黄河源区径流量对地表覆盖动态变化的响应研究

The change of Land surface coverage is important factor expected to have widespread impacts on streamflow in the Yellow River source catchment. The brightness temperature observation of satellite-borne passive microwave radiometer and discharge observation from four hydrologic stations are gathered to project the streamflow response of land cover changes. Passive microwave radiometer SSM/I and SSMIS are used for retrieval of the open water fraction, the microwave vegetation canopy index, the surface soil freeze/thaw states and the snow water equivalent which are considered as indicators for quantifying land surface coverage change. Combining the observation, remote sensing retrieval and estimators from climate elasticity model of streamflow, three objects are planning to discuss during the implementation of this project, 1) Analyze indicators of land surface coverage effects on annual streamflow from 1988 to 2012 and identify the annual variation tendency of sensitivity for the strong impact factor.2) Assess the response of streamflow to monthly indicators and lag relationship between streamflow and indicators. 3) Evaluate sensitivity of monthly streamflow increment or decrement with variability of indicators, especially focus on characteristic of streamflow response with variability of snow water equivalent during transition periods from dry season to wet season and variability of open water fraction in flood season. Based on the above analysis, we are eager to gain a wider comprehension of the land surface coverage impact on water resource amount in the Yellow River source catchment.

评估黄河源区地表覆盖动态变化对河川径流的影响具有重要意义。本项目通过星载微波辐射计SSM/I与SSMIS观测数据，反演黄河源区地表覆盖特征量-地表裸露水体组分、植被冠层特征参数、表层土壤冻融状态及雪水当量，并以径流和地表覆盖特征量的月、年际变化的角度入手，基于径流量的气候弹性模型分析：1）1988-2012年间年径流量对地表裸露水体组分、微波植被指数、表层土壤冻融状态及雪水当量响应的程度有何差异，其中的强影响因子的敏感度的年际变化趋势；2）评估月径流量对地表覆盖特征量的响应程度及月径流量对地表覆盖特征的滞后响应特征；3）评估月径流量增减对地表覆盖特征变率的敏感程度，重点关注枯水期向丰水期转换时段径流量对雪水当量变化、以及汛期径流量对湿地面积变化的响应程度。上述分析将进一步揭示黄河源水源涵养区地表覆盖动态变化对水资源影响。

评估黄河源区地表覆盖动态变化对河川径流的影响具有重要意义。本项目通过星载微波辐射计SSM/I与SSMIS观测数据，反演黄河源区地表覆盖特征量-地表裸露水体组分、植被冠层特征参数、表层土壤冻融状态及雪水当量，并以径流和地表覆盖特征量的月、年际变化的角度入手，基于径流量的气候弹性模型分析：1）1988-2012年间年径流量对地表裸露水体组分、微波植被指数、表层土壤冻融状态及雪水当量响应的程度有何差异，其中的强影响因子的敏感度的年际变化趋势；2）评估月径流量对地表覆盖特征量的响应程度及月径流量对地表覆盖特征的滞后响应特征；3）评估月径流量增减对地表覆盖特征变率的敏感程度，重点关注枯水期向丰水期转换时段径流量对雪水当量变化、以及汛期径流量对湿地面积变化的响应程度。上述分析将进一步揭示黄河源水源涵养区地表覆盖动态变化对水资源影响。.