Study On The Influence Of The Longmen Mountain Tunnel On The Groundwater Environment In Longmen Mountain Region

Tunnel excavation is equivalent to adding a new underground water drainage corridor, breaking the groundwater balance years formed by years, and have some impact to the local groundwater. If the groundwater discharge from the tunnel without control,it will result in a decline of the groundwater table, making the impact to groundwater outcrop within a radius of less,making spring, caves, underground rivers and other water of different degrees of reduced or disappeared, resulting in crop failures and the surface Plants wilt or death, directly or indirectly affecting the lives and production of local residents.Longmen tunnel will pass through environment sensitive areas. This article aims to become the Blue Line as an example of the Longmen Shan-lane tunnel to analyze the impact to the regional groundwater after the tunnel excavation. Firstly, analyzing the karst conditions, groundwater recharge discharged directly into the state of the environment, on the basis of the field investigation, data collection and analysis of water chemistry data, and specific analyze of groundwater of the tunnel discharge Longmenshan size and might of the environmental impact of groundwater in the study area affected by the extent of groundwater district with systems point, through the analysis that the tunnel section through Suishui River soluble rock have the greatest impact on the groundwater environment, and Crossing the environment because of the depth of groundwater large karst development and other reasons are not affected to a lesser extent. Thousand Buddha Mountain Tunnel on the panda habitat area and the impact is small. Finally, the article by fuzzy AHP of the Longmen Shan tunnel excavation on groundwater environment.By the analysis ,the LonMen tunnel have a certain influence to the groundwater environment of the Longmen mountains, but, overall,the impact on the environment of sensitive areas is not large. The affected zone is the main river through Suishui soluble rock segment, especially the GaoChuanping. Specific results are as follows:(1)Karst structures are controlled by the North East to the development of NE characteristics. Tunnel D1K91+166.08-D1K95+818 belong to the karst middle section,which passing through the level of karst water runoff zone. Tunnel Crossing D1K95+410-D1K111+35.88 belong to the weak karst section,which passing through the layer depth are mainly karst belt loop.(2)Advantages water ions in the study area are Ca²⁺, Mg²⁺, HCO₃^-and SO₄^2-, the average salinity is 327mg / L. Jinxi Gully upstream water samples which have Na⁺, SO₄^2-, SiO₂ and high in that it flows through the karst formation of the Sinian weak. The chemical and isotope analysis through the study area that is mainly precipitation of groundwater recharge, runoff generally shorter, Golden Gully drainage area flowing through the non-karst formation.(3)Tunnel through the area is divided into four major groundwater systems, including groundwater systems Maliuping, groundwater system Dawuji, groundwater system Damacao and groundwater system Banpo,the groundwater system Maliuping is the main type of carbonate cave water fissure water, groundwater is most enriched in the most complicated hydrogeological conditions.(4)The tunnel is divided into five sections of Gushing water and groundwater for environmental impact analysis,a.D1K91+166.08-D1K95+822 cross the Suishui river section of the strata based mainly on soluble rock strata, the possibility of Water Maliuping of the maximum. Maliuping water that happens under the ground water system division, risk of Gushing water tunnel sections, etc. impact on the groundwater district, through the division of that section of the tunnel starting soluble rock through the greatest impact on the groundwater environment. Thousand Buddha Mountain tunnel on the panda habitat area and environmentally sensitive areas of the two small.(5)We predict the water inflow mainly by two ways, groundwater runoff is 12196 m³/d by the modulus method,and by the rainfall infiltration method is 15970m³/d, in general the results of little difference.Maliuping after considering estimates of groundwater runoff modulus by law 12196m³/d, where a section of floor Maliuchang groundwater system accounted for 32.2%, as the main water gushing paragraph.(6)Negative Environmental Assessment: A fuzzy AHP evaluation negative effect of the tunnel environment, the negative effect of the environment caused by the tunnel is divived into five levels, evaluation results caused by 2.69, that is, tunneling Longmen Negative effects of the degree of water between weak and middle. From the results of Longmen Longmen tunnel groundwater environment has some negative effect, but on balance assessment that the project feasible.