Study On The Control Of Structure To Karst And Karst Water In The Source Area Of Yihe River

Yihe River is the largest river in Shandong Province,which isoriginated from Yiyuan County of Zibo.The origin of Yiyuan county is also related to it.The study area covers most parts of the headwaters of Yihe River.The carbonate strata of the Cambrian and Ordovician systems are widely distributed in the study area,and the karst development is high.The karst cave group in the NanLushan Mountain fault basin,located in the Nan Lu Mountain Town,Yiyuan County,is called "the first karst cave group in the north".In this paper,the formation mechanism of the main fault zone and the Shangwujing fault zone in the study area and its influence on the regional geomorphologic pattern are analyzed,and the relationship between the characteristics of regional tectonic movement and the lithology of karst rock mass is studied,and the distribution characteristics and causes of karst cave in the Nan Lushan Mountain are analyzed.Then,through the study of remote sensing image,hydrogeological map and the lithology of karst,combined with the theory of tectonic water control,the control effect of geological structure on karst water is judged in macroscopic view.Then through the macroscopic understanding of the geological structure of karst water control,combined with the lithology of regional strata,underground watershed and the boundary of surface flow,the study area is divided into four five grade karst water systems.Finally,through the analysis of local faults,folds,stratigraphic lithology and groundwater flow,fifteen karst water enrichment blocks are divided in the study area,and eight types of reservoir structure in the rich water block are summarized.The following points are made in this paper:1.The Shangwujing fault zone is a first-order structural belt in the area,which not only controls the distribution of the lithology of the formation,but also controls the formation of the Lucun basin and the South Ma Basin.2.The soluble salt content and the combination of rock strata and geological structure are the geological factors of karst development.3.The karst cave in the fault basin of nanlu mountain is divided into three layers,distributed on the third-level planation surface?The elevation fitting equations were established for the three-layer karst caves,and the effects of different tectonic movements on the Nanlushan cave group were obtained.4.The water control mechanisms of the Songxianling-Dapo fault and the Hanwang fault are similar,and the fissure water in the metamorphic rock area is replenished to the carbonate rock area through the structural diversion.The Shangwujing fault zone resulted in the differentiation of formation lithology in the carbonate rock area,and the poor permeability of the formation blocked the karst water runoff.5.The study area was divided into four Karst systems of Nanlushan,Lucun,Nanma,and Dongli.On this basis,the 15 water-rich sections of Shuimetou,Zhifang,Yutai,Shilou,Xihebei,Xili,Haoshan,Shanggao,Zhonghanzhuang,Chechang,Siling,Anleguanzhuang,Chaijiazhuang,Shanglongxiang and Fenshuguangzhuang were identified.6.The Water storage structure in the reservoir structure of the study area was divided into eight types of monoclinic water bearing structure,the fault waterblock water bearing structure,monoclinic-fault composite water bearing structure,Karst fault block water bearing structure,and the lithologic waterblock water bearing structure,fault broken water bearing structure,anticlinal water bearing structure,and syncline water bearing structure,which were analyzed one by one.