Indicators of Coastal Water Quality: Change in Chlorophyll-a Concentration 1998-2007

The Change in Chlorophyll-a Concentrations 1998-2007 component of the Indicators of Coastal Water Quality Collection represents a tabular time series of the chlorophyll-a concentrations for each grid cell, derived from the "Indicators of Coastal Water Quality: Annual Chlorophyll-a Concentration 1998-2007" data set. Chlorophyll-a concentrations are derived from NASA's Sea-viewing Wide Field-of-view Sensor (SeaWiFS). The grid cells are organized by country, and the percentage of change from 1998-2007 is calculated for each cell. Each time series was assessed with a linear regression, and cells with statistically significant trends in chlorophyll-a concentrations are identified. The rows of the table are linked to a sequence grid from the "Indicators of Coastal Water Quality: Ancillary Data" collection to facilitate the mapping of the trend values for selected countries and areas of interest. The data are processed and compiled by the Columbia University Center for International Earth Science Information Network (CIESIN).

《1998-2007年叶绿素a浓度变化》数据集组件属于海岸水质指标集合，该集合包含每个网格单元的叶绿素a浓度的时间序列表格，数据来源于“海岸水质指标：年度叶绿素a浓度1998-2007”数据集。叶绿素a浓度由美国国家航空航天局（NASA）的海洋观测宽视场传感器（SeaWiFS）获得。网格单元按国家组织，并计算了1998年至2007年间每个网格单元的百分比变化。每个时间序列均经线性回归分析评估，并识别出叶绿素a浓度具有统计学显著趋势的网格单元。表格的行与“海岸水质指标：辅助数据”集合中的序列网格相连接，以便利选定国家和感兴趣区域的趋势值映射。数据由哥伦比亚大学国际地球科学信息网络中心（CIESIN）处理和汇编。