获取长时间序列的高山内陆湖泊变化信息,对研究高山环境变化和气候变化的响应具有重要的意义.近几十年,阿牙克库木湖湖泊面积发生了较大的变化,因此本文以阿牙克库木湖为研究对象,利用1976年至2019年的Landsat系列卫星影像,采用NDWI水...获取长时间序列的高山内陆湖泊变化信息,对研究高山环境变化和气候变化的响应具有重要的意义.近几十年,阿牙克库木湖湖泊面积发生了较大的变化,因此本文以阿牙克库木湖为研究对象,利用1976年至2019年的Landsat系列卫星影像,采用NDWI水体指数法提取阿牙克库木湖8期湖泊面积信息,并结合降雨和气温等气象数据进行变化分析.结果表明:阿牙克库木湖在1976年至2019年面积由611.023 km 2增加到1084.73 km 2,增加了473.707 km 2.其中,1976年至1996年呈小幅度的萎缩或扩张,在1996年以后湖泊面积加速扩张.从1980年至2015年的降雨和气温数据看,湖泊面积与年平均降水量以及年平均温度具有正相关关系.展开更多
The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this stu...The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this study,4 D seismic monitoring technology that is effective in reservoir development was used to monitor abnormal changes in coal-mine underground goaf to explore the feasibility of the method.Taking a coal mine in Hancheng,Shaanxi as an example,we used the aforementioned technology to dynamically monitor the abnormal changes in the goaf.Based on the 4 D seismic data obtained in the experiment and the abnormal change characteristics of the coal-mine goaf,the method of 4 D seismic data processing in reservoir was improved.A set of 4 D data processing flow for the goaf was established,and the anomalies in the surface elevation and overlying strata velocity caused by collapse were corrected.We have made the following improvements to the method of 4 D seismic data processing in the reservoir:(1)the static correction problem caused by the changes of surface elevation and destruction of the low-velocity layer has been solved through fusion static correction to comb the low-frequency components of elevation statics with the high-frequency components of refraction statics;(2)the problem of overlying strata velocity changes in the goaf caused by collapse has been solved through the velocity consistency method;(3)the problem of reflection event pull-down in the disturbance area has been solved through space-varying moveout correction based on cross-correlation;and(4)amplitude anomalies in the coal seam caused by the goaf have been addressed using the correction method of space-varying amplitude.Results show that the 4 D seismic data processing and interpretation method established in this study is reasonable and effective.展开更多
文摘获取长时间序列的高山内陆湖泊变化信息,对研究高山环境变化和气候变化的响应具有重要的意义.近几十年,阿牙克库木湖湖泊面积发生了较大的变化,因此本文以阿牙克库木湖为研究对象,利用1976年至2019年的Landsat系列卫星影像,采用NDWI水体指数法提取阿牙克库木湖8期湖泊面积信息,并结合降雨和气温等气象数据进行变化分析.结果表明:阿牙克库木湖在1976年至2019年面积由611.023 km 2增加到1084.73 km 2,增加了473.707 km 2.其中,1976年至1996年呈小幅度的萎缩或扩张,在1996年以后湖泊面积加速扩张.从1980年至2015年的降雨和气温数据看,湖泊面积与年平均降水量以及年平均温度具有正相关关系.
基金funded by the National Key Research and Development Program Subject(No.2018YFC0807804)。
文摘The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this study,4 D seismic monitoring technology that is effective in reservoir development was used to monitor abnormal changes in coal-mine underground goaf to explore the feasibility of the method.Taking a coal mine in Hancheng,Shaanxi as an example,we used the aforementioned technology to dynamically monitor the abnormal changes in the goaf.Based on the 4 D seismic data obtained in the experiment and the abnormal change characteristics of the coal-mine goaf,the method of 4 D seismic data processing in reservoir was improved.A set of 4 D data processing flow for the goaf was established,and the anomalies in the surface elevation and overlying strata velocity caused by collapse were corrected.We have made the following improvements to the method of 4 D seismic data processing in the reservoir:(1)the static correction problem caused by the changes of surface elevation and destruction of the low-velocity layer has been solved through fusion static correction to comb the low-frequency components of elevation statics with the high-frequency components of refraction statics;(2)the problem of overlying strata velocity changes in the goaf caused by collapse has been solved through the velocity consistency method;(3)the problem of reflection event pull-down in the disturbance area has been solved through space-varying moveout correction based on cross-correlation;and(4)amplitude anomalies in the coal seam caused by the goaf have been addressed using the correction method of space-varying amplitude.Results show that the 4 D seismic data processing and interpretation method established in this study is reasonable and effective.
