面积高度积分的面积依赖与空间分布特征  

Influence of area and space dependence for hypsometric integral and its geological implications

作　　者：赵洪壮[1,2] 李有利[1,2] 杨景春[1] 吕红华[1,2] 司苏沛[1] 

机构地区：[1]北京大学城市与环境学院,北京100871 [2]北京大学地理科学中心地表过程分析与模拟教育部重点实验室,北京100871

出　　处：《地理研究》2010年第2期271-282,共12页Geographical Research

基　　金：国家自然科学基金项目(40571013)

摘　　要：面积高度积分作为揭示区域构造相对活动性的指标,其面积依赖和空间分布两大特性会影响到它对构造活动的解释。以北天山10条河流流域作为研究区域,研究表明,在不同集流面积阈值下,天山北麓流域次集水盆地的平均面积高度积分与平均面积、平均高差都具有负相关关系。受北天山褶皱逆断裂构造带的影响,流域面积高度积分值的分布与构造带走向相一致,上游山地型次集水盆地面积高度积分值大于中游山麓丘陵型次集水盆地面积高度积分,揭示了面积高度积分存在空间分布依赖的特性。在大小不同观测尺度下,构造活动和基岩岩性差异对面积高度积分有着不同的影响。在玛纳斯河流域中,以不同集流阈值提取的不同面积大小的次集水盆地与各年代地层以及活动构造做GIS叠加分析,可以发现当集流阈值小于9km2时,面积高度积分值受到岩性与构造的双重影响,而当集流阈值大于20km2时,面积高度积分值主要反映构造活动的影响。The hypsometric integral（HI）of a drainage basin is a morphometric parameter for describing basin geomorphology.Lately the HI has become an index to infer activities of active tectonics in some orogenic belts.Some scholars take the hypsometric integral as an index to deduce the regional active tectonism.This paper examines two issues related to the HI：area dependence and space dependence.Our study calculates and analyzes the 10 rivers＇ hypsometric integrals of the Northern Tianshan Mountains,and the relations of the HI influencing factors.The result shows that there are x-logarithmic negative correlations not only between the average HI and the average area,but also between the average HI and the average drop,sorted by the different threshold accumulations of the drainage sub-basins in the Northern Tianshan Mountains.Moreover,there are higher HIs on moutain-type subbasins at upper stream and lower HIs on hill-type subbasins at piedmont.The three east-west trending thrust-fold belts along the southern flank of the Jungar basin divide the study area based on HIs into several regions with the same tendency of the three thrust-fold belts.It opens out the spatial dependence of the HI.The abnormal districts of the HI in the smaller drainage basin,present the remarkable influence of the rocky ingredient and the lithologic difference.In Manas river basin,by overlaying lithologic and tectonic maps on different drainage areas of subbasin groups,we found that the HIs of subbasins showed the effect of lithology and tectonics using a threshold less than 9km2.However,the HIs showed almost entirely the effect of tectonic elements using a threshold more than 20km2.

关 键 词：面积高度积分 面积依赖 空间分布 构造活动 天山 

分 类 号：P542[天文地球—构造地质学]