土地利用变化下的水文响应及其可检测性分析

以涪江桥流域为研究区域,采用SWAT模型模拟流域水文过程,将相同水文气象条件下1985和1995年2个时期土地利用情景的SWAT模型模拟结果与土地利用空间转化图相结合,分析土地利用变化引起的水文要素变化及其可检测性问题。结果表明:1985—1995年间涪江桥流域发生较为剧烈的土地利用变化,但并未检测到足够显著的水文要素变化;不同土地利用类型水文效应的相似性、不同土地利用类型水文效应差异性以及统计中和效应和统计均化效应是导致土地利用变化引起的水文要素变化难以检测的主要原因。在此基础上,提出了水文动态响应度指标,来消除统计中和效应。该指标可以在一定程度上帮助研究者了解研究区特定水文要素变化的相对剧烈程度。研究结果可为土地利用总体规划和流域水资源保护与合理配置提供参考。

Detectability of Hydrological Response to Land Use Change

The hydrological response to land use change and the detectability of such response are researched in thispaper by SWAT model. The hydrological processes in Fujiangqiao catchment under two land use scenarios (1985and 1995) are simulated, and diagrams of land use conversion are obtained for analysis. Identical climate drivers are used in both scenarios to eliminate the effect of climate difference. Results reveal that no apparent hydrological responses are detected in spite of dramatic land use changes in Fujiangqiao catchment from 1985 to 1995. The similarity of hydrological effect of different land use types, the variation of hydrological effect of different land use types, the statistical compensation effect, and the statistical average effect are main reasons of the difficulty in detecting the hydrological responses. In view of this, a hydrological dynamic response degree is proposed to eliminate the statistical compensation effect, which helps researchers understand the degree of hydrological responses.