• Journal of Environmental Science International
• /
• v.13 no.7
• /
• pp.637-643
• /
• 2004

A new method of automatic recording raingauge is developed to measure rainfall with 0.01mm resolution. This use two different signals to measure rainfall more accurately compare than other raingauges. One is weight of the tipping bucket with rainfall amount and the other is pulse from tipping bucket reverse. New method applied 1 mm tipping bucket mechanism and install loadcell under tipping bucket mechanism for measuring rainfall weight. Loadcell measure weight of rainfall until 1 mm with 0.01 mm resolution and more than 1 mm than bucket reverse and pulse signal generate, after that loadcell measure weight again. The validation of new instrument was examined in the room 65 mm/hour rainfall rate total 53 mm range. There is below than 1 % error of absolute rainfall amount and 0.01 mm resolution. The field test of instrument was carried out by comparing its measured values with values recorded by weight type and standard type on June 1 2003 at Terrestrial Environmental Research Center at Tsukuba University in Tsukuba of Japan, when it has recorded total amount of 40.58 mm rainfall by standard raingauge and new raingauge recorded 41.032 mm. Same rainfall intensity pattern observed in field observation with weight type raingauge. Rainfall intensity between weight type and Lee-A type raingauge reached 0.9947 correlation in 3 minute average.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2007.05a
• /
• pp.178-182
• /
• 2007

In this study, we evaluated current raingauge network of Soyanggang dam region applying spatial-correlation analysis and Entropy theory to recommend an optimized raingauge network. In the process of analysis, correlation distance of raingauge stations is estimated and evaluated via spatial-correlation method and entropy method. From this correlation distances, respective influencing radii of each dataset and each methods is assessed. The result of correlation and entropy analysis has estimated correlation distance of 25.546km and influence radius of 7.206km, deducing a decrease of network density from $224.53km^2$ to $122.47km^2$ which satisfy the recommended minimum densities of $250km^2$ in mountainous regions(WMO, 1994) and an increase of basin coverage from 59.3% to 86.8%. As for the elevation analysis the relative evaluation ratio increased from 0.59(current) to 0.92(optimized) resulting an obvious improvement.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2003.05a
• /
• pp.93-100
• /
• 2003

In order to use radar rainfall data for flood management, it is necessary to study and develop a method for optimum error correction to obtain radar rainfall values that agree closely with surface rainfall data. This paper proposes an optimum estimation method for calculating rainfall in a river basin by using data from surface raingauges and radar raingauge systems. This paper also reports on recent applications of radar raingauge systems for accurate simulation of flood discharge based on river basin rainfall values obtained from radar raingauge systems.

• Atmosphere
• /
• v.27 no.2
• /
• pp.251-258
• /
• 2017

The standard weighing raingauges have a capacity limit in measuring the amounts of precipitation. Exceptions are those using a siphon to drain the collected water during observations. To reduce the drain time of the siphon type or to overcome the hassles associated with the manual emptying of the bucket for measuring, the most of weighing gauges use a large bucket for storing of rainwater to be measured. To avoid the above-mentioned adverse requirements, we propose a paired barrel for a weighing raingauge. The paired barrel may improve the accuracy of the weighing raingauges by getting rid of their capacity limit and make the gauges smaller in size and lighter in weight than the conventional ones. We showed its proper function and the feasibility of realization by testing a prototype paired barrel.

• Journal of Environmental Science International
• /
• v.11 no.10
• /
• pp.1055-1060
• /
• 2002

A new method of automatic recording raingauge is developed to measure rainfall 1200mm full scale with high accuracy and resolution. The principle of new instrument is to detect a weight change of a buoyant weight according to a change in water level of raingauge measured by the use of a strain gauge load cell. This method has the advantage of increasing measurement accuracy, since no moving equipment is used. Laboratory test of the instrument was recorded 0.4% error of 190mm rainfall amount. The validity of new instrument was examined by comparing its measured values with values recorded by automatic weather station on June 24 to 25 2001 at Daegu Meteorological Station, when there is 148.3mm rainfall amount. In spite of much rainfall there is only 0.77mm difference of total rainfall amount. This instrument was accomplished high accuracy and resolution at field test in much rainy day.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.607-614
• /
• 2000

A cost-effective automated slope monitoring system is developed to monitor hazardous cut slopes along highways. This automated slope monitoring system consists of data-collection and visual monitoring, data-transmitting, database and internet service, and alarm system. Wire-line extensometer, automatic raingauge, and CCD camera are selected as monitoring instruments in this system, after consideration of failure characteristics of roadside cut slopes in the country. This paper describes the important features of this newly developed automated slope monitoring system.

• Journal of Wetlands Research
• /
• v.16 no.1
• /
• pp.103-112
• /
• 2014

Area average rainfall estimation is important to determine the exact amount of the available water resources and the essential input data for rainfall-runoff analysis. Like that, the necessary criterion for accurate area average rainfall estimate is the uniform spatial distribution of raingauge network. In this study, we suggest the spatial distribution evaluation methodology of raingauge network to estimate better area average rainfall and after the suggested method is applied to Han River and Geum River basin. The spatial distribution of rainfall network can be quantified by the nearest neighbor index. In order to evaluate the effects of the spatial distribution of rainfall network by each basin, area average rainfall was estimated by arithmetic mean method, the Thiessen's weighting method and estimation theory for 2013's rainfall event, and evaluated the involved errors by each cases. As a result, it can be found that the estimation error at the best basin of spatial distribution was lower than the worst basin of spatial distribution.

• Journal of Korea Water Resources Association
• /
• v.36 no.2
• /
• pp.173-181
• /
• 2003

This study has evaluated the raingauge network of Nam-Han River Basin by assuming that the rainfall field is homogeneous in space and its spatial correlation structure is exponential. The results of the study was compared with the standard of WMO. Summarizing the results are as follows: (1) The Nam-Han River Basin is not the mountain area, nor the plain area of the WMO standard. However, the correlation length of the downstream part is longer than that of the upstream part, enough to differentiate the rainfall fields in both areas. (2) It seems that the standard for the evaluation of the raingauge network of Nam-Han River Basin should be decided to represent upper 50% of correlations derived, when the maximum intervals between neighboring gauges are estimated to be 18.2km for the upstream area and 21.1km for the downstream area. Simply evaluating the raingauge density, the Nam-Han River Basin has enough raingauges exceeding the WMO standard for the mountain area in the temperate region. (3) Evaluation of the spatial distribution of raingauges in the Nam-Han River Basin shows that its spatial distribution Is not in a proper level, especially when applying the WMO standard for the mountain area in the temperate region. However, when applying the new standard proposed in this study, only five to six more raingauges are required to be added.

• Water for future
• /
• v.48 no.9
• /
• pp.36-49
• /
• 2015

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2016.09a
• /
• pp.91-93
• /
• 2016