| The northeast side of kunming basin exposed a large area of carbonate rocks, carbonate rocks from the edge to the center of the basin gradually changed from bare-to covered to buried distribution pattern, as an aqueous medium, characteristics of karst water system is very complicated. Kunming basin is covered by Quaternary, flat terrain, human engineering activities, is the main activity area of groundwater, at the same time the area mainly affected supply by the karst water system in the northeastern side of the basin. Therefore, research on Kunming basin north east side of karst water system characteristics is of great significance. In addition, in order to solve the serious shortage of water resources in central region of Yunnan including Kunming, a growing number of cross-regional water diversion project is in planning and construction. Affected by the restrictions of geological conditions, mostly engineering in the region are in form of tunnel, and it will lead to a great impact on the regional groundwater environment, The study of this paper will provide a scientific basis for the working of choosing line, construction, groundwater environment evaluation for the engineering.This paper departured from the background characteristics of the study area environmental geology and karst development features, devide the karst water system, and each karst water system characteristics were studied. On the basis of analysis of karst water system, use3D groundwater simulation software Visual Modflow to analysis the study area. The main study results are as follows:(1) The study area is mainly exposed in the Sinian Dengying Formation (Zbdn), lower Cambrian Longwangmiao formation (∈1l) and middle Shuanglongtan Formation (∈2S), lower Ordovician Noldor Formation (O1n), the upper Devonian Zaige Formation (D3zg), lower Carboniferous Dakuang order Formation the boss segments (C1d2) and middle Weining formation (C2w) and lower Permian Yangxin formation (P1y) and soluble stratum. According to karst stratum lithology, karst strata in the research area into three types:①layer Formation thick layered homogeneous pure carbonate rock Formation;②thick layered medium purity carbonate Formation I;③interstratified carbonate and clastic rocks with carbonate rock Formation, and analyzes the space relationship of rock formations.(2) Study area in the north east of the rocky mountains, karst bare surface, karst form is rich, rare karst depression, sinkholes, karst valley, stone bud; basin, karst quaternary stratigraphic coverage, local lavas overlying third clay layer, locally confined groundwater, development of buried karst. Study area is a bare-covered-burial type karst distribution patterns from edge to center of basin. According to relevant borehole shows study area, karst underground corrosion phenomenon more concentrated within the height range of1849-1955m, developing depth of shallow underground solution in the0-50m range.(3) The study area of thick layered homogeneous pure carbonate rock formation of Lower Permian Yangxin formation (P1y) limestone karst development degree, water rich and strong, exposed on the surface area of191.33km2; thick layered medium purity carbonate group karst water rich medium, medium strong, exposed on the surface area of235.71km2, in the layer group of karst development intensity between C+D> Zbdn; layered carbonate rock and clastic rocks with carbonate rocks of Cambrian Longwangmiao formation, Ssangyong group Tan group due to differences in lithology and purity limestone karst development degree is not high, weak, watery medium, outcropped area of40.62km2.(4) According to the regional water system, structure, moisture-rich water-based rock group factors such as karst water system in the study area is divided into West White River karst water system (Ⅰ), Panlong River karst water system (Ⅱ), golden juice river karst water system (Ⅲ), Eastern white River karst water system (Ⅳ), Po River karst water system (Ⅴ), Wu camp karst water system (Ⅵ) of six two karst water system. And further refinement of karst water system in each row of characteristic differences complement diameter secondary karst water system in accordance with, is divided into14sub-karst water levels, and the characteristics of the various subsystems of karst water for a detailed description and analysis.(5) On the basis of analysis of the characteristics of karst water system, the use of Visual Modflow karst water system established in the study area three-dimensional groundwater flow field model. Model results match the groundwater flow field is more real situations. By calculation, the model area karst groundwater hydraulic gradient is small, generally distributed between0.002to0.008, non-karst groundwater hydraulic gradient can be significantly increased over the lava area, generally distributed between0.008to0.015, partial watertight bands such as the snake mountain on the north side P1d mudstone confining effect is very obvious, groundwater hydraulic gradient of up to0.2to0.5, there is a certain pressure of groundwater.(6) Water balance using Visual Modflow calculated separately for each module karst water system to recharge basin to Kunming lateral groundwater recharge system (Ⅰ～Ⅵ) respectively,12957m3/d,101534m3/d,27451m3/d,9635m3/d,213980m3/d,115136m3/d, total480693m3/d. And each system can be partially and non-partial lava flow recharge basins, single-wide traffic were calculated. The results show that each system can be single-wide lava flow is non-soluble in5to7times. |
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