[Objective] The aim was to assess regional eco-environmental quality by means of grey clustering method based on normalized index value. [Method] Eco-environmental quality in Chaohu basin was assessed by using grey cl...[Objective] The aim was to assess regional eco-environmental quality by means of grey clustering method based on normalized index value. [Method] Eco-environmental quality in Chaohu basin was assessed by using grey clustering method based on normalized index value, and the evaluation results were compared with those of unascertained measure method to verify the feasibility of grey clustering method used to evaluate regional eco-environmental quality. [Result] In the grey clustering assessment method based on normalized index value, indices whose standard normalized values in the same grade were close to each other were classified into one class and had the same whitening function, which reduced the number of whitening functions. Grey clustering method based on normalized index value was used to assess eco-environmental quality in Chaohu basin, and the evaluation results were basically in accordance with those of unascertained measure method, namely eco-environmental quality in Hefei, Chaohu and Lu’an belonged to the third (pass), fourth (worse) and fifth grade (bad), except for one grade difference in overall basin, and the results showed that the method had practicality and could be applied to assess regional eco-environmental quality. [Conclusion] The study could provide theoretical foundation for the establishment of comprehensive management countermeasures of regional ecological environment.展开更多
[Objective] The aim was to evaluate the regional eco-environmental quality by using the universal index formula of parameterization combination operator based normalized index values.[Method] Through setting reference...[Objective] The aim was to evaluate the regional eco-environmental quality by using the universal index formula of parameterization combination operator based normalized index values.[Method] Through setting reference values and normalized transformation formulae for typical ecological environmental indexes appropriately,the difference among the standard normalized values would become very small after normalized transformation,and the ecological environmental indices expressed by normalized values can be equivalent to normalized indices.Under certain optimization conditions,shuffled frog leaping based on immune evolutionary particle swarm optimization algorithm was applied to optimize the parameters in parameterization combination operator formula,and the universal index formula suited to eco-environmental quality assessment was established finally.[Result] The universal index formula of parameterization combination operator,appropriate for any m(1≤m≤23) ecological environmental indices,was used to assess the eco-environmental quality of towns surrounding Headland Reservoir,and the results were in full accordance with those of unascertained measure method,that is,the eco-environmental quality of five towns around Headland Reservoir was the fourth grade.[Conclusion]The universal index formula of parameterization combination operator,suited to eco-environmental quality evaluation,is simple and intuitive in form,easy in computation and universal in application.展开更多
The presence of shale oil in the Cretaceous Hengtongshan Formation in the Tonghua Basin, drilled by the well TD-01, has been discussed in this geological investigation for the first time. To evaluate the high-quality ...The presence of shale oil in the Cretaceous Hengtongshan Formation in the Tonghua Basin, drilled by the well TD-01, has been discussed in this geological investigation for the first time. To evaluate the high-quality source rocks of Cretaceous continental shale oil, the distribution characteristics and the evolution of the ancient environment, samples of shale were systematically analyzed in terms of sedimentary facies, organic geochemistry, and organic carbon isotopic composition. The results demonstrate that a TOC value of 1.5% represents the lower-limit TOC value of the high-quality source rocks. Source rocks have an aggregate thickness of 211 m and contain abundant organic matter, with TOC values of 2.69% on average and a maximum value over 5.44%. The original hydrocarbon-generative potential value(S_1+S_2) is between 0.18 mg/g and 6.13 mg/g, and the Ro is between 0.97% and 1.40%. The thermal maturation of the source rocks is relatively mature to highly mature. The δ^(13)C value range is between -34.75‰ and -26.53‰. The ratio of saturated hydrocarbons to aromatic hydrocarbons is 1.55 to 5.24, with an average of 2.85, which is greater than 1.6. The organic types are mainly type Ⅱ_1, followed by type Ⅰ. The organic carbon source was C_3 plants and hydrophytes. The paleoclimate of the Hengtongshan Formation can be characterized as hot and dry to humid, and these conditions were conducive to the development of high-quality source rocks. A favorable paleoenvironment and abundant organic carbon sources provide a solid hydrocarbon generation base for the formation and accumulation of oil and gas in the shale of the Tonghua Basin.展开更多
基金Supported National Natural Science Foundation of China(50739002)
文摘[Objective] The aim was to assess regional eco-environmental quality by means of grey clustering method based on normalized index value. [Method] Eco-environmental quality in Chaohu basin was assessed by using grey clustering method based on normalized index value, and the evaluation results were compared with those of unascertained measure method to verify the feasibility of grey clustering method used to evaluate regional eco-environmental quality. [Result] In the grey clustering assessment method based on normalized index value, indices whose standard normalized values in the same grade were close to each other were classified into one class and had the same whitening function, which reduced the number of whitening functions. Grey clustering method based on normalized index value was used to assess eco-environmental quality in Chaohu basin, and the evaluation results were basically in accordance with those of unascertained measure method, namely eco-environmental quality in Hefei, Chaohu and Lu’an belonged to the third (pass), fourth (worse) and fifth grade (bad), except for one grade difference in overall basin, and the results showed that the method had practicality and could be applied to assess regional eco-environmental quality. [Conclusion] The study could provide theoretical foundation for the establishment of comprehensive management countermeasures of regional ecological environment.
基金Supported by Groundwork Project of Science and Technology(2009IM020100)National Natural Science Foundation of China(50779042,50739002,41101542)
文摘[Objective] The aim was to evaluate the regional eco-environmental quality by using the universal index formula of parameterization combination operator based normalized index values.[Method] Through setting reference values and normalized transformation formulae for typical ecological environmental indexes appropriately,the difference among the standard normalized values would become very small after normalized transformation,and the ecological environmental indices expressed by normalized values can be equivalent to normalized indices.Under certain optimization conditions,shuffled frog leaping based on immune evolutionary particle swarm optimization algorithm was applied to optimize the parameters in parameterization combination operator formula,and the universal index formula suited to eco-environmental quality assessment was established finally.[Result] The universal index formula of parameterization combination operator,appropriate for any m(1≤m≤23) ecological environmental indices,was used to assess the eco-environmental quality of towns surrounding Headland Reservoir,and the results were in full accordance with those of unascertained measure method,that is,the eco-environmental quality of five towns around Headland Reservoir was the fourth grade.[Conclusion]The universal index formula of parameterization combination operator,suited to eco-environmental quality evaluation,is simple and intuitive in form,easy in computation and universal in application.
基金supported by the National Natural Science Foundation of China(grants No.41430322 and 41472304)a project of the Key-Lab for Evolutionof Past Lift and Environment in Northeast Asia,Ministry of Education,China
文摘The presence of shale oil in the Cretaceous Hengtongshan Formation in the Tonghua Basin, drilled by the well TD-01, has been discussed in this geological investigation for the first time. To evaluate the high-quality source rocks of Cretaceous continental shale oil, the distribution characteristics and the evolution of the ancient environment, samples of shale were systematically analyzed in terms of sedimentary facies, organic geochemistry, and organic carbon isotopic composition. The results demonstrate that a TOC value of 1.5% represents the lower-limit TOC value of the high-quality source rocks. Source rocks have an aggregate thickness of 211 m and contain abundant organic matter, with TOC values of 2.69% on average and a maximum value over 5.44%. The original hydrocarbon-generative potential value(S_1+S_2) is between 0.18 mg/g and 6.13 mg/g, and the Ro is between 0.97% and 1.40%. The thermal maturation of the source rocks is relatively mature to highly mature. The δ^(13)C value range is between -34.75‰ and -26.53‰. The ratio of saturated hydrocarbons to aromatic hydrocarbons is 1.55 to 5.24, with an average of 2.85, which is greater than 1.6. The organic types are mainly type Ⅱ_1, followed by type Ⅰ. The organic carbon source was C_3 plants and hydrophytes. The paleoclimate of the Hengtongshan Formation can be characterized as hot and dry to humid, and these conditions were conducive to the development of high-quality source rocks. A favorable paleoenvironment and abundant organic carbon sources provide a solid hydrocarbon generation base for the formation and accumulation of oil and gas in the shale of the Tonghua Basin.
