洞庭湖区洲土变化特征与地壳沉降遥感研究

THE CHARACTERISTIC OF CONTINENT SOIL CHANGE IN DONGTING LAKE DISTRICT AND REMOTE SENCING RESEARCH ON CRUST SUBSIDENCE

洞庭湖泥沙淤积严重,多年平均泥沙淤积量达万;同时,洞庭湖又处于不均14,334t/a匀的地壳沉降中,沉降速率达～。作者应用世纪年代和年代两个时段个时5.0031.3 mm/a 20709018相卫星遥感数据,系统地调查量算了不同水位时洲滩的出露面积。在此基础上,根据不同水位时来水来沙规律及洲土面积与水位的变化关系,利用现代航天对地观测技术有效地论证了洞庭湖的地壳沉降与湖盆泥沙淤积。研究表明,洞庭湖仍处于不断沉降中,在平水位以下或洪水位以上,地壳沉降速率均大于泥沙淤积速率。

The bedload's filling up in Dongting Lake is serious, the average silt sediment of many years reach up to 143,340,000 t/ a ;At the same time, crust of Dongting Lake again subsides in ～asymmetry with the settlement velocity of 5.00 31.3 mm/ a. The areas of continent soil above water at various water level were systematically investigated according to satellite remote sensing data in two period of time and 18 planes of time in the 1970's and 1990's. On this base, the settlement of crust in Dongting Lake and bedload's filling up in the lake basin were demonstrated effectively by means of the modern technique of spaceflight observation on terra, according to the variety of flowing water and sand and the relationship between the continent soil area and water level.The research shows that Dongting Lake is still subsiding at the level both below water and above flood, and the velocity of the crust Subsidence all exceeds that of bedload's filling up.