The Da Hinggan Mountains metallogenic belt extends eastwards from arid desert area and the semi arid desert grassland area to the forest swamp areas and mostly belongs to the trouble areas in regional geochemical exploration. Due to the influence of the eolian sand and organic matter, anomaly verification fails to show obvious ore exploration effects. In view of such a situation, the authors put forward the opinion of carrying out 1:500000 geochemical survey in the Da Hinggan Mountains metallogenic belt, with the analysis and demonstration of the necessity and feasibility of this opinion. From such aspects as sampling method, analysis index and metallogenic prediction technology, the authors put forward some assumptions and suggestions. It can be expected that 1:500000 geochemical survey in the Da Hinggan Mountains metallogenic belt can not only realize the macroscopic evaluation of the metallogenic belt but also establish a wider geochemical field closer to the reality for the understanding, assessment and utilization of the 1:200000 regional geochemical exploration data.

This paper puts forward the suitable sampling particle size for the stream sediments survey in the study area through the test of survey method of stream sediments in northern Huaiyang area. 1:50000 geochemical survey experiment was carried out in the typical ore district by choosing the sample granularity of two kinds of mesh, and the results indicate that the concentration centers of elements coincide with the ore blocks in the ore district. The test results have shown that taking samples of 10~60 mesh coarse fragment media from the surface of valley within each 1000 m² can clearly determine the mineralization anomaly and correctly reflect the shape of the orebody. This result validates the feasibility of sampling granularity and provides guidance for geochemical survey in northern Huaiyang area.

Based on an analysis of elements association characteristics and anomalous element assemblage and a discussion on the basic geology of Yanshiping area, the authors have obtained the following new evidence for ore-forming geological background: There are big scale intermediate basic volcanic rocks in Yanshiping area, and there are some intermediate — acid intrusive rocks or vein rocks. Yanshiping fracture and Wenquanbinzhan fracture are deep fractures with rock-guiding and rock-control characteristics; NW-trending Chuduo-Chaqiong fracture is also rock-guiding and rock-control structure, and the ore-forming role of anticline structure is better than that of synclinal structure. According to the above conclusions, the authors hold that the Yanshiping mineralization is closely connected with intermediate basic volcanic rock and intermediate — acid intrusive rocks, and mesothermal and epithermal deposits and iron-copper polymetallic ore deposits are regarded as belonging to volcanic type and sedimentary- reworked type.

Owing to mining in the past successive years,the reserves have become less and less in Yichuan area.In order to speed up exploration of lead-zinc polymetallic deposits,the authors systematically analyzed metallogenic geological background and ore-controlling conditions of known deposits in Yichuan area,conducted proper conversion processing and analysis of the aeromagnetic data of the related deposits,and inferred and extracted aeromagnetic indicators of the deposits.Combined with the analysis of metallogenic geological conditions,the aeromagnetic anomalies with prospecting potential could be quickly identified.With two examples of aeromagnetic anomaly inspection,the better geophysical and geochemical anomaly features were found.The mineralization belt (body) exposed by trenching shows that the aeromagnetic indicators have high practicality and can be adopted as clues in search for the same type of lead-zinc polymetallic deposits in Yichuan area.

Through the electrical structure model of AMT inversion for G01 and G02 line in northern Jiling rock mass, combined with regional geology and geological profile data of No. 89 prospecting line, the authors basically clarified the electrical structural features of the hanging and lower walls of Geminggou fracture, and then inferred its location, attitude, deep extension and some other information. The results show that AMT can objectively reflect the electrical distribution pattern of geological body in the underground half-space of the section, and it can also reveal the structural features of ore-controlling structure, i.e., the Geminggou fracture. The hanging wall is reflected as tongue-like low resistance band that extends to the depth, while the siliceous marble and breccias developed close to the lower might reflect a wedge-shaped high resistance body that is narrow at the top and wide at the bottom, This can strictly control the strike and distribution pattern of ore-bearing siliceous marble and breccia.

Over 4000 meters of lacustrine face coal and oil-bearing clastic rock are deposited above the lower Permian base rock in Hurenbuqi sag, suggesting a good prospect of oil and gas geological conditions and resources. In this paper, the authors discuss the anomaly pattern of soil hydrocarbon geochemical exploration based on the magnetotelluric sounding interpretation of fracture structure and stratigraphic distribution as well as anomaly characteristics of southern sag. The formation mechanism of the surface geochemical anomalies are investigated, and the geochemical anomaly models are analyzed. The results obtained by the authors will play an extremely important role in oil and gas prospect evaluation.

Located in the eastern Central Asian orogenic belt, Ar Horqin area has widely distributed Mesozoic magmatic rocks. In this paper, petrologic and element geochemical studies were carried out for the early Cretaceous intrusive rocks in Ar Horqin area. The study of petrology indicates that the granitoids are mainly composed of granodiorite, adamellite and granite-porphyry. Major element geochemistry shows that the rocks are quasi-aluminous cal-alkaline granites, which are characterized by relatively rich silicon and sodium and poor potassium. Trace elements have a similar variation trend characterized by low REE, fractionation of REE, significant negative anomaly of Eu, depletion of Nb, Ta, P, Ti, and enrichment of LREE, Rb, Th, U, Zr, La. Main body of the granites belongs to calc-alkaline I genetic type. The magmas were formed by partial melting of the crust in an extensional setting after the collision, which was a favorable metallogenic tectonic evolution stage. DI values, K/Rb and Rb/Sr ratios are larger, SI values are smaller, and Fe₂O₃/FeO ratios are also larger, suggesting that the granites belong to low evolution, highly fractionated oxidation type or magnetite series. Their geochemical ore parameters indicate that Mo, Cu, Pb-Zn mineralization potentiality decreases systematically, and Au mineralization potentiality is poorer.

Based on the multi-purpose regional geochemical survey, the authors discovered a large area of selenium-rich soils on the north slope of the Tianshan Mountains in Xinjiang from Urumqi to Shawan County. The selenium content is relatively high, and a variety of fertile elements are rich. The study shows that the selenium is mostly distributed in the surface soil and exhibits the positive correlation with the organic content. It is indicated that the selenium originates in parent soil materials while the enrichment state of selenium depends on the supergene geochemical circumstance of local fluvio-lacustrine deposits.

The well-to-ground TEM Is an advanced borehole geophysical measurement method introduced in recent years. The method is characterized by sensing changes in the secondary field in space and time. With this method, researchers can achieve the purpose of discussing the borehole electrical nature and to discover the bottom hole blind ore or infer the spatial distribution and extension direction of the orebody. In this paper, the authors analyzed the well-to-ground TEM static and dynamic response characteristics and, through the research on well-to-ground TEM measurements in Heshang ZK39-7 in Jiangxi and Changpai ZK8-2 in Guangdong, found that this method can not only reflect lots of broken structure and alteration information around the borehole but also detect the information on the uranium mineralization. The results obtained by the authors provide a more accurate basis for further drilling construction

In fine precision magnetic survey data processing and interpretation usually requires quantitative interpretation of the magnetic body depth information for the study of regional tectonic,magmatic rocks and ore analysis also has important significance.Power spectrum method is a common method for calculating the depth of the magnetic material but the program uses the sliding window method.And parameter selection subjectivity can cause a calculation error.The author through computer interaction 2.5D gravity and magnetic joint inversion fitting and drilling data comparative analysis,select the optimal parameter combination,uses the power spectrum method to calculate the depth information of magnetic substance in Yin-E basin Juyanhai depression.

In order to expand reserve resources of the Qiongkuer iron deposit in Nilka County,Xinjiang, the authors conducted surface magnetic survey for 1:50000 geochemical Hs-19 anomaly.Through such means as reduction to the pole and continuation,the spatial distribution of attitude characteristics of three delineated high-magnetic anomalous bodies was detected;through two and a half dimensional interactive inversion,the buried depth and shape of the orebody were fitted;through drilling verification,the Qiongkuer iron deposit was discovered.At the late stage,a concealed orebody of certain size was found in the vegetation cover area on the western side of the main ore block according to the result of magnetic inversion,thus providing geophysical basis for the exploration of the deposit and the expansion of resource quantity.

The strata and rock masses in Baoyintu area show obvious magnetic and electrical differences.In order to understand geological and geophysical characteristics of the aeromagnetic anomaly,the authors delineated the areas of ground magnetic anomaly and composite aeromagnetic anomaly by 1:10000 precision ground magnetic survey.The aeromagnetic data processed with methods of reduction to the pole and upward continuation could obtain the magnetic anomaly features such as shape,size and buried depth.The IP sounding could be used to invert the size and extension of the deep orebody or mineralization in the area where there were obvious mineralization characteristics.Then drilling engineering could validate the result of the IP sounding.Finally,combined with the information of geology,IP sounding and drill verification,the authors used Oasis Montaj software to perform human-machine joint constrained inversion for 2.75D magnetic profile data,fitted out the morphological characteristics,and drew relative depth,width and thickness of the anomaly body, thus providing reliable geophysical basis for ore prospecting.

This paper briefly describes the principle and characteristics of the dual frequency induced polarization method on the basis of the application in typical overburden area (savanna area coverage) of Western Australia, and discusses such aspects as to how to solve the problems met in work plan design, array selection, selection of working frequency, and conductivity improvement, and how to overcome inductively coupled problems under the special geological landscape condition. What is more, the authors give the solutions of these problems and make a summary of some work principles of universal value. In conclusion, the dual frequency induced polarization method has good application effect in the special environment of a gold mine in Australia, the delineation of the IP anomalies is consistent with the expectation of geologists, and engineering verification is necessary for further work. It is held that the dual-frequency IP method in the process of design and field construction in overseas mineral exploration work should be based on the comprehensive analysis of the influencing factors in various aspects as well as scientific decision-making, and effective measures should be adopted to eliminate the possible factors affecting the accuracy of the measurement data. Only in this way can we enjoy the full play of the technical advantages of the dua-frequency IP method and obtain satisfactory results.

The author mainly introduces the application and research of comprehensive geophysical prospecting method in iron and copper poly-metallic ore prospecting target area in nanmentou exploration area of Nanjing,Jiangsu province.By analyzing the gravity-magnetic-electrical abnormal distribution characteristics,to explain and infer the anomalies delineation of gravity low and magnetic values high gravity high and magnetic values high and electrical property.The selection of important anomalies in the area are analyzed combined with geological and geophysical data,and has been verified by drilling holes,and three iron and copper poly-metallic ore prospecting target areas delineated and better prospecting results achieved.

Marine controlled-source electromagnetic (MCSEM) method is an important geophysical tool in ocean oil and gas resource exploration. As a key device of MCSEM observing system, the ocean bottom electromagnetic (OBEM) receiver is decisive in marine observation. As for a newly developed OBEM receiver, comparison test is necessary to evaluate its performance before it is used to conduct data acquisition in sea. Because of the high cost and difficulties of ocean tests, an alternative field comparison test is designed in this paper. A series of tests including channel consistency, instrument consistency and measuring result repeatability were carried out with existing MT observing system providing comparing results. The results obtained by testing data analysis can provide a basis for performance evaluation of OBEM receivers.

The Chengkou arc fault in the Daba Mountain is one of the focus areas in the domestic geological research. With the development of unconventional energy exploration work, especially shale gas exploration work, in recent years, a new round of exploration work has been carried out in this area. Because of the close folds and the dense faults, this area is an area with complex surface exploration condition and complex underground geological structure. The authors deployed some points of log, a test line of seismic survey and a test line of WFEM (Wide Field Electromagnetic Method) in this area. Some conclusions have been reached:logging has the characteristics of high resolution and precise measurement, but due to its limited "a peephole view", the signal-to-noise ratio of seismic data is low and hence fails to provide accurate information of lithology and fracture; therefore, in the areas of complex surface exploration condition and complex underground geological structure, it is very difficult to use seismic exploration; nevertheless, WFEM is applicable and effective in complex geological conditions, as shown by an example. WFEM can be used to find the stratigraphic distribution, structure and fracture characteristics; it can provide electrical distribution characteristics and predict the prospect of oil gas, thus laying the foundation for the next step of 3D exploration.

Pre-stack seismic full waveform inversion (FWI) is based on wave equation forward modeling technology to describe the propagation characteristics of seismic wave,using non-constrained iterative local optimization method to get high resolution inversion result.Compared with other inversion methods,FWI uses pre-stack common shot gather to perform inversion,in which the seismic data are free of the process of stack and preserve the features of waveform parameters variation with offset.The inversion result is no longer simple interface and traveltime information but depth-domain data volume which reflects formation velocity and structural characteristics,and this is helpful to the analysis and understanding of the geological body.In this paper,the technical advantages are analyzed in the aspect of pre-stack full waveform inversion methods,and the key technology to do a good job of pre-stack full waveform inversion is also analyzed through synthetic data.Furthermore,the technical advantages of pre-stack full waveform inversion are illustrated through inversion results in migration processing and its application in reservoir description of fluvial facies,and the existing difficulties and the future development direction of pre-stack seismic full waveform inversion are also analyzed,which will provide reference for further development and application of pre-stack seismic full waveform inversion.

Strong reflector is widespread in the actual data analysis.The traditional description method of this kind of reservoir is based on certain time window to extract property,reservoir analysis and description directly,which greatly affect the precision of reservoir research.In this paper,with a practical example from Fuyu oil layer (T2) in Punan area of Songliao basin,in combination with the geological situation and drilling and logging data,and through the forward modeling technique,the authors analyzed the causes of T2 strong reflection and influence range.After an analysis of clear formation mechanism,the authors propose a strong reflector influence removing technology based on matching pursuit algorithm,calculation and analysis of actual seismic data.The research results show that,with the elimination of strong reflector effect before seismic attribute extraction,the prediction accuracy of the underlying layer can be greatly improved.

Complex traveltime of seismic wave plays an important role in dealing with caustics with which geometric ray theory faces.To obtain a higher accuracy and a more efficient method for calculating the complex traveltime,the authors introduce the L-BFGS optimization method to calculate the imaginary slowness.In addition,orthogonal condition of the real part and imaginary part of complex traveltime are taken as the objective function,and then a new L-BFGS-FMM method is obtained for computing complex traveltime.The numerical examples demonstrate the effectiveness of L-BFGS-FMM used in this paper.An analysis of accuracy and efficiency of the results obtained by using the analytical method,dynamic ray tracing method,Gauss-Newton-conjugate gradient method and L-BFGS-FMM method shows that the L-BFGS-FMM method introduced in this paper is superior to all the other methods,and hence the method introduced in this paper can meet the large-scale computing requirement in practical applications.

A NI inversion method of linear rock physical properties transformation was introduced in previous studies,which can be used to predict gas saturation on the basis of prestack seismic data.The problem as to how to make the sensitivity analysis of the inversion results in order to correctly predict commercial gas reservoirs was discussed.By increasing the rock physical properties transform precision and strengthening the constraint of pore fluid transformation the authors further improved the inversion algorithm,which raises the accuracy of inversion effectively.The practical application results show that the quadratic equation NI inversion method can effectively predict the gas saturation in complex area.

Magnetotelluric method (MT) is applied so widely that improving the method of inversion and the interpretation of MT data become very important. This paper summarizes different inversion algorithms and points out their limitations. Then an overview is given on neighborhood algorithm (NA) and its application to the MT inversion. The maximum likelihood model from NA is very close to the theoretical model. Although NA and genetic algorithm (GA) have the same capability for resisting the local minimum value, NA algorithm shows better similarity between the density distribution of sampling points and the error function, so NA is more conducive to inversion application based on the integral parameter appraisal method. In this study, the authors found that NA converges much faster than GA, whereas NA algorithm is more advantageous than GA algorithm in 1D MT inversion.

The least-square migration methods can make the seismic profile imaging quality higher,and are conducive to better imaging for lithologic reservoir and reservoir parameter inversion.However,in the process of practical application,it is very difficult for least square migration to achieve high accuracy of lithology imaging.Based on an analysis of the problems existing in the traditional least squares migration,the authors have developed a least squares migration method based on phase matching,which abandons the quadratic function used frequently by the traditional methods,and employs the cross-correlation function;in this way,this method emphasizes more on the role of the seismic phase information in the least squares inversion imaging;in theory,and it can be better applied to real data.Based on the cross-correlation function building,synthesizing prediction data by reverse time demigration,gradient precondition,and pre-conditional conjugate gradient,the authors explored and realized a cross-correlation objective function for least-squares reverse migration.Simple sub-sag model and complex salt model tests show that the proposed method has applicability and effectiveness.

At present,the study of loose sand mainly focuses on some commonly used models which are based on the Hertz-Mindlin and Walton contact theories.In this paper,the authors tested the capability of various rock physics models to predict dry modulus of the sand samples by comparing the estimates with results measured in laboratory.The study shows that the traditional model of unconsolidated sand is not good at characterizing its elastic properties.Using either the HMR or HMS theories to define the high porosity endpoint gives a lower-prediction of the dry bulk modulus which will have a much bigger error when combined with HS lower bounding equation.Both HMR and WR result in an over-prediction of the dry shear modulus because they do not consider the deformation across the contact.As WS cannot give a good fit to all the areas,it is rarely used.Despite the fact that the results are somewhat lower than the real data,the dry modulus is best described by HMS.With the help of the HS higher bounding equation,the predicted dry modulus agrees fairly well with the measured data.So the new constructed method has better application effect and deserves much attention.

The principle of airborne time domain electromagnetic system is that Tx coil transmits electromagnetic pulse into ground, and Rx coil receives the induced secondary EM fields from conductive bodies in the earth. The secondary fields generated by induced current of conductive bodies contain geological information. Data processing and interpretation help to achieve prospecting for multi-metal mineral resources. The authors analyzed features of time constant reflection to power line interference under the conditions of near surface conductive bodies, near surface weak conductive bodies, and deep conductive bodies respectively and summarized the characteristics of time constant of different geological bodies based on knowledge of known mineral formation and two years' experience in airborne EM surveys. Some conclusions have been reached: the power line interference generally shows a discontinuous linear anomaly in τ map and electromagnetic response is jumping like irregular attenuation; low resistivity anomaly generally shows high value area in τ map and the electromagnetic response decays exponentially. The low resistance body decays more slowly when the conduction is better and the body is bigger.

Inductively coupled plasma atomic emission spectrometry (ICP-AES) technology has been rapidly developed in recent years, which includes a plasma source, a beam system and detection devices that have been effectively improved. This technology has been widely used in the sample analysis, especially in geological laboratories. With the progress of the instruments for promoting the development of exploration geochemistry, ICP-AES is a powerful technology that can solve the accurate determination of elements in geological samples. This paper outlines the progress of ICP-AES measurement technology, highlighting the impact of the instrument's measurement conditions on the interference elements, elements exposure strength and elements in the analysis of spectral lines. This paper also describes the application of ICP-AES technology in geological samples analysis, and emphatically points out that the determination of the elements in the soil, rock, stream sediments, ore samples, plant samples and water samples should be based on the utilization of different properties of digestion systems (such as acid digestion, alkaline fusion method and microwave digestion) for different elements in different samples. A comparison of different characteristics of the digestion systems in the determination of soil, rock and stream sediment samples and a comparison of the method detection limits of the elements by using different digestion systems show that the detection limit of the acid digestion method is much better than that of alkali fusion. The precision of the determination of the elements in ore samples in different digestion systems was also comparatively studied. The results show that the measurement accuracy is good. This paper also summarizes the typical pre-treatment method for the inorganic elements in plant samples, the utilization of ICP-AES to determine elements in water samples, which includes the total amount of each element and the amount of different valence states in each element. Finally, ICP-AES measurement techniques in geology applications are put forward, and it is believed that the ICP-AES will surely play a key role in the analysis of geological samples.

This paper introduces the data acquisition and processing system of WD intelligent natural source surface wave designed and developed independently by Chinese researchers,which has changed the situation that the in-site instrument can only collect natural microvibration wave form record.Utilizing such techniques as large data calculation,sieving,stacking and normalization,this system has innovatively developed the direct demonstration of surface wave frequency-discretion curves of exploration results simultaneously with the acquisition of the micro seismic signal.During the signal acquisition,seismic source and human control are not needed.The equipment is installed on the ground,and can obtain transverse wave velocity curve of the strata within one hundred meters in 5~30 minutes and reflect the hardness of the strata.Test results in areas of different lithologic characters have proved that this system can divide strata rapidly and accurately.With the advantages of easy operation and high adaptability,this system provides technological guarantee for extensively applying the natural source surface wave exploration to the engineering exploration.

The Dajingpo airborne geophysical field test site is the first comprehensive test site for airborne geophysical instruments in China,which could better meet the requirement of airborne geophysical instruments and software system test and software technology research.Based on the requirements analysis of current data format and storage management,the authors constructed the Dajingpo airborne geophysical information management system and services platform,including the system requirement analysis,system designing, and system function.The designed system has been proved to be highly effective in providing data services for the field users.

To get accurate background value and anomaly threshold, it is necessary to iterate abnormally distributed geochemical data for deleting outliers in geochemistry. To analyze deeply the complex iteration procedure, actual data and "outliers check" the authors used iteration procedure to detect the effect of different parameters and reliability of logarithm transformation. Some conclusions have been reached: According to the goal and 3σrule of normal distribution, in x_i±kS_i,k=3 is suitable. The higher anomaly threshold of logarithm transformation is not correct and the true value of logarithm standard deviation is not in accord with the standard deviation of the true value, so the the threshold is equal to the sum of geometric mean and standard deviation of the true value.

The triangular subdivision method can maximally retain the original information when generating geochemical contour in the MapGIS automatically, but its surface visual effect is poor and huge finishing workload will be changed later. When Gird generates isoline grid data, there will be a condition that the accumulation centers of elements and the point location of extreme value will change to some extent, and it is not convenient for analysis of the geochemical characteristics and the anomaly verification work in late stage. Based on studies, the author found that if the extremum points in the discrete sampling point analysis data are extracted, buffer is established for the extremum value points according to a certain threshold, through point-to-area spatial analysis, the deformed grid nodes in the regular grid which are relatively close to the extremum points and might affect the triangle subdivision mesh optimization are rejected. After that, the discrete extreme value point data and the regular grid data that have rejected the deformed grid nodes grid data are merged, followed by triangular subdivision contour tracking. These measures satisfactorily make up the shortcomings of the two methods mentioned above. This method does not need using other software tools and only employs the MapGIS. The method can generate geochemical contour of extreme values without deviation, and both the mapping accuracy and the visual effect are fairly good, thus having good practicability.

With the ever increasing data quantity of three-dimensional seismic geometry, geometry throughput on the GPU is becoming a severe performance limitation in petroleum exploration software.This paper presents an efficient way to render large three-dimensional seismic geometry on level-of-detail digital elevation models(DEMs). By using the OpenGL frame buffer object, the terrain elevation values are rendered directly to depth texture. And then GPU shader is employed for acquiring elevation of points in real time. With 3ds model and point texture, level-of-detail point models are established. In the detailed level, the 3ds models are used to render shots and receivers accurately, and in the coarse level point textue techniques are used to render shots and receivers approximately yet more quickly. The method proposed in this paper is universally applicable to rendering seismic geometry on various LOD terrain models, and the rendering performance is independent of the complexity of underlying terrain surfaces. The experimental results show that, the method can achieve seamless and rapid rendering of large 3D seismic geometry on LOD terrain surfaces.

Determining the locations and the dipping angles of the faults is one of the most important issues in the interpretation of the gravity profile data.The authors first construct a series of 2D fault models with different geometric parameters (e.g., locations and dipping angles).Then the theoretical gravity responses of the models are applied to the correlation scanning with the observing gravity profile data in the moving windows.According to the comparison between the calculated correlation values and the threshold value,we can judge whether the faults exist or not beneath the centers of the windows.If the faults exist,the corresponding geometric parameters of the maximum correlation value are treated as the interpretation results.The synthetic model tests suggest that it is effective to identify the faults with different dipping angles.Moreover,the correlation scanning method is applied to an actual profile of the gravity data in field,and the results show that the determined locations and dipping angles of the faults by the proposed method are consistent well with those of the known faults detected by surface geological survey and other geophysical probes.Therefore,both the synthetic tests and the field example indicate the validity of the method presented in this paper.

In high accuracy aeromagnetic survey, the magnetic interference of aircraft must be effectively eliminated, and the method is compensation flight. The compensation has a direct influence on the flight data quality of geophysical exploration; nevertheless, because China's magnetometers have different models, so how to perform unified evaluation is very important. According to the specification, the criterion of aeromagnetic survey (DZ/T1402-2010) provides specific measures for assessing the performance of digital magnetic compensation; nevertheless,it does not define the method of quality assessment. This paper introduces the parameter of IR and three components as well as different directions of flight so as to verify the effect of compensation.

As a geophysical method based on the reflection of electromagnetic wave, ground penetrating radar (GPR) is interfered by the underground metal pipeline in underground disease detection of urban road. In order to find out the interference region around the metal pipeline, the authors deduced the calculating formula of the interference region based on the resolution of GPR. After the numerical simulation and the physical model simulation, the authors found that there is an interference region with a vertical height of the electromagnetic wave length beside the metal pipeline. When the underground disease is located in this region, its reflection wave group will be disturbed, which is not conducive to the interpretation of disease's attribute and scale. And when the underground disease is located under the metal pipeline, it cannot be detected by the current single type antenna.

In this study, the authors built five kinds of pollution models and carried out numerical simulation with the finite-difference method to tackle different ways and different media of groundwater pollution, based on GPR forward modeling software (GPRMax). The simulation results show that GPR exhibits fairly good application effects in detecting groundwater pollution.