Subsurface Pipe Drainage Research Articles

Environmental and socio-economic impacts of pipe drainage in Pakistan

Many drainage schemes and salinity control projects have been executed world wide. Pipe drainage has widely been used in Pakistan, Egypt and India to control waterlogging. The impact of pipe drainage on land and water was evaluated in this paper using data of three pipe drainage projects in Pakistan namely Khushab Salinity Control and Reclamation Project, Fourth Drainage Project in Faisalabad and Swabi Salinity Control and Reclamation Project. Data by regular monitoring of these projects were collected. The effect of pipe drainage on water table depth at these three locations has been compared. Water quality and soil salinity improvement due to the pipe drainage has also been investigated. Data, related to water table depths and discharges from drain pipes/wells, was collected. Observation wells, installed at various places by the Water and Power Development Authority, were used for collection of this data. To evaluate the impact of the projects on salinity, soil samples from all the three locations were tested. A questionnaire was prepared to get the view of the people about the projects. It was revealed that in these areas, due to subsurface pipe drainage, the percentage of the abandoned land has been considerably decreased. Over drainage was observed in a few places of the projects. The farmers at such places were asked to change their cropping patterns. Ultimately, there has been an increase in area under cultivation, crop yields and cropping intensity in the projects' area.

Evaluation of the rainfall effectiveness for reclaim of saline soil by subsurface pipe drainage system in coastal saline regions of Hebei Province

在河北滨海盐碱荒地和盐碱低产田开展暗管改碱技术面临淡水资源严重短缺、灌溉条件差的问题,降水资源的利用对于该区域暗管改碱技术实施效果的影响很大。本文以河北省黄骅市为研究区域, 对河北滨海盐碱区的降水特征及其对暗管改碱技术的影响进行分析。结果表明: 当土壤含盐量<0.3%时, 年内次降水量可完全满足土壤初次淋洗脱盐过程需要; 当土壤盐分含量>0.3%但<0.5%时, 在较容易淋洗的土壤上, 暗管埋深合适时, 脱盐需要的次降水量仍可基本满足; 但当土壤含盐量达到0.5%左右时, 仅靠自然降水不能保证土壤脱盐需要。暗管埋设条件下, 雨季(6~9 月)降水量对大面积的轻度盐碱地淋洗脱盐效果非常显著; 但重度盐碱地却不能达到理想脱盐效果。从年降水量的变化情况看, 研究区域降水量逐年降低的趋势比较明显, 干旱年份多于洪涝年份, 且旱情较为严重。因此未来推广实施暗管改碱工程时有必要考虑亏缺灌溉对自然降水淋盐的补充效果。

Assessment of aquatic pollution, remedial measures and juridical obligations of an acid sulphate soil area in western Finland

Reclaiming of Holocene sulphide-bearing sediments, widespread in the coastal areas of Finland, has enabled oxidation of sulphides to a depth of 1–3 m and the subsequent development of acid sulphate soils (pH &lt; 4). This work is concerned with spatial hydrogeochemical patterns, remediation measures and the juridical obligation to improve water quality in one such area, i.e. the Rintala plain (23 km2) in mid-western Finland. Streams draining acid sulphate soils in Rintala are more acid (pH ~ 4 and acidity ~ 4 mmol l-1) and carry significantly higher concentrations of SO4 2-, Al, Ca, Cd, Co, Cu, F, Mn, Ni, Pb, Se, Sr and Zn than those draining forest and rural areas in the vicinity of the Rintala plain and organic-rich soils located on the plain. The juridical obligation to improve the water quality is inappropriate as it does not consider the main reason for the poor water quality, i.e. drainage by subsurface drainage pipes, and because of the equality principle (other acid sulphate soil areas have just as poor water quality but do not have such an obligation). Groundwater management, i.e. keeping the groundwater level as high as possible, is recommended as the best management practice.;

Evaluation of impact of Khushab sub surface pipe drainage project in Pakistan

This paper describes the essential contents of research at a recently completed subsurface pipe drainage project located in the Khushab district of Pakistan. The paper explores the need and decision by Government of Pakistan to install a Sub Surface Pipe Drainage Project near Khushab where an old Surface Drainage System was already installed by the Provincial Irrigation and Power Department, Government of Punjab, Pakistan, since 1960. The new Sub Surface Pipe Drainage Project’s planning and executing agency M/S Euro-Consultant used existing Surface Drains with remodeling for to carry the additional drainage effluent of newly constructed sump pumps of the pipe drainage system connected to the old drains by means of small outfall drains. Until now the new system is working well in lowering the water table as well as increasing the agro-socio-economic status of the local population.

An estimation of subsurface total drainage quantity in non-steady state drainage flow, and its verification in loamy soils

The subsurface total drainage quantity is a very important hydrological indicator to solve the drainage problems in a&amp;nbsp;field of water management in the landscape, especially in a situation after massive floods. Described in this paper is an estimation of the subsurface total drainage quantity, which was developed by the operation of a subsurface pipe drainage system in saturated, middle permeable soil under unsteady state drainage flow with the application of the Dupuit&amp;rsquo;s assumptions and Darcy&amp;rsquo;s law, by analytical approximation. The correctness and applicability of this estimation of the subsurface total drainage quantity was verified by field measurements on the loamy soils of an experimental watershed area of the Research Institute for Soil and Water Conservation (RISWC) Prague-Zbraslav, Czech Republic. The parameters and the shape of this subsurface total drainage quantity equation were also proved with the help of nonlinear regression analysis, with application of the method of Marquardt. This analytical approximation should serve as an elementary tool of water engineering practice for an immediate estimation of the values of subsurface total drainage quantities from field pipe drainage systems in saturated loamy soils. It requires only a minimum amount of information (fundamental soil hydrology data and drainage system basic design parameters) and its use is often viewed, it is simple, user-friendly and is possible for a wide range of drainage policies.

Golf Course Applications of Near-Surface Geophysical Methods: A Case Study

As of the year 2000, there were over 15,000 golf course facilities in the U.S.A. alone. The upkeep of these facilities requires continual maintenance and occasional remodeling. The superintendents and architects responsible for the maintenance and remodeling efforts need non-destructive tools for obtaining information on shallow subsurface features within parts of the golf course, particularly tees and greens. The subsurface features of importance include, but are not limited to, constructed soil layer characteristics and drainage system infrastructure. Near-surface geophysical methods can potentially provide a non-destructive means for golf course superintendents and architects to obtain the shallow subsurface information required to address their maintenance and remodeling concerns. This case study assessment of near-surface geophysical methods in regard to golf course applications focused on electromagnetic induction (EMI) and ground penetrating radar (GPR) techniques. The investigation employed two different EMI ground conductivity meters. Two GPR systems were also tested including the evaluation of antenna center frequencies ranging from [Formula: see text]. The study incorporated three separate sites. Measurements with both EMI and GPR were collected on a tee and a green at the Muirfield Village Golf Club in Dublin, Ohio, U.S.A. and on a practice green at the Golf Club of Dublin in Dublin, Ohio, U.S.A. GPR was also tested on a golf course green at the Guelph Turfgrass Institute &amp; Environmental Research Centre in Guelph, Ontario, Canada. Results indicate that use of the appropriate EMI equipment can provide information on spatial changes of shallow apparent electrical conductivity [Formula: see text] within golf course green constructed soil layers. This [Formula: see text] data could potentially be employed to gauge constructed soil layer conditions, including wetness, salinity, etc., within different areas of a green. GPR proved quite capable of obtaining useful information on the golf course tee and greens that were studied, at least in regard to constructed soil layer thicknesses∕depths or their areal extent and in locating the subsurface drainage pipe systems present. For the GPR center antenna frequencies evaluated, ranging from [Formula: see text], all seemed to work relatively well for mapping tee and green constructed soil layer areal extent and drainage pipe locations. The higher frequency 900 and [Formula: see text] antennas appeared to work best for resolving thicknesses∕depths of constructed soil layers within the tee and greens investigated. In addition, computer modeling of synthetic GPR profiles provide valuable insight and help considerably with data interpretation. While more research is certainly warranted, near-surface geophysical methods, especially EMI and GPR, appear to show promise with respect to acquiring the data needed in golf course maintenance and remodeling applications.

GROUND-BASED MAGNETIC SURVEYS AS A NEW TECHNIQUE TO LOCATE SUBSURFACE DRAINAGE PIPES: A CASE STUDY

Identifying the existence and orientation of buried drainage systems is necessary to incorporate the impact of these features in solute transport and hydrologic models. This study was conducted to determine if a cesium magnetometer survey could identify clay tile locations. A cesium magnetometer survey with a sampling interval of 10 cm along the survey transect and 50-cm spaced transects was used at the Oregon State University Research Dairy in an attempt to map clay tile orientation and location. A shaded-relief plot of the magnetic data from a 100- . 100-m portion of the Dairy successfully identified clay tile in the western part of the study area, but was unable to identify clay tile in the eastern part of the study area. Probing and trenching confirmed the existence of clay tile in both portions of the site. This case study has shown that cesium magnetometer surveys can locate clay tile with a spatial accuracy (horizontally) of .25 cm, and offers a new technique for non-invasive subsurface drainage pipe location. This study has also elucidated potential limitations in this method for identifying subsurface drainage pipe locations that may depend on soil type, management strategies, and soil magnetic properties.

IMPORTANT CONSIDERATIONS FOR LOCATING BURIED AGRICULTURAL DRAINAGE PIPE USING GROUND PENETRATING RADAR

Enhancing the efficiency of soil water removal on land already containing a subsurface drainage system typically involves installing new drain lines between the old ones. However, the older drainage pipes need to be located before this approach can be attempted. In ongoing research, a near-surface geophysical method, ground penetrating radar (GPR), has been successful in locating on average 72% of the total amount of drainage pipe present at 13 test plots in southwest, central, and northwest Ohio. The effective use of GPR for drainage pipe detection requires careful consideration of computer processing procedures, equipment parameters, site conditions, and field operations, all of which were thoroughly investigated in this study. Application of a signal saturation correction filter along with a spreading and exponential compensation gain function were the computer processing steps most helpful for enhancing the drainage pipe response exhibited within GPR images of the soil profile. GPR amplitude maps that show the overall subsurface drainage pipe system required additional computer processing, which included 2-D migration, signal trace enveloping, and in some cases, a high frequency noise filter and a spatial background subtraction filter. Equipment parameter test results indicate that a 250-MHz antenna frequency worked best, and that data quality is good over a range of spatial sampling intervals and signal trace stacking. In regard to the site conditions present, shallow hydrology, soil texture, and drainage pipe orientation all substantially influence the GPR response. Additionally, drainage pipe that are as small as 5 cm (2 in.) in diameter can be detected. However, the fired clay or plastic material of which the drainage pipe is comprised does not appear to have much of an impact. Finally, with respect to GPR field operations, bidirectional surveys offer the best chance for finding all the buried drainage pipe possible, and for displaying a subsurface drainage system on an amplitude map, the narrower the spacing between GPR measurement lines, the better the result. Although it is important to note that the amplitude maps generated with a wider spacing between GPR measurement lines, still provided plenty of useful data on drainage pipe location. The information supplied by this study can be employed to formulate guidelines that will enhance the potential of success for using ground penetrating radar in locating buried agricultural drainage pipe.

Effects of Depth and Slope on Flow in Rice Paddy Subsurface Drainage Pipes

Effects of Depth and Slope on Flow in Rice Paddy Subsurface Drainage Pipes

Analysis of DRAINMOD performances with different detail of soil input data in the Veneto region of Italy

The deterministic field scale model DRAINMOD was tested in an experiment on subsurface pipe drainage in the Veneto region, in an environment of NE Italy characterised by the presence of a shallow water table in a flat area. The objective was to determine whether a minimal set of field data would suffice to use DRAINMOD for predictive purposes. The measured water table depth and drain outflow from a 5-year field experiment were compared to those determined by DRAINMOD using three levels of detail in input data. The results indicated that even very limited input data (texture and porosity of the top 30 cm of soil) gave good predictions. More elaborate data improved the estimates.

Soil Compaction as a Constraint to Tree Growth in Tropical &amp; Subtropical Urban Habitats

Of the many forms of above- and below-ground stresses facing urban trees, physical soil limitations are generally among the most persistent and least amenable to amelioration. Soil compaction is a common soil malady that afflicts many planting-sites and causes tree decline. The concept of soil structure in terms of porosity and moisture-suction is reviewed, to provide a basis for the interpretation of compaction as structural degradation. The reorganization of solid and interstitial void constituents, which can result in increased dentity of packing, is related to some fundamental physical and physico-chemical soil properties.Compaction brings about changes in a wide spectrum of related geometric and other soil attributes, the consequences of which are often inimical to plant growth. Many deliberate and inadvertent actions in urban areas increase packing density, which can be diagnosed through some field and laboratory tests. The harmful effects of compaction is exertedviamechanical impediment and other indirect impacts on root growth. Excessively loose soils and soil crusts are discussed in the light of compaction concepts and in relation to tree growth.A wide range of measures could be adopted to alleviate the problems of soil compaction. Preventive actions taken before tree planting are preferred to post-planting remedies which are cumbersome, and injurious to roots. Soils at planting sites could be partially improved by various mechanical means to reduce packing density and enhance aggregation. Coarse-textured materials with inherently high strength and resistance to dense packing could provide a stable medium for tree growth. The installation of subsurface aeration and drainage pipes could alleviate the ill-effects of compaction. Care should be taken to avoid structural degradation in stockpiling and construction activities.

Review of some case studies on the abundance and on the hydraulic efficiency of earthworm channels in czechoslovak soils, with reference to the subsurface pipe drainage

During the last 22 yr, 16 case studies were performed on different agricultural soils, both arable and grasslands, in different zones of Czechoslovakia, in order to evaluate the hydrological role of soil macropores, including earthworm channels. The abundance and hydraulic efficiency of the channels are presented, related to the site, depth and size of the channels. The positive influence of earthworms upon the preservation of high permeability in drain trench backfills was demonstrated quantitatively, both by infiltration experiments and by casting the channels with gypsum. Additional semiquantitative estimates of the variance of channel abundance, water retention capability and discharge of water through the channels are also presented.

Mineral and ochre clogging of subsurface land drainage systems in the Netherlands

Dutch research into mineral and ochre clogging of subsurface land drainage pipes and envelopes aims at developing design criteria for drainage envelopes. Research outcomes are often conflicting and tend to have only regional validity. The present recommendations for envelope applications are comparatively reliable but they are based on the results of contemporary empirical research techniques. Still, little is known about the underlying soil movement mechanisms which appear to be more complicated than has been assumed for a long time. Current empirical research methods are not suited to solve the problem because they are inadequate in monitoring these mechanisms. During a nationwide field inspection programme, 1200 drain sections were dug out revealing a substantial variability of soil/envelope performance. Many soil/envelope combinations are being subjected to empirical permeameter flow tests. Simultaneously, field data are being collected at three pilot areas. The results indicate that soil structure, which is not included in traditional filter rules, has a defective impact on the clogging risk. The existing knowledge of clogging phenomena is insufficient. Many drainage systems function well, but too many do not. The Computer Assisted Tomography (CT) X-ray scanner appears to be a promising new research tool for determining soil structure.

Effects of agricultural drainage on streamflow in the Middle Thames River, Ontario, 1949–1980

The effects of surface and subsurface agricultural drainage on streamflow in the Middle Thames River have been studied through the analysis of changes in the volumetric response, changes in the seasonal distribution of streamflow volumes, and changes in the time distribution of runoff response of the Middle Thames in the period 1949–1980.The results indicated that only small changes in streamflow behaviour occurred in the Middle Thames for the period studied. There is evidence of a reduction of less than 25% in the time-to-peak of storm hydrographs on the watershed, but with little change in peak flow rate or centroid-to-centroid lag time. This is consistent with increased channel velocities in hydraulically improved municipal drains, coupled with an increased proportion of storm flow being diverted from overland runoff to rapid subsurface runoff through subsurface pipe drainage. There is no evidence of appreciable changes in volumes of runoff for individual storms or as annual total streamflow or changes in seasonal distribution of streamflow. Key words: agricultural drainage, streamflow, unit hydrograph, storm runoff.