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1.
Groundwater data (water level, electrical conductivity (EC) and temperature) have been collected since 1995 from the national groundwater-monitoring stations in South Korea. Recently, substantial groundwater-level decline and deterioration of groundwater quality were reported at several stations. Relevant authorities undertook to investigate the groundwater hazards and to devise mitigation measures for selected monitoring stations. However, there were no criteria to determine the status of the groundwater level and EC, compared with historic data. A methodology is presented, which defines the groundwater condition. Using the suggested criteria, water level and EC data are classified into normal, watch and warning levels, leading to different administrative measures and technical investigations. The primary criterion compares the observed values for the evaluation year (e.g. 2003) and the historic values of normal years preceding the evaluation year (e.g. 1996–2002), using box plots. The secondary criterion uses variation trends of the values with the aid of parametric and non-parametric trend tests. Final decisions are dependent on scores assigned to each test. According to the criteria suggested, detailed investigations and mitigation measures for water level decline are required for seven stations and those for water quality are needed for 18 stations because they reside within the warning classification. 相似文献
2.
A properly designed groundwater-monitoring network is critical to evaluate groundwater management policies and regulations and establish a scientifically credible, risk-informed approach towards management of aquifer resources. To achieve proper design, the network must comprise a sufficient number of wells that comprehensively covers the area of interest. In this study, statistical power analysis is utilized to define the size of a proposed monitoring network within the Victoria County Groundwater Conservation District (VCGCD). In particular, the network seeks to provide empirical information to evaluate whether the VCGCD is meeting the criteria of the desired future conditions (DFC) established by the Groundwater Management Area 15 (GMA 15) through the joint planning process, as required by the statutes of Texas. The evaluation of DFCs is expressed as a hypothesis-testing problem with the null hypothesis stating that the VCGCD complies with the DFC, and the alternative hypothesis stating that the VCGCD does not comply with the DFC. The power analysis quantifies the ability of the statistical test to correctly reject the null hypothesis. The power of the statistical test is a function of the sample size and this relationship can be exploited to determine the size of the required groundwater-monitoring network if the effect size can be specified. However, prior to establishing a monitoring network, the groundwater level monitoring tends to be ad hoc; therefore, the statistical moments required for characterizing the effect size are not likely to be known with a high degree of certainty. As such, an innovative framework that integrates power analysis with bootstrap resampling protocols was developed to estimate monitoring network size under uncertainty. The results of the study indicated that a minimum set of approximately 70 wells is required within the VCGCD to statistically evaluate the compliance with DFCs with 90 % reliability and at a significance level of 10?% and 90 % power. The number of wells increased to about 85 when the significance level was reduced to 5 %. Geostatistical analysis indicated that these monitoring wells must be at least 3 miles apart to ensure statistically independent information. The developed methodology provides a practical framework to size a groundwater-monitoring network under data sparse situations. 相似文献
3.
Groundwater has played an important role in economic development in Southeast Asian countries, but some problems caused by
nature or human actions such as contamination, over pumping, and land subsidence bring the necessity of more systematic groundwater
monitoring wells. The analytical hierarchy process with pairwise comparison was used to allocate and organize the regional
groundwater monitoring wells in five regions, Thailand, Cambodia, East/West Malaysia, and South Korea. Five different multi
criteria decision models, which were composed of three primary criteria and eight secondary criteria, were developed based
on the answers of the questionnaire from 76 groundwater experts in Thailand, 100 in Cambodia, 101 in East Malaysia, 87 in
West Malaysia, and 93 in South Korea. It was revealed that the weights of model criteria for each country, which also represent
relative importance on groundwater monitoring, were different according to the diverse groundwater situation. The most important
factor to determine the number of monitoring well was ‘number of households using only groundwater as a water source’ for
Thailand and South Korea, ‘number of contamination sources’ for Cambodia, ‘amount of groundwater use for drinking-water supply’
for East Malaysia, and ‘number of wells with contaminated water’ for West Malaysia. 相似文献
4.
In the Daqing region of China there are 34 groundwater well fields with a groundwater withdrawal of 81.9×104 m3/d. Due to over-abstraction of the groundwater resources from the 1960s to present, a cone of depression up to 4,000 km2 has formed in the area. To monitor the change in the groundwater environment, it is necessary to design an effective groundwater-monitoring network. The sites for monitoring groundwater level were selected by applying the finite-element method coupled with Kalman filtering to the area in which the groundwater resources have been extensively exploited. The criterion is a threshold value of the standard deviation of estimation error. This threshold value is determined by the tradeoff between maximum information and minimum cost, in which the maximum information is characterized by the standard deviation and the minimum cost is equivalent to the number of observation wells. The groundwater flow model was calibrated by an optimal algorithm coupled the finite-element method with Kalman filtering by using the data from 16 observation wells from 1986 to 1993. A simulation algorithm coupled with the finite-element method with Kalman filtering analyzed the location data obtained from the existing 38 observation wells in the same region. The spatial distribution of standard deviation of estimation error is computed and the locations that have the maximum standard deviation are selected as additional sites for augmenting the existing observational well network at a given threshold value of the standard deviation surface. Based on the proposed method for selecting a groundwater level monitoring network, an optimal monitoring network with 88 observation wells with the measurement frequency of 12 times per year is selected in the Daqing region of China. 相似文献
5.
The analytical hierarchy process (AHP) is one of the most effective methods for criteria ranking/weighting to have been successfully incorporated into GIS analyses. We present a new method for optimizing pairwise comparison decision-making matrices in AHP method, which has been developed on the basis of an interval pairwise comparison matrix (IPCM) derived from expert knowledge. The method has been used for criteria ranking in land subsidence susceptibility mapping (LSSM) as a practical test case, for which an interval matrix was generated by pairwise comparison. To compare the capability of the AHP method (a traditional approach) with that of the proposed IPCM method (a novel approach), 11 creations of LSSM were ranked using each approach in turn. The criteria weightings obtained were then used to produce LSSM maps based on each of these approaches. The results were tested against a data set of known land subsidence occurrences, indicating an improvement in accuracy of about 14% in the LSSM map that was developed using the IPCM method. This improvement was achieved by minimizing the uncertainty associated with criteria ranking/weighting in a traditional AHP and could form a basis for future research into minimizing the uncertainty in weightings derived using the AHP method. Our results will be of considerable importance for researchers involved in GIS-based multi-criteria decision analysis (MCDA) and those dealing with GIS-based spatial decision-making methods. 相似文献
6.
Because the mixture of seawater and freshwater in the Gyeongin-Ara Waterway in South Korea can lead to the intrusion of saline water into surrounding aquifers, systematic management through the establishment of a groundwater protection area is required. The analytic hierarchy process (AHP) model is used to delineate this protection area based on two primary factors and five secondary factors related to saline water intrusion. The study area is divided into 987 gridded cells with a unit size of 100 × 100 m, and the final evaluation score for each cell is calculated using the AHP model. Consequently, several artificial neural network models based on a multilayer perceptron are developed using the AHP’s secondary criteria and the evaluation score. Comparing the evaluation scores of ANN and AHP, more than 180 samples are required in the ANN model to insure high R2 between the original and estimated values. The ANN model is more consistent than the AHP model when determining groundwater protection area, because it can be re-constructed due to the changes in some secondary criteria and also changed due to a standardization process. The final evaluation score by the ANN model based on 300 samples, with the highest R2, is calculated and the regions with a score higher than 2.0 are selected as the groundwater protection area, accounting for 15% of the total cells. This area is similar to the range within approximately 200 m of the GA Waterway and also includes some changing sites in hydrogeochemistry and electric conductivity, which is produced by saline water intrusion. If the land-use type, groundwater levels, and some other criteria change at any cell, the ANN model can be re-executed to verify whether the cell belongs to a groundwater protection area. Considering that salinity of groundwater near the waterway can be affected by various factors including well depth, pumping conditions, and groundwater levels, the ANN model, which is a non-linear model, can be more effective for prediction than the AHP model. 相似文献
7.
An entropy-based approach is applied to identify redundant wells in the network. In the process of this research, groundwater-monitoring network is considered as a communication system with a capability to transfer information, and monitoring wells are taken as information receivers. The concepts of entropy and mutual information are then applied to measure the information content of individual monitoring well and information relationship between monitoring well pairs. The efficiency of information transfer among monitoring wells is the basis to judge the redundancy in the network. And the capacity of the monitoring wells to provide information on groundwater is the point of evaluation to identify redundant monitoring wells. This approach is demonstrated using the data from a regional-scale groundwater network in Hebei plain, China. The result shows that the entropy-based method is recommendable in optimizing groundwater networks, especially for those within media of higher heterogeneities and anisotropies. 相似文献
8.
Landfill site selection by decision-making tools based on fuzzy multi-attribute decision-making method 总被引：2，自引：2，他引：0
Abdolhadi Nazari Mohammad Mehdi Salarirad Abbas Aghajani Bazzazi 《Environmental Earth Sciences》2012,65(6):1631-1642
Landfill site selection is a complex and time-consuming process, which requires evaluation of several factors where many different
attributes are taken into account. Decision makers always have some difficulties in making the right decision in the multiple
attribute environments. After identifying candidate sites, these sites should be ranked using decision-making methods. This
study applies Chang’s fuzzy AHP-based multiple attribute decision-making (MADM) method for selection of the best site of landfills
based on a set of decision criteria. The Fuzzy Analytic Hierarchy Process (FAHP) was designed to make pairwise comparisons
of selected criteria by domain experts for assigning weights to the decision criteria. Analytic Hierarchy Process (AHP) is
used to make pairwise comparisons and assign weights to the decision criteria. It is easier for a decision maker to describe
a value for an alternative by using linguistic terms and fuzzy numbers. In the fuzzy-based AHP method, the rating of each
alternative was described using the expression of triangular fuzzy membership functions. Once the global weights of the criteria
is calculated by AHP, they are incorporated into the decision matrices composed by decision maker and passed to fuzzy-AHP
method which is used to determine preference order of siting alternatives. In this study, a computer program based on the
Chang’s fuzzy method was also developed in MATLAB environment for ranking and selecting the landfill site. As an example of
the proposed methodology, four different hypothetical areas were chosen and implemented to demonstrate the effectiveness of
the program. By using this program, the precision was improved in comparison with traditional methods and computational time
required for ranking and selecting the suitable landfill site was significantly reduced. 相似文献
9.
基于我国南方地区岩溶发育极不均匀、水位水质动态变化快的特点,通过对信息熵法和防污性能法所得结果的对比,分析在缺少系列监测资料条件下,利用岩溶水系统防污性能评价结果快速布设地下河系统水动态监测网的可行性及其布设原则。根据防污性能评价结果,结合水循环特征,桂林海洋-寨底地下河系统水动态监测网需由17个监测站组成;采用信息熵法对现有35个监测站进行优化后,认为只需要12个监测站就可组成最优监测网,但这12个监测站点与采用防污性能评价法得到的点位完全重合,且均位于防污性能差的地区。对比分析认为,以地下水系统防污性能评价结果布设地下水动态监测网是可行性的,因为岩溶发育区既是防污性能差的地区,也是地下水动态变化快的地区,能充分反映地下河系统水质水量变化。采用防污性能评价法布设地下水动态监测网时,需要充分认识和了解地下河系统水文地质条件和地下河管道结构特征,且需要遵循以下原则:(1)在岩溶发育相对较弱的系统中部(基本上不存在防污性能差的地区)不设置监测站点;(2)在距离地下河出口较近的岩溶发育区内(即防污性能差的地区)监测站点可由地下河出口替代;(3)对于多支管道系统,岩溶发育相对较弱且距离较短的小型支管道上可以不布设监测站,由支管道与主管道交汇处的监测站代替。 相似文献
10.
层次分析法在致密油有利区优选中的应用——以川中侏罗系大安寨段为例 总被引：1，自引：0，他引：1
层次分析法常用于解决复杂系统分析与决策中目标优选、排序等问题,也适用于油气勘探领域。在前人致密油地质特征研究的基础上,总结了致密油有利区优选指标。使用层次分析法优选有利区的核心内容是建立层次结构模型和构建2类矩阵。以四川盆地中部侏罗系大安寨段为例,介绍了使用层次分析法优选有利区5个主要步骤:1根据研究区地质特征,确定目标及方案,构建目标层和方案层;2根据影响致密油富集的要素,确定准则层;3构建准则层中各要素的成对比较矩阵,确定各准则要素的相对权重;4构建各准则要素对不同方案的判断矩阵,确定不同方案中各准则要素的权重;5将不同方案各准则要素的权重矩阵与准则要素的相对权重矩阵相乘,得到各方案的层次排序,进而选出最佳方案。优选的川中侏罗系大安寨段致密油最有利勘探区为金华—莲池区。操作简单、不需考虑下限值、适用范围广是层次分析法优选有利区的优点,但由于层次分析中的标度根据人为经验赋值,不同评价人员给出的评价结果有所不同。将层次分析法与GIS、特尔菲法、模糊数学法相结合,可以提高准则要素的优选合理性及赋值准确性。 相似文献
11.
A groundwater tracing investigation as an aid of locating groundwater monitoring stations on the Mitchell Plain of southern Indiana 总被引：1，自引：0，他引：1
Wanfang Zhou Barry F. Beck Arthur J. Pettit Brad J. Stephenson 《Environmental Geology》2002,41(7):842-851
12.
C.-L. Chang Y.-T. Lin 《International Journal of Environmental Science and Technology》2014,11(2):303-310
Water quality monitoring stations play critical roles for analyzing the information of water quality conditions in a watershed. The understanding of water quality conditions of a river system is very important for water resource management. This study applied the VIKOR method, a commonly used method in multiple criteria analysis, to evaluate the design of the water quality monitoring network in the Taipei Water Resource Domain (TWRD). Five criteria were selected for multiple criteria analysis: non-point source pollution, green cover ratio, landslide area ratio, over-utilization area ratio of hillsides, and density of water quality monitoring stations. This study recommended several areas where there is a need for sufficient monitoring records of water quality. The result shows that more monitoring stations are needed in the Bei-Shih Creek Basin. Although the Nan-Shih Creek Basin covers larger area than the Bei-Shih Creek Basin and the Sin-Dian Creek Basin, it can accept less density of water quality monitoring stations. 相似文献
13.
Duong Du Bui Akira Kawamura Thanh Ngoc Tong Hideo Amaguchi Naoko Nakagawa 《Hydrogeology Journal》2012,20(8):1635-1650
A groundwater-monitoring network has been in operation in the Red River Delta, Vietnam, since 1995. Trends in groundwater level (1995?C2009) in 57 wells in the Holocene unconfined aquifer and 63 wells in the Pleistocene confined aquifer were determined by applying the non-parametric Mann-Kendall trend test and Sen??s slope estimator. At each well, 17 time series (e.g. annual, seasonal, monthly), computed from the original data, were analyzed. Analysis of the annual groundwater-level means revealed that 35?% of the wells in the unconfined aquifer showed downward trends, while about 21?% showed upward trends. On the other hand, confined-aquifer groundwater levels experienced downward trends in almost all locations. Spatial distributions of trends indicated that the strongly declining trends (>0.3?m/year) were mainly found in urban areas around Hanoi where there is intensive abstraction of groundwater. Although the trend results for most of the 17 time series at a given well were quite similar, different trend patterns were detected in several. The findings reflect unsustainable groundwater development and the importance of maintaining groundwater monitoring and a database in the Delta, particularly in urban areas. 相似文献
14.
15.
Groundwater monitoring in Denmark: characteristics, perspectives and comparison with other countries 总被引：1，自引：0，他引：1
More than 99% of water use in Denmark is based on groundwater. Denmark has had a comprehensive national groundwater-monitoring programme since 1988 based on 74 well catchment areas and six small agricultural catchments with more than 1,500 screens at different depths for regular, mostly annual, water quality sampling. In addition, water samples from 10,000 abstraction wells are analysed every 3–5 years. The water is analysed for main components, inorganic trace elements, organic micro pollutants, and pesticides and their metabolites. A unique feature is the 20-year time-series data of inorganic pollutants. Groundwater modelling supports traditional monitoring to improve the conceptual geological understanding and to assess the quantitative status and the interaction between groundwater and surface water. The programme has been continuously adjusted to incorporate new knowledge from research programmes and meet new policy demands, currently the European Union Water Framework Directive, particularly with respect to an increased focus on quantitative aspects and on the groundwater/surface water interaction. The strengths and weaknesses of the Danish programme are assessed and compared with other national groundwater-monitoring programmes. Issues discussed include: strategic considerations for monitoring design, the link between research and monitoring, and adoption of responses to climate changes. 相似文献
16.
区域地下水位监测网优化设计方法 总被引：8，自引：4，他引：8
区域地下水位监测提供了定量评价含水层地下水位持续下降及其对环境影响必不可少的信息。历史上的地下水位监测网是为了评价地下水资源或监测水源地降落漏斗而设立的,目前它们已经不能适应为流域水资源综合管理提供必需的信息。本文在综述国际地下水位监测现状的基础上,介绍了区域地下水位监测网优化设计的方法。采用地理信息系统编制的地下水动态类型图为地下水位监测井位置的选择提供了坚实的水文地质基础;克里金插值法能定量评价监测网观测值绘制的地下水位等高线的精度,因而可以用来定量设计地下水位监测网;时间序列分析和统计检验提供了优化地下水位监测频率的定量标准。这些方法已被应用于北京平原、乌鲁木齐河流域和济南岩溶泉域,其成果将在本刊分期发表。 相似文献
17.
Paul F. Hudak 《Hydrogeology Journal》1998,6(3):341-348
A method was devised for designing configurations of monitoring wells, consisting of vertically nested intakes in boreholes.
The network-design method involves analyzing a subset of potential contaminant plumes emerging from the downgradient margin
of a landfill. Plume widths are evaluated along selected equipotential lines and compared to the lengths of those lines. The
method was applied to a 32-ha solid-waste landfill in Tarrant County, Texas, USA. Sixtynine potential source nodes were considered.
A 15-borehole network devised by the method registered 93 detections in total, detecting all 69 model-generated plumes by
at least one borehole. Based on an enumeration procedure, a minimum of 10 boreholes was needed to detect all of the model-generated
plumes. However, the less conservative 10-borehole network had little capability for backup detection. An existing monitoring
network of seven downgradient wells detected only 38 model-generated plumes. Results of this study illustrate a practical
need for structured approaches to designing detection-based groundwater-monitoring configurations.
Received, February 1997 · Revised, July 1997, December 1997 · Accepted, November 1997 相似文献
18.
Data inadequacy is a common problem in designing or updating groundwater monitoring systems. The developed methodologies for the optimal design of groundwater monitoring systems usually assume that there is a complete set of data obtained from existing monitoring wells and provide a revised configuration for the system by analyzing the current data. These methodologies are not usually applicable when the current groundwater quantity and quality data are highly sparse. In this paper, a new simulation–optimization approach based on Bayesian maximum entropy theory (BME) is proposed for revising spatial and temporal monitoring frequencies in a sparsely monitored aquifer. The BME is used to simulate the spatial and spatiotemporal variations of groundwater indicators, incorporating the space/time uncertainties due to insufficient data. Comparing the obtained estimations with observations, the best BME model was selected to be linked with an optimization model. The main goal of optimization was to find out the spatial and temporal sampling characteristics of the monitoring stations using the concepts of Entropy theory and a groundwater vulnerability index. The results show the BME estimations are less biased and more accurate than Ordinary Kriging in both spatial and spatiotemporal analysis. The improvements in the BME estimates are mostly related to incorporating hard (accurate) and soft (uncertain) data in the estimation process. The applicability and efficiency of the proposed methodology have been evaluated by applying it to the Tehran aquifer in Iran which is suffering from high groundwater table fluctuations and nitrate pollution. Based on the results, in addition to the existing monitoring wells, seven new monitoring stations have been proposed. Few stations which potentially can be removed or combined with other stations have been identified and a monthly sampling frequency has been suggested. 相似文献
19.
Holistic approach of GIS based Multi-Criteria Decision Analysis (MCDA) and WetSpass models to evaluate groundwater potential in Gelana watershed of Ethiopia 
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下载免费PDF全文 Appropriate quantification and identification of the groundwater distribution in a hydrological basin may provide necessary information for effective management, planning and development of groundwater resources. Groundwater potential assessment and delineation in a highly heterogeneous environment with limited Spatiotemporal data derived from Gelana watershed of Abaya Chamo lake basin is performed, using integrated multi-criteria decision analysis (MCDA), water and energy transfer between soil and plant and atmosphere under quasi-steady state (WetSpass) models. The outputs of the WetSpass model reveal a favorable structure of water balance in the basin studied, mainly using surface runoff. The simulated total flow and groundwater recharge are validated using river measurements and estimated baseflow at two gauging stations located in the study area, which yields a good agreement. The WetSpass model effectively integrates a water balance assessment in a geographical information system (GIS) environment. The WetSpass model is shown to be computationally reputable for such a remote complex setting as the African rift, with a correlation coefficient of 0.99 and 0.99 for total flow and baseflow at a significant level of p-value<0.05, respectively. The simulated annual water budget reveals that 77.22% of annual precipitation loses through evapotranspiration, of which 16.54% is lost via surface runoff while 6.24% is recharged to the groundwater. The calibrated groundwater recharge from the WetSpass model is then considered when determining the controlling factors of groundwater occurrence and formation, together with other multi-thematic layers such as lithology, geomorphology, lineament density and drainage density. The selected five thematic layers through MCDA are incorporated by employing the analytical hierarchy process (AHP) method to identify the relative dominance in groundwater potential zoning. The weighted factors in the AHP are procedurally aggregated, based on weighted linear combinations to provide the groundwater potential index. Based on the potential indexes, the area then is demarcated into low, moderate, and high groundwater potential zones (GWPZ). The identified GWPZs are finally examined using the existing groundwater inventory data (static water level and springs) in the region. About 70.7% of groundwater inventory points are coinciding with the delineated GWPZs. The weighting comparison shows that lithology, geomorphology, and groundwater recharge appear to be the dominant factors influence on the resources potential. The assessment of groundwater potential index values identify 45.88% as high, 39.38% moderate, and 14.73% as low groundwater potential zones. WetSpass model analysis is more preferable in the area like Gelana watershed when the topography is rugged, inaccessible and having limited gauging stations. 相似文献
20.
Compilation of Groundwater Quality Map and study of hydrogeochemical characteristics of groundwater in Asia 下载免费PDF全文
下载免费PDF全文 YI Qing GE Li-qiang CHENG Yan-pei DONG Hua LIU Kun ZHANG Jian-kang YUE Chen 《地下水科学与工程》2015,3(2):176-185
The groundwater quality map is among a series of Asian groundwater environment maps, which has been compiled and is about to be published. The article introduces the central theme and main content of the map, evaluates the method applied for groundwater quality gradation, and discusses hydrogeochemical characteristics of Asian groundwater. The distribution of water quality is investigated through the data collection of selected elements; hydrogeochemical characteristics are demonstrated via the analysis of elements’ allocation in horizontal and vertical zones; whilst the groundwater quality is evaluated by the Analytic Hierarchy Process (AHP). 相似文献