European catchments and Rivers network system (Ecrins) - version 1, Jun. 2012

Ecrins is acronym for European catchments and Rivers network system. It is a geographical information system of the European hydrographical systems with a full topological information. Ecrins is a composite system made from the CCM developed by the JRC, Corine land Cover, WFD reporting elements, etc. It is organised from a layer of 181,071 “functional elementary catchments (FECs)” which average size is ~62 km2, fully connected with explicit identifier (ID) relationships and upstream area. Catchments are grouped as sub-basins, river basin districts (actual and functional to meet hydrographical continuity). The catchments are as well organised according to their sea shore of emptying to meet Marine Strategy delineations. Catchments are drained by 1,348,163 river segments, sorted as “main drains” (connecting together the FECs) and secondary drains (internal to a FEC). river segments mimic the natural drainage, however fulfilling the topological constraint of “0,1 or 2 upstreams, single or 0 downstream”. Each segment is populated with distance to the sea, to ease further processing. They are connected to elementary catchments and nodes documented with altitude. Segments are as well documented with a “dummy river code”, fully populated that earmark each segment with the most distant to the outlet in each drainage basin and, everywhere this has been possible, with a “true river” ID based on river naming. A layer of lakes and dams has been elaborated. Lakes polygons (70,847) are taken from Corine Land cover , WFD Art. 13 and in some cases, from CCM “water layer”. Lakes inlets and outlets are set with the segment ID and where relevant, the dams making the lake is documented. All lakes which depths and volume was found have been updated. Version 1.0 here presented still contain some topological errors (e.g. incorrect segment branching), because inaccurate geometry. They are noted and a correction procedure is underway.Ecrins是欧洲流域与河流网络系统（European catchments and Rivers network system）的首字母缩写，是一套涵盖完整拓扑信息的欧洲水文地理系统地理信息系统。该系统为复合数据集，由欧盟联合研究中心（Joint Research Centre, JRC）开发的CCM、科琳娜土地覆盖（Corine Land Cover）、水框架指令（Water Framework Directive, WFD）报告要素等整合而成。 该数据集以181071个功能基本流域（functional elementary catchments, FECs）为基础图层搭建，单幅流域平均面积约62平方千米，所有要素均通过明确的标识符（ID）关联关系与上游汇水区域实现完全连通。流域可被聚合为子流域与流域分区，兼顾实际与功能属性以满足水文连续性要求。 同时，流域还将按照其入海河口进行分组，以契合海洋战略的划定标准。 该数据集包含1348163条河道段，用于表征流域汇水路径，河道段分为“主河道”（用于连接各功能基本流域）与“次级河道”（仅存在于单个功能基本流域内部）两类。河道段的构建模拟自然汇流路径，同时严格遵循拓扑约束：每条河道段仅可拥有0、1或2条上游河道，且仅可拥有0或1条下游河道。每条河道段均附带至河口的距离属性，以方便后续处理工作。河道段与基本流域及带有高程属性的节点建立关联。 河道段还附带“虚拟河道代码”属性，该属性已完成全量填充，可标记每个汇水盆地中距出水口最远的河道段；在条件允许的情况下，还会基于河道命名赋予每条河道段“真实河道ID”。 数据集还构建了湖泊与大坝图层。湖泊多边形要素（共70847个）的数据来源包括科琳娜土地覆盖数据集、水框架指令第13条相关数据，部分案例还采用了CCM的“水体图层”数据。湖泊的入水口与出水口均关联了对应的河道段ID，若存在相关大坝，则会记录构成该湖泊的大坝信息。 所有已获取水深与容积数据的湖泊信息均已完成更新。 本次发布的1.0版本仍存在部分因几何精度不足导致的拓扑错误（如河道段分支错误），相关问题已被记录，修正流程正在推进中。