AIM:To evaluate the association between genetic polymorphisms in CYP2E1, ALDH2 and ADH1B and the risk of esophageal squamous cell carcinoma (ESCC) in a high risk area of Gansu Province, in Chinese males. METHODS: A ca...AIM:To evaluate the association between genetic polymorphisms in CYP2E1, ALDH2 and ADH1B and the risk of esophageal squamous cell carcinoma (ESCC) in a high risk area of Gansu Province, in Chinese males. METHODS: A case-control study was conducted to investigate the genetic polymorphisms of these enzymes (CYP2E1 *c1/*c2, ALDH2 *1/*2 and ADH1B *1/*1 genotypes). A total of 80 esophageal cancer cases and 480 controls were recruited. RESULTS: Compared with controls, cases had a greater prevalence of heavier alcohol consumption (53.8% vs 16.2%) and a higher proportion of alcohol drinkers with > 30 drink-years (28.8% vs 13.5%). Heavier alcohol consumption and alcohol drinking with > 30 drink- years increased the risk of ESCC, with ORs (95% CI) of 3.20 (1.32-9.65) and 1.68 (0.96-3.21). CYP2E1 (*c1/*c1), ALDH2 (*1/*2) and ADH1B (*1/*1) genotype frequencies were higher among patients with squamous cell carcinomas, at a level close to statistical significance (P = 0.014; P = 0.094; P = 0.0001 respectively). There were synergistic interactions among alcohol drinking and ALDH2, ADH1B and CYP2E1 genotypes. The risk of the ESCC in moderate-to-heavy drinkers with an inactive ALDH2 encoded by ALDH2 *1/*2 as well as ADH1B encoded by ADH1B *1/*1 and CYP2E1 encoded by CYP2E1 *c1/*c1 was higher than that in the never/rare-to-light drinkers with an active ALDH2 (*1/*1 genotype) as well as ADH1B (*1/*2 + *2/*2) and CYP2E1 (*c1/*c2 + *c2/*c2) genotypes, with a statistically significant difference; ORs (95% CI) of 8.58 (3.28-22.68), 27.12 (8.52-70.19) and 7.64 (2.82-11.31) respectively. The risk of the ESCC in moderate-to-heavy drinkers with ALDH2 (*1/*2) combined the ADH1B (*1/*1) genotype or ALDH2 (*1/*2) combined the CYP2E1 (*c1/*c1) genotype leads to synergistic interactions, higher than drinkers with ALDH2 (*1/*1) + ADH1B (*1/*2 + *2/*2), ALDH2 (*1/*1) + CYP2E1 (*c1/*c2 + *c2/*c2) respectively , ORs (95% CI) of 7.46 (3.28-18.32) and 6.82 (1.44-9.76) respectively. Individuals with the ADH1B combined the CYP2E1 genotype showed no synergistic interaction. CONCLUSION: In our study, we found that alcohol consumption and polymorphisms in the CYP2E1, ADH1B and ALDH2 genes are important risk factors for ESCC, and that there was a synergistic interaction among polymorphisms in the CYP2E1, ALDH2 and ADH1B genes and heavy alcohol drinking, in Chinese males living in Gansu Province, China.展开更多
Three new Tenthredinidae species are reported from Gansu and three from Qinghai Provinces of China. Tenthredo (Tenthredo) sinotemula sp. nov., Tenthredo (Tenthredella) labrangensis sp. nov. and Tenthredo (Tenthre...Three new Tenthredinidae species are reported from Gansu and three from Qinghai Provinces of China. Tenthredo (Tenthredo) sinotemula sp. nov., Tenthredo (Tenthredella) labrangensis sp. nov. and Tenthredo (Tenthredella) sinosimplex sp. nov. are described from Gansu, Tenthredo (Tenthredella) rolleri sp. nov., Tenthredo (Tenthredella) qinghaiensis sp. nov. and Tenthredo (Tenthredella) yunningsiensis sp. nov. from Qinghai Province.展开更多
Bailongjiang watershed in southern Gansu province, China, is one of the most landslide-prone regions in China, characterized by very high frequency of landslide occurrence. In order to predict the landslide occurrence...Bailongjiang watershed in southern Gansu province, China, is one of the most landslide-prone regions in China, characterized by very high frequency of landslide occurrence. In order to predict the landslide occurrence, a comprehensive map of landslide susceptibility is required which may be significantly helpful in reducing loss of property and human life. In this study, an integrated model of information value method and logistic regression is proposed by using their merits at maximum and overcoming their weaknesses, which may enhance precision and accuracy of landslide susceptibility assessment. A detailed and reliable landslide inventory with 1587 landslides was prepared and randomly divided into two groups,(i) training dataset and(ii) testing dataset. Eight distinct landslide conditioning factors including lithology, slope gradient, aspect, elevation, distance to drainages,distance to faults, distance to roads and vegetation coverage were selected for landslide susceptibility mapping. The produced landslide susceptibility maps were validated by the success rate and prediction rate curves. The validation results show that the success rate and the prediction rate of the integrated model are 81.7 % and 84.6 %, respectively, which indicate that the proposed integrated method is reliable to produce an accurate landslide susceptibility map and the results may be used for landslides management and mitigation.展开更多
The calculation of Ecological Footprint (EF) on the basis of Input-Output model (I-O model) was advanced by Bicknell, and modified and improved hy Ferng who corrected the footprint's aggregation to each sectors. ...The calculation of Ecological Footprint (EF) on the basis of Input-Output model (I-O model) was advanced by Bicknell, and modified and improved hy Ferng who corrected the footprint's aggregation to each sectors. For the lack of sufficient teehnique to deal with the trade between the research areas and the rest of the world, it it necessary to improve this method. And a dynamic analysis of the change of footprint based on I-O model, which could explore the factor impacting the footprint using the ,special advantage of I-O model, ought to be put into practice. After introducing the new method in detail, we calculate and compare the EF and the change of Gansu Province in the northwest of China in 1997 and 2002. The result shows that there was an increase of EF in 2002 caused by final domestic demand. Further; the inerement in EF export was 2.0 × 10^5 ha and 1.6 × 10^6 ha in import. The out-of- region support dropped from 22.6% to 18. 6%. We introduce three factors causing the EF change based on the character of I-O model: the productivity of the resourve which is explained by the change of resource used to obtain one unit output in a sector, the improvement of the economics and the final demand. Finally, we find that the effects of the three factors on the EF change are not identical except the industry sectors and the change of factors in the agriculture and the industry sectors works notably.展开更多
This paper presents an integrated study of urban spatial expansion in the Hexi Corridor, Gansu Province, China based on TM, ETM remote sensing data in 1987, 1990, 1995, 2000, 2006 and 2011. The study explores the char...This paper presents an integrated study of urban spatial expansion in the Hexi Corridor, Gansu Province, China based on TM, ETM remote sensing data in 1987, 1990, 1995, 2000, 2006 and 2011. The study explores the characteristics of urban spatial expansion and dynamic mechanism by using expansion speed index, expansion intensity index, compact index, fractal dimension, and extended flexibility index. We built the index system of influencing factors of urban spatial expansion by using the grey incidence model. The results showed that urban spatial expansion rate in the Hexi Corridor has been on the upward trend since 1987. Expansion intensity showed an obvious upward trend, however, the upward trend varied in different urban areas. In addition, the urban structure was loose relatively, but the urban compactness was more obvious. The urban spatial form tended to be simple, and the urban land use tended to become more intensive. Urban spatial expansion experienced several stages: padding internally, external expansion and padding internally. The main driving factors of urban spatial expansion are not the urban water resources and the oasis scale, but one or several factors such as economy, traffic, population, resource and national policy.展开更多
Twenty isolated strains of Blumeria graminis f.sp. tritici collected from central Gansu province were studied with random amplified polymorphic DNA (RAPD) analysis. PCR amplifications using nine random primers gener...Twenty isolated strains of Blumeria graminis f.sp. tritici collected from central Gansu province were studied with random amplified polymorphic DNA (RAPD) analysis. PCR amplifications using nine random primers generated a total of 81 bands, of which, 54 were polymorphic. The total percentage of polymorphic bands varied from 50.0% to 88.9%. The average percentage based on RAPD patterns was approximately 66.7%, which indicated high heredity differentiation among isolates. Clustering analysis showed that the polymorphism of the twenty isolates was related to geographical origins but had little relationship with the physiological race.展开更多
According to historical records,in July of 1590 A.D.,a destructive earthquake occurred near Lintao county in Gansu Province,in which "… city walls and houses collapsed,and countless people and domestic animals w...According to historical records,in July of 1590 A.D.,a destructive earthquake occurred near Lintao county in Gansu Province,in which "… city walls and houses collapsed,and countless people and domestic animals were killed".In the same month,Binggou town in eastern Qinghai Province(now northeastern Ledu county),was also damaged by an earthquake.These two earthquakes were listed as two different cases in the published earthquake catalogues,recorded separately as the Lintao M_S5.5 earthquake with epicentral intensity Ⅶ in Gansu Province and the Ledu M_S5.0 earthquake with epicentral intensity Ⅵ in Qinghai Province.However,based on comprehensive analysis of research on historical records and field investigations,it is concluded in this paper that these two earthquakes could be the same one with magnitude 6.5 and epicentral intensity Ⅷ~Ⅸ.Its epicenter was in the Maxian Mt.,which is located in southeastern Yongjing and its seismogenic structure might be the mid-western segments of the north fringe fault zone of Maxian Mt.of Lanzhou.展开更多
We report a fossil specimen referable to Sinomastodontinae gen. et sp. indet, from the Neogene strata at Yanghecun locality, Xihe County, Gansu Province, China. The specimen is characterized by a brevirostrine mandibl...We report a fossil specimen referable to Sinomastodontinae gen. et sp. indet, from the Neogene strata at Yanghecun locality, Xihe County, Gansu Province, China. The specimen is characterized by a brevirostrine mandible, complete pretrite trefoils, and relatively simple posttfite half lophids, showing typical features of Sinomastodon. It differs from the other known species of Sinomastodon by the following features: relatively short and wide m3 due to fewer lophid numbers, less inflated pretrite ac- cessory central conules, poorly developed secondary trefoils and cementum, and relatively strong cingulid. All of these fea- tures indicate a bias towards pleisiomorphies of Sinomastodon, implying that this specimen is more ancestral than any known species of Sinomastodon. The symphysis of the new specimen is relatively long, which differs from the typical brevirostrine Sinomastodon, and thus we consider it a gen. et sp. indet, in the Subfamily Sinomastodontinae. In addition, the horizon in which the present specimen was found probably represents the Upper Miocene because it is lower than Pliocene strata yielding Hipparion (Proboscidipparon) pater. Generally, Sinomastodon is considered to have migrated from North America at about the time of the Miocene/Pliocene boundary, and to have been derived from a certain clade of American gomphotheres. However, the discovery of the Yanghecun specimen verifies that Sinomastodon lived in East Asia during the Late Miocene, and probably derived from Old World gomphotheres (e.g., G. wimani). The similarity between the members of the Subfamilies Sinomastodontinae and those of Cuvieroniinae is suggested to have been the result of parallel evolution.展开更多
The Yangouxia dinosaur tracksites are well known for a diverse assemblage of tetrapod tracks preserved as natural impressions (concave epireliefs) on large bedding planes, representing a locally widespread surface m...The Yangouxia dinosaur tracksites are well known for a diverse assemblage of tetrapod tracks preserved as natural impressions (concave epireliefs) on large bedding planes, representing a locally widespread surface marking the transition from a sand- to a mud-dominated sequence in the Hekou Group. Previous ichnological studies at these large sites have focused on the morphology and ichnotaxonomy of the tracks, including a single trackway representing the first pterosaur tracks reported from China. Here, we report a distinctly different assemblage associated with minor sandstones in the mud-dominated sequence 20 m above the main tracksite level. This assemblage consists of at least 20 pterosaur manus track casts attributed to a single ichnotaxon (Pteraichnus). No pes tracks have been identified. These tracks mostly occur in random orientations, although one possible trackway segment is inferred, to represent walking progression.Manus-only pterosaur track assemblages are common and likely reflect differential registration depths of manus and pes and/or sub optimal preservation conditions. The tracks are associated with distinctive invertebrate traces including Cochlichnus, Spongeliomorpha and Paleophycus and suggest the pterosaurs were likely feeding on the invertebrate tracemakers.展开更多
The quality of altimeter data and ocean tide model is critical to the recovery of coastal gravity anomalies. In this contribution, three retracking methods (threshold, improved threshold and Beta-5) are investigated w...The quality of altimeter data and ocean tide model is critical to the recovery of coastal gravity anomalies. In this contribution, three retracking methods (threshold, improved threshold and Beta-5) are investigated with the aim of improving the altimeter data over a shallow water area. Comparison indicates that the improved threshold is the best retracking method over China Sea. Two ocean tide models, NAO99b and CSR4.0, are analyzed. Results show that different tide models used in the processing of altimeter data may result in differences more than 10 mGal in recovered coastal gravity anomalies. Also, NAO99b is more suitable than CSR4.0 over the shallow water area of China Sea. Finally, gravity anomalies over China Sea are calculated from retracked Geosat/GM and ERS-1/GM data by least squares collocation. Comparison with shipborne gravimetry data demonstrates that gravity anomalies from retracked data are significantly superior to those from non-retracked data. Our results have the same order as the other two altimeter-derived gravity models: Sandwell&Smith(V16) and DNSC08.展开更多
文摘AIM:To evaluate the association between genetic polymorphisms in CYP2E1, ALDH2 and ADH1B and the risk of esophageal squamous cell carcinoma (ESCC) in a high risk area of Gansu Province, in Chinese males. METHODS: A case-control study was conducted to investigate the genetic polymorphisms of these enzymes (CYP2E1 *c1/*c2, ALDH2 *1/*2 and ADH1B *1/*1 genotypes). A total of 80 esophageal cancer cases and 480 controls were recruited. RESULTS: Compared with controls, cases had a greater prevalence of heavier alcohol consumption (53.8% vs 16.2%) and a higher proportion of alcohol drinkers with > 30 drink-years (28.8% vs 13.5%). Heavier alcohol consumption and alcohol drinking with > 30 drink- years increased the risk of ESCC, with ORs (95% CI) of 3.20 (1.32-9.65) and 1.68 (0.96-3.21). CYP2E1 (*c1/*c1), ALDH2 (*1/*2) and ADH1B (*1/*1) genotype frequencies were higher among patients with squamous cell carcinomas, at a level close to statistical significance (P = 0.014; P = 0.094; P = 0.0001 respectively). There were synergistic interactions among alcohol drinking and ALDH2, ADH1B and CYP2E1 genotypes. The risk of the ESCC in moderate-to-heavy drinkers with an inactive ALDH2 encoded by ALDH2 *1/*2 as well as ADH1B encoded by ADH1B *1/*1 and CYP2E1 encoded by CYP2E1 *c1/*c1 was higher than that in the never/rare-to-light drinkers with an active ALDH2 (*1/*1 genotype) as well as ADH1B (*1/*2 + *2/*2) and CYP2E1 (*c1/*c2 + *c2/*c2) genotypes, with a statistically significant difference; ORs (95% CI) of 8.58 (3.28-22.68), 27.12 (8.52-70.19) and 7.64 (2.82-11.31) respectively. The risk of the ESCC in moderate-to-heavy drinkers with ALDH2 (*1/*2) combined the ADH1B (*1/*1) genotype or ALDH2 (*1/*2) combined the CYP2E1 (*c1/*c1) genotype leads to synergistic interactions, higher than drinkers with ALDH2 (*1/*1) + ADH1B (*1/*2 + *2/*2), ALDH2 (*1/*1) + CYP2E1 (*c1/*c2 + *c2/*c2) respectively , ORs (95% CI) of 7.46 (3.28-18.32) and 6.82 (1.44-9.76) respectively. Individuals with the ADH1B combined the CYP2E1 genotype showed no synergistic interaction. CONCLUSION: In our study, we found that alcohol consumption and polymorphisms in the CYP2E1, ADH1B and ALDH2 genes are important risk factors for ESCC, and that there was a synergistic interaction among polymorphisms in the CYP2E1, ALDH2 and ADH1B genes and heavy alcohol drinking, in Chinese males living in Gansu Province, China.
文摘Three new Tenthredinidae species are reported from Gansu and three from Qinghai Provinces of China. Tenthredo (Tenthredo) sinotemula sp. nov., Tenthredo (Tenthredella) labrangensis sp. nov. and Tenthredo (Tenthredella) sinosimplex sp. nov. are described from Gansu, Tenthredo (Tenthredella) rolleri sp. nov., Tenthredo (Tenthredella) qinghaiensis sp. nov. and Tenthredo (Tenthredella) yunningsiensis sp. nov. from Qinghai Province.
基金supported by the Project of the 12th Five-year National Sci-Tech Support Plan of China(2011BAK12B09)China Special Project of Basic Work of Science and Technology(2011FY110100-2)
文摘Bailongjiang watershed in southern Gansu province, China, is one of the most landslide-prone regions in China, characterized by very high frequency of landslide occurrence. In order to predict the landslide occurrence, a comprehensive map of landslide susceptibility is required which may be significantly helpful in reducing loss of property and human life. In this study, an integrated model of information value method and logistic regression is proposed by using their merits at maximum and overcoming their weaknesses, which may enhance precision and accuracy of landslide susceptibility assessment. A detailed and reliable landslide inventory with 1587 landslides was prepared and randomly divided into two groups,(i) training dataset and(ii) testing dataset. Eight distinct landslide conditioning factors including lithology, slope gradient, aspect, elevation, distance to drainages,distance to faults, distance to roads and vegetation coverage were selected for landslide susceptibility mapping. The produced landslide susceptibility maps were validated by the success rate and prediction rate curves. The validation results show that the success rate and the prediction rate of the integrated model are 81.7 % and 84.6 %, respectively, which indicate that the proposed integrated method is reliable to produce an accurate landslide susceptibility map and the results may be used for landslides management and mitigation.
基金supported by National Natural Science Foundation of China (Grant No.40671076)CAS (Chinese Academy of Sciences) Action Plan for West Development Project (Grant No.KZCX2-XB2-04-04)
文摘The calculation of Ecological Footprint (EF) on the basis of Input-Output model (I-O model) was advanced by Bicknell, and modified and improved hy Ferng who corrected the footprint's aggregation to each sectors. For the lack of sufficient teehnique to deal with the trade between the research areas and the rest of the world, it it necessary to improve this method. And a dynamic analysis of the change of footprint based on I-O model, which could explore the factor impacting the footprint using the ,special advantage of I-O model, ought to be put into practice. After introducing the new method in detail, we calculate and compare the EF and the change of Gansu Province in the northwest of China in 1997 and 2002. The result shows that there was an increase of EF in 2002 caused by final domestic demand. Further; the inerement in EF export was 2.0 × 10^5 ha and 1.6 × 10^6 ha in import. The out-of- region support dropped from 22.6% to 18. 6%. We introduce three factors causing the EF change based on the character of I-O model: the productivity of the resourve which is explained by the change of resource used to obtain one unit output in a sector, the improvement of the economics and the final demand. Finally, we find that the effects of the three factors on the EF change are not identical except the industry sectors and the change of factors in the agriculture and the industry sectors works notably.
基金Under the auspices of National Natural Science Foundation of China(No.41271133,41261104)National Social Science Foundation of China(No.12CTJ001)
文摘This paper presents an integrated study of urban spatial expansion in the Hexi Corridor, Gansu Province, China based on TM, ETM remote sensing data in 1987, 1990, 1995, 2000, 2006 and 2011. The study explores the characteristics of urban spatial expansion and dynamic mechanism by using expansion speed index, expansion intensity index, compact index, fractal dimension, and extended flexibility index. We built the index system of influencing factors of urban spatial expansion by using the grey incidence model. The results showed that urban spatial expansion rate in the Hexi Corridor has been on the upward trend since 1987. Expansion intensity showed an obvious upward trend, however, the upward trend varied in different urban areas. In addition, the urban structure was loose relatively, but the urban compactness was more obvious. The urban spatial form tended to be simple, and the urban land use tended to become more intensive. Urban spatial expansion experienced several stages: padding internally, external expansion and padding internally. The main driving factors of urban spatial expansion are not the urban water resources and the oasis scale, but one or several factors such as economy, traffic, population, resource and national policy.
文摘Twenty isolated strains of Blumeria graminis f.sp. tritici collected from central Gansu province were studied with random amplified polymorphic DNA (RAPD) analysis. PCR amplifications using nine random primers generated a total of 81 bands, of which, 54 were polymorphic. The total percentage of polymorphic bands varied from 50.0% to 88.9%. The average percentage based on RAPD patterns was approximately 66.7%, which indicated high heredity differentiation among isolates. Clustering analysis showed that the polymorphism of the twenty isolates was related to geographical origins but had little relationship with the physiological race.
基金sponsored by the Active Faults Exploration and Seismic Risk Assessment in Lanzhou City,a National Tenth"Five-Year Plan"Significant Project,and Scientific and Technological Key Project in Gansu Province(2GS054-A44-015)Treatise No.of Lanzhou Institute of Seismology,CEA:LC20070037
文摘According to historical records,in July of 1590 A.D.,a destructive earthquake occurred near Lintao county in Gansu Province,in which "… city walls and houses collapsed,and countless people and domestic animals were killed".In the same month,Binggou town in eastern Qinghai Province(now northeastern Ledu county),was also damaged by an earthquake.These two earthquakes were listed as two different cases in the published earthquake catalogues,recorded separately as the Lintao M_S5.5 earthquake with epicentral intensity Ⅶ in Gansu Province and the Ledu M_S5.0 earthquake with epicentral intensity Ⅵ in Qinghai Province.However,based on comprehensive analysis of research on historical records and field investigations,it is concluded in this paper that these two earthquakes could be the same one with magnitude 6.5 and epicentral intensity Ⅷ~Ⅸ.Its epicenter was in the Maxian Mt.,which is located in southeastern Yongjing and its seismogenic structure might be the mid-western segments of the north fringe fault zone of Maxian Mt.of Lanzhou.
基金supported by Chinese Academy of Sciences(Grant No.XDB03020104)National Basic Research Program of China(GrantNo.2012CB821900)+1 种基金National Natural Science Foundation of China(Grant Nos.41372001,41002010,40730210)the Important Research Plan of IVPP
文摘We report a fossil specimen referable to Sinomastodontinae gen. et sp. indet, from the Neogene strata at Yanghecun locality, Xihe County, Gansu Province, China. The specimen is characterized by a brevirostrine mandible, complete pretrite trefoils, and relatively simple posttfite half lophids, showing typical features of Sinomastodon. It differs from the other known species of Sinomastodon by the following features: relatively short and wide m3 due to fewer lophid numbers, less inflated pretrite ac- cessory central conules, poorly developed secondary trefoils and cementum, and relatively strong cingulid. All of these fea- tures indicate a bias towards pleisiomorphies of Sinomastodon, implying that this specimen is more ancestral than any known species of Sinomastodon. The symphysis of the new specimen is relatively long, which differs from the typical brevirostrine Sinomastodon, and thus we consider it a gen. et sp. indet, in the Subfamily Sinomastodontinae. In addition, the horizon in which the present specimen was found probably represents the Upper Miocene because it is lower than Pliocene strata yielding Hipparion (Proboscidipparon) pater. Generally, Sinomastodon is considered to have migrated from North America at about the time of the Miocene/Pliocene boundary, and to have been derived from a certain clade of American gomphotheres. However, the discovery of the Yanghecun specimen verifies that Sinomastodon lived in East Asia during the Late Miocene, and probably derived from Old World gomphotheres (e.g., G. wimani). The similarity between the members of the Subfamilies Sinomastodontinae and those of Cuvieroniinae is suggested to have been the result of parallel evolution.
基金supported by the Liujiaxia Dinosaurs National Geoparkthe 2013 Supporting Fund for Graduate Student’s Science and Technology Innovation from China University of Geosciences(Beijing),China
文摘The Yangouxia dinosaur tracksites are well known for a diverse assemblage of tetrapod tracks preserved as natural impressions (concave epireliefs) on large bedding planes, representing a locally widespread surface marking the transition from a sand- to a mud-dominated sequence in the Hekou Group. Previous ichnological studies at these large sites have focused on the morphology and ichnotaxonomy of the tracks, including a single trackway representing the first pterosaur tracks reported from China. Here, we report a distinctly different assemblage associated with minor sandstones in the mud-dominated sequence 20 m above the main tracksite level. This assemblage consists of at least 20 pterosaur manus track casts attributed to a single ichnotaxon (Pteraichnus). No pes tracks have been identified. These tracks mostly occur in random orientations, although one possible trackway segment is inferred, to represent walking progression.Manus-only pterosaur track assemblages are common and likely reflect differential registration depths of manus and pes and/or sub optimal preservation conditions. The tracks are associated with distinctive invertebrate traces including Cochlichnus, Spongeliomorpha and Paleophycus and suggest the pterosaurs were likely feeding on the invertebrate tracemakers.
基金Supported by the National Natural Science Foundation of China(No.40704003)the National 973 Program of China(No.2007CB714405)the Key Laboratory of Surveying and Mapping Technology on Island and Reef,State Bureau of Surveying and Mapping,China(No.2009B04)
文摘The quality of altimeter data and ocean tide model is critical to the recovery of coastal gravity anomalies. In this contribution, three retracking methods (threshold, improved threshold and Beta-5) are investigated with the aim of improving the altimeter data over a shallow water area. Comparison indicates that the improved threshold is the best retracking method over China Sea. Two ocean tide models, NAO99b and CSR4.0, are analyzed. Results show that different tide models used in the processing of altimeter data may result in differences more than 10 mGal in recovered coastal gravity anomalies. Also, NAO99b is more suitable than CSR4.0 over the shallow water area of China Sea. Finally, gravity anomalies over China Sea are calculated from retracked Geosat/GM and ERS-1/GM data by least squares collocation. Comparison with shipborne gravimetry data demonstrates that gravity anomalies from retracked data are significantly superior to those from non-retracked data. Our results have the same order as the other two altimeter-derived gravity models: Sandwell&Smith(V16) and DNSC08.