| The eastern part of Kunming is one of important Yunnan industrial and agricultural industrialization base areas, where is frequent human activities. It mainly consists of Panlong District of Kunming City, Kunming City, Guandu District, Kunming City, Songming County, Chenggong District, Yang Zong district and others. This area is mainly in Karst Area. At the same time, the Industrial, agricultural production water and living water is mainly from groundwater. Distribution and occurrence of karst groundwater is very irregular. This is often caused by the shortage of water resources in the local area. In order to solve the serious water shortage in the middle area of Yunnan, particularly in the area of Kunming,more and more cross regional drainage, water diversion project is in the planning and construction. In the area, the complex terrain conditions is a difficult problem in the process of selecting line construction, engineering layout, construction and it is be solved. In this paper, the study on the development characteristics of karst negative landforms. This can provide a scientific basis for the engineering optimization, line construction measures, assessment of groundwater environment, geological environment protection work.This paper is based on the understanding of the regional geological background and the karst hydrogeological conditions. Methods using a combination of conventional statistics and fractal theory were used for statistical analysis of the study of karst landforms. This research reveals the karst landforms spatial distribution. Finally, through the water diversion line in different negative landform areas, to forecast the water gushing of karst formation through the tunnel from the surface negative terrain influence catchment conditions and infiltration intensity. The main research results are as follows:(1)Through the analysis of the new to old the rock lithology, exposure, moisture content, development degree of karst, the aquifers of groundwater connectivity and other aspects of comparison on the research area, some strata can be generalized as a kind of high purity, thickness of the strata of Karst. These strata include Yangxin formation, Permian(P1y), and Shangsi member, Dakuangjie formation, Carboniferous(C1d2), and Weining-Mapingqun formation, Carboniferous(C2+3), and Zaige formation, Devonian(D3zg).(2) Based on the study area terrain conditions, karst formation lithology and spatial distribution, tectonic features and karst hydrogeological conditions differences, the study area was divided into three sub-geological units namely:(â… ) east Pudu break- heap mountain, Wushan, yesterday clouds along the northern part of Kunming,(â…¡) heap mountain, Wushan, yesterday clouds along ~ vintage Hill-Longtan broken wedge formation region,(â…¢) classic Hill- Longtan Mountain- a large area southeast of the study area.(3)Based on statistical analysis of the polygon depressions and basin(valley) in the study area,the depressions mainly developed in Yangxin formation(P1y), accounting for about 62.4% of the proportion of the total. It is concentrated in the area of 0-0.6km2, accounting for the total proportion of 64.4.0%. The development height of depression is divided into three levels, the high altitude depressions developed between 2200-2500 m, accounting for about 6.3% of the total,the low altitude depressions developed between 1600-1900 m, accounting for about 14.4%, the rest of the medium altitude depressions, at an elevation of 1900-2200 m, about 79.3% of the total. Most basin(valley) belongs to the quaternary erosion or corrosion valley basin, which base is karst. The basin deposits are relatively thin, generally only the first and second terrace are developed. Its area is not large and irregular dendritic.(4)Radius of gyration method is used to calculate the distribution radius dimension of three secondary negative relief, the fractal dimension D value is less than 2. Reference theory of city of fractal method, the distribution of hollow area are decreasing outward from the core.But the north of Kunming distinguished to two scale area including 1-4 km and 4-44 km, and the fractal dimension value was 1.8866 and 0.6761, respectively. The depression is concentrated clusters development in the fist scale area.And the depression is scattered in the second scale area.In the fault zone of Gudui Mountain~Zuoriyun~Longtan Mountain,the depression belongs to clusters of distributiong,and the only fractal dimension value is 1.4899.In the southeast of study area,it has only one fractal dimension value that the randomness of negative terrain is stronger.( 5) In order to study a single depression of vertical and horizontal development relations, compare three secondary depression development areas and the correlation of peak of elevation difference value of hollow. The corrosion and lateral erosion ability is stronger in the fault zone of Gudui Mountain~Zuoriyun~Longtan Mountain.The area of maximum erosion is distributed in the southern of Longtan Mountain fault zone.The northern region of Kunming belongs to the fault fold belt,the intensity of surface karst development is relatively large,the erosion and lateral erosion ability under relative times.(6)The author using two-dimensional grid method to calculate linear fractal dimension value of the contour line in the karst negative terrain development zone.In general, it is It is the largest fractal dimension of about 1.3798 in fracture dimension value of Gudui Mountain~Zuoriyun~Longtan Mountian.Fissure groundwater connectivity region in internal fault and the core of fold,there are underground cave and negative terrain landforms type development. Along with the development of the fault depression, sinkholes, corrosiongrooves along the faulted blocks bar. So the combination of terrain fractal dimension value of the shape of contour line is bigger, such as Langchong Mountain anticline, Gongmiao anticline,and both sides of lake of Yangzhonghai, etc. In addition a single larger area karst negative terrain or small place of the development of quaternary basin terrain contour comparison rules, the approximate close to elliptic, its linear fractal dimension value slightly smaller,such as Baiyi Village valley basin,Chengjiang County valley basin and Longgang depression,etc.(7)From the surface of the negative terrain catchment condition and in filtration intensity perspective, fitting water diversion lines tunnel across differ ent regions of negative landform fractal characteristics to predict the tunnel se ction of the water fathering.The most serious problem of water fathering inclu des km42+729-km44+150, km48+904-km49+903 and km49+903-km51+509 sec tion of Longquan tunnel, prediction of normal water inflow were 10041.97 m3/d, 10806 m3/d and 19950.93 m3/d.In the section of km77+304-km79+520, k m84+133-km85+492 and km88+173-km91+390 of kuncheng tunnel, prediction of normal water inflow were 2373.90 m3/d, 20966.31 m3/d and 17848.23 m3/d. |
