Due to global warming, the general circulation, underlying surfaces characteristics, and geophysical and meteorological elements all show evident secular trends. This paper points out that when calculating the correla...Due to global warming, the general circulation, underlying surfaces characteristics, and geophysical and meteorological elements all show evident secular trends. This paper points out that when calculating the correlation of two variables containing their own obvious secular trends, the interannual correlation characteristics between the two variables may be distorted （overestimated or underestimated）. Numerical experiments in this paper show that if two variables have opposite secular trends, the correlation coefficient between the two variables is reduced （the positive correlation is underestimated, or the negative correlation is overestimated）; and if the two variables have the same sign of secular trends, the correlation coefficient between the two variables is increased （the positive correlation is overestimated, or the negative correlation is underestimated）. Numerical experiments also suggest that the effect of secular trends on the interannual correlation of the two variables is interchangeable, that is to say, as long as the values of the two trends are not changed, the two variables interchange their positions, and the effect of the secular trends on the interannual correlation coefficient of the two variables remains the same. If the two variables have the same-（opposite-） sign trends, the effect of secular trends on the interannal correlation coefficient is more （less） distinctive. A meteorological example is given.展开更多
Objective To explore the influence of secular trends in body height and weight on the prevalence of overweight and obesity among Chinese children and adolescents. Methods The data were obtained from five cross-section...Objective To explore the influence of secular trends in body height and weight on the prevalence of overweight and obesity among Chinese children and adolescents. Methods The data were obtained from five cross-sectional Chinese National Surveys on Students＇ Constitution and Health. Overweight/obesity was defined as BMI-for-age Z-score of per the Wold Health Organization （WHO） reference values. Body height and weight for each sex and age were standardized to those reported in 1985 （standardized height＂ SHY, standardized weight： SWY） and for each sex and year at age 7 （standardized height： SHA; standardized weight： SWA） using the Z-score method. Results The prevalence of overweight/obesity in Chinese children was 20.2% among boys and 10.7% among girls in 2010 and increased continuously from 1985 to 2010. Among boys and girls of normal weight, SHY and SHA were significantly greater than SWY and SWA, respectively （P 〈 0.001）. Among boys and girls with overweight/obesity, SHY was significantly lower than SWY （P 〈 0.001）, and showed an obvious decreasing trend after age 12. SHA was lower than SWA among overweight boys aged 7-8 years and girls aged 7-9 years. SHY/SHW and SHA/SWA among normal-weight groups were greater than among overweight and obese groups （P 〈 0.001）. Conclusion The continuous increase in the prevalence of overweight/obesity among Chinese children may be related to a rapid increase in body weight before age 9 and lack of secular increase in body height after age 12.展开更多
BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is one of the most aggressive malignancies.However,because of its scarcity there are limited population-based data available for investigations into its epidemiologic cha...BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is one of the most aggressive malignancies.However,because of its scarcity there are limited population-based data available for investigations into its epidemiologic characteristics.In Taiwan,we have a national cancer registry database that can be used to evaluate the secular trends of ICC.AIM To evaluate secular trends of ICC according to age,sex,and risk factors in Taiwan.METHODS In this population-based study,we used the national Taiwan Cancer Registry database.Age-standardized and relative percent changes in incidence rates were used to describe secular trends in incidence rates and sex ratios of ICC in Taiwan.RESULTS The age-standardized ICC incidence rate among males increased from 1.51 per 100000 in 1993-1997 to 4.07 per 100000 in 2013-2017 and among female from 1.73 per 100000 to 2.95 per 100000.The incidence in females tended to plateau after 2008-2012.For males,the ICC incidence increased as age increased.In the long-term incidence trend of ICC in females,the incidence of the four age groups(40-44,45-49,50-54 and 55-59 years)remained stable in different years;although,the incidence of the 60-64 group had a peak in 2003-2007,and the peak incidence of the 65-69 and 70-74 groups occurred in 2008-2012.Among males,beginning at the age of 65,there were increases in the incidence of ICC for the period of 2003-2017 as compared with females in the period of 2003-2017.CONCLUSION Increased incidence of ICC occurred in Taiwan over the past two decades.The increased incidence has progressively shifted toward younger people for both males and females.展开更多
Objective Over the last century, a progressive rise in stature, known as the ‘secular trend’, was documented worldwide, and especially in Sardinia, it has reached a peak in Europe. However, this situation recently c...Objective Over the last century, a progressive rise in stature, known as the ‘secular trend’, was documented worldwide, and especially in Sardinia, it has reached a peak in Europe. However, this situation recently ceased in several populations. In this study, we tested the hypothesis that the stature secular trend has significantly leveled off in the Sardinian younger generations.Methods Height measurements were retrieved from a database of patients undergoing digestive endoscopy, spanning generations between 1920 and 1990. Sex-specific principal component regression models were fitted to decompose stature variation into the contribution of age, period, and birth cohort.Results A steady increase in stature was observed in generations born after 1920, with an upward surge in those born after 1950. However, a significant leveling off was observed among cohorts born after 1970 among both sexes, as mean heights stabilized at 171.1 cm with a standard error(SE) of 0.9 cm among men and a mean of 160.1 cm(SE = 0.9 cm) among women.Conclusion Our findings support a significant slowdown in the secular trend of stature among the latest Sardinian generations. Several factors, including the consumption of low-quality food, lack of physical activity, and late motherhood, among others, may explain the decline in the secular trend.展开更多
Objective: The objective of this study was to characterize secular trends in the sex-specific, age-standardized incidence of lung cancer by histological type in Beijing, China, from 2000 to 2016 based on data from a p...Objective: The objective of this study was to characterize secular trends in the sex-specific, age-standardized incidence of lung cancer by histological type in Beijing, China, from 2000 to 2016 based on data from a populationbased cancer registry.Methods: Data on the incidence of cancer from 2000 to 2016 were obtained from the Beijing Cancer Registry.We examined trends in the sex-specific, age-standardized incidence of lung cancer by histological type using a Joinpoint regression model.Results: A total of 117,409 cases of lung cancer were diagnosed from 2000 to 2016. Overall, 73,062(62.23%)patients were males. The most common histological type among both sexes was adenocarcinoma; however, the proportion of adenocarcinoma differed significantly between males and females(45.36% vs. 77.14%, respectively,P<0.0001). The age-standardized incidence of total lung cancer increased from 2000 to 2010 with an annual percent change(APC) of 2.2% [95% confidence interval(95% CI), 1.5% to 2.9%] and stabilized thereafter. Among males, the incidence of total lung cancer peaked in 2008 and then decreased slightly, with an APC of-1.1%(95%CI,-2.1% to-0.1%). Among females, the incidence increased continuously during the study period, with an APC of 1.4%(95% CI, 0.9% to 1.9%). The incidence of squamous cell carcinoma decreased significantly in recent years among both sexes, with APCs of-2.6%(95% CI,-4.5% to-0.6%) from 2007 to 2016 for males and-5.4%(95%CI,-7.2% to-3.6%) from 2004 to 2016 for females. In contrast, the incidence of adenocarcinoma increased continuously throughout the study period, by APCs of 4.0%(95% CI, 2.6% to 5.4%) for males and 6.2%(95% CI,4.8% to 7.6%) for females. The incidence of small cell carcinoma peaked in 2007 and stabilized thereafter among males, whereas it peaked in 2012 and then decreased with an APC of-14.7%(95% CI,-25.3% to-2.6%) among females. The incidence of large cell carcinoma and other specified malignant neoplasm did not change much,whereas the incidence of unspecified type decreased among both sexes during the study period.Conclusions: Although the incidence of squamous cell carcinoma decreased significantly among both sexes in recent years in Beijing, China, adenocarcinoma increased continuously throughout the study period among both sexes. Knowledge of differences in trends is useful for surveillance and control of lung cancer. However, the reason for the increase in adenocarcinoma remains unclear and warrants investigation.展开更多
Background:With industrial and economic development in recent decades in South China,cancer incidence may have changed due to the changing lifestyle and environment.However,the trends of lung cancer and the roles of s...Background:With industrial and economic development in recent decades in South China,cancer incidence may have changed due to the changing lifestyle and environment.However,the trends of lung cancer and the roles of smoking and other environmental risk factors in the development of lung cancer in rural areas of South China remain unclear.The purpose of this study was to explore the lung cancer incidence trends and the possible causes of these trends.Methods:Joinpoint regression analysis and the age-period-cohort(APC) model were used to analyze the lung cancer incidence trends in Sihui,Guangdong province,China between 1987 and 2011,and explore the possible causes of these trends.Results:A total of 2,397 lung cancer patients were involved in this study.A 3-fold increase in the incidence of lung cancer in both sexes was observed over the 25-year period.Joinpoint regression analysis showed that while the incidence continued to increase steadily in females during the entire period,a sharp acceleration was observed in males starting in 2005.The full APC model was selected to describe age,period,and birth cohort effects on lung cancer incidence trends in Sihui.The age cohorts in both sexes showed a continuously significant increase in the relative risk(RR)of lung cancer,with a peak in the eldest age group(80-84 years).The RR of lung cancer showed a fluctuating curve in both sexes.The birth cohorts identified an increased trend in both males and females;however,males had a plateau in the youngest cohorts who were born during 1955-1969.Conclusions:Increasing trends of the incidence of lung cancer in Sihui were dominated by the effects of age and birth cohorts.Social aging,smoking,and environmental changes may play important roles in such trends.展开更多
Background:Few studies on spatial patterns or secular trends in human leishmanias have been conducted in Morocco.This study aimed to examine spatial patterns and trends associated with the human leishmaniasis incidenc...Background:Few studies on spatial patterns or secular trends in human leishmanias have been conducted in Morocco.This study aimed to examine spatial patterns and trends associated with the human leishmaniasis incidence rate(HLIR)at the province/prefecture level between 2003 and 2013 in Morocco.Methods:Only the available published country data on the HLIR between 2003 and 2013,from the open access files of the Ministry of Health,were used.Secular trends were examined using Kendall’s rank correlation.An exploratory spatial data analysis was also conducted to examine the spatial autocorrelation(Global Moran’s I and local indicator of spatial association[LISA]),and spatial diffusion at the province/prefecture level.The influence of various covariates(poverty rate,vulnerability rate,population density,and urbanization)on the HLIR was tested via spatial regression(ordinary least squares regression).Results:At the country level,no secular variation was observed.Poisson annual incidence rate estimates were 13 per 100000 population(95%CI=12.9–13.1)for cutaneous leishmaniasis(CL)and 0.4 per 100000 population(95%CI=0.4–0.5)for visceral leishmaniasis(VL).The available data on HLIR were based on combined CL and VL cases,however,as the CL cases totally outnumbered the VL ones,HLIR may be considered as CL incidence rate.At the provincial level,a secular increase in the incidence rate was observed in Al Hoceima(P=0.008),Taounate(P=0.04),Larache(P=0.002),Tétouan(P=0.0003),Khenifra(P=0.008),Meknes(P=0.03),and El Kelaa(P=0.0007),whereas a secular decrease was observed only in the Chichaoua province(P=0.006).Even though increased or decreased rate was evident in these provinces,none of them showed clustering of leishmaniasis incidence.Significant spatial clusters of high leishmaniasis incidence were located in the northeastern part of Morocco,while spatial clusters of low leishmaniasis incidence were seen in some northwestern and southern parts of Morocco;there was spatial randomness in the remaining parts of the country.Significant clustering was seen from 2005 to 2013,during which time the Errachidia province was a permanent‘hot spot’.Global Moran’s I increased from 0.2844(P=0.006)in 2005 to 0.5886(P=0.001)in 2011,and decreased to 0.2491(P=0.004)in 2013.It was found that only poverty had an effect on the HLIR(P=0.0003),contributing only 23%to this(Adjusted R-squared=0.226).Conclusion:Localities showing either secular increase in human leishmaniasis or significant clustering have been identified,which may guide decision-making as to where to appropriately allocate funding and implement control measures.Researchers are also urged to undertake further studies focusing on these localities.展开更多
本文采用最新的GRACE(Gravity Recovery and Climate Experiment)(RL05)数据,通过水文模型(Global Land Data Assimilation System,GLDAS与Climate Prediction Center,CPC)扣除土壤水及雪水的影响,利用Paulson提供的冰川模型结果扣除GIA...本文采用最新的GRACE(Gravity Recovery and Climate Experiment)(RL05)数据,通过水文模型(Global Land Data Assimilation System,GLDAS与Climate Prediction Center,CPC)扣除土壤水及雪水的影响,利用Paulson提供的冰川模型结果扣除GIA(Glacial Isostatic Adjustment)的影响,采用尺度因子的方法减少数据处理过程中误差的影响,最终基于最小二乘计算方法得到2003—2013中国及周边地区长期性重力异常变化情况.结果发现青藏高原有较为明显的重力上升信号,我们认为该信号可能由印度板块俯冲欧亚板块导致青藏高原地壳增厚所引起.接着依据GPS观测结果和艾黎均衡假说构建了地壳形变模型并通过直立长方体模型予以正演模拟分析.以班公湖—怒江断裂带为界将青藏高原划分为南北两大区块,结果显示青藏高原重力异常大致以0.2μGal·a-1的速率在递增,小于GRACE得到的0.3±0.08μGal·a-1的增长速率(对应于地壳增厚速率约3mm·a-1),剩余未解释部分可能与湖水、冰川因素、冻土因素等有关.该结果对于认识青藏高原隆升动力学有一定参考意义.展开更多
文摘Due to global warming, the general circulation, underlying surfaces characteristics, and geophysical and meteorological elements all show evident secular trends. This paper points out that when calculating the correlation of two variables containing their own obvious secular trends, the interannual correlation characteristics between the two variables may be distorted （overestimated or underestimated）. Numerical experiments in this paper show that if two variables have opposite secular trends, the correlation coefficient between the two variables is reduced （the positive correlation is underestimated, or the negative correlation is overestimated）; and if the two variables have the same sign of secular trends, the correlation coefficient between the two variables is increased （the positive correlation is overestimated, or the negative correlation is underestimated）. Numerical experiments also suggest that the effect of secular trends on the interannual correlation of the two variables is interchangeable, that is to say, as long as the values of the two trends are not changed, the two variables interchange their positions, and the effect of the secular trends on the interannual correlation coefficient of the two variables remains the same. If the two variables have the same-（opposite-） sign trends, the effect of secular trends on the interannal correlation coefficient is more （less） distinctive. A meteorological example is given.
基金supported by the National Natural Science Foundation of China(81502823)
文摘Objective To explore the influence of secular trends in body height and weight on the prevalence of overweight and obesity among Chinese children and adolescents. Methods The data were obtained from five cross-sectional Chinese National Surveys on Students＇ Constitution and Health. Overweight/obesity was defined as BMI-for-age Z-score of per the Wold Health Organization （WHO） reference values. Body height and weight for each sex and age were standardized to those reported in 1985 （standardized height＂ SHY, standardized weight： SWY） and for each sex and year at age 7 （standardized height： SHA; standardized weight： SWA） using the Z-score method. Results The prevalence of overweight/obesity in Chinese children was 20.2% among boys and 10.7% among girls in 2010 and increased continuously from 1985 to 2010. Among boys and girls of normal weight, SHY and SHA were significantly greater than SWY and SWA, respectively （P 〈 0.001）. Among boys and girls with overweight/obesity, SHY was significantly lower than SWY （P 〈 0.001）, and showed an obvious decreasing trend after age 12. SHA was lower than SWA among overweight boys aged 7-8 years and girls aged 7-9 years. SHY/SHW and SHA/SWA among normal-weight groups were greater than among overweight and obese groups （P 〈 0.001）. Conclusion The continuous increase in the prevalence of overweight/obesity among Chinese children may be related to a rapid increase in body weight before age 9 and lack of secular increase in body height after age 12.
文摘BACKGROUND Intrahepatic cholangiocarcinoma(ICC)is one of the most aggressive malignancies.However,because of its scarcity there are limited population-based data available for investigations into its epidemiologic characteristics.In Taiwan,we have a national cancer registry database that can be used to evaluate the secular trends of ICC.AIM To evaluate secular trends of ICC according to age,sex,and risk factors in Taiwan.METHODS In this population-based study,we used the national Taiwan Cancer Registry database.Age-standardized and relative percent changes in incidence rates were used to describe secular trends in incidence rates and sex ratios of ICC in Taiwan.RESULTS The age-standardized ICC incidence rate among males increased from 1.51 per 100000 in 1993-1997 to 4.07 per 100000 in 2013-2017 and among female from 1.73 per 100000 to 2.95 per 100000.The incidence in females tended to plateau after 2008-2012.For males,the ICC incidence increased as age increased.In the long-term incidence trend of ICC in females,the incidence of the four age groups(40-44,45-49,50-54 and 55-59 years)remained stable in different years;although,the incidence of the 60-64 group had a peak in 2003-2007,and the peak incidence of the 65-69 and 70-74 groups occurred in 2008-2012.Among males,beginning at the age of 65,there were increases in the incidence of ICC for the period of 2003-2017 as compared with females in the period of 2003-2017.CONCLUSION Increased incidence of ICC occurred in Taiwan over the past two decades.The increased incidence has progressively shifted toward younger people for both males and females.
文摘Objective Over the last century, a progressive rise in stature, known as the ‘secular trend’, was documented worldwide, and especially in Sardinia, it has reached a peak in Europe. However, this situation recently ceased in several populations. In this study, we tested the hypothesis that the stature secular trend has significantly leveled off in the Sardinian younger generations.Methods Height measurements were retrieved from a database of patients undergoing digestive endoscopy, spanning generations between 1920 and 1990. Sex-specific principal component regression models were fitted to decompose stature variation into the contribution of age, period, and birth cohort.Results A steady increase in stature was observed in generations born after 1920, with an upward surge in those born after 1950. However, a significant leveling off was observed among cohorts born after 1970 among both sexes, as mean heights stabilized at 171.1 cm with a standard error(SE) of 0.9 cm among men and a mean of 160.1 cm(SE = 0.9 cm) among women.Conclusion Our findings support a significant slowdown in the secular trend of stature among the latest Sardinian generations. Several factors, including the consumption of low-quality food, lack of physical activity, and late motherhood, among others, may explain the decline in the secular trend.
基金supported by the Beijing Young Talent Program (No. 20160000 21469G189)
文摘Objective: The objective of this study was to characterize secular trends in the sex-specific, age-standardized incidence of lung cancer by histological type in Beijing, China, from 2000 to 2016 based on data from a populationbased cancer registry.Methods: Data on the incidence of cancer from 2000 to 2016 were obtained from the Beijing Cancer Registry.We examined trends in the sex-specific, age-standardized incidence of lung cancer by histological type using a Joinpoint regression model.Results: A total of 117,409 cases of lung cancer were diagnosed from 2000 to 2016. Overall, 73,062(62.23%)patients were males. The most common histological type among both sexes was adenocarcinoma; however, the proportion of adenocarcinoma differed significantly between males and females(45.36% vs. 77.14%, respectively,P<0.0001). The age-standardized incidence of total lung cancer increased from 2000 to 2010 with an annual percent change(APC) of 2.2% [95% confidence interval(95% CI), 1.5% to 2.9%] and stabilized thereafter. Among males, the incidence of total lung cancer peaked in 2008 and then decreased slightly, with an APC of-1.1%(95%CI,-2.1% to-0.1%). Among females, the incidence increased continuously during the study period, with an APC of 1.4%(95% CI, 0.9% to 1.9%). The incidence of squamous cell carcinoma decreased significantly in recent years among both sexes, with APCs of-2.6%(95% CI,-4.5% to-0.6%) from 2007 to 2016 for males and-5.4%(95%CI,-7.2% to-3.6%) from 2004 to 2016 for females. In contrast, the incidence of adenocarcinoma increased continuously throughout the study period, by APCs of 4.0%(95% CI, 2.6% to 5.4%) for males and 6.2%(95% CI,4.8% to 7.6%) for females. The incidence of small cell carcinoma peaked in 2007 and stabilized thereafter among males, whereas it peaked in 2012 and then decreased with an APC of-14.7%(95% CI,-25.3% to-2.6%) among females. The incidence of large cell carcinoma and other specified malignant neoplasm did not change much,whereas the incidence of unspecified type decreased among both sexes during the study period.Conclusions: Although the incidence of squamous cell carcinoma decreased significantly among both sexes in recent years in Beijing, China, adenocarcinoma increased continuously throughout the study period among both sexes. Knowledge of differences in trends is useful for surveillance and control of lung cancer. However, the reason for the increase in adenocarcinoma remains unclear and warrants investigation.
基金supported by the National High Technology Research and Development Program of China(No.2012AA02A501)the Special Fund for Public Health Trade(No.201202014)
文摘Background:With industrial and economic development in recent decades in South China,cancer incidence may have changed due to the changing lifestyle and environment.However,the trends of lung cancer and the roles of smoking and other environmental risk factors in the development of lung cancer in rural areas of South China remain unclear.The purpose of this study was to explore the lung cancer incidence trends and the possible causes of these trends.Methods:Joinpoint regression analysis and the age-period-cohort(APC) model were used to analyze the lung cancer incidence trends in Sihui,Guangdong province,China between 1987 and 2011,and explore the possible causes of these trends.Results:A total of 2,397 lung cancer patients were involved in this study.A 3-fold increase in the incidence of lung cancer in both sexes was observed over the 25-year period.Joinpoint regression analysis showed that while the incidence continued to increase steadily in females during the entire period,a sharp acceleration was observed in males starting in 2005.The full APC model was selected to describe age,period,and birth cohort effects on lung cancer incidence trends in Sihui.The age cohorts in both sexes showed a continuously significant increase in the relative risk(RR)of lung cancer,with a peak in the eldest age group(80-84 years).The RR of lung cancer showed a fluctuating curve in both sexes.The birth cohorts identified an increased trend in both males and females;however,males had a plateau in the youngest cohorts who were born during 1955-1969.Conclusions:Increasing trends of the incidence of lung cancer in Sihui were dominated by the effects of age and birth cohorts.Social aging,smoking,and environmental changes may play important roles in such trends.
文摘Background:Few studies on spatial patterns or secular trends in human leishmanias have been conducted in Morocco.This study aimed to examine spatial patterns and trends associated with the human leishmaniasis incidence rate(HLIR)at the province/prefecture level between 2003 and 2013 in Morocco.Methods:Only the available published country data on the HLIR between 2003 and 2013,from the open access files of the Ministry of Health,were used.Secular trends were examined using Kendall’s rank correlation.An exploratory spatial data analysis was also conducted to examine the spatial autocorrelation(Global Moran’s I and local indicator of spatial association[LISA]),and spatial diffusion at the province/prefecture level.The influence of various covariates(poverty rate,vulnerability rate,population density,and urbanization)on the HLIR was tested via spatial regression(ordinary least squares regression).Results:At the country level,no secular variation was observed.Poisson annual incidence rate estimates were 13 per 100000 population(95%CI=12.9–13.1)for cutaneous leishmaniasis(CL)and 0.4 per 100000 population(95%CI=0.4–0.5)for visceral leishmaniasis(VL).The available data on HLIR were based on combined CL and VL cases,however,as the CL cases totally outnumbered the VL ones,HLIR may be considered as CL incidence rate.At the provincial level,a secular increase in the incidence rate was observed in Al Hoceima(P=0.008),Taounate(P=0.04),Larache(P=0.002),Tétouan(P=0.0003),Khenifra(P=0.008),Meknes(P=0.03),and El Kelaa(P=0.0007),whereas a secular decrease was observed only in the Chichaoua province(P=0.006).Even though increased or decreased rate was evident in these provinces,none of them showed clustering of leishmaniasis incidence.Significant spatial clusters of high leishmaniasis incidence were located in the northeastern part of Morocco,while spatial clusters of low leishmaniasis incidence were seen in some northwestern and southern parts of Morocco;there was spatial randomness in the remaining parts of the country.Significant clustering was seen from 2005 to 2013,during which time the Errachidia province was a permanent‘hot spot’.Global Moran’s I increased from 0.2844(P=0.006)in 2005 to 0.5886(P=0.001)in 2011,and decreased to 0.2491(P=0.004)in 2013.It was found that only poverty had an effect on the HLIR(P=0.0003),contributing only 23%to this(Adjusted R-squared=0.226).Conclusion:Localities showing either secular increase in human leishmaniasis or significant clustering have been identified,which may guide decision-making as to where to appropriately allocate funding and implement control measures.Researchers are also urged to undertake further studies focusing on these localities.
文摘本文采用最新的GRACE(Gravity Recovery and Climate Experiment)(RL05)数据,通过水文模型(Global Land Data Assimilation System,GLDAS与Climate Prediction Center,CPC)扣除土壤水及雪水的影响,利用Paulson提供的冰川模型结果扣除GIA(Glacial Isostatic Adjustment)的影响,采用尺度因子的方法减少数据处理过程中误差的影响,最终基于最小二乘计算方法得到2003—2013中国及周边地区长期性重力异常变化情况.结果发现青藏高原有较为明显的重力上升信号,我们认为该信号可能由印度板块俯冲欧亚板块导致青藏高原地壳增厚所引起.接着依据GPS观测结果和艾黎均衡假说构建了地壳形变模型并通过直立长方体模型予以正演模拟分析.以班公湖—怒江断裂带为界将青藏高原划分为南北两大区块,结果显示青藏高原重力异常大致以0.2μGal·a-1的速率在递增,小于GRACE得到的0.3±0.08μGal·a-1的增长速率(对应于地壳增厚速率约3mm·a-1),剩余未解释部分可能与湖水、冰川因素、冻土因素等有关.该结果对于认识青藏高原隆升动力学有一定参考意义.
