There maybe many layers in a database, e. g. soil type, elevation, land use, land cover.

一个数据库中可能有许多层，例如土壤类型、海拔、国土利用、国土覆盖。

youdao

The effects of vegetation type, rainfall intensity, surface crust, and weed cover on rainfall infiltration and runoff on grassland and bare land were studied under simulated rainfall conditions.

利用野外模拟降雨试验，研究了植被类型、降雨强度、地表结皮、覆盖杂草等对荒草地和裸地降雨入渗、产流的影响。

youdao