CSIRO Mathematics, Informatics and Statistics, Ecoscience Precinct, GPO Box 2583, Brisbane, QLD 4001, Australia.
Mar Pollut Bull. 2012;65(4-9):203-9. doi: 10.1016/j.marpolbul.2012.04.002. Epub 2012 May 1.
The export of pollutant loads from coastal catchments is of primary interest to natural resource management. For example, Reef Plan, a joint initiative by the Australian Government and the Queensland Government, has indicated that a 20% reduction in sediment is required by 2020. There is an obvious need to consider our ability to detect any trend if we are to set realistic targets or to reliably identify changes to catchment loads. We investigate the number of years of monitoring aquatic pollutant loads necessary to detect trends. Instead of modelling the trend in the annual loads directly, given their strong relationship to flow, we consider trends through the reduction in concentration for a given flow. Our simulations show very low power (<40%) of detecting changes of 20% over time periods of several decades, indicating that the chances of detecting trends of reasonable magnitudes over these time frames are very small.
污染物负荷从沿海流域的输出对自然资源管理具有主要的意义。例如，由澳大利亚政府和昆士兰州政府共同发起的珊瑚礁计划，就已经指出到 2020 年，需要减少 20%的沉积物。如果我们要设定现实的目标，或者可靠地识别集水区负荷的变化，那么显然需要考虑我们检测任何趋势的能力。我们研究了检测趋势所需的监测水生污染物负荷的年数。我们不是直接模拟年度负荷的趋势，因为它们与流量有很强的关系，而是考虑在给定流量下浓度的减少来反映趋势。我们的模拟结果显示，在几十年的时间内，检测到 20%的变化的能力非常低（<40%），这表明在这些时间框架内检测到合理幅度的趋势的机会非常小。
