Analysis Of The Hydrogeological Structure Of The Red Layer In The Middle Of Longquan Mountain,Chengdu

As an important central city in Southwest China,Chengdu is implementing a new urban development strategy of “Dongjin,Nantuo,Xikong,Beibei and Zhongyou” in order to accelerate the construction of a national central city that fully reflects the new development concept.Identify the hydrogeological conditions of Longquan Mountain and the red layer of the eastern hills,divide the regional basic hydrogeological units,establish standard hydrogeological structures,and further analyze the groundwater hydrochemical characteristics and cyclic evolution laws,which can be implemented for Chengdu's “Dongjin” strategy.Provide basic geological support for the Longquanshan National Urban Park Planning and the ecological environment protection of the Lancang River Basin.From the point of view of structural cybernetics,this paper uses the internal structure of the analysis system to quantitatively or qualitatively understand the functional characteristics and behaviors of the system,and explores its internal structure and mechanism,and depicts the hydrogeological structure of the red layer in the middle part of Longquan Mountain.Combined with the groundwater system,the water chemistry and cyclic evolution of the shallow groundwater system in the red layer hydrogeological structure are characterized in a concise manner.The main conclusions are as follows:(1)Based on the hydrogeological complex with the same hydrogeological characteristics,the hydrogeological structure types of the red beds in the study area are divided into three categories and six categories.The hydrogeological structure of the superficial weathering zone(the hydrogeological structure of the shallow weathering zone in the hilly area and the hydrogeological structure of the shallow weathering zone in the low mountainous area),the layered hydrogeological structure(the sandy layered hydrogeological structure,the argillaceous layered hydrology)Geological structure,silt interbedded layered hydrogeological structure and layered dissolution pore hydrogeological structure)and fractured vein hydrogeological structure.(2)According to the type of red-layer hydrogeological structure,the spatial hydrogeological structure of the middle red section of Longquan Mountain is finely divided and characterized.Cretaceous: The hydrogeological structure of the Qiqusi Formation is divided into 8 layers in the space of 200.2m from the top to the bottom.The 5 layers of hydrogeological structure are medium-rich,and the 3 layers of hydrogeological structure are weak;the Bailong Formation hydrogeological structure It has 8 layers in its 172.5m space from the top to the bottom.The 3 layers of hydrogeological structure are extremely rich in water,1 layer of hydrogeological structure is rich in water,3 layers of hydrogeological structure are rich in water,and 1 layer of hydrogeological structure is rich in water.Weak;the hydrogeological structure of Cangxi Formation is divided into 13 layers in the space of 167 m from the top to the bottom.The 8 layers of hydrogeological structure are extremely rich in water,the 2 layers of hydrogeological structure are rich in water,and the 3 layers of hydrogeological structure are rich in water..Jurassic: The hydrogeological structure of Penglai Town Group is divided into 10 layers in the space of 865.23 m from the top to the bottom.The 4 layers of hydrogeological structure are rich in water,the 3 layers of hydrogeological structure are rich in water,and the 3 layers are rich in hydrogeological structure.The water-based geological structure of the Suining Formation is divided into 9 layers in the space of 258 m from the top to the bottom plate.The 5 layers of hydrogeological structure are medium-rich,and the 4 layers of hydrogeological structure are weak;the hydrogeological structure of the Shaximiao Formation is The top plate is divided into 11 layers in the 446 m space.The 1 layer hydrogeological structure is rich in water,the 5 layers hydrogeological structure is rich in water,and the 5 layers hydrogeological structure is weak.(3)Dividing the hydrogeological unit of the study area,combined with the red-layer hydrogeological structure model of the study area,and analyzing the cyclic evolution of the shallow groundwater system in the hydrogeological structure of the red bed space.Hydrogeological unit of the west wing of Longquan Mountain(I): The source of groundwater recharge is atmospheric precipitation,the runoff channel is dominated by hydrological and geological structures in shallow weathering zone,the drainage reference surface is Minjiang River and Minjiang River;Longquan Shandong Wing-Liangjiang Hydrogeological Unit(II): Groundwater The source of recharge is atmospheric precipitation,the low-mountain runoff channel is dominated by hydrological geological structure in shallow weathering zone,the runoff in layered hydrogeological structure in hilly area is obviously increased,and the layered hydrogeological structure is the main runoff channel in some areas,excretion datum For the Lijiang River.From the perspective of the study area as a whole,the shallow groundwater in the low mountainous area mainly flows along the hydrogeological structure of the superficial weathering zone to the two-wing runoff of the Longquan Mountain,and some of the inter-layer water along the layered hydrogeological structure runoff or the runoff formation along the fault-like vein-like hydrogeological structure.Fissure water;the shallow groundwater in the hilly area is mainly along the runoff of layered hydrogeological structure with strong water-rich structure,forming inter-layer water,locally under the influence of structure,forming confined water,hydrogeological structure in the shallow weathering zone of hilly area Groundwater mainly flows along the surface and is relatively weak in mountainous areas.The Bailong Formation and Cangxi Formation of the Cretaceous in the hilly area are dominated by multi-layered water-rich hydrogeological structures.In the Lancang area,the hydro-geological structures with strong water-rich structure in the two strata are 20 m,40m,90 m and 130 m deep,extending to the north at an inclination of about 1°-2°,and southward in the vicinity of Jiajia Town.The hydrogeological structure and the sandy layered hydrogeological structure of the layered dissolution pores of the Cangxi Formation are buried at 50 m and 90 m.The Bailong Formation is completely weathered and denuded,and the depth of the extension to the east and west wings of Jiajiachang is shallow.The inclination angles are 4°-7° and 9°-13°,respectively.