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从2003年开始,中国三峡水库将进入蓄水期。到2009年,从长江中段起大约600km长的广阔区域内注水,三峡水库将蓄水40km~3。蓄水过程代表着地球物理学的“控制实验”为详细研究经典的正向/反向模拟地表荷载问题提供了独一无二的机会。尽管Wang(2000)研究了局部尺度的大荷载效应,但我们的目标是从数百千米向上游更长的空间尺度,重点在通过新近发射的GRACE卫星可检测到的随时间变化的重力信号。该卫星寿命期为5年(至2007年),将跨越主要蓄水期。我们采用PREM弹性地球模型用格林函数法所得结果表明,大地水准面高度的年增加值在直到20阶球谐函数的尺度上都高于GRACE卫星的观测灵敏度,而5年周期的累积增加值则在直到50阶球谐函数的尺度上(相当于波长800km)都高于观测灵敏度。
Since 2003, the Three Gorges Reservoir in China will enter a water storage period. By 2009, water injection will take place in a vast area of about 600 km from the middle of the Yangtze River, and the Three Gorges Reservoir will have an impoundment of 40 km -3. The impoundment process represents a geophysical “controlled experiment” that offers a unique opportunity to study in detail the classical forward / reverse modeling of surface loading problems. Although Wang (2000) studied the large-scale local-scale loading effect, our goal is to extend the spatial scale from hundreds of kilometers upstream to above, focusing on gravitational signals that are detectable over the newly launched GRACE satellite over time . The satellite’s lifespan is 5 years (up to 2007) and will span the main water-storage period. Our results using the Green’s function method for the PREM elastic Earth model show that the annual increase in geoid height is above the GRACE satellite’s observability sensitivity up to the 20th order spherical harmonics, whereas the cumulative increase in the 5-year period The magnitudes of the spherical harmonics up to the 50th order (equivalent to a wavelength of 800 km) are above observation sensitivity.