DDM30 river routing network for ISIMIP3

The Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) provides a framework for the collation of a consistent set of climate impact data across sectors and scales. It also provides a unique opportunity for considering interactions between climate change impacts across sectors through consistent scenarios.<br>The ISIMIP3a part of the third simulation round is dedicated to i) impact model evaluation and improvement and ii) detection and attribution of observed impacts according to the framework of IPCC AR5 Working Group II Chapter 18. To this end all simulations are driven by observed socio-economic information combined with either observed (factual) climate data or a detrended (counterfactual) version of the observed climate allowing for the generation of a "no climate change" baseline.<br>The ISIMIP3b part of the third simulation round is dedicated to a quantification of climate-related risks at different levels of global warming and socio-economic change. ISIMIP3b group I simulations are based on historical climate change as simulated in CMIP6 combined with observed historical socio-economic forcing. ISIMIP3b group II simulations are based on climate change according to the CMIP6 future projections combined with socio-economic forcings fixed at 2015 levels. ISIMIP3b group III simulations additionally account for future changes in socio-economic forcing.<br>This dataset contains the river routing network input for ISIMIP3 simulations: DDM30 is a raster map which describes the drainage directions of surface water with a spatial resolution of 30’ longitude by 30’ latitude, and covers the land surface of the globe (without Antarctica). In addition to the routing network, DDM30 includes raster maps for basin numbers and slopes. More information can be found on the ISIMIP Homepage: https://www.isimip.org/gettingstarted/input-data-bias-adjustment/details/20/.

跨部门影响模型比较计划（Inter-Sectoral Impact Model Intercomparison Project，ISIMIP）提供了一套框架，用于整合不同部门、不同尺度下的一致性气候影响数据集。同时，它也为通过统一情景分析跨部门气候变化影响间的相互作用提供了独特机遇。
第三轮模拟中的ISIMIP3a模块聚焦两大目标：其一为影响模型的评估与优化；其二为依据政府间气候变化专门委员会第五次评估报告第二工作组第18章（Intergovernmental Panel on Climate Change Fifth Assessment Report Working Group II Chapter 18，IPCC AR5 WGII Ch18）的框架，对已观测到的气候影响开展检测与归因研究。为此，所有模拟均以观测得到的社会经济信息作为驱动因子，并结合两类气候数据：一类为观测到的（事实性）气候数据，另一类为经去趋势处理的观测气候数据（反事实场景），借此可生成“无气候变化”的基准情景。
第三轮模拟中的ISIMIP3b模块则旨在量化不同全球增温水平与社会经济变化情景下的气候相关风险。其中，ISIMIP3b第一组模拟以耦合模式比较计划第六阶段（Coupled Model Intercomparison Project Phase 6，CMIP6）模拟得到的历史气候变化为基础，结合观测到的历史社会经济强迫因子；ISIMIP3b第二组模拟以CMIP6未来情景下的气候变化为基础，同时将社会经济强迫因子固定在2015年水平；ISIMIP3b第三组模拟额外纳入了社会经济强迫因子的未来变化。
本数据集包含ISIMIP3模拟所需的河道汇流网络输入数据：DDM30是一套栅格地图，以30角分经度×30角分纬度的空间分辨率描述地表径流的汇流方向，覆盖全球除南极洲以外的陆地区域。除汇流网络外，DDM30还包含流域编号与坡度的栅格地图。更多详细信息可查阅ISIMIP官方网站：https://www.isimip.org/gettingstarted/input-data-bias-adjustment/details/20/。

搜集汇总

背景与挑战

背景概述

DDM30河流路由网络数据集为ISIMIP3项目提供全球30’x30’分辨率的河流排水方向、流域编号和坡度信息，适用于水模型的径流模拟。该数据集基于DDM30并针对ISIMIP3的CRU陆地-海洋掩膜进行了优化调整，特别处理了海岸带和内陆汇水区标识。