Distribution and characteristics of landslides induced by the Iwate–Miyagi Nairiku Earthquake in 2008 in Tohoku District, Northeast Japan

The Iwate–Miyagi Nairiku Earthquake in 2008, whose seismic intensity was M. 7.2 in Japan Meteorological Agency (JMA) scale, induced innumerable landslides on the southern flank of Mt. Kurikoma volcano allocated along the Ou Backbone Range in Northeast Japan. Most landslides are detected in a hanging wall side of the seismic fault. Those landslides are classified into five types: deep-seated slide, debris slide, shallow debris slide, secondary shallow debris slide, and debris flow. Most common landslide types induced by the earthquake are shallow debris slides and subsequent debris flows. They are intensively distributed along steep gorges incising a volcanic skirt of Mt. Kurikoma, consisting of welded ignimbrite of the Pleistocene age. Debris flows are also distributed even along gentle river floors in the southern lower flank of the volcano. The area of densely distributed debris slides, shallow debris slides, and debris flows is concordant with that of severe seismic tremor. Thus, genetic processes of landslides induced by the Iwate–Miyagi Nairiku Earthquake in 2008 are attributed to multiple causative factors such as geology, topography, and seismic force.     

Characteristics of earthquake-induced landslides in a heavy snowfall region—landslides triggered by the northern Nagano prefecture earthquake, March 12, 2011, Japan

The northern Nagano Prefecture earthquake, M_JMA?6.7 (Mw?6.2), which is inferred to have been triggered by the huge (Mw?9.0) March 11, 2011 Tohoku earthquake, occurred on March 12, 2011, in northern Nagano Prefecture, an area in Japan famous for heavy snowfall. A large number of landslides were triggered by the 12 March earthquake, and it caused building damage in the area of the epicenter. To clarify characteristics of the distribution and dynamic behavior of these landslides, we analyzed aerial photographs and conducted field surveys in and around the epicentral area. Large-scale landslides with long distance run-outs are a remarkable characteristic of the landslides induced by this earthquake. The long travel distance is considered to be related to the thick snowpack at the time the earthquake occurred. Moderate scale deep-seated landslides and shallow landslides were also observed in the study area. Based on an analysis of landslides with the active fault on which the earthquake is believed to have occurred, most of these landslides were distributed on the hanging wall of the active fault, within a distance of 12?km from the fault.     

Reconnaissance report on landslide disasters in northeast Japan following the M 9 T��hoku earthquake

An earthquake of M_w 9.0 struck the Pacific coast in northeast Japan on March 11, 2011 and was followed by a hugely damaging tsunami along 500 km of the Japanese coastline. An inland aftershock of M. 7.0 occurred on April 11; during which, surface fault ruptures appeared on land. A large variety of landslide disasters resulted from these earthquakes in various parts of northeastern Honshu, Japan. The full extent of the landslides is still being determined. This brief report introduces some of the landslide phenomena so far investigated by the Japanese Landslide Society. These are (1) failure of a water reservoir embankment dam in Sukagawa, Fukushima prefecture, (2) landslides and surface seismic fault rupture from the April 11 aftershock in Iwaki, Fukushima, (3) a concentration of surface failures at Matsushima Bay in Miyagi prefecture, and (4) small landslides on modified slopes in residential areas around Sendai city.     

Iron–bentonite interactions in the Kawasaki bentonite deposit,Zao area,Japan

Greenish veins occurring in brecciated bentonite were found in the Kawasaki bentonite deposit of the Zao region in Miyagi Prefecture, Japan. Their occurrence possibly indicates the interaction of bentonite with Fe-rich hydrothermal solutions. In order to prove the hypothesis and understand the long-term mineralogical and petrographic evolution of bentonite during such interactions, the greenish veins and the surrounding altered bentonite were analyzed using X-ray fluorescence (XRF), scanning electron microscopy (SEM), X-ray diffraction (XRD), electron probe micro-analysis (EPMA), scanning transmission electron microscopy with energy dispersed spectroscopy (STEM-EDS) and micro X-ray absorption near-edge structure (XANES). The greenish veins resulting from hydrothermal solution are composed of mixed-layer minerals consisting of smectite and glauconite (glaucony), pyrite and opal. The occurrences indicate that glaucony and pyrite formed almost simultaneously from hydrothermal solution prior to opal precipitation. The mineral assemblages of the greenish veins and their surroundings indicate that the hydrothermal activity had most likely taken place at a temperature of less than 100 °C and that the pH and Eh conditions of the reacted solution were neutral to alkaline pH and reducing. The unaltered bentonite is composed mainly of Al smectite and opal. These minerals coexist as a mixture within the resolution level of the microprobe analyses. On the other hand, the bentonite in contact with the greenish veins consists of discrete opal grains and dioctahedral Al smectite containing Fe and was altered mineralogically and petrographically by the hydrothermal activity. Both the clay minerals and the opal were formed by dissolution and subsequent precipitation from the interaction of the original bentonite with the hydrothermal solution.     

An open dataset for landslides triggered by the 2016 Mw 7.8 Kaikōura earthquake,New Zealand

On November 14, 2016, the northeastern South Island of New Zealand was hit by the magnitude Mw 7.8 Kaikōura earthquake, which is characterized by the most complex rupturing mechanism ever recorded. The widespread landslides triggered by the earthquake make this event a great case study to revisit our current knowledge of earthquake-triggered landslides in terms of factors controlling the spatial distribution of landslides and the rapid assessment of geographic areas affected by widespread landsliding. Although the spatial and size distributions of landslides have already been investigated in the literature, a polygon-based co-seismic landslide inventory with landslide size information is still not available as of June 2021. To address this issue and leverage this large landslide event, we mapped 14,233 landslides over a total area of approximately 14,000 km². We also identified 101 landslide dams and shared them all via an open-access repository. We examined the spatial distribution of co-seismic landslides in relation to lithologic units and seismic and morphometric characteristics. We analyzed the size statistics of these landslides in a comparative manner, by using the five largest co-seismic landslide inventories ever mapped (i.e., Chi-Chi, Denali, Wenchuan, Haiti, and Gorkha). We compared our inventory with respect to these five ones to answer the question of whether the landslides triggered by the 2016 Kaikōura earthquake are less numerous and/or share size characteristics similar to those of other strong co-seismic landslide events. Our findings show that the spatial distribution of the Kaikōura landslide event is not significantly different from those belonging to other extreme landslide events, but the average landslide size generated by the Kaikōura earthquake is relatively larger compared to some other large earthquakes (i.e., Wenchuan and Gorkha).

     

Performance of structures in the rural area during the March 8, 2010 Elazığ-Kovancılar earthquake

Numerous studies demonstrated the possibility of utilizing fly ash in the construction of embankments, road subgrades and stabilization of a wide range of soils. The present investigation aims at determining the optimum fly ash (OFA) for mechanical stabilization of expansive soils. Four different soils were tested for compaction characteristics and unconfined compressive strength with and without the addition of fly ash to determine the OFA. The liquid limit (LL) and the fraction coarser than 425 μ (CF) of these soils range from 50 to 120 and 25 to 70%, respectively. An experimental strategy called two-factor factorial design was adopted in the conducting experiments. LL and CF present in the soil are the two factors considered to influence the OFA content. Factorial experimentation enables relative quantification of the effect of each factor as well as their interaction with the OFA. The OFA was found to range from 5 to 40% depending upon the two factors. The LL and the CF were found to have dominating influence on OFA content in that order, whereas the interaction effect of these two factors was marginal to fair. A statistical regression model was developed for determination of the OFA in terms of the influencing factors. The validity of the model developed was verified by conducting laboratory tests on two more soils that were not used in the development of the model. Swell potential and swelling pressure of expansive soils were reduced to non-critical levels when treated with OFA.     

Hydraulic fracturing stress measurements and in-situ stress field in the Kanto — Tokai area,Japan

Hydraulic fracturing stress measurements have been made in fifteen boreholes of various depths from 100 to 800 m in the Kanto-Tokai area since 1978. About 90 sets of in-situ stresses have been obtained successfully. The maximum and minimum horizontal compressive stresses increase linearly with depth in each borehole. The difference between the maximum and minimum principal stresses also increases with depth. The increase of stress difference with depth is interpreted in terms of large stress relaxation in shallow parts of the boreholes where low confining pressure and many pre-existing microcracks are dominant. The maximum shear stress at a depth of 400 m ranges from 1 to 8 MPa depending on the site. It is not always the case that the regions of small shear stresses are inactive in microseismicity and crustal movement. This phenomenon is attributed to the relaxation of shear stress at the measured depths and to the regional variation in increasing rate of shear stress. The maximum compressive stress direction is obtained from detection of the fracture azimuth after hydraulic fracturing. Stress direction measured at each borehole agrees well with that estimated from geologic and seismic methods near the measurement site. Several stress provinces where the stress directions appear almost uniform are defined in the Kanto-Tokai area. The regional distribution of the stress directions is understood in terms of the relative movement of three plates, the Philippine Sea, Pacific, and Eurasian plates, which are in contact with each other in this area.     

Landslides triggered by the 22 July 2013 Minxian–Zhangxian,China, Mw 5.9 earthquake: Inventory compiling and spatial distribution analysis

On July 22, 2013, an earthquake of Ms. 6.6 occurred at the junction area of Minxian and Zhangxian counties, Gansu Province, China. This earthquake triggered many landslides of various types, dominated by small-scale soil falls, slides, and topples on loess scarps. There were also a few deep-seated landslides, large-scale soil avalanches, and fissure-developing slopes. In this paper, an inventory of landslides triggered by this event is prepared based on field investigations and visual interpretation of high-resolution satellite images. The spatial distribution of the landslides is then analyzed. The inventory indicates that at least 2330 landslides were triggered by the earthquake. A correlation statistics of the landslides with topographic, geologic, and earthquake factors is performed based on the GIS platform. The results show that the largest number of landslides and the highest landslide density are at 2400 m–2600 m of absolute elevation, and 200 m–300 m of relative elevation, respectively. The landslide density does not always increase with slope gradient as previously suggested. The slopes most prone to landslides are in S, SW, W, and NW directions. Concave slopes register higher landslide density and larger number of landslides than convex slopes. The largest number of landslides occurs on topographic position with middle slopes, whereas the highest landslide density corresponds to valleys and lower slopes. The underlying bedrocks consisting of conglomerate and sandstone of Lower Paleogene (E^b) register both the largest number and area of landslides and the highest landslide number and area density values. Correlations of landslide number and landslide density with perpendicular- and along-strike distance from the epicenter show an obvious spatial intensifying character of the co-seismic landslides. The spatial pattern of the co-seismic landslides is strongly controlled by a branch of the Lintan-Dangchang fault, which indicates the effect of seismogenic fault on co-seismic landslides. In addition, the area affected by landslides related to the earthquake is compared to the relationship of “area affected by landslides vs. earthquake magnitude” constructed based on earthquakes worldwide, and it is shown that the area affected by landslides triggered by the Minxian–Zhangxian earthquake is larger than that of almost all other events with similar magnitudes.     

Seismogenesis of the uninterrupted occurrence of the aftershock activity in the 2001 Bhuj earthquake zone, Gujarat, India, during 2001�C2010

Seismogenesis of aftershocks occurring in the Kachchh seismic zone for more than last 10?years is investigated through modeling of fractal dimensions, b-value, seismic velocities, stress inversion, and Coulomb failure stresses, using aftershock data of the 2001 Bhuj earthquake. Three-dimensional mapping of b-values, fractal dimensions, and seismic velocities clearly delineate an area of high b-, D-, and Vp/Vs ratio values at 15?C35?km depth below the main rupture zone (MRZ) of the 2001 mainshock, which is attributed to higher material heterogeneities in the vicinity of the MRZ or deep fluid enrichment due to the release of aqueous fluid/volatile CO₂ from the eclogitisation of the olivine-rich lower crustal rocks. We notice that several aftershocks are occurred near the contacts between high (mafic brittle rocks) and low velocity regions while many of the aftershocks including the 2001 Bhuj mainshock are occurred in the zones of low velocity (low dVp, low dVs and large Vp/Vs) in the 15?C35?km depth range, which are inferred to be the fractured rock matrixes filled with aqueous fluid or volatiles containing CO₂. Further support for this model comes from the presence of hydrous eclogitic layer at sub-lithospheric depths (34?C42?km). The depth-wise stress inversions using the P- and T-axes data of the focal mechanisms reveal an increase in heterogeneity (i.e., misfit) with an almost N?CS ??₁ orientation up to 30?km depth. Then, the misfit decreases to a minimum value in the 30?C40?km depth range, where a 60^o rotation in the ??₁ orientation is also noticed that can be explained in terms of the fluid enrichment in that particular layer. The modeling of Coulomb failure stress changes (??CFS) considering three tectonic faults [i.e., NWF, GF, and Allah bund fault (ABF)] and the slip distribution of the 2001 mainshock on NWF could successfully explain the occurrences of moderate size events (during 2006?C2008) in terms of increase in positive ??CFS on GF and ABF. In a nutshell, we propose that the fluid-filled mafic intrusives are acting as stress accentuators below the Kachchh seismic zone, which generate crustal earthquakes while the uninterrupted occurrence of aftershocks is triggered by stress transfer and aqueous fluid or volatile CO₂ flow mechanisms. Further, our results on the 3-D crustal seismic velocity structure, focal mechanisms, and b-value mapping will form key inputs for understanding wave propagation and earthquake hazard-related risk associated with the Kachchh basin.     

On a damaging earthquake-induced landslide in the Algerian Alps: the March 20, 2006 Laâlam landslide (Babors chain,northeast Algeria), triggered by the Kherrata earthquake (<Emphasis Type="Italic">M</Emphasis><Subscript>w</Subscript> = 5.3)

On March 20, 2006, an earthquake (M _w = 5.3; SED) struck the mountainous region of the Babors chain (Wilaya of Bejaia, northeast Algeria). The seismic epicenter was located near the Kherrata village. This earthquake was felt on a large area of the northeastern part of Algeria. It reached an intensity of VII (EMS scale) at the Laalam village, situated at about 20 km northeast of Kherrata. Here, many old and recent houses were damaged or collapsed totally, four people died and 68 were injured. Field investigations revealed that these casualties were caused by a landslide triggered by the earthquake. Many fissures were visible on ground throughout the site. They were generated by both sliding and settling phenomena. The Laalam site is prone to landslide, as revealed by some evidences on old instabilities. This is due to two main factors: local geomorphology and geology. These factors intervene synchronously for reducing the slope instability at the Laalam village. The March 20, 2006 Kherrata earthquake was the trigger that released the Laalam landslide.     

Does vertical seismic force play an important role for the failure mechanism of rock avalanches? A case study of rock avalanches triggered by the Wenchuan earthquake of May 12, 2008, Sichuan,China

The Wenchuan earthquake triggered 15,000 rock avalanches, rockfalls and debris flows, causing a large number of causalities and widespread damage. Similar to many rock avalanches, field investigations showed that tensile failure often occurred at the back edge. Some soil and rock masses were moved so violently that material became airborne. The investigation indicates that this phenomenon was due to the effect of a large vertical seismic motion that occurred in the meizoseismal area during the earthquake. This paper analyses the effect of vertical earthquake force on the failure mechanism of a large rock avalanche using the Donghekou rock avalanche as an example. This deadly avalanche, which killed 780 people, initiated at an altitude of 1,300 m and had a total run-out distance of 2,400 m. The slide mass is mainly composed of Sinian limestone and dolomite limestone, together with Cambrian slate and phyllite. Static and dynamic stability analysis on the Donghekou rock avalanche has been performed using FLAC finite difference method software, under the actual seismic wave conditions as recorded on May 12, 2008. The results show that the combined horizontal and vertical peak acceleration caused a higher reduction in slope stability factor than horizontal peak acceleration alone. In addition, a larger area of tensile failure at the back edge of the avalanche was generated when horizontal and vertical peak acceleration were combined than when only horizontal acceleration was considered. The force of the large vertical component of acceleration was the main reason rock and soil masses became airborne during the earthquake.     

Regional landslide susceptibility following the Mid NIIGATA prefecture earthquake in 2004 with NEWMARK’S sliding block analysis

This study proposes a calculation method for regional earthquake-induced landslide susceptibility that applies the permanent seismic displacement calculated using Newmark’s sliding block analysis with estimated vertical and horizontal seismic motions. The proposed method takes into account the direction of slope failure based on the specified slope azimuth. The study results reveal the importance of predominant slope failure direction using a simple infinite slope model subjected to earthquakes. The target area for the earthquake-induced landslide susceptibility analysis constituted a region of more than 2000 km² surrounding the epicenter of the Mid Niigata prefecture earthquake in 2004. An earthquake-induced landslide susceptibility map was created based on the proposed method with a specific combination of friction angle and cohesion, and the resulting data were compared to the landslide inventory map produced from aerial photographs following the Mid Niigata prefecture earthquake in 2004. To create the susceptibility map, geomaterial cohesion values for the slope were back-calculated to satisfy the minimum safety factor in the static state. This study also proposes a calculation method for the prediction rate and determines the back-calculated strength parameters of geomaterials. The proposed regional landslide susceptibility map will be useful for understanding potential slope failure locations and magnitude of damage, as well as for planning field investigation and preventing secondary disasters immediately after earthquakes.     

Sedimentology and facies analysis of Miocene mixed siliciclastic–carbonate deposits of the Dam Formation in Al Lidam area,eastern Saudi Arabia

The Burdigalian mixed siliciclastic–carbonate deposits of the Dam Formation are well-exposed in Al Lidam area, in the eastern province of Saudi Arabia. They represent a shallow part of the Arabian plate continental margin. The Dam Formation is correlatable to the Miocene reservoirs in both Iran and Iraq. Therefore, studying the Dam Formation lithologic heterogeneity in a small distance with high resolution could help in further work related to pattern prediction of the Miocene reservoir properties. High-resolution sedimentological investigation was carried out through six outcrops. The facies parameters (lithology, sedimentary structures, main fossils, paleocurrent patterns and geometries of the sedimentary bodies) were described. The results revealed 15 lithofacies that have been further grouped into 7 lithofacies associations 5 of which are carbonates and include (1) interbedded dolostone and evaporates, (2) microbialite buildup, (3) ooid-dominated grainstones, (4) burrowed skeletal peloidal wackestone–packstone and (5) mollusc-dominated wackestone–packstone. The remaining two associations are of siliciclastics and include (6) intertidal siliciclastics and (7) wave-dominated siliciclastics. These lithofacies were interpreted to reflect deposition in a mixed siliciclastic–carbonate ramp system that includes subtidal, shoreface, intertidal, foreshore, supratidal and estuarine deposits in a shallowing-upward succession. Each one of these lithofacies association has distinct geometry and architecture pattern. Oolites and heterozoan lithofacies occur as sheets and show great continuity along the strike direction. Oolites pass laterally in the dip direction into more skeletal- and peloid-dominated zones, whereas heterozoan lithofacies stay continuous in the dip directions and change from siliciclastic to carbonate heterozones. In contrast, microbialite lithofacies lack continuous beds and occur as localised bioherms and biostroms. Channelised lithofacies are restricted laterally into isolated channel bodies and vertically in the contact boundary between siliciclastic and carbonate lithofacies, whereas the interbedded dolostone and evaporite lithofacies form distinct, relatively thick continuous layers. With continuous exposures in both strike (1.2 km) and dip (0.15 km) directions, the outcrops in the Al Lidam area provide unique opportunity to study the heterogeneity among lithofacies of the mixed siliciclastic–carbonate system of the Dam Formation. Such study may provide insights to predict occurrence and distribution of lithofacies bodies in their equivalent reservoirs which are important for reservoir characterisation.     

Fluoride exposure in the endemic fluorosis area of Guizhou, China

The dental and skeletal fluorosis is highly prevalent in Zhijin, Guizhou, especially at Hualuo Village, Hehua Village and Majiazhuang Village. The contents of fluorine in coal, clay used for coal combustion, mixed fuel of coal and clay, corn, and chili from households of the three villages were determined by the pyrohydrolysis-fluorine ion-selective electrode method. The average contents of fluorine in the above samples respectively are 237 mg/g, 2262 mg/g, 828 mg/g, 1419 mg/g, and 110 mg/g. The clay used for coal combustions is the main fluorine source of endemic fluorosis and the inferior coal and weathered coal are the secondary source of fluorine. During the combustion of mixed fuel of coal and clay, about eighty percent of fluorine was volatilized, approximately two thirds of which was from the clay and the other one third from the coal. The occurrence of fluorine in clay used for coal combustion is closely related to apatite and hornblende. The contents of fluorine in corn and chili, dried by coal-clay mixed fuel are about 1400 and 73 times higher than the permitted level of fluorine in foods according to the Chinese Standard. It is worth paying attention to the high-fluorine indoor surroundings, such as coal, clay, corn, and chili, particularly ash from boiler bottom with the fluorine content of 15738 μg/g. Besides the technologies of fluorine fixation during the combustion,     

Radon,Cl− and SO42− anomalies in hot spring water associated with the 1995 earthquake swarm off the east coast of the Izu Peninsula,Central Japan

Radon concentrations were continuously monitored in hot spring water in a 200-m-deep well in the Yugano hot spring area, Izu Peninsula, Japan from July to December 1995. Concentrations of Cl⁻ and SO₄²⁻ were measured in the hot spring water about once a month from May to December 1995. The Rn concentrations in the hot spring water increased significantly in September and October 1995, when the 1995 earthquake swarm off the E coast of the Izu Peninsula occurred at a distance of about 30 km from the observation well. The 1995 earthquake swarm began on 11 September and became most active from the end of September to the beginning of October. The Rn concentration rose gradually from 8 September, 3 days before the onset of the swarm activity, increasing by about 50% by 17 September. It remained high in October but had returned to normal by the end of November. However, Cl⁻ and SO₄²⁻ concentrations doubled suddenly from 22 to 23 September and remained high until the end of November. A good correlation between Cl⁻ and SO₄²⁻ concentrations suggests the same mechanism for their anomalous increases, probably mixing of water with high Cl⁻ and SO₄²⁻ concentrations caused by crustal deformation related to the seismic swarm activity. However, the anomalous increase in Rn concentration, which began 15 days before these anion increases, cannot be explained by the same water mixing mechanism. A possible mechanism for the anomalous Rn increase is the formation of microcracks caused by compressional stress, which preceded the onset of the earthquake swarm.     

Landslides induced by the April 2007 Aysén Fjord earthquake, Chilean Patagonia

On the 21st of April 2007, the Aysén Fjord earthquake (Mw 6.2) in southern Chile (45.3° S, 73.0° W) triggered hundreds of landslides in the epicentral area along the fjord coast and surroundings. Some of these landslides induced large tsunami waves within the fjord causing fatalities and damaging several salmon farms, the most important economic activity of the area. The landslides included rock slides and avalanches, rock falls, shallow soil and soil–rock slides, and debris flows. The earthquake was the climax of a seismic swarm that began 3 months earlier. The seismicity is associated with tectonic activity along the Liquiñe–Ofqui fault zone (LOFZ), a major structural feature of the region. The earthquake-induced landslides were mapped and classified from field observations and remote sensing analysis. The landslide areas and epicentral distances are within the expected range for the earthquake magnitude according to worldwide data, while the position of landslides on the slopes strongly suggests topographic amplification effects in triggering the failures. The location of the landslides is also clearly related to some of the main fault branches of the LOFZ. The seismic event has configured a new situation of seismic and landslide hazard in the Aysén region and along the LOFZ, where the presence of towns and economic infrastructure along the coasts of several fjords constitutes a potential risk that was not considered before this seismic event.     

Landslides at Qingjiang River in the Downstream Area of Shuibuya Dam Site, China

INTRODUCTIONLandslides annually cause a great amount of cas-ualties withinthe Chinese population and great lossesin the Chinese economy . The number of casualtiesreached 232 killed and 2 missing people in 2003 and283 killed and 69 missing people in 2004 . The eco-nomic losses amount to a total of 730 billion US $in2003 and 475 billion US $in 2004 (Zanetti ,2005 ,2004) .The DAAD (German Academic Exchange Serv-ice) is financing a project to investigate landslides .The project is a coo…     

Distribution and behavior of heavy metals in a river polluted by acid mine drainage in the Dabaoshan mine area, China

Acid mine drainage （AMD） has been recognized as a major environmental pollution problem over past decades. This pollutant effluent is complex and is characterized by elevated concentrations of iron and sulfate, low pH, and high concentrations of a wide variety of metals depending on the host rock geology. Massive inadvertent discharges from acid mines have given rise to dramatic cases of ecological damage. These events indicate an improved understanding of the mechanism controlling metal transport to the river is important, since the aquatic ecology will be affected, to some degree, dependent on the phase （dissolved or particulate） in which the metal is transported. In this study, polluted water samples were collected along the Hengshi River near the Dabaoshan mine, Guangdong, China, in April 2005. The concentrations of dissolved Cu, Zn, Cd and Pb have been determined using ICP-MS and the chemical speciation of those metals in suspended particles was examined using BCR methods and SEM/EDX mineralogical analysis. Combining these two sets of data, the intention was to develop geochemical concepts, which explain the behavior of Cu, Zn, Cd and Pb in particle-water interactions of heavy metals in AMD. The results show that the dissolved heavy metals exhibited non-conservative behavior in the Hengshi River. The dissolved and particulate Cu, Zn, Cd and Pb have the similar spatial distribution, which decreased gradually along the river except in the lower reaches because of the absorption-desorption between dissolved and particulate phases. Although the metal concentrations in both phases were elevated, dissolved metals were dominant and had the maximum concentrations in the low pH region.