Sediment accumulation rates and age of sediments were determined using 210 Pb dating method by applying constant rate of supply model of six bottom sediment cores, collected from various locations (Rehri Creek, Ghizri Creek, Korangi Creek, Manora Picnic Point, Sandspit and Sunairi Point) of Karachi coastal area of Pakistan. The results showed that an increase in accumulation rate was observed in the recent years in all the sediment cores which may be attributed to human activities and changes in patterns of water circulation. The mean values of sediment accumulation rates varied between 0.43 and 1.45 kg m −2 y −1 and the highest accumulation rates were observed in recent sediments of Manora Picnic Point (3.40 kg m −2 y −1 ), Korangi creek (2.88 kg m −2 y −1 ) and Ghizri creek (2.13 kg m −2 y −1 ), which may owe to the anthropogenic inputs (direct discharge of massive amount of industrial and domestic wastewaters into the sea) and addition of sediment loads by river run off during monsoon season. It was also inferred from the study that the bottom most layers of different sediment cores were estimated to be accumulated between 1889 and 1911.

中文翻译：

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巴基斯坦卡拉奇沿海地区沉积物积累率使用 210Pb 测年法

通过应用从不同地点（Rehri Creek、Ghizri Creek、Korangi Creek、Manora Picnic Point、Sandspit 和 Sunairi Point）收集的六个底部沉积物岩心的恒定供应速率模型，使用 210 Pb 测年法确定沉积物积累率和沉积物年龄巴基斯坦卡拉奇沿海地区。结果表明，近年来所有沉积物岩心的积累率均有所增加，这可能与人类活动和水循环模式的变化有关。沉积物积累率的平均值在 0.43 和 1.45 kg m -2 y -1 之间变化，并且在 Manora Picnic Point（3.40 kg m -2 y -1 ）、Korangi 小溪（2.88 kg m -2 y -1 ) 和 Ghizri 小溪 (2.13 kg m -2 y -1 )，这可能是由于人为输入（将大量工业和生活废水直接排放到海中）和季风季节河流径流增加的沉积物负荷。研究还推断，不同沉积岩心的最底层估计是在 1889 年至 1911 年之间积累的。