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Characterizing rainfall–groundwater dynamics in a hard‐rock aquifer system using time series,geographic information system and geostatistical modelling 
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下载免费PDF全文 The aim of this study was to investigate rainfall–groundwater dynamics over space and annual time scales in a hard‐rock aquifer system of India by employing time series, geographic information system and geostatistical modelling techniques. Trends in 43‐year (1965–2007) annual rainfall time series of ten rainfall stations and 16‐year (1991–2006) pre‐monsoon and post‐monsoon groundwater levels of 140 sites were identified by using Mann–Kendall, Spearman rank order correlation and Kendall rank correlation tests. Trends were quantified by Kendall slope method. Furthermore, the study involves novelty of examining homogeneity of pre‐monsoon and post‐monsoon groundwater levels, for the first time, by applying seven tests. Regression analysis between rainfall and post‐monsoon groundwater levels was performed. The pre‐monsoon and post‐monsoon groundwater levels for four periods – 1991–1994, 1995–1998, 1999–2002 and 2003–2006 – were subjected to geographic information system‐based geostatistical modelling. The rainfall showed considerable spatiotemporal variations, with a declining trend at the Mavli rainfall station (p‐value < 0.05). The Levene's tests revealed spatial homogeneity of rainfall at α = 0.05. Regression analyses indicated significant relationships (r2 > 0.5) between groundwater level and rainfall for eight rainfall stations. Non‐homogeneity and declining trends in the groundwater level, attributed to anthropogenic and hydrologic factors, were found at 5–61 more sites in pre‐monsoon compared with post‐monsoon season. The groundwater declining rates in phyllite–schist, gneiss, schist and granite formations were found to be 0.18, 0.26, 0.21 and 0.14 m year?1 and 0.13, 0.19, 0.16 and 0.02 m year?1 during the pre‐monsoon and post‐monsoon seasons, respectively. The geostatistical analyses for four time periods revealed linkages between the rainfall and groundwater levels. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Determination of hydraulic parameters of an unconfined alluvial aquifer by the floodwave-response technique 总被引：3，自引：2，他引：1
Madan?K.?JhaEmail author K.?Jayalekshmi Deepesh?Machiwal Y.?Kamii K.?Chikamori 《Hydrogeology Journal》2004,12(6):628-642
Groundwater constitutes a vital component of the water-resource system. Adequate knowledge of aquifer parameters is of utmost importance for proper groundwater management. In the present study, an attempt has been made to critically analyze the river–aquifer interaction and to explore the practicability and reliability of the floodwave-response technique in estimating the hydraulic parameters of the Konan aquifer, Japan. The analysis of the pertinent hydrologic and hydrogeologic data revealed a strong relationship between the Monobe River stage and the groundwater levels over a major portion of the Konan basin. Inverse modeling, using the floodwave-response model at four sites, yielded high values of hydraulic diffusivity that ranged from 16 to 194 m2/s. However, the overall average aquifer diffusivity was found to be reasonable (0.7–3.5 m2/s). All the selected flood events were not found suitable for determining reasonable values of hydraulic diffusivity at a given site. Using the optimal diffusivities at two sites and the aquifer transmissivity from the pumping tests at these sites, the storage coefficient values were estimated as those of truly confined aquifers. In contrast, reasonable values of storage coefficient were obtained based on the average aquifer diffusivity estimates. The sensitivity analysis of the floodwave-response model indicated that the optimal hydraulic diffusivity is very sensitive to the distance parameters of the model, which necessitate precise measurement of these parameters. It is concluded that a judicious application of the floodwave-response technique is essential, especially in the case of unconfined aquifers.
Resumen El agua subterránea constituye un componente vital de los sistemas de recursos hídricos. El conocimiento adecuado de los parámetros del acuífero es de suma importancia para el manejo apropiado del agua subterránea. En el presente estudio se ha realizado un intento para analizar críticamente la interacción río-acuífero y explorar la confiabilidad y utilidad de la técnica de respuesta de onda de crecida para estimar los parámetros hidráulicos del acuífero Konan, Japón. El análisis de datos hidrológicos e hidrogeológicos pertinentes muestra una relación fuerte entre el nivel del Río Monobe y los niveles de agua subterránea en gran parte de la cuenca Konan. El modelizado de inversión utilizando el modelo de respuesta de onda de crecida en cuatro sitios generó valores altos de difusividad hidráulica que varían de 16 a 194 m2/s. Sin embargo, se encontró que la difusividad promedio global del acuífero tenía valores razonables (0.7 a 3.5 m2/s). Todos los eventos de crecida seleccionados no fueron encontrados satisfactorios para determinar valores razonables de difusividad hidráulica en un sitio determinado. Utilizando las difusividades óptimas en dos sitios y la transmisividad del acuífero proveniente de pruebas de bombeo en esos sitios se estimaron valores del coeficiente de almacenamiento como los que se obtendrían para acuíferos completamente confinados. En contraste, se obtuvieron valores razonables del coeficiente de almacenamiento basados en los cálculos de difusividades promedio del acuífero. Los análisis de sensitividad del modelo de respuesta de onda de crecida indicaron que la difusividad óptima hidráulica es muy sensitiva a los parámetros de distancia del modelo por lo que se necesitan mediciones precisas de esos parámetros. Se concluye que es esencial una aplicación sensata de la técnica de respuesta de onda de crecida, especialmente en el caso de acuíferos no confinados.
Resumé Leau souterraine constitue une composante vitale des systèmes de ressource en eau. Une connaissance adéquate des paramètres des aquifères est importante pour une gestion correcte de ces systèmes. Dans cette étude, la démarche consiste à analyser linteraction rivière–aquifère de manière critique et dexplorer la technique permettant destimer les paramètres hydrauliques de laquifère Konan, Japon. Lanalyse pertinente des données hydrologiques et hydrogéologiques révèle une relation forte entre le niveau de la rivière Monobe et les niveaux piézométriques sur une grande partie du bassin de Konan. La modélisation inverse utilisant le modèle de réponse aux vagues de crue sur quatre sites fournit des valeurs de diffusivité comprises entre 16 et 194 m2/s. Néanmoins la valeur moyenne de diffusivité est apparue raisonnable (entre 0.7 et 3.5 m2/s). Tous les évènements de crue nont pas été retenus comme permettant de calculer avec une bonne fiabilité la diffusivité sur un site donné. En utilisant les données optimales de diffusivité provenant de deux sites, et la transmissivité fournie par les essais de pompage, le coefficient demmagasinement a été déterminé et correspond bien à un aquifère confiné. Par contraste, des valeurs raisonnables de coefficient demmagasinement ont été déterminées par estimation de la diffusivité moyenne de laquifère. Lanalyse de sensibilité du modèle de réponse aux vagues de crue indique que la diffusivité hydraulique optimale est très sensible à la distance utilisée dans le modèle, qui nécessite dés lors une mesure précise. En conclusion il est essentiel que ce type dapplication doit tre judicieusement mis en oeuvre, et spécialement dans le cadre daquifères captifs.相似文献
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This study examined trends and change points in 100-year annual and seasonal rainfall over hot and cold arid regions of India. Using k-means clustering, 32 stations were classified into two clusters: the coefficient of variation for annual and seasonal rainfall was relatively high for Cluster-II compared to Cluster-I. Short-term and long-term persistence was more dominant in Cluster-II (entirely arid) and Cluster-I (partly arid), respectively. Trend tests revealed prominent increasing trends in annual and wet season rainfall of Cluster-II. Dry season rainfall increased by 1.09 mm year?1 in the cold arid region. The significant change points in annual and wet season rainfall mostly occurred in the period 1941–1955 (hot and cold), and in the dry season in the period 1973–1975 (hot arid) and in 1949 (cold arid). The findings are useful for managing a surplus or deficiency of rainwater in the Indian arid region.
EDITOR A. Castellarin; ASSOCIATE EDITOR S. Kanae 相似文献
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Deepesh Machiwal S. K. Srivastava Sadhna Jain 《Journal of the Indian Society of Remote Sensing》2010,38(4):696-707
The present study aimed at quantification of sediment yield for Ahar River basin of Udaipur district in Rajasthan, India by
a regional empirical model using RS and GIS techniques. The land use/land cover (LULC) map of the study area was prepared
by supervised classification using satellite imagery of IRS-P6 LISS III. Overall accuracy of the prepared LULC map was 90.78%.
The major portion of the study area (49%) is covered with rangeland. Slope map for the study area was developed using digital
elevation model. The slope in most of the study area (40% of the total area) ranges from 1% to 4%. In addition, drainage density
map of the study area was generated on micro-watershed basis. The study area is covered by a dendritic pattern of drainage
which shows that rocks in the area are homogeneous and uniformly resistant to water flow. The drainage density in the study
area is 1.11 km km−2. Annual sediment yield of the study area was quantified by Garde model. The mean annual runoff and sediment yield for the
area was 37.58 million m3 and 8,760 m3/year, respectively. Finally, appropriate sites for construction of soil conservation measures are suggested using Boolean
logic analysis method on combined slope and drainage maps. 相似文献
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Modeling Short-Term Spatial and Temporal Variability of Groundwater Level Using Geostatistics and GIS 总被引：1，自引：0，他引：1
Deepesh Machiwal Amit Mishra Madan K. Jha Arun Sharma S. S. Sisodia 《Natural Resources Research》2012,21(1):117-136
Continuous depletion of groundwater levels from deliberate and uncontrolled exploitation of groundwater resources lead to
the severe problems in arid and semi-arid hard-rock regions of the world. Geostatistics and geographic information system
(GIS) have been proved as successful tools for efficient planning and management of the groundwater resources. The present
study demonstrated applicability of geostatistics and GIS to understand spatial and temporal behavior of groundwater levels
in a semi-arid hard-rock aquifer of Western India. Monthly groundwater levels of 50 sites in the study area for 36-month period
(May 2006 to June 2009; excluding 3 months) were analyzed to find spatial autocorrelation and variances in the groundwater
levels. Experimental variogram of the observed groundwater levels was computed at 750-m lag distance interval and the four
most-widely used geostatistical models were fitted to the experimental variogram. The best-fit geostatistical model was selected
by using two goodness-of-fit criteria, i.e., root mean square error (RMSE) and correlation coefficient (r). Then spatial maps of the groundwater levels were prepared through kriging technique by means of the best-fit geostatistical
model. Results of two spatial statistics (Geary’s C and Moran’s I) indicated a strong positive autocorrelation in the groundwater levels within 3-km lag distance. It is emphasized that the
spatial statistics are promising tools for geostatistical modeling, which help choose appropriate values of model parameters.
Nugget-sill ratio (<0.25) revealed that the groundwater levels have strong spatial dependence in the area. The statistical
indicators (RMSE and r) suggested that any of the three geostatistical models, i.e., spherical, circular, and exponential, can be selected as the
best-fit model for reliable and accurate spatial interpolation. However, exponential model is used as the best-fit model in
the present study. Selection of the exponential model as the best-fit was further supported by very high values of coefficient
of determination (r
2 ranging from 0.927 to 0.994). Spatial distribution maps of groundwater levels indicated that the groundwater levels are strongly
affected by surface topography and the presence of surface water bodies in the study area. Temporal pattern of the groundwater
levels is mainly controlled by the rainy-season recharge and amount of groundwater extraction. Furthermore, it was found that
the kriging technique is helpful in identifying critical locations over the study area where water saving and groundwater
augmentation techniques need to be implemented to protect depleting groundwater resources. 相似文献
7.
Deepesh?MachiwalEmail author Madan?Kumar?Jha 《Theoretical and Applied Climatology》2017,128(3-4):689-708
In this study, 43-year (1965–2007) monthly and annual rainfall time series of ten rainfall stations in a semi-arid region of western India are analyzed by adopting three tests for testing normality and by applying autoregressive technique for exploring persistence. Gradual trends are identified by three tests, and their magnitudes are assessed by the Sen’s slope estimator. Also, abrupt changes are detected by using four tests and they are further confirmed by two tests. Box-whisker plots revealed that the rainfalls of June and September are right skewed for all the stations. The annual rainfalls of Bhinder, Dhariawad, and Gogunda stations are found considerably right skewed. The normality tests indicated that the rainfall of July does not deviate from the normal distribution at all the stations. However, the annual rainfall is found non-normal at five stations. The monthly rainfalls of June, July, and August have persistence respectively at three (Mavli, Salumber, and Sarada), two (Kherwara and Sarada), and one (Mavli) stations, whereas the annual rainfall has persistence at Girwa and Mavli stations. Significantly increasing trend is detected at Mavli in the rainfall of July and in the annual rainfall (p value?>?0.05), while the negative trend in August rainfall at Dhariawad is found significant (p value?>?0.10). This study revealed that the presence of serial correlation does not affect the performance of the Mann-Kendall test. Mean values of trend magnitudes for the rainfalls of June, July, August, and September are 0.3, 0.8, ?0.4, and 0.4 mm year?1, respectively, and the overall mean value for the annual rainfall is 0.9 mm year?1. It is found that the standard normal homogeneity test and the Pettitt test are biased towards the end of the series to locate a change point. Conversely, the Bayesian test has a tendency to look for a change point in the beginning of time series. Confirmed abrupt changes in the rainfall time series are found in the year 2003 (Bhinder) in June; years 1974 (Mavli) and 1989 (Dhariawad and Salumber) in July; years 1972 (Sarada), 1990 (Dhariawad), and 2003 (Mavli) in August; years 1977 (Dhariawad), 1991 (Sarada), and 2004 (Kotra) in September; and in the year 1972 (Mavli and Sarada stations) in the annual series. It is emphasized that the significantly increasing trend of rainfall may have linkages with climate change and/or variability. Finally, this study recommends use of multiple statistical tests for analyzing hydrologic time series in order to ensure reliable decisions. 相似文献
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This study developed a standard methodology for identifying spatial trends using satellite-based raster datasets. It involves the novelty of exploring the capabilities of a geographic information system in implementing the procedures of three trend tests, the Spearman rank order correlation (SROC) test, the Kendall rank correlation (KRC) test and the Mann-Kendall (MK) test, on raster datasets of the Tropical Rainfall Measuring Mission at 0.25° × 0.25° resolution. Comparative evaluation of the three tests revealed fair agreement of a major part of the test results for pre-, post- and non-monsoon and one-day maximum rainfall. Also, similar results from KRC and MK tests were obtained over a considerable area for annual, monsoon and monthly maximum rainfall. These findings suggest the importance of selecting the appropriate test depending on rainfall magnitudes at the chosen time scale and emphasize the robustness of the KRC and MK tests. 相似文献
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Deepesh Kumar Jain Arindam Chakraborty Ravi S. Nanjundiah 《Meteorology and Atmospheric Physics》2012,115(1-2):1-13
The precipitation by Relaxed Arakawa–Schubert cumulus parameterization in a General Circulation Model (GCM) is sensitive to the choice of relaxation parameter or specified cloud adjustment time scale. In the present study, we examine sensitivity of simulated precipitation to the choice of cloud adjustment time scale (τadj) over different parts of the tropics using National Center for Environmental Prediction (NCEP) Seasonal Forecast Model (SFM) during June–September. The results show that a single specified value of τadj performs best only over a particular region and different values are preferred over different parts of the world. To find a relation between τadj and cloud depth (convective activity) we choose six regions over the tropics. Based on the observed relation between outgoing long-wave radiation and τadj,?we propose a linear cloud-type dependent relaxation parameter to be used in the model. The simulations over most parts of the tropics show improved results due to this newly formulated cloud-type dependent relaxation parameter. 相似文献