Hydrographic sections — Guyana 2015 — BD Carthage

Descriptive definition of BD Carthage content: an elementary hydrographic section corresponds to the axis of the bed of a river, creek or canal

The polylines are drawn a priori in the direction of the flow of the section.

The minimum length of a section is 200 metres on the ground.
The cutting of the sections shall be carried out according to:
— A change of attribute in the fields of the table,
— A change in the type of medium: the section crosses a surface area, for example,
— A modification of the morphological facies of the watercourse (single arm, anastomosis),
— The presence of a jump (expressed by a break of slope),
These changes are identified by photo-interpretation of available orthoimages.

BD Carthage数据集内容的描述性定义：基础水文河段对应河流、溪流或运河的河床轴线。
该多段线按照河段的水流方向先验绘制。
单河段的实地最小长度为200米。
河段的分割需遵循以下规则：
—— 数据表字段中的属性发生变更；
—— 介质类型发生变化：例如河段跨越某一地表区域时；
—— 河道地貌相态发生改变（如单一河道、网状河道）；
—— 存在坡度突变点（以坡折表示）；
上述变更均可通过对现有正射影像（orthoimage）的影像解译完成识别。