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921.
Magdy T. Khalil 《International Journal of Salt Lake Research》1997,6(4):323-330
Four limnological models (lake shoreline development (DL), Morphoedaphic Index (MEI), primary production and total nutrient input) have been applied to Lake Borollus to estimate
existing fish yield and future potential productivity. The estimated existing fish yield from the lake is about 1260 kg/ha
(i.e. 53,000 tons/annum), which is at or near its existing potential and is considered in the ultra enriched category. From
1931 to 1935, the estimated fish production of Lake Borollus was about 68 kg/ha, which is considered low enriched category,
while from1960 to 1970, the lake belonged to the moderately enriched category, where the estimated fish production was about
155 kg/ha, and then tremendously increased to about 580 kg/ha during the 1980's.Thisincrease in fish yield is mainly attributed
to the nutrient loading of the southern and eastern drains to the lake. In the long term, and based on existing nutrient input
to fish yield relationships, it is estimated that increased nutrient loading from drainage water may elevate its yield by
24, 580 tons by the year 2005 (i.e. total fish yield could be increased to 77,500 tons/annum).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
922.
923.
Bred-ensemble ocean forecast of loop current and rings 总被引:1,自引:0,他引:1
Ocean forecasting with a General Circulation Model (GCM) commonly begins from an initial analysis obtained by data assimilation. Instead of a single initial state, bred-ensemble forecast [BEnF; which is used for weather forecasting at the National Centers for Environmental Prediction] begins from an ensemble of initial states obtained by using the GCM to breed fast-growing modes into the analysis. Here we apply the technique to forecast the locations and strengths of the Loop Current and rings from July through September 2005. Model results are compared against satellite observations, surface drifter trajectories, and moored currents. It is found that BEnF gives closer agreements with observations than the conventional single forecast. The bred-vectors (perturbed minus unperturbed state-vectors) have growth rates ≈0.04–0.08 day−1 and spatial (cyclone–anticyclone) scales ≈200–300 km suggestive of baroclinic instability mode in the Loop Current and rings. As in atmospheric applications, initializations with these growing vectors contribute to the more accurate ensemble mean forecast. 相似文献
924.
本文根据野外调查,研究了闽江口琅岐岛土地资源的形成与特点,把它划分为“1纲3类10型”,在此基础上提出了今后开发利用的原则与措施。 相似文献
925.
本文综合叙述了我国海洋开发的现状,从我国海区的区位条件,资源潜势,市场需求,经济基础、基础设施、科技实力等方面探讨了我国海洋经济持续、稳定,高速、协调发展的可能性。 相似文献
926.
An Nd:YAG-based airborne lidar system has been used to measure the optical properties of littoral waters off the northwest Scottish coast. The small-scale structure of subsurface scattering layers was also investigated. Methods of solving the Lidar Sensing Equation in the single scattering approximation are described and the values of the derived extinction indices presented. The extinction index averaged over a series of five flights to the northeast of the Gulf Stream was ε= 0.224 m -1 with a standard deviation of 0.212 m -1 . Further, it was demonstrated that, in coastal waters, optical inhomogeneities with dimensions between 50 m and 200 km obey the power law Sp ε ~ k -P with the parameter P close to two. In turbid or transparent areas, the water extinction index can change by several tenths of a percent with respect to the surrounding water mass. This suggests that the observed nonmonotonic behavior of the power spectra of the water extinction index fluctuations is caused by the outer scale of turbulence, in particular, by the bottom depth at the measurement site. 相似文献
927.
928.
黄、渤海表层沉积物中钙质超微化石有较广泛分布,属种较大洋和开阔海少而单调。黄海南部见有14个种,北黄海及渤海海峡4~5个种,渤海沿岸区2~3个种。钙质超微化石分异度D_H以及主要化石种相对百分含量的高值区的主轴线的走向与现代黄海暖流的流路密切相关。得出黄海暖流由南黄海东南部流入北黄海,通过渤海海峡的北侧进入渤海,在渤海中部呈南北向伸展。 相似文献
929.
The Law of the Sea Convention constrains regional environmental regimes, especially with respect to navigation beyond the territorial sea. Existing soft-law institutions, notably the Arctic Council, have already strengthened environmental governance in the region by (1) improving the knowledge base; (2) preparing practical guidance on risk reduction; (3) highlighting in broader regulatory fora the Arctic dimension of problems like long-range transported hazardous compounds; and (4) supporting the capacity of Arctic states to implement existing commitments. None of those functions would be much enhanced by a legally binding Arctic environmental regime. The political impediments to reaching circumpolar agreement on a single comprehensive legal regime would suggest a flexible approach to norm building that seeks productive interplay with existing institutions. 相似文献
930.
KV法在判定岩体完整性中的应用 总被引:4,自引:0,他引:4
使用某花岗岩体内16个钻孔的资料,用KV法分别对该岩体的强、中等、微风化层的完整性作出判断,并与钻孔揭示的实际情况进行比对,结果证明:在具备大量、较准确的波速测试数据的前提下,用KV法判断岩石的完整性所得出的结论和实际情况几乎完全一致。 相似文献