scholarly journals Spatial Recognition of Regional Maximum Floods in Ungauged Watersheds and Investigations of the Influence of Rainfall

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 800
Author(s):  
Nam-Won Kim ◽  
Ki-Hyun Kim ◽  
Yong Jung
Keyword(s):  
Rainfall Intensity ◽  
Distribution Analysis ◽  
Water Control ◽  
Envelope Curve ◽  
Streamflow Data ◽  
Maximum Minimum ◽  
Spatial Recognition ◽  
Ungauged Watersheds ◽  
Shape And Size ◽  
Watershed Size

This study primarily aims to develop a method for estimating the range of flood sizes in small and medium ungauged watersheds in local river streams. In practice, several water control projects have insufficient streamflow information. To compensate for the lack of data, the streamflow propagation method (SPM) provides streamflow information for ungauged watersheds. The ranges of flood sizes for ungauged watersheds were generated using a specific flood distribution analysis based on the obtained streamflow data. Furthermore, the influence of rainfall information was analyzed to characterize the patterns of specific flood distributions. Rainfall location, intensity, and duration highly affected the shape of the specific flood distribution. Concentrated rainfall locations affected the patterns of the maximum specific flood distribution. The shape and size of the minimum specific flood distribution were dependent on the rainfall intensity and duration. The Creager envelope curve was used to generate equations for the maximum/minimum specific flood distribution for the study site. The ranges of the specific flood distributions were produced for each watershed size.

Non-parametric error distribution analysis from the laboratory calibration of various rainfall intensity gauges

2012 ◽  
Vol 65 (10) ◽  
pp. 1745-1752 ◽  
Author(s):  
L. G. Lanza ◽  
L. Stagi
Keyword(s):  
Rainfall Intensity ◽  
Mean Value ◽  
Distribution Analysis ◽  
Underlying Distribution ◽  
Accuracy And Precision ◽  
Laboratory Calibration ◽  
Field Intercomparison ◽  
Relative Errors ◽  
One Way Anova ◽  
Non Parametric

The analysis of counting and catching errors of both catching and non-catching types of rain intensity gauges was recently possible over a wide variety of measuring principles and instrument design solutions, based on the work performed during the recent Field Intercomparison of Rainfall Intensity Gauges promoted by World Meteorological Organization (WMO). The analysis reported here concerns the assessment of accuracy and precision of various types of instruments based on extensive calibration tests performed in the laboratory during the first phase of this WMO Intercomparison. The non-parametric analysis of relative errors allowed us to conclude that the accuracy of the investigated RI gauges is generally high, after assuming that it should be at least contained within the limits set forth by WMO in this respect. The measuring principle exploited by the instrument is generally not very decisive in obtaining such good results in the laboratory. Rather, the attention paid by the manufacturer to suitably accounting and correcting for systematic errors and time-constant related effects was demonstrated to be influential. The analysis of precision showed that the observed frequency distribution of relative errors around their mean value is not indicative of an underlying Gaussian population, being much more peaked in most cases than can be expected from samples extracted from a Gaussian distribution. The analysis of variance (one-way ANOVA), assuming the instrument model as the only potentially affecting factor, does not confirm the hypothesis of a single common underlying distribution for all instruments. Pair-wise multiple comparison analysis revealed cases in which significant differences could be observed.

scholarly journals Analisa Karakteristik Dan Distribusi Hujan Pada Kawasan DAS Batang Hari Kabupaten Dharmasraya

2019 ◽  
Vol 14 (2) ◽  
pp. 15
Author(s):  
Hartati -
Keyword(s):  
Catchment Area ◽  
Rainfall Intensity ◽  
Global Climate ◽  
Intensity Data ◽  
Water Control ◽  
Rainfall Distribution ◽  
Thiessen Polygon ◽  
Curve Method ◽  
Log Normal ◽  
Polygon Method

Batang Hari is the 2nd biggest DAS in Indonesia. About 76% of Batang Hari DAS is located in Jambi Province, the entire 24%is in West Sumatera Province. Batang Hari dam which was built on 1997 is one of infrastrcture at Public Work ministery under management at Balai Wilayah Sungai Sumatera V (BWSS V) his high potential of water stock. Optimum discharge of Batang Hari Dam is about 86 m3/sec. In the recently years DAS Batang Hari has been disturbed by some changes like catchment area utilized fot other purpose, change on global climate done to greenhouse effectwhich causingintensity of rain as well as flood. This climate change then will affected standard for engineering design for making a water control buiding which may injuireaccurate waterfall intensity data. Study of rainfall intensity obtained from 3 (three) nearby stations will show the characteristic dam trend of distribution with reperted period. Cousistency of data using Mass Curve method and local rain analysis to be done by Arithmatic & Thiessen Polygon method. To analysis trend of rainfall distribution. We use : Normal, Log Normal, Log Person type III and Gumbel methods. For complaince test of distribution, we use Chi-Kuadrat and Smirnov-Kolmogorov methods. Refer to result of distribution using Chi-Kuadrat and Smirnov-Kolmogorov methods for Arithmatic methods it is adviced to use Gumbel method to evaluate distribution trend; because critical deviation is smell comparing to available in table, with rainfall with repeating period 2,5,10,25,50 and 100 years are 124,08 mm, 1168,56 mm, 198,01 mm, 235,22 mm, 262,83 mm, 290,23 mm and Thiessen Polygon 106,93 mm, 138,22 mm, 158,94 mm, 185,11 mm, 204,53 mm, 223,81 mm

scholarly journals PENGGUNAAN EMBUNG GEOMEMBRANE SEBAGAI PENAMPUNGAN AIR BERSIH DESA TANGGUNG PRIGEL

Jurnal CIVILA ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 108
Author(s):  
Mukhammad Alifuddin ◽  
Sugeng Dwi Hartantyo
Keyword(s):  
Rainfall Intensity ◽  
Statistical Parameter ◽  
Dry Season ◽  
Clean Water ◽  
Water Tank ◽  
Distribution Analysis ◽  
Alternative Source ◽  
Small Reservoir ◽  
The Village ◽  
Arithmetic Method

The technology of artificial geomembrane reservoir or water tank is the small reservoir in the village land (TKD) which is built to collect the water in the rainy season by using waterproof material as the layer by utilizing the rainwater through the river around which is then used as an alternative source of clean water (water supply) in the dry season. As for the calculation methods used for this research include: analysis of rainfall area using algebra average method (arithematic mean), the calculation of rainfall plan can be done by using disperse measurement, with the statistical parameter of calculation result of Sd= 23.884 Cs= 1.933 Ck= 4.031 Cv= 0.233. The distribution analysis is done using Gumbel 1 method for 10 years plan amounted to 146.601 mm/day. Rainfall intensity analysis is done by using Mononobe method for 10 years rainfall intensity plan amounted to 6.108 mm/hour. For the next 10 years population projection is done using calculation of Arithmetic method of 2.795 populations. The conclusion of this research indicates that the clean water need in the dry season at Tanggung Prigel Village, Glagah District in 2026 is approximately 0.001941 m3/sec. While the plan for reservoir debit of 0.003254 m3/sec so it is considered sufficient to fulfill the clean water need in the Tanggung Prigel Village, Glagah District.

scholarly journals Physical simulation for water invasion and water control optimization in water drive gas reservoirs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xuan Xu ◽  
Xizhe Li ◽  
Yong Hu ◽  
Qingyan Mei ◽  
Yu Shi ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Physical Simulation ◽  
Control Measures ◽  
Production Performance ◽  
Distribution Analysis ◽  
Water Control ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Gas Well ◽  
Gas Recovery

AbstractThe development of water drive gas reservoirs (WDGRs) with fractures or strong heterogeneity is severely influenced by water invasion. Accurately simulating the rules of water invasion and drainage gas recovery countermeasures in fractured WDGRs, thereby revealing the mechanism of water invasion and an appropriate development strategy, is important for formulating water management measures and enhancing the recovery of gas reservoirs. In this work, physical simulation methods were proposed to gain a better understanding of water invasion and to optimize the water control of fractured WDGRs. Five groups of experiments were designed and conducted to probe the impacts of the distance between the fractures and the gas well, the drainage position, the drainage timing and the aquifer size on the water invasion and production performance of a gas reservoir. The gas and water production and the internal pressure drop were monitored in real time during the experiments. Based on the above experimental works, a theoretical analysis was conducted to quantitatively evaluate the performance of the gas reservoir recovery via the gas well production performance, water invasion, dynamic pressure drop and residual gas and water distribution analysis. The results show that when the fracture scale was appropriate, a gas well drilled close to a fracture (Experiment 1-3) or a high-permeability formation could also produce gas and achieve drainage efficiently. The recovery factor of Experiment 1-3 reached 62.5%, which was 24.6% and 21.1% higher than those of Experiments 1-1 and 1-2, respectively, which had wells drilled in low-permeability areas. Draining water near an aquifer can effectively inhibit water invasion during the early stage of gas recovery. The setup in Experiment 2-1 effectively inhibited water invasion and avoided the formation of water-sealed volumes of gas to recover 30% more gas than recovered with that of Experiment 1-1 without drainage wells. A shorter distance between the drainage well and the aquifer increased the drainage capacity and decreased the gas production capacity, respectively (Well 2 at Point A vs Point B). A larger aquifer had a lower gas recovery, which reduced the economic benefit. For example, due to an infinitely large aquifer, the reserves in Experiment 4-1 were developed by a single well, the gas recovery was only 33.4%. These research results are expected to be beneficial for the preparation of development plans and the optimization of water control measures for WDGRs.

scholarly journals Spatial propagation of streamflow data in ungauged watersheds using a lumped conceptual model

2018 ◽  
Vol 10 (1) ◽  
pp. 89-101
Author(s):  
N. W. Kim ◽  
Y. Jung ◽  
J. E. Lee
Keyword(s):  
Conceptual Model ◽  
Initial Conditions ◽  
Flood Damage ◽  
Error Rates ◽  
Time To Peak ◽  
Propagation Parameters ◽  
Spatial Propagation ◽  
Streamflow Data ◽  
Peak Streamflow ◽  
Ungauged Watersheds

Abstract Streamflow data are required for the effective management of flood damage; however, streamflow is rarely measured in small watersheds. In this study, a lumped conceptual model was adopted to generate streamflow values at small, ungauged watersheds using the spatial propagation concept. During the process of spatial propagation, parameters related to physical properties were fixed, while event-based initial conditions were optimized to ensure that error rates on the simulated streamflow data were comparable to those for measured data. Then the concept was validated using data from 21 flood events in the ChungJu Dam (CJD) watershed, Korea, which was divided into 22 small, ungauged watersheds. The propagated peak streamflow data at ungauged cross-validation points have average Nash-Sutcliffe efficiency (NSE) values of 0.91–0.99. Averages of NSE values for volume and time to peak streamflow are over 0.85 which satisfies the model criterion (NSE > 0.5). It is concluded that streamflow data for small, ungauged watersheds located upstream can be generated by one gauged downstream streamflow without an extensive amount of gauged streamflow data from other locations using the proposed concept. For accurate simulation, availability of rainfall data is essential for accurately modeling the spatial propagation of streamflow using a lumped conceptual model.

scholarly journals Physical Simulation for Water Invasion and Water Control Optimization in Water Drive Gas Reservoirs

2021 ◽  
Author(s):  
xuan xu ◽  
Xizhe li ◽  
yong hu ◽  
yu shi ◽  
qingyan mei ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Physical Simulation ◽  
Control Measures ◽  
Production Performance ◽  
Distribution Analysis ◽  
Water Control ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Gas Well ◽  
Gas Recovery

Abstract The development of water drive gas reservoirs (WDGRs) with fractures or strong heterogeneity is severely influenced by water invasion. Accurately simulating the rules of water invasion and drainage gas recovery countermeasures in fractured WDGRs, thereby revealing the mechanism of water invasion and an appropriate development strategy, is important for formulating water management measures and enhancing the recovery of gas reservoirs. In this work, physical simulation methods were proposed to gain a better understanding of water invasion and to optimize the water control of fractured WDGRs. Five groups of experiments were designed and conducted to probe the impacts of the distance between the fractures and the gas well, the drainage position, the drainage timing and the aquifer size on the water invasion and production performance of a gas reservoir. The gas and water production and the internal pressure drop were monitored in real time during the experiments. Based on the above experimental works, a theoretical analysis was conducted to quantitatively evaluate the performance of the gas reservoir recovery via the gas well production performance, water invasion, dynamic pressure drop and residual gas and water distribution analysis. The results show that when the fracture scale was appropriate, a gas well drilled close to a fracture (Experiment 1–3) or a high-permeability formation could also produce gas and achieve drainage efficiently. The recovery factor of Experiment 1–3 reached 62.5%, which was 24.6% and 21.1% higher than those of Experiments 1–1 and 1–2, respectively, which had wells drilled in low-permeability areas. Draining water near an aquifer can effectively inhibit water invasion during the early stage of gas recovery. The setup in Experiment 2 − 1 effectively inhibited water invasion and avoided the formation of water-sealed volumes of gas to recover 30% more gas than recovered with that of Experiment 1–1 without drainage wells. A shorter distance between the drainage well and the aquifer increased the drainage capacity and decreased the gas production capacity, respectively (Well 2 at Point A vs Point B). A larger aquifer had a lower gas recovery, which reduced the economic benefit. For example, due to an infinitely large aquifer, the reserves in Experiment 4 − 1 were developed by a single well, the gas recovery was only 33.4%. These research results are expected to be beneficial for the preparation of development plans and the optimization of water control measures for WDGRs.

scholarly journals PENAMPUNGAN AIR BERSIH PADA MUSIM KEMARAU DENGAN PEMANFAATAN EMBUNG GEOMEMBRANE (Studi Kasus: Desa Tanggung Prigel, Glagah, Lamongan)

2020 ◽  
Vol 25 (1) ◽  
pp. 55
Author(s):  
Hammam Rofiqi Agustapraja ◽  
Mukhammad Alifuddin
Keyword(s):  
Rainfall Intensity ◽  
Statistical Parameter ◽  
Dry Season ◽  
Clean Water ◽  
Water Tank ◽  
Distribution Analysis ◽  
Alternative Source ◽  
Small Reservoir ◽  
The Village ◽  
Arithmetic Method

Water is a major and important resource in the process of life in the world because of every living creature whether human, animal, and plant needs water. The technology of artificial geomembrane reservoir or water tank is the small reservoir in the village land (TKD) which is built to collect the water in the rainy season by using waterproof material as the layer by utilizing the rainwater through the river around which is then used as an alternative source of clean water (water supply) in the dry season. As for the calculation methods used for this research include: analysis of rainfall area using algebra average method (arithmetic mean), the calculation of rainfall plan can be done by using disperse measurement, with the statistical parameter of the calculation result of Sd= 23.884 Cs= 1.933 Ck= 4.031 Cv= 0.233. The distribution analysis is done using the Gumbel 1 method for 10 years plan amounted to 146.601 mm/day. Rainfall intensity analysis is done by using the Mononobe method for 10 years rainfall intensity plan amounted to 6.108 mm/hour. For the next 10 years, population projection is done using a calculation of the Arithmetic method of 2.795 populations. The conclusion of this research indicates that the clean water need in the dry season at Tanggung Prigel Village, Glagah District in 2026 is approximately 0.001941 m3/sec. While the plan for reservoir debit of 0.003254 m3/sec so it is considered sufficient to fulfill the clean water need in the Tanggung Prigel Village, Glagah District.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

A New System For Optomanual Semiautomatic Quantitative Image Analysis

1977 ◽  
Vol 35 ◽  
pp. 210-211
Author(s):  
H.P. Rohr
Keyword(s):  
Image Analysis ◽  
Volume Density ◽  
List Type ◽  
Distribution Analysis ◽  
Type Number ◽  
Point Counting ◽  
Human Eye ◽  
Quantitative Image ◽  
Point Density ◽  
Electronic Counting

Today, in image analysis the broadest possible rationalization and economization have become desirable. Basically, there are two approaches for image analysis: The image analysis through the so-called scanning methods which are usually performed without the human eye and the systems of optical semiautomatic analysis completely relying on the human eye.The new MOP AM 01 opto-manual system (fig.) represents one of the very promising approaches in this field. The instrument consists of an electronic counting and storing unit, which incorporates a microprocessor and a keyboard for choice of measuring parameters, well designed for easy use.Using the MOP AM 01 there are three possibilities of image analysis:the manual point counting,the opto-manual point counting andthe measurement of absolute areas and/or length (size distribution analysis included).To determine a point density for the calculation of the corresponding volume density the intercepts lying within the structure are scanned with the light pen.

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