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111.
112.
AbstractThis study modified the BTOPMC (Block-wise TOPMODEL with the Muskingum-Cunge routing method) distributed hydrological model to make it applicable to semi-arid regions by introducing an adjustment coefficient for infiltration capacity of the soil surface, and then applied it to two catchments above the dams in the Karun River basin, located in semi-arid mountain ranges in Iran. The application results indicated that the introduced modification improved the model performance for simulating flood peaks generated by infiltration excess overland runoff at a daily time scale. The modified BTOPMC was found to fulfil the need to reproduce important signatures of basin hydrology for water resource development, such as annual runoff, seasonal runoff, low flows and flood flows. However, it was also very clear that effective model use was significantly constrained by the scarcity of ground-gauged precipitation data. Considerable efforts to improve the precipitation data acquisition should precede water resource development planning.Editor D. Koutsoyiannis 相似文献
113.
A. A. Peyve S. G. Skolotnev M. Ligi N. N. Turko E. Bonatti S. Yu. Kolodyazhnyi N. P. Chamov N. V. Tsukanov Yu. E. Baramykov A. E. Eskin N. Grindlay J. G. Sclater D. Brunelly A. N. Pertsev A. Cipriani G. Bortoluzzi R. Mercuri E. Paganelli F. Muccini Ch. Takeuchi F. Zaffagnini K. O. Dobrolyubova 《Doklady Earth Sciences》2007,416(1):991-994
114.
115.
Tests for the acute toxicity of tributyltin (TBT) were conducted on amphipod crustaceans collected from Otsuchi Bay, Japan. Five species of caprellids and three species of gammarids, which belong to a closely related ecological niche, were used for the exposure experiments at seven test concentrations (0, 0.001, 0.01, 0.1, 1, 10 and 100 microg TBTCl/l) for 48 h at 20 degrees C. The 48-h LC50 values of the caprellids were 1.2-6.6 microg TBTCl/l, and these were significantly lower than those of the gammarids (17.8-23.1 microg TBTCl/l). This suggests that caprellids are more sensitive to TBT than gammarids. Furthermore, the proportions of TBT and its derivatives, dibutyltin (DBT) and monobutyltin (MBT), were measured in the amphipods collected from Otsuchi Bay. In the caprellids, TBT was the predominant compound, accounting for 72% of the total butyltin which reflected the butyltin ratio in seawater, while in the gammarids, TBT's breakdown products (DBT and MBT) predominated, accounting for 75% of the total butyltin. This difference suggests that caprellids may have lower metabolic capacity to degrade TBT than gammarids. Therefore, the difference in sensitivity to TBT among the amphipods is thought to be related to the species-specific capacity to metabolize TBT. 相似文献
116.
XiaoYu Zhang ShengJie Wang Xin Zhang Ping Zhou Shuang Jin ZhongQin Li Nozomu Takeuchi 《寒旱区科学》2017,9(5):455-466
Aerosol samples were collected at altitudes from 584 m a.s.l.to 3,804 m a.s.l.at seven sites of the eastern Tianshan.The occurrence,distribution,and possible sources of 47 trace metals—including alkali metals and alkali earth metals,transition metals,lanthanoids,and heavy metals—were investigated.It was found that four sampling sites(Shuinichang,1,691 m a.s.l.;Urumqi City,809 m a.s.l.;Fu Kang Station,584 m a.s.l.;and Bogeda Glacier No.4,3,613 m a.s.l.)were contaminated mainly by heavy metals.Other three high-altitude sites(Urumqi Glacier No.1,3,804 m a.s.l.;Wang Feng road-maintenance station,3,039 m a.s.l.;and Tianshan Glaciology Station,2,135 m a.s.l.)were not polluted.The aerosol particles were clustered into two dominant types:crust-originated particles and pollution-derived particles.Aerosols from UG1,WF,and TGS were characterized by crust-originated particles such as clay,plagioclase,dolomite,alkali feldspar,and biotite;while those from SNC,Urumqi,FK,and BG4 were characterized by high content of Cl-rich particles,S-rich particles,and soot.The backward-trajectories results indicated that air masses arriving at SNC,Urumqi,FK,and BG4 were identified as the more polluted source,when compared to the short-range air mass transport from the North to UGI and WF.Relatively lower altitude,as well as terrain blocking,might be another important reason for the gradient difference in pollution influence among these seven places in the Urumqi River Basin. 相似文献
117.
In the southwestern Okhotsk Sea off Hokkaido we observed chemical components related to the carbonate system for 1 year from
August 1997 to June 1998. Using the conservative components salinity and water temperature, we confirmed the existence of
two water masses flowing into the intermediate layer of the Okhotsk Sea, the East Sakhalin Current Water (ESCW) which becomes
denser by mixing of brine water, and the Forerunner of Soya Warm Current Water (FSWW) which becomes denser due to cooling
of the saline Kuroshio water. The ΔNTCx values were calculated by comparing the ESCW and the FSWW with the Pacific Deep Water (PDW). The ΔNTCx values obtained are 100–110 μmol/kg and 70–100 μmol/kg for the ESCW and the FSWW off Hokkaido, respectively, which are considerably
larger than that of the Kuroshio water. These large ΔNTCx values may be due to both low DIC concentration in the surface water and intense gas exchange under the cold and stormy winter
conditions for the ESCW and the cooling of the FSWW as it flows northward. Since the flow rates of dense waters concerned
with the ESCW and the FSWW have previously been estimated as 0.9 Sv and 0.2 Sv, respectively, the amount of atmospheric CO2 absorbed and transported to the intermediate layer turns out to be 3.9−4.1 × 1013 gC/yr. This flux is small on a global scale, but the flux divided by the surface layer of the Okhotsk Sea is 30 gC/m2/yr, which is 5 times greater than the mean absorption flux of anthropogenic CO2 in the world's oceans. It is thus considered that atmospheric CO2 is efficiently absorbed in the Okhotsk Sea.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
118.
The Richardson number dependence of vertical eddy diffusion coefficients in the western Equatorial Pacific Ocean was examined on the basis of a Microstructure Profiler (MSP) observations during the cruise of Natsushima (JAPACS-89). The Richardson numberR
i
was estimated by using the mean shear of velocity profile measured by an Acoustic Doppler Current Profiler (ADCP) with the vertical interval of 15 meters within one or two hours of the each MSP cast. The raw data plot of the vertical eddy diffusion coefficientK
p
shows a large scatter with increasing tendency belowR
i
=0.5. The relation between the mean vertical eddy diffusion coefficientK
p
and the Richardson numberR
i
, averaged over every 0.025 in theR
i
, supports the model of Pacanowski and Philander (1981) in the range ofR
i
>0.5, but coincides with the result of Peterset al. (1988) in the range ofR
i
<0.5. 相似文献
119.
Yuichi Koike Yuzuru Nakaguchi Keizo Hiraki Terufumi Takeuchi Tomoyoshi Kokubo Takashi Ishimaru 《Journal of Oceanography》1993,49(6):641-656
A red tide due toGymnodinium nagasakiense was observed in August 1988 in Tanabe Bay, Wakayama Prefecture, Japan. The maximum cell concentration ofG. nagasakiense reached 1×105 cells ml–1 at the surface water. From May to September 1988, the following were monitored: water temperature, salinity, chlorophylla, D.O., dissolved nutrients (NO2–N, NO3–N, NH4–N, PO4–P DON, DOP), particulate nutrients (PON, POP) and three dissolved selenium species [Se(IV), Se(VI), Organic Se]. Dissolved inorganic nitrogen (NO3–N, NH4–N) decreased but PON, POP, DON, DOP and inorganic phosphate increased at the peak of the bloom. The concentration of organic selenium increased up to the bloom initiation period which started on 5 July, and then the concentration of Se(IV) increased as the concentration of organic selenium decreased at the peak of the bloom (3 August). The strong relationship was found between the concentration of Se(IV) and the cell concentration ofG. nagasakiense (r
2=0.98). The Se(IV) requirement ofG. nagasakiense was 2.89×10–17 moles cell–1, which was agreed well with 4.4×10–17 moles cell–1 found in a laboratory experiment onG. nagasakiense using selenium spiked artificial sea water medium. The average ratio of Se(IV) to dissolved inorganic nitrogen (DIN) during the red tide bloom was 11441, the ratio of Se(IV) to DIN at the surface with the maximum cell concentration ofG. nagasakiense of 1×105 cells ml–1 was 1137. These results suggested that selenium may play an important role in red tide outbreak ofG. nagasakiense. 相似文献
120.
Radii and angular velocities in the motions of drifting buoys deployed in the Kuroshio are estimated by fitting circles to the trajectories of two drifting buoys, one with a drogue at 300 m depth and the other at 800 m depth. The buoys were deployed in the Kuroshio where it was flowing counter-clockwise around the large cold water mass south of Honshu. The same technique was applied to two drifting buoys with drogues at 300 m depth placed in the Kuroshio where it flowed clockwise around Oshima Island in Sagami Bay. The centrifugal forces were 7% and 6% as large as the Coriolis forces in the Kuroshio around the cold water mass, and they were –56% and –42% as large as the Coriolis forces in the current around the Oshima Island. The temperature gradient observed in the Oshima-West Channel suggested that the pressure gradient there was smaller due to the centrifugal force acting against the Coriolis force than the pressure gradient to be balanced with the Coriolis force. 相似文献