Journal articles: 'Ponding'

1

Dunbabin, J. S., I. H. Hume, and M. E. Ireson. "Effects of irrigation frequency and transient waterlogging on the production of a perennial ryegrass - white clover pasture." Australian Journal of Experimental Agriculture 37, no. 2 (1997): 165. http://dx.doi.org/10.1071/ea96057.

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Summary. Perennial ryegrass–white clover swards were irrigated for 3 years every 50, 80 and 120 mm of crop evapotranspiration minus rainfall (ETc–R) and water ponded on the soil surface for either 4, 12 or 24 h at each irrigation. Pasture production and clover content were highly seasonal, peaking in spring and autumn. Frequent irrigation increased dry matter production by an average of 56%. When irrigating at 50 mm ETc–R, dry matter production was decreased by ponding water on plots, 17% for 12 h ponding and 14% if ponded for 24 h. However, when irrigating at an interval of 80 mm ETc–R ponding increased dry matter production by 7% for 12 h ponding and by 25% for 24 h ponding. Ponding also increased production at an irrigation interval of 120 mm ETc–R by 25% for 12 h ponding but only by 2.4% for 24 h ponding. While these increases in dry matter production are large in relative terms the absolute increase in production is small. More water infiltrated per irrigation at longer irrigation intervals, and at longer ponding times. Frequently irrigated, rapidly drained swards used irrigation water most efficiently. The small gain in dry matter production achieved by prolonging ponding at longer irrigation intervals is an inefficient use of water and likely to recharge regional groundwater systems. Oxygen diffusion rate measurements suggested that ponding for as short as 4 h was likely to cause waterlogging stresses and that these stresses were higher when irrigating frequently. The relative increase in waterlogging stress by extending the period of ponding from 4 to 24 h was small.

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Chen, Shuaihua, and Xiaoping Wang. "Design of Monitoring System for Urban Low-Lying Water." Journal of Physics: Conference Series 2029, no. 1 (September 1, 2021): 012128. http://dx.doi.org/10.1088/1742-6596/2029/1/012128.

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Abstract The Internet of things technology is applied to establish a low-lying ponding monitoring system, which includes information acquisition system and information management system. This GPRS, 4G, Java, Internet of things and large database technology are applying to build a data acquisition hardware platform. On this basis, the basic database of road ponding and the monitoring and early warning system of road ponding in low-lying land are established. Thus, the application requirements of road ponding information query, management, monitoring, water level change analysis and water level overrun alarm based on map are realized. At the same time, the control of relevant drainage facilities has been integrated. The modern management means of road low-lying land ponding monitoring has been improved. And the management and control level of municipal road ponding has been comprehensively improved.

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Shoemaker, E. M. "On the formation of large subglacial lakes." Canadian Journal of Earth Sciences 28, no. 12 (December 1, 1991): 1975–81. http://dx.doi.org/10.1139/e91-179.

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The role of subglacial water storage beneath continental ice sheets is investigated, primarily for a deformable bed. Subglacial ponding is shown to occur under most regions of warm-based ice sheets, and large subglacial lakes can become established, for example in the Hudson Bay basin. The formation of large lakes depends upon the fact that the ice-surface gradient is reduced once subglacial ponding occurs and upon the feedback between the reduced ice-surface gradient and increased subglacial ponding. Subglacial ponding likely played a large role in determining the ice-sheet topography during late deglaciation and in speeding up the deglaciation process.

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4

Hashim, Ahmad Ezanee, Mohd Ikmal Fitri Maruzuki, Norngainy Mohd Tawil, Mohd Zulhanif Abd-Razak, and Adi Irfan Che-Ani. "Flat Roof Defect: Preliminary Condition Survey for Water Ponding Monitoring." Applied Mechanics and Materials 747 (March 2015): 351–54. http://dx.doi.org/10.4028/www.scientific.net/amm.747.351.

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Roof is among defect-prone building part as it exposed to natural factor especially rainfall and sunlight. Thus, the inspection on roof part must be done more frequent compare to other parts of building. However, roof is the most difficult part to inspect because of limited access and safety concern. This paper presents the result of preliminary condition survey for water ponding monitoring on flat roof surface and discussion on the solving method. The survey has been carried out on flat roof of an academic building in Penang, Malaysia on a rainy day. Based on the condition survey, we found that water ponding occurs on some parts of the flat roof. Water ponding on flat roof will cause moisture problem that trigger severe problem on building. Since water ponding problem ineffectively do monitor by traditional method, we proposed to design an intelligent system to monitor water ponding problem on flat roof. By using an intelligent system, water ponding existence can be detected at a real-time. Furthermore, the system is time saving, manpower saving and the data can be manage systematically without the presence of surveyor on site.

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Hidayati, I. K., Suhardjono, D. Harisuseno, and A. Suharyanto. "Ponding time in infiltration process for different land use." IOP Conference Series: Earth and Environmental Science 930, no. 1 (December 1, 2021): 012054. http://dx.doi.org/10.1088/1755-1315/930/1/012054.

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Abstract Ponding time is the period from the beginning of rainfall/infiltration until the occurrence of ponding. This paper aims to determine the infiltration rate and ponding time on different land uses, such as open fields, residential, agriculture, and vegetation. This research was conducted in one of the watersheds in the Brantas River Basin, namely the Lesti River Basin, which is administratively included in the Malang Regency, East Java. The Lesti River is one of the tributaries of the Brantas River, which originates around Mount Semeru, a very intensive area for planting rice, sugar cane, and coffee. Infiltration data were collected at 35 points using a double-ring infiltrometer spread across the Lesti watershed with Andosol, Mediterranean, and Regosol soil types. At the same time, ponding time was obtained from infiltration measurements in the field using the flooding method. The physical properties of the soils were tested in the laboratory to obtain water content, porosity, and bulk density values. This study resulted in the infiltration rate and ponding time for each land use and shows how the physical properties of the soil affect the ponding time.

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Yang, Dan, Mengzhou Xiong, Tao Wang, and Guangtao Lu. "Percussion-Based Pipeline Ponding Detection Using a Convolutional Neural Network." Applied Sciences 12, no. 4 (February 18, 2022): 2127. http://dx.doi.org/10.3390/app12042127.

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Pipeline transportation is the main method for long-distance gas transportation; however, ponding in the pipeline can affect transportation efficiency and even cause corrosion to the pipeline in some cases. A non-destructive method to detect pipeline ponding using percussion acoustic signals and a convolution neural network (CNN) is proposed in this paper. During the process of detection, a constant energy spring impact hammer is used to apply an impact on the pipeline, and the percussive acoustic signals are collected. A Mel spectrogram is used to extract the acoustic feature of the percussive acoustic signal with different ponding volumes in the pipeline. The Mel spectrogram is transferred to the input layer of the CNN and the convolutional kernel matrix of the CNN realizes the recognition of pipeline ponding volume. The recognition results show that the CNN can identify the amount of pipeline ponding with the percussive acoustic signals, which use the Mel spectrogram as the acoustic feature. Compared with the support vector machine (SVM) model and the decision tree model, the CNN model has better recognition performance. Therefore, the percussion-based pipeline ponding detection using the convolutional neural network method proposed in this paper has high application potential.

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7

Mirjat, M. S., D. A. Rose, and M. A. Adey. "Desalinisation by zone leaching: laboratory investigations in a model sand-tank." Soil Research 46, no. 2 (2008): 91. http://dx.doi.org/10.1071/sr07112.

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We report a laboratory study in a model sand-tank to investigate improvements using partial ponding over the common method of leaching salts from soils by flooding the entire area above equally spaced subsurface drains. The physical basis of the theory developed by E. G. Youngs and P. B. Leeds-Harrison was demonstrated in the model. We traced the streamline patterns for complete ponding and 3 situations of partial ponding of the soil surface to demonstrate the flow paths. We also leached saline water, initially uniformly distributed in the sand, with sweet water and recorded the breakthrough curves of the leaching water for the same situations of complete and partial ponding. The results demonstrate that partial ponding is more effective than complete ponding in that it requires less time to carry solute towards the drain and saves water of good quality needed to leach salts through drains. They also confirm the theoretical findings that more uniform leaching with less water can be achieved by constraining the infiltrating area with bunds, initially flooding only the region midway between the drains and then progressively increasing the flooded area until the entire surface above the drains is ponded.

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Nerantzaki, Maria S., and John T. Katsikadelis. "Ponding on floating membranes." Engineering Analysis with Boundary Elements 27, no. 6 (June 2003): 589–96. http://dx.doi.org/10.1016/s0955-7997(02)00114-5.

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9

Tuan, Christopher Y. "Ponding on circular membranes." International Journal of Solids and Structures 35, no. 3-4 (January 1998): 269–83. http://dx.doi.org/10.1016/s0020-7683(97)00076-0.

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10

Zhang, Lei, Lin Xu, Yong Xiao, and NingBo Zhang. "Application of Comprehensive Geophysical Prospecting Method in Water Accumulation Exploration of Multilayer Goaf in Integrated Mine." Advances in Civil Engineering 2021 (September 24, 2021): 1–12. http://dx.doi.org/10.1155/2021/1434893.

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A coal mine in Datong is an integrated mine. At present, there is goaf in the upper and lower part of the mining coal seam. There is a lot of ponding in the goaf, which has great potential safety hazards for production. In order to find out the scope and location of ponding in goaf, the comprehensive geophysical exploration method combining transient electromagnetic method and high-density resistivity method is used to carry out the research. Firstly, the time-base, turn-off time, receiving delay, current, superposition times, and other parameters of the instrument are tested on the surface of known goaf to obtain the best instrument parameters, and the parameters are used to verify the feasibility of the research scheme; then, the transient electromagnetic method is used for large-area exploration on the surface of the mine, the suspected goaf ponding area is found through comprehensive analysis, and the high-density resistivity exploration is arranged in the suspected goaf ponding area. According to the obtained results, the scope and location of the goaf ponding area are accurately located through comprehensive analysis. The results show that there are two goaf ponding areas in the exploration area, which are located above the 8# coal seam currently mined; the range and location of goaf ponding area can be accurately obtained by using the comprehensive geophysical method of high-density electrical method and transient electromagnetic method. This method can provide reference for mine water prevention and control in Datong area and has great practical significance to ensure coal mine safety production.

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11

Dahiya, I. S., K. S. Grewal, and D. J. Dahiya. "Desodification of a salt-affected soil in plots of various sizes under two modes of water application." Journal of Agricultural Science 108, no. 2 (April 1987): 453–58. http://dx.doi.org/10.1017/s0021859600079491.

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SummaryDesodification of a highly saline-sodic, permeable, sandy loam soil was accomplished in 2 × 2 m (S1), 4 × 4 m (S2) and 6 × 6 m (S3) plots under continuous and intermittent ponding. The soil contained large amounts of soluble salts and exchangeable sodium throughout the profile to the water table. The chief salts were chlorides and sulphates of sodium, calcium, and magnesium. The leaching curves with respect to desodification did not differ significantly between the S1, S2 and S3 plots under continuous ponding but did under intermittent ponding. With intermittent ponding, the efficiency of leaching exchangeable sodium in the S1 plots was very significantly higher than that in the S2 and S3 plots, i.e. the leaching efficiency decreased sharply with increased plot size. The leaching efficiency in the S1 plots was significantly greater with intermittent than with continuous ponding, but the reverse was true in the S2 and S3 plots. The results further indicated that there is no need to apply an amendment such as gypsum, mainly because calcium and magnesium present in such soils are adequate to replace the initially high exchangeable sodium during leaching. The displacement of exchangeable sodium in the S1 plots under intermittent ponding was nearly piston-like. With increased plot size, it tended to deviate from this behaviour. It is concluded that under practical situations in which reclamation is accomplished in large plots, the practice of leaching the saline constituents with intermittent ponding would be less effective. Thus, leaching of salts down into the soil with a single heavy irrigation would be more desirable.

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12

Liu, Yongzhi, Wenting Zhang, Ying Yan, Zhixuan Li, Yulin Xia, and Shuhong Song. "An Effective Rainfall–Ponding Multi-Step Prediction Model Based on LSTM for Urban Waterlogging Points." Applied Sciences 12, no. 23 (December 2, 2022): 12334. http://dx.doi.org/10.3390/app122312334.

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With the change in global climate and environment, the prevalence of extreme rainstorms and flood disasters has increased, causing serious economic and property losses. Therefore, accurate and rapid prediction of waterlogging has become an urgent problem to be solved. In this study, Jianye District in Nanjing City of China is taken as the study area. The time series data recorded by rainfall stations and ponding monitoring stations from January 2015 to August 2018 are used to build a ponding prediction model based on the long short-term memory (LSTM) neural network. MSE (mean square error), MAE (mean absolute error) and MSLE (mean squared logarithmic error) were used as loss functions to conduct and train the LSTM model, then three ponding prediction models were built, namely LSTM (mse), LSTM (mae) and LSTM (msle), and a multi-step model was used to predict the depth of ponding in the next 1 h. Using the measured ponding data to evaluate the model prediction results, we selected rmse (root mean squared error), mae, mape (mean absolute percentage error) and NSE (Nash–Sutcliffe efficiency coefficient) as the evaluation indicators. The results showed that LSTM (msle) was the best model among the three models, with evaluation indicators as follows: rmse 5.34, mae 3.45, mape 53.93% and NSE 0.35. At the same time, we found that LSTM (mae) has a better prediction effect than the LSTM (mse) and LSTM (msle) models when the ponding depth exceeds 30 mm.

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Andri, Andri, Murtiningrum Murtiningrum, and Ngadisih Ngadisih. "Estimation of Irrigation Water Requirement for Land Preparation of Ricefield in Irrigation Modernization." Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) 11, no. 4 (December 26, 2022): 700. http://dx.doi.org/10.23960/jtep-l.v11i4.700-712.

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Irrigation water requirement for irrigation for land preparation is the highest water requirement in rice cultivation therefore it was essential to determine it based on recent condition in order to support the irrigation modernization. This research aimed to determine the irrigation requirement and tillage specific drafts based for various water ponding level in rice field as well as to determine parameters of irrigation requirement for land preparation to support irrigation modernization. Determination of irrigation water requirement is computed based on equation developed by Van de Goor and Zijlstra (1968) with variation of water volume supplied for saturation and ponding level. Variation of water supplied during land preparation resulted in the variation of tillage specific drafts according to empirical formula developed by Kisu (1972). Water level ponding of 0 mm, 5 mm, 30 mm, and 74 mm resulted in water requirements for land preparation (Project Water Requirement/PWR) of 112 mm, 122 mm, 139 mm, and 198 mm, respectively. The mentioned water ponding level resulted in the tillage specific draft of 1.131 kg/cm2, 1.101 kg/cm2, 0.886 kg/cm2, and 0.954 kg/cm2, respectively. The thicker water ponding in the rice field, the more water requirement for land preparation, but the less energy needed for tillage. Recommended irrigation requirement for land preparation was 139 mm with 15-day duration of land preparation. Keywords: Irrigation modernization, Irrigation requirement, Land preparation, Tillage specific draft, Ponding

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Rombough, Peter J. "Initial Egg Weight, Time to Maximum Alevin Wet Weight, and Optimal Ponding Times for Chinook Salmon (Oncorhynchus tshawytscha)." Canadian Journal of Fisheries and Aquatic Sciences 42, no. 2 (February 1, 1985): 287–91. http://dx.doi.org/10.1139/f85-036.

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Eggs of chinook salmon (Oncorhynchus tshawytscha) were segregated into eight size groups (range 163–437 mg) and incubated at 5, 7.5, 10, and 12.5 °C. The time required to reach maximum alevin wet weight (MAWW) varied significantly (p < 0.01) both with mean incubation temperature (T °C) and with initial egg weight (W mg). A good (R2 = 98.4%, n = 21) prediction of days postfertilization to MAWW (D) is given by[Formula: see text]Optimal ponding times are closely associated with the attainment of MAWW and can be estimated using this equation. Data relating mean incubation temperatures (T) to actual ponding time were collected from 17 hatcheries throughout British Columbia. The equation[Formula: see text]where D′ is days postfertilization to ponding, provided the best fit to the data (R2 = 97.5%, n = 85). Hatchery ponding times were not significantly different from times to MAWW predicted for 200-mg eggs.

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Nguyen, Hung Tan, Truong Phu Nguyen, Tan Nhat Phan, Phuong Thi Tran, and Phu Ba Nguyen. "INVESTIGATION ON HYDROLOGIC PERFORMANCE OF PERVIOUS CONCRETE PAVEMENT BY FINITE ELEMENT ANALYSIS." TRA VINH UNIVERSITY JOURNAL OF SCIENCE; ISSN: 2815-6072; E-ISSN: 2815-6099 1, no. 46 (March 28, 2022): 56–63. http://dx.doi.org/10.35382/tvujs.1.46.2022.862.

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Pervious concrete pavement has been used widely as an effective practice for water management in low-impact development techniques. The hydrologic performance of pervious concrete pavement depends significantlyon the rainfall intensity and the designed slope. This study assessed the hydrologic performance of pervious concrete pavement by evaluating the time for surface ponding via finite element analysis. A series of simulations were carried out to explore the relationship between hydrologic performance and pervious concrete pavement by the Hydrus 2D program. The research’s results showed that as the slope increased, the time of surface ponding also increased. The data indicated that the slope variable had a low impact on the water level in pervious concrete pavement under a constant rainfall intensity. Observation of the effect of rainfall intensity showed that when the rainfall intensity increased twofold, the time for surface ponding dropped about two times. Furthermore, when surface ponding appeared, pervious concrete pavement at higher rainfall intensity had lower water content. The rainfall intensity also significantly affects the hydrologicperformance of the pervious concrete pavement. This study only assessed the hydrologic performance by using the time for surface ponding via finite element analysis. Further experimental studies should be conducted to examine the relationship of other factors to the hydrologic performance of pervious concrete pavement.

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Kazemi, Honeyeh, Ali Ashraf Sadraddini, Amir Hossein Nazemi, and Charles A. Sanchez. "Moment Analysis for Modeling Soil Water Distribution in Furrow Irrigation: Variable vs. Constant Ponding Depths." Water 13, no. 10 (May 18, 2021): 1415. http://dx.doi.org/10.3390/w13101415.

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Despite increasing use of pressurized irrigation methods, most irrigation projects worldwide still involve surface systems. Accurate estimation of the amount of infiltrating water and its spatial distribution in the soil is of great importance in the design and management of furrow irrigation systems. Moment analysis has previously been applied to describe the subsurface water distribution using input data from numerical simulations rather than field measured data, and assuming a constant ponding depth in the furrow. A field experiment was conducted in a blocked-end level furrow at Maricopa Agricultural Center, Arizona, USA, to study the effect of time-variable ponding depths on soil water distribution and the resulting wetting bulb under real conditions in the field using moment analysis. The simulated volumetric soil water contents run with variable and constant (average) ponding depths using HYDRUS 2D/3D were almost identical, and both compared favorably with the field data. Hence, only the simulated soil water contents with variable ponding depths were used to calculate the moments. It was concluded that the fluctuating flow depth had no significant influence on the resulting time-evolving ellipses. This was related to the negligible 10-cm variation in ponding depths compared to the high negative matric potential of the unsaturated soil.

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Urbano, Carlo A. "Ponding Effect on Flat Roofs." Structural Engineering International 10, no. 1 (February 2000): 39–43. http://dx.doi.org/10.2749/101686600780620946.

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altaiee, Mohammad, Haqqi Yasin, and Younis Hassan. "Infiltration Characteristics under Intermittent Ponding." Al-Rafidain Engineering Journal (AREJ) 27, no. 1 (March 1, 2022): 207–12. http://dx.doi.org/10.33899/rengj.2022.132303.1144.

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Zheng, Xinyu, Fei Xu, Songtao Shi, Yang Gao, and Qi Li. "Evolution Patterns of Frost-Heaving Pressure with Partial Ponding in Cold Region Tunnels." Geofluids 2022 (February 23, 2022): 1–14. http://dx.doi.org/10.1155/2022/1883973.

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The calculation of the frost-heaving pressure is one of the key issues in the frost-resistant design of tunnels in cold regions. To reveal the frost heave mechanism of partial ponding behind the tunnel linings, a three-dimensional geo-mechanical model test was developed that only considered the frost heave load. A self-designed water bladder equipment was set up to simulate the partial ponding. The frost heave response characteristics of the surrounding rock with partial ponding were simulated to analyze the change law of temperature field and frost-heaving pressure under freezing by using air-conditioning to reduce the ambient temperature of the model test. The changes in the internal temperature of the surrounding rock and the evolution of the frost-heaving pressure over time under different thicknesses of partial ponding and different levels of surrounding rock were compared. The theoretical calculation value of frost-heaving pressure and the test values of the model test were compared and analyzed using the numerical simulation method. The results showed that the temperature of the surrounding rock presented three-stage changes, which showed a lagging characteristic relative to the environmental temperature. The empirical equation for the relationship between the frost-heaving pressure and time was obtained by nonlinear fitting of the experimental results. Taking advantage of the regular tetrahedron calculation model, the paper established a semiempirical frost-heaving pressure model considering time and space effects, which was identical with the frost-heaving phenomenon from the experiments. Theoretical analysis, experiments, and numerical simulation show that the frost-heaving pressure increased along with the depth of partial ponding and the elastic resistance coefficient of surrounding rock, which could provide references for revealing the frost-heaving pressure of partial ponding behind tunnels of cold regions and has a significant meaning in the engineering application.

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Melhuish, FM, E. Humphreys, WA Muirhead, and RJG White. "Flood irrigation of wheat on a transitional red-brown earth. I. Effect of duration of ponding on soil water, plant growth, yield and N uptake." Australian Journal of Agricultural Research 42, no. 7 (1991): 1023. http://dx.doi.org/10.1071/ar9911023.

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Long periods of waterlogging during irrigation are thought to adversely affect wheat growth and yield. This work quantifies these effects for wheat (Triticum aestivum L. cv. Bindawarra) growing on a transitional red-brown earth. The crop was irrigated on four occasions during spring. At each irrigation six ponding treatments were imposed involving sprinkler irrigation (SP) or flooding for 1, 12, 24, 48 or 96 h. Each plot always received the same treatment. Nitrogen fertilizer was applied at sowing (23 kg N ha-1 as ammonium phosphates) and at the end of tillering, 3 weeks before the first irrigation (100 kg N ha-1 as urea). There was also a 1 h ponding treatment which did not receive urea at the end of tillering. Grain yield on the 48 h and 96 h ponding treatments was significantly lower than on SP, 1 h and 12 h. Yield declined by 69 kg ha-1 for each day that water was ponded on the surface, or by 55 kg ha-1 for each day that the estimated soil water depletion was below 25 mm. The wheat crop suffered stress due to lack of aeration for periods varying from 42% (1 h and SP) to 68% (96 h) of the time interval between early stem elongation and physiological maturity. The grain yield and N uptake data indicate that the site was highly responsive to N fertilizer. However, there was no significant effect of ponding treatment on total N uptake, suggesting that the yield differences between the ponding treatments were not caused by differences in N availability. The results demonstrate that yield loss through waterlogging can be minimized by changing to irrigation management practices that minimise the period of ponding.

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Ahmed, M., S. A. AI-Rawahy, M. S. AI-Kalbani, and J. K. AI-Handaly. "Leaching Potential of Some Omani Soils: Soil Column and Drip Irrigation Studies." Journal of Agricultural and Marine Sciences [JAMS] 4, no. 2 (June 1, 1999): 65. http://dx.doi.org/10.24200/jams.vol4iss2pp65-70.

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This paper reports the findings from leaching experiments conducted on some Omani soils. Seven samples from two locations in the Batinah coastal area of Oman were analyzed. Repacked soil columns of up to 30 cm in length were used in laboratory experiments to estimate the amount of water required for adequate leaching of salts from the soil profile. Two methods of leaching: continuous ponding and intermittent ponding were investigated. Results show that most of the salt (50-90%) is removed from the soil profile by the application of water equal in amount to the depth of soil to be leached. The results also show that intermittent ponding method of leaching is more efficient than the continuous ponding method of leaching if initial salinity level is high. Soil samples were also collected to find out the salinity status under drip irrigation. It clearly demonstrates that drip irrigation is very effective in removing salts from soil near the emitters although there is a marked accumulation of salts on the soil surface between emitters.

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Lichvar, Robert, Greg Gustina, and Robert Bolus. "Ponding duration, ponding frequency, and field indicators: A case study on three California, USA, playas." Wetlands 24, no. 2 (June 2004): 406–13. http://dx.doi.org/10.1672/0277-5212(2004)024[0406:pdpfaf]2.0.co;2.

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Dahiya, I. S., K. S. Grewal, R. Anlauf, and J. Richter. "Desalinization of a salt-affected soil in plots of various sizes under two modes of water application." Journal of Agricultural Science 104, no. 1 (February 1985): 19–26. http://dx.doi.org/10.1017/s0021859600042945.

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SummaryLeaching in a salt-affected, permeable, sandy loam soil was evaluated under continuous and intermittent ponding conditions in 2 × 2 m (S1), 4 × 4 m (S2) and 6 × 6 m (S3) plots. The soil contained large amounts of soluble salts throughout the profile to the water table, chiefly chlorides and sulphates of sodium, calcium and magnesium. The leaching curves did not differ significantly between Slf Sa and S3 plots under continuous ponding but did under intermittent ponding. The leaching efficiency decreased sharply with increased plot size. The leaching efficiency in Sj plots was significantly greater with intermittent than with continuous ponding, but the reverse was true in S3 plots. The displacement of the resident soil solution in S1 plots under intermittent ponding was nearly piston-like. With increased plot size, it tended to deviate from this behaviour. The leaching curves from S3 plots (this size being reasonable in farmers' fields) were compared with those obtained from numerical solution of a simplified steady-state salt transport model. The model also included a source term, solubility rate constant, for the slightly soluble salts present in the experimental soil. The pore water velocity was estimated from field capacity and time-averaged infiltration rate. The effective dispersion coefficient and solubility rate constant were estimated by a least-squares minimization technique. A reasonably good agreement was obtained between simulated and experimental leaching curves. For practical purposes, this simple model may be adequate to predict leaching in salt-affected soils similar to the one under consideration.

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Shook, Kevin, Raymond Spiteri, John Pomeroy, Tonghe Liu, and Oluwaseun Sharomi. "WDPM: the Wetland DEM Ponding Model." Journal of Open Source Software 6, no. 64 (August 13, 2021): 2276. http://dx.doi.org/10.21105/joss.02276.

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Kumke, T., and C. E. Mullins. "Field measurement of time to ponding." Soil Use and Management 13, no. 1 (March 1997): 24–28. http://dx.doi.org/10.1111/j.1475-2743.1997.tb00552.x.

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Daniel Yaw Osei, Zakari Mustapha, and Mohammed D.H. Zebilila. "Compressive Strength of Concrete Using Different Curing Methods." Journal of Social and Development Sciences 10, no. 3(S) (January 10, 2020): 30–38. http://dx.doi.org/10.22610/jsds.v10i3(s).2983.

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The structural use of concrete depends largely on its strength, especially compressive strength.Various tests were carried out to ascertain the properties of concrete materials, whereas test performances ofthe concrete with different mix ratios at specific ages of curing were undertaken. The study determined thecompressive strength of concrete using different curing methods. Four different methods of curing (ponding,continuous wetting, open-air curing and sprinkling with water) were used. Seventy-two (72) cubes were castusing a mix ratio of 1:2:4 and 1:3:6 with 0.5 water cement ratio and with 0.6 waters cement ratio respectively.The compressive strengths were determined after 7 days, 14 days and at 28 days of curing. Findings showthat for 1:2:4 concrete, maximum of 28-day compressive was the highest for concrete cured by ponding andthe least was by sprinkling water. Further findings show that for 1:3:6 concrete, maximum of 28-daycompressive strength was obtained using ponding and the least was open air curing. Despite ponding methodproducing the highest compressive strength of concrete, it is practically impossible to cure cubes aboveground structural elements. Wet-covering method is recommended for structural elements, such as columns,beams and slabs in other to produce concreteof a required compressive strength.

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Paul, Robert F., Yaping Cai, Bin Peng, Wendy H. Yang, Kaiyu Guan, and Evan H. DeLucia. "Spatiotemporal Derivation of Intermittent Ponding in a Maize–Soybean Landscape from Planet Labs CubeSat Images." Remote Sensing 12, no. 12 (June 16, 2020): 1942. http://dx.doi.org/10.3390/rs12121942.

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Climate change is increasing the frequency and intensity of heavy precipitation in the US Midwest, overwhelming existing tile drainage, and resulting in temporary soil ponding across the landscape. However, lack of direct observations of the dynamics of temporal soil ponding limits our understanding of its impacts on crop growth and biogeochemical cycling. Satellite remote sensing offers a unique opportunity to observe and analyze this dynamic phenomenon at the landscape scale. Here we analyzed a series of red–green–blue (RGB) and near infrared (NIR) remote sensing images from the Planet Labs CubeSat constellation following a period of heavy precipitation in May 2017 to determine the spatiotemporal characteristics of ponding events in the maize–soybean cropland of Champaign County, Illinois USA. We trained Random Forest algorithms for near-daily images to create binary classifications of surface water versus none, which achieved kappa values around 0.9. We then analyzed the morphology of classification results for connected pixels across space and time and found that 2.5% (5180 ha) of this cropland was classified as water surface at some point during this period. The frequency distribution of areal ponding extent exhibited a log–log relationship; the mean and median areas of ponds were 1231 m2 and 126 m2, respectively, with 26.1% of identified ponds being at the minimum threshold area of 45 m2, and 2.5% of the ponds having an area greater than 104 m2 (1 ha). Ponds lasted for a mean duration of 2.4 ± 1.7 days, and 2.3% of ponds lasted for more than a week. Our results suggest that transient ponding may be significant at the landscape scale and ought to be considered in assessments of crop risk, soil and water conservation, biogeochemistry, and sustainability.

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Bridge, BJ, and PJ Ross. "A portable microcomputer-controlled drip infiltrometer. II. Field measurement of sorptivity, hydraulic conductivity and time to ponding." Soil Research 23, no. 3 (1985): 393. http://dx.doi.org/10.1071/sr9850393.

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The lightweight portable drip infiltrometer described in Part I was used to determine the infiltration characteristics of a sandy loam soil. Sorptivity was determined by varying the application rate to maintain surface ponding and by measuring the time to ponding at a constant application rate. Saturated hydraulic conductivity was equated to the long-time steady-state application rate needed to maintain surface ponding. This rate could be determined to a precision of 0.5 �m s-1 (2 mm h-1) and agreed well with core data from 0.5 to 1.0 m depth in the profile. The results obtained were compared with ponded ring infiltrometer measurements. Sorptivities calculated from the ring infiltrometers were greater than those from the variable rate drip infiltrometer which in turn were greater than those from the constant rate drip infiltrometer. This was attributed to the effect of the macropores under the ponded rings and to confining the depth over which sorptivity was measured under constant application rate to the wetter surface soil. In dry soil, the drip infiltrometer measured low initial infiltration rates caused by poor wetting of the soil, but these were not measured by the ponded ring infiltrometers, which had a 50 mm head. In moist soil, poor wettability did not occur. Five equations for calculating sorptivity from measurements of time to ponding under a constant application rate of 8.3 �m s-1 (30 mm h-1) were used and four of these equations agreed within 20%. This was less than the range of sorptivities arising from uncertainties in determining the time to ponding, and the differences between the equations were attributed to the assumptions used in their derivation. It was concluded that any measurement of sorptivity on this soil was difficult to interpret because of non-uniformity in the upper soil profile.

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Bridge, BJ, and PJ Ross. "Corrigenda - A portable microcomputer-controlled drip infiltrometer. II. Field measurement of sorptivity, hydraulic conductivity and time to ponding." Soil Research 23, no. 3 (1985): 393. http://dx.doi.org/10.1071/sr9850393c.

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The lightweight portable drip infiltrometer described in Part I was used to determine the infiltration characteristics of a sandy loam soil. Sorptivity was determined by varying the application rate to maintain surface ponding and by measuring the time to ponding at a constant application rate. Saturated hydraulic conductivity was equated to the long-time steady-state application rate needed to maintain surface ponding. This rate could be determined to a precision of 0.5 �m s-1 (2 mm h-1) and agreed well with core data from 0.5 to 1.0 m depth in the profile. The results obtained were compared with ponded ring infiltrometer measurements. Sorptivities calculated from the ring infiltrometers were greater than those from the variable rate drip infiltrometer which in turn were greater than those from the constant rate drip infiltrometer. This was attributed to the effect of the macropores under the ponded rings and to confining the depth over which sorptivity was measured under constant application rate to the wetter surface soil. In dry soil, the drip infiltrometer measured low initial infiltration rates caused by poor wetting of the soil, but these were not measured by the ponded ring infiltrometers, which had a 50 mm head. In moist soil, poor wettability did not occur. Five equations for calculating sorptivity from measurements of time to ponding under a constant application rate of 8.3 �m s-1 (30 mm h-1) were used and four of these equations agreed within 20%. This was less than the range of sorptivities arising from uncertainties in determining the time to ponding, and the differences between the equations were attributed to the assumptions used in their derivation. It was concluded that any measurement of sorptivity on this soil was difficult to interpret because of non-uniformity in the upper soil profile.

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Yang, Kai, Muhammed Basheer, Sreejith Nanukuttan, Yun Bai, and Adrian Long. "Effectiveness of two field methods of saturating near surface concrete on the water permeability of in situ concrete." MATEC Web of Conferences 289 (2019): 06004. http://dx.doi.org/10.1051/matecconf/201928906004.

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Determining the water permeability of concrete in structures remains a challenge because of difficulties in removing the influence of its moisture content. Saturating concrete with water could be one option, but this is not easy to achieve on site. This paper reports a testing programme carried out to assess the reliability and effectiveness of two field saturation methods, viz. vacuum saturation and ponding. The water permeability test results after applying the vacuum saturation and ponding were compared with that obtained after incremental immersion. It was found that ponding was unable to remove the influence of moisture, whilst vacuum saturation was effective for wet concretes. The results obtained from the electrical resistance measurements after incremental immersion suggested that the water permeability of concretes can be accurately determined by carrying out in situ permeability tests if the near surface region up to a depth of 25 mm is fully saturated.

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Cai, L., SA Prathapar, and HG Beecher. "Modelling leaching and recharge in a bare transitional red-brown earth ponded with low salinity water in summer." Australian Journal of Experimental Agriculture 34, no. 7 (1994): 1085. http://dx.doi.org/10.1071/ea9941085.

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A modelling study was conducted to evaluate water and salt movement within a transitional red-brown earth with saline B horizon soil when such waters are used for ponding in summer. The model was calibrated using previously published experimental data. The calibrated model was used to evaluate the effect of depth to watertable, saturated hydraulic conductivity, and ponding water salinity on infiltration, water and salt movement within the soil profile, and recharge. The study showed that when initial soil water content and the saturated hydraulic conductivity (Ks) are low, infiltrating water will be stored within the soil profile even in the absence of a shallow watertable. Once the soil water content is high, however, recharge will be significant in winter, even if there is no net infiltration at the soil surface. Infiltration rates depend more on Ks than the depth to watertable if it is at, or below, 1.5 m from the soil surface. When Ks is high, recharge under ponding will be higher than that under winter fallow. Subsequent ponding in summer and fallow in winter tend to leach salts from the soil profile, the leaching rate dependent on Ks. During winter fallow, due to net evaporation, salts tend to move upwards and concentrate near the soil surface. In the presence of shallow watertables, leached salts tend to concentrate at, or near, the watertable.

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Arias, Luis, Jean-Luc Bertrand-Krajewski, and Pascal Molle. "Simplified hydraulic model of French vertical-flow constructed wetlands." Water Science and Technology 70, no. 5 (July 10, 2014): 909–16. http://dx.doi.org/10.2166/wst.2014.309.

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Designing vertical-flow constructed wetlands (VFCWs) to treat both rain events and dry weather flow is a complex task due to the stochastic nature of rain events. Dynamic models can help to improve design, but they usually prove difficult to handle for designers. This study focuses on the development of a simplified hydraulic model of French VFCWs using an empirical infiltration coefficient – infiltration capacity parameter (ICP). The model was fitted using 60-second-step data collected on two experimental French VFCW systems and compared with Hydrus 1D software. The model revealed a season-by-season evolution of the ICP that could be explained by the mechanical role of reeds. This simplified model makes it possible to define time-course shifts in ponding time and outlet flows. As ponding time hinders oxygen renewal, thus impacting nitrification and organic matter degradation, ponding time limits can be used to fix a reliable design when treating both dry and rain events.

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Umbara, Raditya Panji, and Deliyanti Ganesha. "PEMETAAN BAHAYA BANJIR DI KABUPATEN BANGGAI KEPULAUAN." Jurnal Sains dan Teknologi Mitigasi Bencana 12, no. 1 (August 6, 2019): 10–20. http://dx.doi.org/10.29122/jstmb.v12i1.3696.

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Pemetaan Bahaya Banjir di Kabupaten Banggai Kepulauan telah dilakukan dengan menggunakan metode TWI (Topographic Wetness Index). Metode tersebut menggunakan variabel topografi secara dominan dengan tetap mempertimbangkan variabel curah hujan, penggunaan lahan, geologi dan data historis banjir. Hasil perhitungan dan analisis data diperkuat dengan survei lapangan. Peta Bahaya Banjir di Kabupaten Banggai Kepulauan terbagi menjadi 3 klasifikasi, yaitu tinggi, sedang dan rendah. Wilayah dengan bahaya banjir tinggi dan daerah langganan banjir berdasarkan BPBD Kabupaten Banggai Kepulauan berada di Desa Ponding Ponding, Tatakalai, Luk Sago Kecamatan Tinangkung Utara serta di Desa Lopito Kecamatan Totikum.

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34

Raza, Muhammad Saleem, Haresh Kumar, Danish Kumar, and Naraindas Bheel. "Effect of Various Curing Methods and Curing Days on Compressive Strength of Plain Cement Concrete." Quaid-e-Awam University Research Journal of Engineering, Science & Technology 18, no. 02 (December 31, 2020): 29–32. http://dx.doi.org/10.52584/qrj.1802.04.

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Concrete is the most important and most consumed construction material in global construction industry. The properties of concrete are greatly influenced by properties of its constituents and curing methods utilized for preparation of specimens. This study is focused on investigating the influence of three common curing methods, i.e., ponding, sprinkling and wet cover curing on compressive strength behavior of concrete. In total, 45 cubes were casted and tested after curing for 3, 7, 14, 28 and 56 days. The obtained results suggest that ponding method of concrete curing is most effective among all the three methods of concrete curing considered in this study. After ponding, the performance of concrete cured with wet cover curing method was quite acceptable. Moreover, the study also suggested that sprinkling method of curing gives lowest compressive strength due to greater moisture movement which abates the hydration of binder in concrete. This study will be helpful for construction practitioners in deciding the best-suited curing method under given conditions and available methods of preparation of concrete.

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35

Oswald, William J. "Introduction to Advanced Integrated Wastewater Ponding Systems." Water Science and Technology 24, no. 5 (September 1, 1991): 1–7. http://dx.doi.org/10.2166/wst.1991.0106.

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36

Warrick, A. W., D. Zerihun, C. A. Sanchez, and A. Furman. "Infiltration under Variable Ponding Depths of Water." Journal of Irrigation and Drainage Engineering 131, no. 4 (August 2005): 358–63. http://dx.doi.org/10.1061/(asce)0733-9437(2005)131:4(358).

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37

Folz, Bryan, and Ricardo O. Foschi. "Reliability of Timber Beams Subjected to Ponding." Journal of Structural Engineering 116, no. 2 (February 1990): 490–99. http://dx.doi.org/10.1061/(asce)0733-9445(1990)116:2(490).

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38

Loáiciga, Hugo A., and Allison Huang. "Ponding Analysis with Green-and-Ampt Infiltration." Journal of Hydrologic Engineering 12, no. 1 (January 2007): 109–12. http://dx.doi.org/10.1061/(asce)1084-0699(2007)12:1(109).

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39

Cheng, Zhen-qiang, Wei Liang, and Du Chen. "Ponding problem of plates in nonlinear nature." Mechanics Research Communications 23, no. 4 (July 1996): 335–37. http://dx.doi.org/10.1016/0093-6413(96)00030-4.

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40

Khanaum, Mosammat Mustari, and Md Saidul Borhan. "Influence of Soil Layers on the Infiltration Rates and Cumulative Infiltration Using Modified Green Ampt Model in the HYDROL-INF Simulation Environment." International Journal of Agriculture System 10, no. 2 (December 17, 2022): 72. http://dx.doi.org/10.20956/ijas.v10i2.3818.

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Soil profiles are generally heterogeneous and consist of various horizontal layers due to geological processes, the formation of crusts, or other artificial or man-made activities. To quantify infiltration into these heterogeneous soil profiles, the Modified Green-Ampt Model (MGAM) is a physically-based hydrologic model that can efficiently perform under both steady and unsteady rainfall events. Based on the secondary data, this study sought to determine the effect of changing soil layers (soil textures) on infiltration rates and cumulative infiltrations in in both laboratory and field settings. Different scenarios were analyzed by rearranging soil layers and evaluating their impacts on corresponding infiltration rates and cumulative infiltrations. Simulations were run with HYDROL-INF software environment using MGAM. Three scenarios were considered for a laboratory experiment with two different types of soil texture coupled with five different soil profiles. Similarly, four scenarios were considered for the field experiments with five different types of soil texture couple with eight different soil profiles. The simulated infiltration rates and cumulative infiltrations were found to vary with soil layer change scenarios. The simulated cumulative infiltrations, ponding times, infiltrating rates at ponding, and total depth of wetting front at ponding of a five-layered laboratory soil column were identical for the three scenarios. Simulated cumulative infiltrations were 33.16, 23.65, 21.29, and 42.77 cm, respectively, for scenarios (combinations) 1, 2, 3, and 4 in the eight-layered soil profile in the field scenarios. Infiltration rates among scenarios at ponding were identical (0.46 to 0.53 cm/h) with field scenario data.

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Dirscherl, Mariel C., Andreas J. Dietz, and Claudia Kuenzer. "Seasonal evolution of Antarctic supraglacial lakes in 2015–2021 and links to environmental controls." Cryosphere 15, no. 11 (November 25, 2021): 5205–26. http://dx.doi.org/10.5194/tc-15-5205-2021.

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Abstract. Supraglacial meltwater accumulation on ice shelves may have important implications for future sea level rise. Despite recent progress in the understanding of Antarctic surface hydrology, potential influences on ice shelf stability as well as links to environmental drivers remain poorly constrained. In this study, we employ state-of-the-art machine learning on Sentinel-1 synthetic aperture radar (SAR) and optical Sentinel-2 satellite imagery to provide new insight into the inter-annual and intra-annual evolution of surface hydrological features across six major Antarctic Peninsula and East Antarctic ice shelves. For the first time, we produce a high-resolution record of supraglacial lake extent dynamics for the period 2015–2021 at unprecedented 10 m spatial resolution and bi-weekly temporal scale. Through synergetic use of optical and SAR data, we obtain a more complete mapping record also enabling the delineation of buried lakes. Our results for Antarctic Peninsula ice shelves reveal below-average meltwater ponding during most of melting seasons 2015–2018 and above-average meltwater ponding throughout summer 2019–2020 and early 2020–2021 considering years 2015–2021 as a reference period. Meltwater ponding on investigated East Antarctic ice shelves was far more variable, with above-average lake extents during most 2016–2019 melting seasons and below-average lake extents during 2020–2021, considering the reference interval 2016–2021. This study is the first to investigate relationships with climate drivers both spatially and temporally including time lag analysis. The results indicate that supraglacial lake formation in 2015–2021 is coupled to the complex interplay of local, regional and large-scale environmental drivers with similar driving factors over both ice sheet regions. In particular, varying air temperature, solar radiation and wind conditions influenced supraglacial lake formation over all six ice shelves despite strong local to regional discrepancies, as revealed through pixel-based correlation analysis. Furthermore, regional climatic conditions were shown to be influenced by Southern Hemisphere atmospheric modes showing large-scale impacts on the spatio-temporal evolution of supraglacial lakes as well as on above- or below-average meltwater ponding with respect to the period 2015–2021. Finally, the local glaciological setting, including melt–albedo feedbacks and the firn air content, was revealed to strongly influence supraglacial lake distribution. Recent increases in Antarctic Peninsula surface ponding point towards a further reduction in the firn air content, implying an increased risk for ponding and hydrofracture. In addition, lateral meltwater transport was observed over both Antarctic regions with similar implications for future ice shelf stability.

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Ge, Ruo Dong, Ai Ping Yu, and Ke Yu Wei. "The Experimental Method Comparison of Concrete Penetration." Advanced Materials Research 374-377 (October 2011): 1215–19. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.1215.

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For comparing the difference between Salt ponding test and ASTMC1202 test, the same batch of specimens divided into two groups are tested, and the chloride ion diffusion coefficient was calculated with the corresponding theory. The results indicate that the concentration gradient is larger, the concentration decreased faster and the slope of figure is more steep in salt ponding test, and the chloride ion diffusion is deeper for the role of the electric field in ASTM test. Although the diffusion mechanism is different in two kinds of test, there is little difference between the two groups of test diffusion coefficient.

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43

Seyama, Tomoko, Ryohei Arakawa, Shogo Machida, Sota Yoshida, Akihiko Maru, Kei’ichi Baba, Yoshinori Kobayashi, et al. "Intake of Radionuclides in the Trees of Fukushima Forests 3. Removal of Radiocesium from Stem Wood, Cryptomeria Japonica (L.f.) D. Don." Forests 11, no. 5 (May 23, 2020): 589. http://dx.doi.org/10.3390/f11050589.

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Nuclear power plant accidents have dispersed radiocesium into the atmosphere to contaminate trees with no turnover in heartwood, as occurred in Fukushima, and as has persisted for over 30 years around Chernobyl. Here we employ the ponding method, in which radiocesium can be flushed out from the cross-cut edges of Japanese cedar, Cryptomeria japonica (L.f.) D. Don., stem with water due to xyloglucan degradation in tracheids. Furthermore, lab-scale ponding experiments have shown that a non-detectable level of radiocesium has been observed not only in the pool water used for 575 days but also in the water containing recombinant xyloglucanase. This traditional technology is now a new biotechnology.

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44

Silburn, DM, and JL Foley. "Evaluation of some methods for measuring transient hydraulic properties of rain-induced surface seals on two clay soils." Soil Research 32, no. 3 (1994): 471. http://dx.doi.org/10.1071/sr9940471.

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Surface sealing of soils can markedly affect infiltration under rain. Robust infiltration models and methods for measuring hydraulic properties are needed. A review of methods of measuring seal hydraulic properties indicated that methods differ greatly in the hydraulic boundary conditions used and this may affect results and make a systematic analysis difficult. Two methods ('post-rain' suction permeameter and rainfall in situ) of measuring seal flux and conductivity under appropriate hydraulic boundary conditions were tested in a laboratory for two clay soils under simulated rain. The suction permeameter tests showed that conductivity of surface seal samples is altered by the suction applied during the measurement. This occurred in the absence of rain and appears to be more general than previously reported. Transient infiltration and conductivity measured by the two methods were in close agreement from ponding time onwards, provided suction equal to that measured under the seal was applied in the suction permeameter. The suction permeameter can provide conductivity data under a wider range of conditions than the rainfall in situ method, including prior to ponding, but requires measured subseal suction data. The two methods are seen to be complementary. The transient conductivity behaviour of the two soils was markedly different-the well aggregated, swelling clay exhibited an exponential decay, similar to commonly used models; the less aggregated, non-swelling clay did not. Desorption moisture characteristic curves (MCC) and measured subseal moisture content gave useful estimates of subseal suction after commencement of surface ponding, provided: (a) a correction from desorption to adsorption is not made, as desorption occurs in the subseal soil after time of ponding; and (b) MCC are measured using appropriate pre-treatment (rainfall wetting of sample in 10-20 mm depth in a soil bed).

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45

ALAKUKKU, L., A. RISTOLAINEN, and I. SARIKKA. "Surface water ponding on clayey soils managed by conventional and conservation tillage in boreal conditions." Agricultural and Food Science 19, no. 4 (December 4, 2008): 313. http://dx.doi.org/10.2137/145960610794197551.

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Surface water ponding and crop hampering due to soil wetness was monitored in order to evaluate the effects of conservation tillage practices and perennial grass cover on soil infiltrability for five years in situ in gently sloping clayey fields. Thirteen experimental areas, each having three experimental fields, were established in southern Finland. The fields belonged to: autumn mouldboard ploughing (AP), conservation tillage (CT) and perennial grass in the crop rotation (PG). In the third year, direct drilled (DD) fields were established in five areas. Excluding PG, mainly spring cereals were grown in the fields. Location and surface area of ponded water (in the spring and autumn) as well as hampered crop growth (during June-July) were determined in each field by using GPS devices and GIS programs. Surface water ponding or crop hampering occurred when the amount of rainfall was clearly greater than the long-term average. The mean of the relative area of the ponded surface water, indicating the risk of surface runoff, and hampered crop growth was larger in the CT fields than in the AP fields. The differences between means were, however, not statistically significant. Complementary soil physical measurements are required to investigate the reasons for the repeated surface water ponding.;

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46

Sleep, Norman H. "Lateral flow and ponding of starting plume material." Journal of Geophysical Research: Solid Earth 102, B5 (May 10, 1997): 10001–12. http://dx.doi.org/10.1029/97jb00551.

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47

Allen R. Dedrick and Yvonne Reinink. "Water Ponding on Level Basins Caused by Precipitation." Transactions of the ASAE 30, no. 1 (1987): 0112–18. http://dx.doi.org/10.13031/2013.30411.

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48

Allen R. Dedrick and Yvonne Reinink. "Water Ponding on Level Basins Caused by Precipitation." Transactions of the ASAE 30, no. 4 (1987): 1057–64. http://dx.doi.org/10.13031/2013.30520.

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49

Colombi, Pierluigi. "The ponding problem on flat steel roof grids." Journal of Constructional Steel Research 62, no. 7 (July 2006): 647–55. http://dx.doi.org/10.1016/j.jcsr.2005.11.010.

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50

Blaauwendraad, Johan. "Modified method for rainwater ponding on flat roofs." Journal of Constructional Steel Research 65, no. 3 (March 2009): 559–68. http://dx.doi.org/10.1016/j.jcsr.2008.03.004.

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Journal articles on the topic 'Ponding'

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