The Shaerqiaoke Gravel, more than 400 m in thickness, on the north piedmont of the Tianshan Mountains, is located at the exit of the Urümqi River Valley and belongs to the Molasse construction of the Tianshan Mou...The Shaerqiaoke Gravel, more than 400 m in thickness, on the north piedmont of the Tianshan Mountains, is located at the exit of the Urümqi River Valley and belongs to the Molasse construction of the Tianshan Mountains. Another uplift event with the tectonic boundary expansion ended the deposition of the Shaerqiaoke Gravel, and resulted in folding, faulting and down-erosion in the frontier of the deposit. The ESR dating indicates that the top of the Shaerqiaoke Gravel accumulated before 1148 kaBP, probably responding to the Kunlun-Huanghe movement of the Qinghai-Tibetan plateau. After that time, erosion-deposition cycle occurred and 9 terraces developed. The TL and ESR dating techniques were employed to date these terraces, and the results indicate that Terrace 3 was formed at MIS 6. Terrace 2 at Houxia also developed simultaneously. Terraces 5 and 6 were accumulated in 338 kaBP and 562-591 kaBP, respectively. The oldest glaciation, named Gao Wangfeng, correlates to MIS 12.展开更多
Natural cosmogenic tritium or artificial tritium from thermonuclear tests takes the form of HTO to circulate. Before thermonuclear tests, the tritium content in precipitation was meagre, mean value 5—10 TU. After 195...Natural cosmogenic tritium or artificial tritium from thermonuclear tests takes the form of HTO to circulate. Before thermonuclear tests, the tritium content in precipitation was meagre, mean value 5—10 TU. After 1954, however, great influence has apparently been exerted by artificial tritium from numerous thermonuclear tests. In 1963,展开更多
The study is an attempt to design a watershed scorecard by identifying and evaluating selected set of indicators,such as surface water quality,ground water quality,soil condition,agriculture condition,and forest condi...The study is an attempt to design a watershed scorecard by identifying and evaluating selected set of indicators,such as surface water quality,ground water quality,soil condition,agriculture condition,and forest condition,which accurately reflect the health of the watershed.Ur River Watershed in Tikamgarh District,Madhya Pradesh was taken as a case study to assess the watershed health.Evaluation was done by calculating different indices for the selected set of indicators and comparing them with the National standards and guidelines.Based on the performance of each indicator,the grades were assigned to the indicators which helped in designing the watershed scorecard.The results revealed that within the watershed,the forest and soil conditions need a considerable plan for improvement in order to maintain the ecosystem whereas the surface water quality,groundwater quality and the agricultural conditions requires protection as well as enhancement in certain areas.展开更多
基金This work was supported by the Foundation of the Tianshan Glaciology Station, the Chinese Academy of Sciences (Grant No. 9905)the National Natural Science Foundation of China (Grant Nos. 49971080 and 49731010)the Cold and Arid Regions Environment
文摘The Shaerqiaoke Gravel, more than 400 m in thickness, on the north piedmont of the Tianshan Mountains, is located at the exit of the Urümqi River Valley and belongs to the Molasse construction of the Tianshan Mountains. Another uplift event with the tectonic boundary expansion ended the deposition of the Shaerqiaoke Gravel, and resulted in folding, faulting and down-erosion in the frontier of the deposit. The ESR dating indicates that the top of the Shaerqiaoke Gravel accumulated before 1148 kaBP, probably responding to the Kunlun-Huanghe movement of the Qinghai-Tibetan plateau. After that time, erosion-deposition cycle occurred and 9 terraces developed. The TL and ESR dating techniques were employed to date these terraces, and the results indicate that Terrace 3 was formed at MIS 6. Terrace 2 at Houxia also developed simultaneously. Terraces 5 and 6 were accumulated in 338 kaBP and 562-591 kaBP, respectively. The oldest glaciation, named Gao Wangfeng, correlates to MIS 12.
文摘Natural cosmogenic tritium or artificial tritium from thermonuclear tests takes the form of HTO to circulate. Before thermonuclear tests, the tritium content in precipitation was meagre, mean value 5—10 TU. After 1954, however, great influence has apparently been exerted by artificial tritium from numerous thermonuclear tests. In 1963,
文摘The study is an attempt to design a watershed scorecard by identifying and evaluating selected set of indicators,such as surface water quality,ground water quality,soil condition,agriculture condition,and forest condition,which accurately reflect the health of the watershed.Ur River Watershed in Tikamgarh District,Madhya Pradesh was taken as a case study to assess the watershed health.Evaluation was done by calculating different indices for the selected set of indicators and comparing them with the National standards and guidelines.Based on the performance of each indicator,the grades were assigned to the indicators which helped in designing the watershed scorecard.The results revealed that within the watershed,the forest and soil conditions need a considerable plan for improvement in order to maintain the ecosystem whereas the surface water quality,groundwater quality and the agricultural conditions requires protection as well as enhancement in certain areas.
