River plastic emissions to the world's oceans

Modelled plastic inputs into the ocean from rivers worldwide. The shapefile contains 40,760 input points (EPSG:4326, WGS 84) with the following attributes:<b>i_[ </b>level <b>]</b>: plastic input in tonnes per year. (<i>level=low, mid or high for lower, midpoint and upper estimates</i>)<b>i_[ </b>level <b>]_[ </b>month <b>]</b>: plastic input in tonnes per month. (<i>level=low,mid,high; month=jan,feb,...,dec</i>)<b>runoff_[ </b>month <b>]</b>: monthly averaged runoff in catchment in mm per day. (<i>month=jan,feb,...,dec</i>)<b>mpw</b>: mismanaged plastic waste production in catchment in tonnes per year. <b>area</b>: catchment area in square kilometers.<br>

本数据集模拟了全球范围内河流向海洋输入的塑料污染物总量。该数据集的矢量文件（shapefile）包含40760个输入点，坐标系采用EPSG:4326（WGS 84），附带以下属性字段：
`i_[level]`：流域年塑料输入量，单位为吨/年，其中level可取low、mid、high，分别对应低、中、高三种估算情景；
`i_[level]_[month]`：流域月塑料输入量，单位为吨/月，其中level取值为low、mid、high，month取值为jan、feb至dec（即1月至12月）；
`runoff_[month]`：流域月均径流量，单位为毫米/日，month取值为jan、feb至dec；
`mpw`：流域内未妥善管理的塑料废弃物年产量，单位为吨/年；
`area`：流域面积，单位为平方千米。