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在海洋渔业GIS应用中,用现有GIS直接计算渔区温度水平梯度时,由实际距离问题引起的相对误差达26％、绝对误差达0.124℃／10km,同时还存在渔区格网不规则问题和渔区格点值问题。本文提出了基于SST等值线计算渔区温度水平梯度一种新的GIS算法。该算法的结果优于用ArcGISTIN计算的结果,并可用于计算盐度、叶绿素等其它海洋要素的水平梯度。

Because the statistical unit of catch production is fishing grid whose size is 30 ×30 or 10 ×10 in marine fishery, the horizontal temperature gradient of fishing grid need to be calculated in order to analyze fishing ground environment by scientists. But there are the questions of real distance, irregular grid (after fishing grid is projected to Mercator projection) , value of grid points ( not cell value) if current commercial GIS software is used to calculated temperature gradients of fishing grid....