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The Niangziguan Spring is one of the largest karst springs in northern China and water in this spring area is the main water-supply source for people in Yangquan City for daily life, industrial processes and agricultural production. However, decreasing groundwater levels and growing waterpollution issues have been observed recently. Therefore, the objective of this study was to conduct a systematic analysis of water-flow reduction and water-quality deterioration of the Niangziguan Spring. The results show that various wastewater sources upstream of the spring, such as coal mining, and urban industrial and domestic effluents, have contributed to the deterioration of the Niangziguan Spring water quality. A mathematical model known as the one-order one-variable grey differential equation model GM(1,1) was employed to evaluate the contribution of climate change versus human activities potentially affecting the reduction of spring-water flow. The calculations for the period from 1979 to 2006 suggest that a contribution of human activities to water-flow reduction was 2.5 times greater than those that can be attributable to climate change. The research results obtained as presented in this paper can provide a scientific basis for rational exploitation of karst-water resources and environmental protection in this karst area of northern China.

As the instability criteria of the singular dimension displacement of a landslide are limited and insufficient, a new appraisal parameter, the vertical displacement direction rate is considered in landslide stability model in this paper. Then, the displacement directional rate variation at different evolutional stages of landslide stability and its significance in landslide forecasting are systematic analyzed. On the basis of the different evolutional rules of the vertical displacement directional rate in the different deformation stages, the destabilized criterion of this kind of parameter is established in terms of the principle of statistics. Furthermore, according to the destabilized criterion, a calculation and evaluation of the stability of Xintan landslide is carried out by means of the appraisal parameter of the vertical displacement direction rate. The result of analysis is basically consistent with the practical deforming law of the landslide. The result above indicates that the vertical displacement direction rate is an effective appraisal parameter serving as an essential and stable criterion for the stability evaluation of a slope. Therefore, this directional appraisal parameter is of very special significance and also suitable and effective in the prediction of landslides.

Fissure karst water system in Jiaozuo coal mining area is one of the typical karst groundwater systems in north China. Based on the research of hydrogeological conditions and tests and monitoring data of karst groundwater systems in Jiaozuo mining area, this paper has carried out a discussion of the evolutionary trend of karst underground water and the origin and distribution rules of environmental geological problems caused by the exploitation. It is found that the mine drainage is the major way of underground water drainage in the mining area, and the actual drainage discharge is equivalent to 50% of the total natural groundwater recharge in Jiaozuo mine. With the increase of exploitation and decrease of precipitation, the karst water level in Jiaozuo mining area decreases in a ladder form and the cones of depression of the groundwater covering the entire mining area are developed rapidly. In addition, mine drainage brings a large number of pulverized coal and rock dust into the soil, causing soil pollution, reduction of the soil quality, and pollution of pore water by different degrees. Meanwhile, the pore groundwater has been also contaminated by mine drainage through irrigation backflow and channel leakage. On the basis of analysis above, some recommendations of prevention and protection measures for the karst water hydrogeological environmental problems in coal mining areas are provided.

On the basis of systematic analysis on the motivation and mechanism of displacement and destabilization of the water-induced landslides, this paper completes a study on the relationship between groundwater dynamic effect laws and displacement response characteristics in the process of the colluvial landslide stability evolution. It is found that the displacement and destabilization of landslide are directly controlled by the underground water level variation and also there exists one-to-one corresponding relation between the deformation of landslide and the groundwater level variation. On the basis of the results above, the underground water level increment and the corresponding deformation variation are taken to be as the dynamic load parameter of landslide and the dynamic incremental displacement response parameter, respectively. Then the displacement dynamic appraisal parameter and prediction model of the groundwater dynamic incremental displacement response ratio are determined in term of the basic principle of elastic–plastic mechanics in this paper. Meanwhile, taking the typical colluvial landslide in the Three Gorges Reservoir Area—Xintan landslide as an example, the values and changing rule of the groundwater dynamic incremental displacement response ratio parameter of the A3 and B3 monitoring points on this landslide are obtained by means of the groundwater dynamic incremental displacement response ratio prediction model, finding that the change rule of the dynamic incremental displacement response ratio-time curve is consistent basically with the dynamic stability evolutional law of the actual slope. The research results show that the groundwater dynamic incremental displacement response ratio prediction model can be used to forecast the kinetics of displacement for this slope, and this method has widely theory and extensive practicality.

As the traditional displacement value of a landslide is very easy to be affected by rainfall, it is very difficult to establish a stable and uniform destabilized criterion of landslide in terms of the displacement value. So, it determines that establishment of an effective and stable dynamic displacement prediction parameter is very important in forecast of the debris landslides caused by rainfall. In order to determine this kind of prediction parameter, this paper first completes analysis on the relationship between the destabilized mechanism of the debris landslide and the rainfall dynamic rules. The relationship above shows that the periodical change value of rainfall can be taken as the dynamic unload–load parameter (ULP) of landslide, and the homologous change value of mensal landslide displacement can be taken as the stability displacement response parameter (DRP). Then, on the basis of the relationship between the ULP and the stability DRP of this kind of landslide, the unload–load displacement response ratio (ULDRR) appraisal parameter of this kind of landslides is established in this paper. Finally, the stability of typical debris landslides in China has been systematically studied by means of ULDRR appraisal parameter and model. We find that the ULDRR values conform to the evolutional rule of slope deformation and instability. So, it has been proved that the ULDRR parameter and the appraisal model are suitable and effective for prediction and evaluation of stability and evolution rule of rainfall-induced landslides.

This paper introduces the statistical methods and application for the quantitative analysis of a site-specific landslide risk on the north slope of Lishan Mountain which is regarded being in an active state that could become a disastrous loess landslide. Based on the theory of probability statistics (Monte Carlo statistical methods) and the slope failure mechanical model, the overall failure probability and the local failure probabilities of the Lishan landslide were calculated. The results of the failure probability and stability analysis showed that the northern slope of Lishan Mountain is highly prone to lose stability during seasonal intense rainfall, whereas it is stable but still exhibits failure probability under arid conditions. The analysis of the safety margin and local failure probability evidenced that the upper part of the slope is less stable than the lower part. Under the intense rainfall condition, the local failure probability and hazard of local unstable failure of the slope will increase. According to the calculation results, it is deduced that the landslide on the north of Lishan Mountain will be a gradual process evolving from the local slope failure to an overall unstable failure.

Karst collapse is a type of complicated environmental and geological hazard that can be caused by many factors: natural factors, such as rainfall, and human activities, such as overpumping of groundwater. Therefore, it is important to make a comprehensive analysis and evaluation on karst collapse risks and impacts of the influencing factors of karst collapse. However, how these factors affect karst collapse is still a problem, which has not yet been well solved. Taking the karst collapse in groundwater exploitation area of Shiliquan of Zaozhuang, China, as the example, and based on the comprehensive analysis of the formation rule and mechanism of karst collapse in this area, this paper mainly employs Quantification Theory to make a quantitative analysis and evaluation of various influencing factors of karst collapse in the groundwater exploitation area of Shiliquan of Zaozhuang. It thereby determines the impact of different influencing factors on karst collapse strength, and identifies the dominant and minor factors that affect the karst collapse. It also provides some criteria for the prevention of karst collapse and protection of karst water resources and environment.

The karst geological system in north China is different from that in the south. Due to differences in basic geological conditions and environment, the karst evolutional pattern and karst water resources, among other things, are also different in the two regions. This paper, based on on-site fieldwork and analysis of an extensive database of karst in China, presents a systematic and contrastive analysis of karst geological environment and karst water resources in north versus south China, highlights the differences between the two regions in basic karst geological conditions, groundwater dynamics and karst water resources, and concludes with the economic, environmental and engineering implications of these differences. These findings will be helpful for the strategic planning and decision-making processes associated with exploitation of karst geological resources and with prevention and control of karst geological hazards.

China, whose distribution area of karst region reaches about 3.63 million km2, is one of the countries that have the widest karst collapse development. In modern-karst collapses, the karst collapse induced by water environment is an important type in karst collapses of North China. This paper completed a systematic study on the relations between groundwater environmental transformation and karst collapses and their distribution rules in northern China and found out that the karst collapses in northern China are closely related to the change of groundwater environment, which increased along with the declining groundwater levels and increasing hydraulic gradient. Meanwhile, it was also found that in all cases of collapse caused by underground-environmental change of northern China, pumping collapses in urban areas appeared to be the commonest and strongest among modern-karst collapses with 20 regions and 796 mining pits in total, which account for 30.7 and 58% of artificial collapses, respectively, followed by collapses that were induced by mining draining and inrushing water with 33 regions and 282 mining pits, accounting for 20.4%. In addition to the conditions listed above, there were also a few water caving collapse and leakage collapse.

The study area is located in Three Gorges Reservoir region, China. Over 200 landslides have been monitored over a number of years with their behavior being compared to the effective rainfall database for the study area. Analysis of the available data indicates that the occurrences of landslides in this region are controlled by rainfall, whose intensity and rainfall processes are the most important dynamic factors in determining the stability of slopes. Therefore, the relationship between rainfall and the movement of typical landslides has been specifically analyzed for the Xintan landslides and the large Huangya landslide by using the loading/unloading response ratio parameter of rainfall. The result of this study indicates that the mutation of the loading/unloading response ratio of rainfall of the Xintan landslide and the large Huangya landslide in the Three Gorges Reservoir region, China occurred just before their destabilization, which shows that the loading/unloading response ratio of rainfall and its changing feature can be taken as a precursor for the landslides induced by rainfall.

In Northern and Southern China, there are two different territorial systems of karst collapse. Because of the differences in basic geological conditions, groundwater dynamic conditions and climatic factors, the karst collapses are different in Northern China from those in Southern China in types, distribution characteristics, development density, scope, and formation mechanism. Based on analysis of statistical data in bulk and analysis of basic rules of the karst collapses in China, this paper systematically analyzed the basic geological conditions, groundwater dynamic conditions and climatic conditions both in North and South when studied and concluded the discrepancy in features, scales, density, regional distribution rules, formation mechanism, etc. The contrast and rules concluded will be of important significance and have great implication value to the exploration and prevention of karst collapse planning and layout of relevant project construction.

On the basis of research and analysis of the landslide system of the Three Gorges Reservoir area, this paper systematically analyzes and studies the temporal–spatial distribution law of landslides of this reservoir area and their impacts on environment of this area. The paper puts forward that the temporal–spatial distribution of this area’s landslides is mainly controlled by lithologic characters of strata, geological structure, valley landscape, and types of bank slope structure; landslide deformation and failure have such characteristics as simultaneity, laggardness, cyclical instability, and stage. Besides, the paper systematically analyzes and studies the main impacts of landslide on environment and points out that landslides and collapses will bring about relatively serious impacts on relocation and layout of cities and towns along the banks. These impacts mainly include the increase of relocation investment, number of migrants, and compensation for losses. Much attention and evaluation should be paid to the impacts of Xintan Landslide and Lianziya Landslide—large landslides near the Dam—on the construction and safety of the Three Gorges Project. However, landslides have relatively small impacts on shipping and reservoir capacity. The above-mentioned research is of great guiding significance for the construction of the Three Georges Project, planning and construction of cities and towns along the banks, and protection of geological environment.

In this paper, a systematic study was completed on the distribution features and origins of karst collapses in north China. There are 65 modern karst collapse areas with 1,416 karst collapse pits and 38 paleo–karst collapse areas with 3,654 paleo-collapse pillars. Modern karst collapses are mainly distributed in the plain region of the east Taihang and Yanshan Mountains and are concentrated in three zones from the west to the east in this region. The regional distribution features of karst collapses in north China are controlled by the boundary of the geological tectonics, condition of soluble rock and the extent of human activities. From the results, three-grade indices have been adopted to establish a classification scheme for karst collapse in north China. The effects of karst collapses on the environments in north China are summarized using a karst collapse classification scheme.

With the development of mining of iron deposits in China, groundwater invasion and the impacts of groundwater drainage, such as regional groundwater table lowering, overlapping cones of depression, subsidence, and water quality deterioration are environmental problems which endanger mining production and human life. Effective prevention of water invasion or timely determination of the mechanism of water bursting and rational design of drainage plans are the most urgent mining challenges. The mechanism of water invasion and the environment impacts on the groundwater system of the Gaoyang Iron Mine, China were dealt with in this paper. A systematical investigation of the hydrogeological conditions and monitoring of groundwater dynamics of the mine were completed. Results show that the limestone of the middle Ordovician System constitutes the under floor of the iron deposit. This limestone is the main source of water invasion into the mine. Groundwater dynamic equilibrium conditions are broken due to mine drainage. Water invasion and drainage have caused a serious impact on the groundwater environment of the area.

Data compiled from monitoring the displacement resulting from the Xintan landslide in China was analyzed. The stability of the demonstrated colluvial slope has a close correlation with two parameters, the velocity of the displacement and the angle of the surface vector. The stability trend can be described and evaluated by both the velocity of the displacement and the vector angles. The displacement vector angle, for which there is no substitute, serves as an explicit criterion for the stability of the slope, hence it is significant in the prediction of the catastrophic movement of landslides. A systematic analysis of the features of the vector angles of the surface displacement space and time was performed. The evolving mechanism of space-time and the characteristics of the displacement vector angles were deduced. On the basis of these deductions and by using principles of statistics, the double-parameter threshold for forecasting the stability of the colluvial slopes was established. According to the double-parameter threshold, a calculation and evaluation of stability was completed in terms of the monitoring data of the F-series of points on the Xintan slope. The forecast results coincided with the destabilized timetable, thus demonstrating that the double-parameter criterion has, to a certain extent, precision and practical application for forecasting of landslides.

If prediction of a debris landslide is to be completed, the first problem is how to determine and correlate the dynamic factors. The special composition and complicated geological conditions of debris landslides have many dynamic factors influencing displacement and stability. Correlations are generally very complicated. The relationship and sequence of factors is too complex to be completed by traditional mathematical model. In order to solve the problem above, a systematical study of the quantitative and qualitative dynamic factors using a model of the quantitative theory was performed based on the displacements of Xintan landslide, China. Rainfall was found to be the most important dynamic factor among the six factors controlling displacements. Relative importance sequence and correlation was also established. All prediction results agree with the mechanism and displacement pattern of the Xintan landslide. Optimized measures of prevention and control for debris landslides can be completed with correlation of the dynamic factors by means of the quantitative theory model.

Through geological investigation of karst collapses at Zaozhuang City, China, it was found that the mechanism of karst collapse in areas of excess water extraction is characterized by a seepage effect and that the seepage-pressure effect is the initial factor that induces karst collapse. The causation mechanisms for karst collapse can be divided into two phases: the inter-collapse phase and the surface-collapse phase. Therefore, based on the limit-equilibrium theory, this paper has established mechanical models for the surface-collapse phase and determined values for the stability of the arch formed by the soil hole in an inter-collapse phase. In addition, an evaluation of a karst collapses at Zaozhuang City, China, was completed using mechanical models. The results show that the mechanical models agree with the theory of karst collapse at Zaozhuang City. Thus, it is proved that the karst collapse models can be used for the evaluation of karst collapse in areas that are over-pumped.

Due to growing water extraction for industry and agriculture, the Dawu Water Supply Base, in the east of Zibo, China, has been in a state of serious over-extraction. It will also be affected by the deep drainage of the Dianzi Iron Mine, which will be exploited in 2005. As to the environmental impact on the groundwater system of the Dawu Water Supply Base is concerned, this paper makes a systematic study about the influence of the mine draining on the water-supply environment of the Dawu Water Supply Base by using the numerical model of groundwater system. The result shows that the groundwater level will have an additional drawdown of 1.2–1.8 m/yr by the mine draining alone. The numerical analysis results indicate that the optimal model for determining the best extraction plan is the solution for the contradiction between water supply and water drainage.

Based on an analysis of displacement-monitoring data of Xintan landslide, China, it was discovered that the whole stability of large-scale colluvial landslides can be more accurately described by taking the displacement vector angle into account, and the stability trend of a slope can be evaluated and predicted using the displacement vector angle. This paper also further indicates that the monitored deformation vector angle can be divided into sliding deformation vector angle, plastic-deformation vector angle, compressive deformation vector angle and creep deformation vector angle in terms of the displacement properties of the slope. Through the analysis it is found that the displacement vector angle, for which there is no substitute, is an important parameter serving as an explicit criterion for the stability of the slope, and hence its significance in the prediction of landslides. It is also shown that as far as the displacement vector angle is concerned, there are different constituents and features in the different deformation stage of colluvial landslide. On the basis of these and using the principles of statistics, a discussion on the stability of the colluvial slopes is carried out in terms of the monitoring data of F-series points on Xintan slope. The analysis results coincided with the destabilized time and the sliding laws, thus demonstrating that the parameter of the displacement vector angle has to a certain extent, very important significance in the forecasting of landslides.