oeste, asì como en la cercanía a Pekín y en zonas locales en otras partes de la planicie, presentan un problema serio al sumunistro de agua potable. En ciertos lugares, la concentracióon de nitratos excede el nivel máximo de seguridad para el agua potable 45 mg NO₃/L. El intenso uso de fertilizantes de nitratos y el abundante uso de agua subterránea sin tratamiento para la irrigación de cultivos contribuyen sustancialmente al problema. Sin embargo, sin lugar a dudas, la descarga de deshechos industriales y municipales en arroyos y en el acuífero también contribuyen al problema. La falta de datos impide la evalución de dichas fuentes. En la zona de recarga se encuentran nitratos hasta los 50 m de profundidad. Cerca a Pekín, concentraciones relativamente altas de nitrato ocurren hasta los 80 m de profunidad. En las zonas de descarga afectadas por el Río Amarillo las concentraciones altas de nitrato se encuentran solamente a menos de 8m de profundidad.

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Resumé Une campagne dévaluation de la qualité de leau souterraine entreprise entre 1998 et 2000 à travers une vaste étendue de la plaine du nord en Chine indique que la pollution par les nitrates est un problème sérieux qui affecte la qualité de leau souterraine pour une abondante population. Lutilisation de fertilisants azotés pour lagriculture a augmenté considérablement durant les 20 dernières années afin de rencontrer les besoins alimentaires dune population à forte croissance. Lors de cette étude, 295 échantillons deau ont été prélevés dans des puits et sources naturelles afin de déterminer la composition chimique de leau souterraine ainsi que létendue de la pollution par les nitrates. Des concentrations élevées de nitrates, en particulier dans une zone de recharge le long de la limite ouest de la plaine, mais aussi dans la région de Beijing et sporadiquement dans la plaine, posent de sérieux problèmes à la consommation de leau souterraine. A certains endroits, la concentration en nitrates excède la valeur maximale acceptée pour la consommation qui est de 45 mg NO₃/L. Lutilisation intensive de fertilisants azotés ainsi que lutilisation répandue deau souterraine non traitée pour lirrigation contribuent pour beaucoup au problème, mais il ne fait pas de doute que le rejet des déchets municipaux et industriels dans les rivières et aquifères y est aussi pour quelque chose. Par contre, le manque de donnés ne permet pas dévaluer la contribution de chacune de ces sources. Dans la zone de recharge, les nitrates se retrouvent à des profondeurs allant jusquà 50 m. Près de Beijing, des concentrations relativement élevées de nitrate ont été mesurées à des profondeurs allant jusquà 80 m. Enfin, dans la zone démergence affectée par la rivière Jaune, les fortes concentrations se retrouvent à une profondeur maximale de 8 m.

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Searching for novel CYP members using cDNA library from a minke whale liver     

Kim EY  Iwata H  Fujise Y  Tanabe S 《Marine environmental research》2004,58(2-5):495-498

The contaminant-induced cytochrome P450 (CYP) members in minke whale (Balaenoptera acutorostrata) can be potential biomarkers of the contaminant exposure and toxic effects. In this study, we constructed a cDNA library from the liver of minke whale from the North Pacific, and further screened a total of 6930 clones randomly selected in the library for the isolation of cDNA clones encoding novel members of CYP superfamily. The screening revealed the isolation of six novel CYP cDNA clones that are classified into CYP1A, CYP2C, CYP2E, CYP3A, CYP4, and CYP4A subfamilies. The BLAST homology search using the partial cDNA fragments of four CYP subfamilies (CYP1A, CYP2C, CYP2E and CYP4A) demonstrated that the minke whale CYPs were most closely related to pig CYPs (81-91%). Identification of multiple CYP genes in marine mammal species such as minke whale will provide new insights into the metabolic or toxicological functions of individual CYP members.  相似文献   

Water exchange in Kabira Cove,Ishigaki Island     

Yoshihiro Mazda 《Journal of Oceanography》1983,39(2):63-72

The mechanism and rate of water exchange were investigated in Kabira Cove, Ishigaki Island, in the southernmost part of Japanese islands, near Taiwan. During observations in the summers of 1976 and 1977, a larger proportion of the salt transport into the bay was derived from the so-called “tidal trapping effect”. In the latter period of observation carried out after heavy rain brought by a seasonal typhoon under annual mean tidal conditions, the turnover time, i.e. the scale of replacement of the whole bay water with the open sea water, is estimated to be 3.6 days. Based on these observational results, a concept of the tidal trapping due to coupling of the actions of tides and buoyancy in a vertical two-dimensional field with a sill at the bay mouth is proposed. Considering the topographical, hydrometeorological and geographical conditions of the cove, it is inferred that this water exchange process tends to be formed in Kabira Cove in summer except during neap tides.  相似文献   

Year-to-year change in water exchange characteristics in a semi-enclosed bya,Lake Hamana     

Yoshihiro Mazda 《Journal of Oceanography》1984,40(3):199-206

The year-to-year change in characteristics of water exchange between Lake Hamana, a semi-enclosed bya, and the adjacent open sea is investigated.The destruction of the bay mouth by a typhoon in 1953 and subsequent stabilization work on the bay mouth from 1954 to 1973 resulted in an increase in the tidal prism volume of the bay (Mazda, 1983). In the present paper, a simple model has been constructed in which the magnitude of water exchange depends on the tidal prism, and using this model, the year-to-year increase in salinity of the bay water after 1953 can be well explained. Consequently, it can be said that the salinity increase after 1953 is a result of a progressive increase in water exchange caused by successive changes in topography of the bay mouth.The extent of water exchange in Lake Hamana, which varies seasonally, has increased gradually since 1953, and became stable after about 1967. For instance, at present the turnover time of the bay for exchange with open sea water reaches a maximum (2.9 months) in January and a minimum (0.9 month) in October, while in 1955 it is estimated to have been about 2.5 times that at the present time.  相似文献   

Vertical two-dimensional mechanism of tidal exchange in a bay with a sill-entrance     

Yoshihiro Mazda 《Journal of Oceanography》1985,41(4):225-234

For a vertical two-dimensional field with a sill at a bay entrance, the tidal exchange mechanism is discussed.The schematic model is proposed as follows. The tidal trapping effect which is detected at the entrance section,i. e., the material transport due to the phase difference between the tidal periodic constituent of material concentration and tidal current at the entrance section, results because the oscillatory tidal flow at the sill entrance induces a gravitational flow along the sill slope inside the entrance. Accordingly, the tidal trapping effect depends largely upon the difference in water density between the bay and open sea and the density stratification in the bay.This model is supported by the observations at Kabira Cove (Okinawa Pref.) and Lake Hamana (Shizuoka Pref.) in 1976 through 1984. In addition, based on this model, in the case of Lake Hamana, the activity of the tidal exchange is inferred to change seasonally.  相似文献   

Recycling of Coal Fly Ash and Paper Waste to Improve Low Productive Red Soil in Okinawa,Japan     

Guttila Yugantha Jayasinghe  Yoshihiro Tokashiki  Kazuthoshi Kinjo 《洁净——土壤、空气、水》2009,37(9):687-695

Coal fly ash (CFA) and paper waste (PW) related environmental problems and its recycling techniques have been a major challenge to society. Therefore, it is of crucial importance to develop new recycling methods for CFA and PW. This work proposes a potential new way of developing synthetic aggregates (SA) using CFA, PW, starch waste and ammonium sulfate (AS) as a granular nitrogen fertilizer medium, and their utilization as a soil amendment to improve crop production in the low productive acidic red soil of Okinawa, Japan. Three types of SA with three different nitrogen (N) percentages were produced and used to amend acidic red soil in a pot experiment for the cultivation of Komatsuna, which is also called as Japanese mustard spinach (Brassica rapa var. pervidis). SA had a low bulk density (0.58–0.62 g/cm³), high water holding capacity (0.60–0.64 kg/kg), high saturated hydraulic conductivity (2.34·10^–2 cm/s), high mean weight diameter (MWD) (4.32–4.48 mm), alkaline pH (8.58–8.61), high electrical conductivity (EC) (82.18–84.35 mS/m) and high carbon (C) content (68.71–70.07 g/kg) in comparison with the acidic red soil. The trace element concentrations of the developed SA were below the maximum pollutant concentration of individual metals for land application of sewage sludge given by the US Environmental Protection Agency. Scanning electron microscopic (SEM) studies showed the higher structural surface area of SA, where round shaped CFA particles were embedded into the fibrous PW matrix. Incorporation of SA into the acidic red soil not only enhanced soil fertility but also improved the physical and chemical properties of the soil compared to soil without SA addition. SA addition to the acidic red soil significantly increased the growth and yield parameters of Komatsuna compared to soil without SA addition.  相似文献   

慢地震与深部不连续颤动和慢滑事件同时发生     

Yoshihiro Ito  Kazushige Obara  Shutaro Sekine  Hitoshi Hirose  乔迎春 《国际地震动态》2009,(10):23-27

我们对日本西南部南海俯冲板块界面过渡带发生的超低频地震进行报道。由矩震级为3.1～3.5的超低频地震引起的地震波显示其卓越长周期约为20s。超低频地震活动伴随深源低频颤动和慢滑事件同时发生,并随之移动。慢地震一直被认为会增加向上倾斜的大型逆冲地震断裂带上的应力,而这3种现象的同时发生提高了人们对慢地震的探测和特性鉴定水平。  相似文献   

Nickel–bearing Djerfisherite in Gehlenite-Spurrite Skarn at Kushiro, Hiroshima Prefecture, Japan     

Yasushi TAKECHI  Isao KUSACHI  Yoshihiro NAKAMUTA  Katsuo KASE 《Resource Geology》2000,50(3):179-184

Abstract: Djerfisherite occurs intimately intergrown with troilite and pentlandite in gehlenite-spurrite skarn at Kushiro, mainly as inclusions in gehlenite and andradite grains. The mode of occurrence indicates that the djerfisherite formed in the culminated stage of the contact metamorphic-metasomatic process. The chemical compositions of the mineral are approximately represented by a formula of K₆Na(Fe, Ni, Cu)₂₄S₂₆Cl with Ni up to 4. 85. It is likely that high temperature condition corresponding to the formation of gehlenite-spurrite skarn as well as low f_O2 and f_S2 conditions are responsible for the formation of djerfisherite in the potassium-rich chemical environments.  相似文献   

Depositional and diagenetic history of limestones and dolostones of the Oligo‐Miocene Kujung Formation in the Northeast Java Basin,Indonesia     

Muhlash Hada Firman Syah  Akihiro Kano  Tsuyoshi Iizuka  Yoshihiro Kakizaki 《Island Arc》2019,28(6)

Lithological and geochemical features of platformal carbonates record the signatures of the global climates and the regional environmental settings and also reconstruct the diagenetic history and porosity evolution, which are essential to evaluate the potential of hydrocarbon reservoirs. This study investigates the platformal carbonates of the Oligo‐Miocene Krunji Formation of North East Java Basin, which are potentially significant hydrocarbon reservoirs. The carbonate sequence in a 283 m thick section at Kranji in East Java is subdivided into three lithological units: limestone unit 1, dolostone unit 2, and limestone unit 3, in ascending order. The strontium‐isotope ratios of well‐preserved calcite samples indicate the depositional period from Chattian (late Oligocene) to Burdigalian (early Miocene), which is consistent with ages of the foraminifer assemblages. Unit 1 consists of low‐porosity limestone, in which two horizons of subaerial exposure are recognized by the occurrence of red‐colored matrix and lower δ¹³C values. Unit 2 consists of dolomitic rock and exhibits coarse‐grained calcitic grains and cross‐stratified structure. Considering that this unit has been subject to dolomitization, the sediment of unit 2 was initially permeable and was likely deposited in a shoal setting. The overlying unit 3 of Aquitanian–Burdigalian age is characterized by a highly granular texture. High porosity and uniformly low δ¹³C and δ¹⁸O values indicate that Unit 3 was subjected to more intense meteoric diagenesis than the Chattian unit 1. This was likely a consequence of the Antarctic ice‐sheet expansion during the Oligocene/Miocene transition, which amplified sea level change. The unit 2 dolomite has high δ¹³C and δ¹⁸O values and a high ⁸⁷Sr/⁸⁶Sr ratio which resulted from the reflux of seawater into permeable the sediment body in middle‐late Miocene (Burdigalian Tortonian) following the deposition of unit 3. The porosity and permeability of the Kujung Formation were initially controlled by sedimentological processes, but largely modified by later diagenetic processes.  相似文献   

Natural and experimental structural evolution of dispersed organic matter in mudstones: The Shimanto accretionary complex,southwest Japan     

Yoshihiro Nakamura  Hidetoshi Hara  Hiroyuki Kagi 《Island Arc》2019,28(5)

Structural changes induced by thermal maturation of dispersed organic matter (OM) in the Shimanto accretionary complex, southwest Japan, were investigated using micro‐Fourier‐transform infrared spectroscopy and micro‐Raman spectroscopy. Natural dispersed OM exhibits systematic structural changes inferred from D1‐ and G‐band FWHM values, Raman band separation (RBS), and intensity ratios of the D1‐ and G‐bands (I_D1/I_G ratio) from diagenetic zone to anchizone (IC values: 0.75–0.30). Infrared spectra indicate a loss of aliphatic CH _x, aromatic CH _x, and oxygen‐containing structures as temperature increases. These changes are consistent with discontinuities in thermal structures bounded by out‐of‐sequence thrusts. Kinetic pyrolysis experiments indicate that the I_D1/I_G ratio of synthesized OM has a power law relationship with heat treatment time. Kinetic models of temperature dependence were fitted using the I_D1/I_G ratio, and an effective activation energy of 106 ±17 kJ/mol was estimated using an Arrhenius equation. The activation energies estimated by power law rate and Avrami models have a least‐square correlation coefficient of 0.93, indicating the temperature dependence of carbonization. The estimated effective activation energy is consistent with that of coal, lignin, cellulose, and hemicellulose during thermal degradation. On the other hand, RBS, and D1‐ and G‐band FWHM values of OM display more complex changes with increasing heating temperature and time, and it is difficult to constrain rate parameters during pyrolysis experiments. Our data indicate that the I_D1/I_G ratio is controlled by a simple thermally activated process, whereas RBS and D1‐ and G‐band FWHM values can be affected by lithostatic pressure, fluid activity, hydrogen index, and host lithology, as well as temperature. Structural evolution of dispersed OM in mudstones differs between natural and anhydrous closed experimental systems. Natural carbonization based on micro‐Raman spectroscopy should be applied for a limited indicator of thermal maturation, especially for dispersed OM in diagenetic zone.  相似文献