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1.
Abstract

The study area is located on the Harat plain, in the central region of Iran. Four local-soil filled, free-drainage lysimeters were installed in wheat and barley farms operating under traditional farm management practices. The volume, electrical conductivity (EC), nitrate and major ions of the applied irrigation water and irrigation return flow (IRF) were measured during the growing season. The total dissolved solids (TDS) of IRF increased three to five times compared to that of the applied water. This enhancement was the same as for the chloride ion ratio, indicating the major impact of evapotranspiration in IRF salinity enhancement. Geochemical modelling using PHREEQCI confirmed the significant role of evapotranspiration and the minor effects of processes such as calcite precipitation, gypsum dissolution, fertilizer nitrification and ion exchange on the values of the IRF TDS. Time variations of EC were functions of the type of flow (preferential or matrix), lithology and soil type. The controlling parameters of the nitrate time series were the frequent applications of N fertilizer and the nitrification process. The annual N loads (NO3-N) of IRF varied from 22 to 195 kg ha-1. These variations were due to the different N loads in the applied water, the amount of fertilizer, soil texture, N uptake and volume of IRF. The annual salt loads of IRF were mainly controlled by the volume of IRF.

Editor Z.W. Kundzewicz

Citation Jafari, H., Raeisi, E., Hoehn, E. and Zare, M., 2012. Hydrochemical characteristics of irrigation return flow in semi-arid regions of Iran. Hydrological Sciences Journal, 57 (1), 173–185.  相似文献   

2.
Abstract

Major ions and stable isotopes in groundwaters of the Plio-Quaternary shallow aquifer of the Djerid oases, southern Tunisia, were investigated to elucidate the origin of groundwater recharge and the mineralization processes. It has been demonstrated that the groundwater composition is mainly controlled by the water–rock interaction, the encroachment of brines from the Chotts and the return flow of irrigation waters. The isotopically depleted groundwater samples suggest that the recharge waters derive from an old palaeoclimatic origin. However, the enriched groundwater samples reflect the presence of evaporated recharge water. Furthermore, the large negative deuterium-excess values indicate the effect of secondary evaporation processes, probably related to the return flow of irrigation waters pumped from the underlying aquifer.

Editor D. Koutsoyiannis; Associate editor E. Custodio

Citation Tarki, M., Dassi, L. and Jedoui, Y., 2012. Groundwater composition and recharge origin in the shallow aquifer of the Djerid oases, southern Tunisia: implications of return flow. Hydrological Sciences Journal, 57 (4), 790–804.  相似文献   

3.
Irrigation return flow coefficients, i.e. the ratio between the quantity of water returned from the cultivated area to the groundwater system and the amount of abstraction, vary by more than 50% for rice cultivation using standing water irrigation to 0% in the case of drip irrigation technique. This component of the groundwater budget plays an important role, particularly in intensively irrigated areas. Thus, to avoid any inaccurate aquifer budgeting, modelling and consequently any erroneous watershed management, this component needs to be accurately assessed for a particular time‐step (e.g. weekly, seasonally) onto the studied area. The present paper proposes a cost‐effective and useful methodology for assessing irrigation return flow coefficients (Cf = irrigation return flow/pumping flow) based on (i) basic crops field survey and meteorological data and (ii) the use of a simple hydraulic model that combines both water balance technique and unsaturated/saturated flow theory. An attempt to estimate the uncertainty of irrigation return flow coefficient estimates based on the uncertainty introduced by the pumping and the natural spatial variability of the soil characteristics is also proposed. Results have been compared to real field conditions and allow us to (i) estimate the uncertainty and (ii) validate and demonstrate the robustness of the applied methodology. The proposed methodology allows relatively good estimates of the irrigation return flow coefficients at watershed and seasonal scale. The irrigation return flow coefficients are calculated as: 51 ± 8% in rainy season (Kharif) and 48 ± 4% in summer (Rabi) for rice; 26 ± 11% in rainy season and 24 ± 4% in summer for vegetables; 13 ± 8% in rainy season and 11 ± 3% in summer for flowers. These results were found to be consistent with the existing literature. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

4.
Extensive implementation of centre pivot irrigation systems occurred between 1970 and 1980 in the lower Flint River Basin (FRB) of southwestern Georgia, USA. Groundwater within this karstic system is in direct hydraulic connection with regional streams, many of which are incised through the overburden into underlying limestone. We used long‐term U.S. Geological Survey gaging station data to evaluate multiple flow metrics of two tributaries (Ichawaynochaway Creek and Spring Creek) in the lower FRB to determine the extent of changes in stream behaviour since irrigation practices intensified. We compared pre‐ and post‐irrigation flow duration curves, 1‐, 7‐, and 14‐day minimum flows, and 8‐day (seasonal) and annual baseflow recession slopes, in addition to evaluating regional climate data to determine whether significant differences existed between the pre‐ and post‐irrigation periods. Our results showed significant changes in low‐flow durations in the post‐irrigation record for both gages, including a decrease by an order of magnitude for 98% exceedance flows at Spring Creek. Both gages indicated significant reductions in 1‐, 7‐, and 14‐day low flows. Eight‐day baseflow recession curves (within early summer months) and annual baseflow recession curves became significantly steeper during the post‐irrigation period for Ichawaynochaway Creek. We also found that a significant relationship existed between winter and summer minimum flows in both streams in the pre‐irrigation period which was disrupted in post‐irrigation years. Regional climate data for the study period revealed no significant changes in rainfall totals or frequency of drought; however, there was evidence for a shift in seasonal rainfall patterns. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

5.
Abstract

Marked oscillations in wind speed, wind direction and pressure with periods of between 5 and 15 minutes were recorded on a number of occasions and it is assumed that they were produced by atmospheric gravity waves. Gossard and Munk (1954) have shown that the phase velocity of a gravity wave can be calculated using wind and pressure fluctuation data from a single station by means of the “impedance equation”. It is also possible to measure the phase velocity of a gravity wave using an array of microbarovariographs. In this investigation, the phase velocity of gravity waves calculated using these two different methods are compared and the feasibility of deriving wave characteristics from single point measurements is discussed. The results show that, while in a few isolated cases the two velocities agree reasonably well, the application of the impedance equation to data from a single station is limited due to the superposition of local wind systems upon the wave-induced perturbations.  相似文献   

6.
Abstract

Since 1995, hydrologists of the HiBAm (Hydrology and Geochemistry of the Amazon Basin) Research Program carried out several hundred discharge measurements in the Amazon basin. Implementation of modern discharge measurement techniques using ultrasonic devices (ADCP), give evidence of a systematic error linked to the displacement of the river bottom due to high water velocity close to the bottom. This error leads to an underestimation of discharge value. It was possible to establish a correlation between the water velocity close to the river bottom and the error between real position and position computed by ADCP when the boat returns to its starting point after a two-way crossing of the river. When there is no bottom displacement, i.e. during low flow period, this return position error is weak (less than 50 m). This has allowed quantification of river bed load speed, or bottom displacement speed. A correction method was developed on the basis of this correlation. This method, systematically applied to ADCP discharge measurements obtained at Óbidos hydrometric station, allowed all measured discharges to be corrected, especially for 1997 and 1999 floods. Another method, based on the analysis of real trajectory of the boat (obtained from topographic measurement or GPS positioning) compared with the ADCP computed trajectory, is under study.  相似文献   

7.
ABSTRACT

Ballona Creek watershed in Los Angeles, California provides a unique combination of heterogeneous urban land cover, a semi-arid environment, and a large outdoor water-use flux that presents a challenge for physically-based models. We ran simulations using the Noah Land Surface Model and Parflow-Community Land Model and compared to observations of evapotranspiration (ET), runoff, and land surface temperature (LST) for the entire 11-year study period. Both models were systematically adjusted to test the impact of land cover and urban irrigation on simulation results. Monthly total runoff and ET results are greatly improved when compared to an in-situ stream gauge and meteorological tower data: from 0.64 to 0.81 for the Nash–Sutcliffe efficiency (NSE) for runoff and from a negative NSE to 0.82 for ET. The inclusion of urban irrigation in semi-arid urban environments is found to be vital, but not sufficient, for the accurate simulation of variables in the studied models.  相似文献   

8.
Abstract

Some commonly used statistical distributions have been compared to find their applicability for describing minimum flows of the Tigris River at Baghdad gauging station. Drought flows with given return period have, thereafter, been predicted by these techniques. The mean of the estimated flows by the various distributions has been calculated to represent a design drought; upper and lower values estimated have been used to give an idea of variation in drought flow estimation. The methodology suggested herein may avoid the dilemma as to which distribution to select for drought flow estimation.  相似文献   

9.
Compared to hydrograph recession analysis, which is widely applied in engineering hydrology, the quantitative assessment of stream salinity with time (i.e. the salinograph) has received significantly less attention. In particular, while in many previous hydrological studies an inverse relationship between hydrograph and salinograph responses is apparent, the concept of salinity accession (the inversely related salinity counterpart to hydrograph recession) has not been introduced nor quantitatively evaluated in previous literature. In this study, we conduct a mathematical analysis of salinograph accession, and determine new quantitative relationships between salinity accession and hydrograph recession parameters. An equation is formulated that reproduces the general trend in salinity accession. A salinity accession parameter kc is then introduced and is shown to be the ratio of direct runoff to total stream flow recession parameters: kr/k. The groundwater recession parameter kg was estimated using a simple and rapid method that uses both salinograph and hydrograph data. Salinity accession type‐curves illustrate that under certain conditions, the relative steepness of individual salinographs is dependent upon the ratio of groundwater salinity to direct runoff salinity: Cg/Cr. The salinity accession algorithms are applied to two contrasting field settings: Scott Creek, South Australia and Sandy Creek, northern Queensland, Australia. It was found that kg > k during periods of obvious stream flow recession, for the events analysed. Salinograph accession behaviour was fairly similar for both sites, despite contrasting environments. Using assumed end‐member salinities for groundwater and direct runoff based upon field observations, the behaviour of kc from the Scott Creek site was approximately reproduced by varying the initial groundwater to runoff flow ratio: Qg0/Qr0, within reasonable parameter ranges. The use of salinograph information when used in addition to standard hydrograph analyses provided useful information on recession characteristics of stream components. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

10.
Abstract

Environmental flows have scarcely been considered in river water management in Bangladesh. This study attempts to assess the environmental flow requirements in the Halda River, Bangladesh. Thus, the objectives are to estimate the Halda River flow with different return periods/probabilities, which was done using the log-Pearson Type III distribution (LPIII), and to mitigate the environmental problems in the Halda River using the building block method. The LPIII distribution was used to estimate the expected extreme and satisfactory flows for fish habitat at Panchpukuria station and the expected extreme water levels at Panchpukuria, Narayanhat, Telpari and Enayethat stations. It was found that floods are likely to occur at least once in 2.1, 1.02, 1.75 and 1.25 years at Panchpukuria, Narayanhat, Telpari and Enayethat stations, respectively. The results of flow and water quality analyses suggest that environmental flow requirements cannot be achieved in this river throughout the year. The environmental flow requirements and conservation of fish resources can be achieved by implementing the suggestions provided in conjunction with a comprehensive awareness programme, investigations and trade-off analyses being among the suggestions.

Editor Z.W. Kundzewicz; Associate editor B. Sivakumar

Citation Akter, A. and Ali, Md. H., 2012. Environmental flow requirements assessment in the Halda River, Bangladesh. Hydrological Sciences Journal, 57 (2), 326–343.  相似文献   

11.
The steady seepage rates at large times from flat-bottomed channels and channels of semi-circular cross-section were determined in laboratory tank experiments using various sands. Good agreement was found with the theoretical relationships which assume the flow to be confined to a saturated region bounded by a capillary-fringe surface and to be uniform and vertical at great depths. The steady large-time seepage rates were also obtained in laboratory sand-tank experiments for the three-dimensional cases of seepage from circular shallow ponds and hemispherical sources. These agreed with relationships obtained using an electrolytic tank analogue with approximate boundary conditions assumed for the flow region. A method of analysis of large-time seepage measurements from irrigation channels and infiltrometer rings is proposed, which yields the hydraulic conductivity and pressure head at the wetting front from experiments with different size channels or rings.  相似文献   

12.
《水文科学杂志》2013,58(4):777-792
Abstract

Based on data from five hydrometric stations, Pingshan station on the Jinshajiang River, Gaochang station on the Minjiang River, Wulong station on the Wujiang River, Wusheng station on the Jialingjiang River and Yichang station on the Yangtze River, a study has been made of the temporal variation in grain size of suspended sediment load in the upper Yangtze River. The results show that in the past 40 years, the grain size of the suspended sediment load in the main stem and major tributaries of the upper Yangtze River has had a decreasing trend, that can be explained by the effect of reservoir construction and implementation of soil conservation measures. The reservoirs in the upper Yangtze River Basin, all used for water storage for hydro-electric generation and/or irrigation, have trapped coarse sediment from the drainage area above the dam and, thus, the sediment released now is much finer than before the construction of the reservoirs. The downstream channels are all gravel-bedded or even in bedrock, with little fine sediment, and thus, the released flow can hardly get a supply of fine sediment through eroding the bed. Then, after the downstream adjustment, the grain size of suspended sediment is still fine. Large-scale soil conservation measures have significantly reduced sediment yield in some major sediment source areas. The relatively coarse sediment is trapped and, thus, the sediment delivered to the river becomes finer.  相似文献   

13.
Deep seepage is a term in the hillslope and catchment water balance that is rarely measured and usually relegated to a residual in the water balance equation. While recent studies have begun to quantify this important component, we still lack understanding of how deep seepage varies from hillslope to catchment scales and how much uncertainty surrounds its quantification within the overall water balance. Here, we report on a hillslope water balance study from the H. J. Andrews Experimental Forest in Oregon aimed at quantifying the deep seepage component where we irrigated a 172‐m2 section of hillslope for 24·4 days at 3·6 ± 3 mm/h. The objective of this experiment was to close the water balance, identifying the relative partitioning of, and uncertainties around deep seepage and the other measured water balance components of evaporation, transpiration, lateral subsurface flow, bedrock return flow and fluxes into and out of soil profile storage. We then used this information to determine how the quantification of individual water balance components improves our understanding of key hillslope processes and how uncertainties in individual measurements propagate through the functional uses of the measurements into water balance components (i.e. meteorological measurements propagated through potential evapotranspiration estimates). Our results show that hillslope scale deep seepage composed of 27 ± 17% of applied water. During and immediately after the irrigation experiment, a significant amount of the irrigation water could not be accounted for. This amount decreased as the measurement time increased, declining from 28 ± 16% at the end of the irrigation to 20 ± 21% after 10 days drainage. This water is attributed to deep seepage at the catchment scale. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

14.
ABSTRACT

A complex of hydrogeological, hydrochemical, and biochemical investigations aimed at developing methods for the quality control of irrigation return water and agricultural nonpoint discharge was conducted from 1981 to 1985. The chemical composition of drainage flow in the zone of transient humidification in the Ukraine has been investigated; some dependencies of salts and humidity transfer rates as a function of a range of irrigation and climatic factors have been established. A new so-called “bioengineering” type of water-protective structure based upon natural mechanisms of water purification has been developed. The efficiency of the bioengineering structure for the reduction of the content of nitrogen, phosphorus and some compounds has been determined as a function of temperature, duration of the flow contact with biogeocenosis, water column depth and other parameters.  相似文献   

15.
Abstract

A watershed's seasonal streamflow fluctuations are caused by meteorological conditions as they are modified by the watershed's inherent characteristics such as size, shape, aspect, geology, and plant cover. Records from Halfway Creek watershed, a perennial tributary to Farmington Creek located on the Wasatch Mountains in northern Utah, show that winter streamflow comprises only a small portion of the total annual yield. The winter contribution, which is low but constant, originates as drainage from deep aquifers. A much greater portion of the water yield comes in the spring as seepage flow derived from melting snow and spring rains, although the highest instantaneous spring peak so far recorded is only 24 csm (cubic feet per second per square mile). Initial recession of the flow of Halfway Creek from its spring peak is rapid, but in a short time its decrease becomes so gradual that in late summer the hydrograph becomes an almost flat line. The summer recession ends when climatic conditions in the autumn cause cessation of plant growth. Rainstorms often interrupt the normal summer recession. Most of these interruptions are brief, but the height of the peak varies widely. For instance, in the 24-year period 1923–1947 when the vegetation cover was depleted, overland flow from short duration intense summer rainstorms caused mud-rock floods from Halfway Creek watershed that had instantaneous peaks 100 to 200 times greater than the spring peak. The relations presented in this report were determined for a small area and are based on specific records. They apply in a general way to a much greater area in northern Utah and the Intermountain West of which they are representative.  相似文献   

16.
ABSTRACT

The possibility was studied of a gradual extension of the irrigable area of the Tarlac Irrigation System, located in the alluvial plain of Luzon Island (Philippines). The extension would be made by integrating groundwater with surface water supplied from a reservoir already designed. Aquifer exploitation was studied adopting the criterion that groundwater is a very expensive resource to be turned to only in severe drought years. The objectives of the study were twofold: (a) planning the distribution of the wells (to be drilled during the various stages of the irrigation system development) so as to minimize the pumping cost; (b) establishing a policy for the well management in conjunction with the reservoir operation. Different schemes of the combined system management were analysed on the basis of the climatic and hydrological regime over the period 1950–1972. For this period the monthly water requirements for the different crops and the monthly values of aquifer recharge were computed. The economic analyses were performed using present prices of agricultural products and power together with several different hypotheses about future prices. A finite element model of the semiconfined aquifer was postulated and calibrated; the importance of the return flow from irrigation was also tested. Simulations of exploitation schemes provided a detailed forecast of the aquifer response to the irrigation demands.  相似文献   

17.
In this paper, we describe the importance of hyporheic dynamics within Andersen Creek and Von Guerard Stream, Taylor Valley, Antarctica, from the 2010–2011 melt season using natural tracers. Water collection started at flow onset and continued, with weekly hyporheic‐zone sampling. The water δ18O and δD values were isotopically lighter in the beginning and heavier later in the season. D‐excess measurements were used as an indicator of mixing because an evaporative signature was evident and distinguishable between 2 primary end‐members (glacier meltwater and hyporheic zone). Hyporheic‐zone influence on the channel water was variable with a strong control on streamwater chemistry, except at highest discharges. This work supports previous research indicating that Von Guerard Stream has a large, widespread hyporheic zone that varies in size with time and discharge. Andersen Creek, with a smaller hyporheic zone, displayed hyporheic‐zone solute interaction through the influence from subsurface hypersaline flow. Overall, the evolution of Taylor Valley hyporheic‐zone hydrology is described seasonally. In mid‐December, the hyporheic zone is a dynamic system exchanging with the glacier meltwater in the channel, and with diminishing flow in January, the hyporheic zone drains back into the channel flow also impacting stream chemistry. This work adds new information on the role of hyporheic zone–stream interaction in these glacier meltwater streams.  相似文献   

18.
Abstract

The segmentation of flood seasons has both theoretical and practical importance in hydrological sciences and water resources management. The probability change-point analysis technique is applied to segmenting a defined flood season into a number of sub-seasons. Two alternative sampling methods, annual maximum and peaks-over-threshold, are used to construct the new flow series. The series is assumed to follow the binomial distribution and is analysed with the probability change-point analysis technique. A Monte Carlo experiment is designed to evaluate the performance of proposed flood season segmentation models. It is shown that the change-point based models for flood season segmentation can rationally partition a flood season into appropriate sub-seasons. China's new Three Gorges Reservoir, located on the upper Yangtze River, was selected as a case study since a hydrological station with observed flow data from 1882 to 2003 is located 40 km downstream of the dam. The flood season of the reservoir can be reasonably divided into three sub-seasons: the pre-flood season (1 June–2 July); the main flood season (3 July–10 September); and the post-flood season (11–30 September). The results of flood season segmentation and the characteristics of flood events are reasonable for this region.

Citation Liu, P., Guo, S., Xiong, L. & Chen, L. (2010) Flood season segmentation based on the probability change-point analysis technique. Hydrol. Sci. J. 55(4), 540–554.  相似文献   

19.
Summary

Refering to numerous ratings of screw type current-meters and to the results of laboratory-experiments the author studies successively the degree of accuracy of measurements in very shallow water, the disturbing influence of a beam on which several current meters are fixed and finally the behaviour of current meters in return flow and in unsteady flow conditions.  相似文献   

20.
Summary

A test is presented to reveal automatically doubtful water levels and to detect sudden or gradual modifications of the stream flow.

Each hydrometric station in a catchment area, homogeneous as to climatic conditions, is compared with a reference station. For this purpose we consider the ratios of the daily “reduced” water levels of the station under examination to the corresponding levels of the reference station. The “reduction” of the daily water stages is achieved by a fictitious shifting of the scale so that the mean yearly water level is placed at a predetermined level (the same everywhere) and by a dilatation (or a shrinking) of this scale so that the range Δ (the difference between the largest and the smallest monthly water levels) is equal to the range Δ0 of the reference station. The daily ratios of the reduced water levels are consequently approximately 1 either with high or low water. When a daily ratio deviates too much (more than 10 % for instance) from the mean monthly ratio, the corresponding water level is considered as doubtful and must be verified. If the running mean monthly ratios do not remain approximately uniform but change suddenly or slowly, it is because the stream flow is disturbed and the reason for this disturbance must be investigated.

The test, used in a converse way, can also be satisfactorily used for filling in gaps in the observational data.

Some examples enable the value of the method to be assessed.  相似文献   

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