Standard Rain Gauge Research Articles

Investigation of process of interception in beech-fir stand on mountain Goch

Part of the precipitation is intercepted by vegetation before reaching the ground. The portion of intercepted water, which is retained in storage of the vegetal cover and evaporates, is called the interception loss. Interception represents important component of water balance, because of reduction of total rainfall. It decreases potential for forming of surface runoff. Depends on complex of vegetative and climate factors. In humid forested regions about 25% of the annual precipitation may become interception loss. Results of investigation in beech-fir stand on mountain Goch are presented in this paper Investigation was carried out on experimental catchment area Vaona IV (A=0.098 km2), in association Abieti-fagetum, on mountain Goch, in Central Serbia. Standard rain gauges were used to determine total precipitation and throughfalls, during vegetation period (1992-1997). Total interception (Ic) depends on total precipitation (Pb), kind of trees, shape and density of the crown, position in the stand and age. Average values of interception (Icsr) during vegetation period (1992-1997), amount to Icsr=43.7-53.3% of total precipitation (fir), and Icsr=17.7-22.8% (beech).

Water balance and nutrient inputs in bulk precipitation in tropical montane cloud forest in Panama

The hydrological balance and nutrient inputs in water were measured in a lower montane rain forest (1200m) in Panama. Rainfall and throughfall were measured daily between July 1988 and July 1989 using a standard rain gauge and 50 longitudinal PVC collectors, respectively. Stemflow was measured daily between November 1990 and December 1991 in nine trees varying from 16 to 54cm diameter at breast height (dbh), using tygon collars. Rainfall and throughfall water samples were collected every 15 days between January and October 1989 for chemical analyses (pH, conductivity, NO3−, NO2−, NH4+, PO43−, SO42−, Ca2+, Cl−, Mg2+, K+, Mn, Fe and Si). Bulk precipitation was 3510mm. Interception was 37.2%, net precipitation was 62.8%, of which, throughfall was 62.4% and stemflow was 0.4%. The probability distribution of throughfall as a proportion of bulk precipitation, showed that 82% of the total variability is lower than a bulk precipitation value of 1.0 and that there are higher values in this mountain forest than in a lowland rain forest in Brazil were this value was also calculated, suggesting that the canopy of this montane forest is more heterogeneous. In only 6 of 140 of the rain events, was net precipitation higher than bulk precipitation, suggesting that direct inputs of cloud water by fog interception, is not an important water source for this forest. Interception at Fortuna is the highest value yet reported for a tropical montane rain forest; it maybe attributed to a very tall canopy (20–30m) and abundant epiphyte load. Nutrient inputs in water varied from 0.70kgha−1 per year of PO4-P to 34.5kg ha−1 per year of Cl. Leaching varied from 1.45kg ha−1 per year for PO4-P to 49.71kgha−1 per year of K. Net absorption by the canopy was measured for S (−7.0kgha−1 per year SO4-S) while for N the total annual input was about the same as the annual throughfall. Annual fluxes of calcium, sodium and potassium in bulk precipitation in the Fortuna forest were in the upper range of values reported for other tropical montane sites, perhaps owing to the proximity to the Caribbean Sea. Nutrient inputs of N, P and K in throughfall are consistent with inputs of throughfall relative to other nutrient pathways in tropical and temperate forests. © 1997 Elsevier Science B.V.

Rainfall Measurement in Canada: Changing Observational Methodsand Archive Adjustment Procedures

Abstract Precipitation is one of the key components in hydrologic modeling and process studies; however, it is widely recognized that significant errors in the measurement of precipitation exist. During its 150-yr history, the Canadian Meteorological Service has employed a number of different precipitation gauges to measure rainfall. This paper will focus on documenting the types of gauges used in rainfall measurement over this period. Systematic errors in gauge catch such as wetting loss, wind-induced error, and trace precipitation, which are a result of method of observation and/or gauge design, have been quantified through field and laboratory experiments. A proposed method of adjusting six hourly archived rainfall data (i.e., 1947–present) to provide a compatible and consistent rainfall record is described. The combined magnitude of the adjustments for the systematic errors quantified for certain standard raingauges can exceed 7%. Results indicate that scientists assessing climate change by using mont...

A field study of orographic precipitation anomalies during high velocity winds using an aerofoil rain gauge

This study was prompted by a need to explain an anomaly in the apparent precipitation distribution over a prominent mountain subject to a high velocity westerly airstream. Historical data reveal that the lee receives 58% more precipitation than the summit. A novel rain gauge with a vertically orientated collecting orifice, 3 standard rain gauges and complementary wind data were procured from 3 sites on the mountain to assess the effect of the airstream on the precipitation distribution. The catch efficiency of standard rain gauges decrease after the wind velocity exceeds 2.5 ms−1 Results indicate that the summit actually receives 59% more precipitation than the lee, where a vortex directly affects the precipitation distribution over, and east, of the mountain.

Small area variability of warm-season precipitation in a semiarid climate

The spatial variability of precipitation, as measured with standard rain gauges spaced 800–4400 m apart, was studied at Swift Current, Saskatchewan, Canada over a 34-year period. Spatial variability, relative to precipitation amount, was greater for small storms of less than 7.5 mm than for larger storms. The probability of the difference in measured precipitation for a storm exceeding a set amount increased approximately linearly with the separation distance between rain gauges although this trend weakened as the size of the difference increased. In several years, measured differences in cumulative precipitation during the growing season indicated important differences between rain gauge locations in growing conditions for spring-sown cereal crops. The probability of the measured difference in cumulative precipitation during the growing season exceeding a set amount increased approximately linearly with the separation distance between rain gauges. Where knowledge of precipitation amount is very important for small-plot biological field experiments, precipitation should be measured at or within a few hundred metres of the experiment site. However, where monthly areal estimates of warm-season precipitation are required, there was little reason for gauging densities of less than 2.6 km 2 per rain gauge.

Cokriging radar‐rainfall and rain gage data

An ordinary cokriging procedure has been developed to optimally merge rainfall data from radars and standard rain gages. The radar‐rainfall data are given in digitized form. The covariance matrices required to perform cokriging are computed from single realization data, using the ergodicity assumption. Since the ground truth and the error structure of the radar data are unknown, parameterization of the covariance between radar data and the true rainfall is required. The sensitivity of the procedure to that parameterization is analyzed within a controlled simulation experiment. The experiment is based on a hypothesized error structure for the rainfall measurements. The effect of measurement noise and network density is examined. The usefulness of the procedure to remove the bias in radar is tested. Daily data are used.

Atmospheric deposition to remote receptors I. Precipitation quantities from the Ilwas-network

A dense precipitation network was operated for 45 mo in three remote watersheds in the Adirondack Park of New York State. The network consisted of 4 to 7 wet/dry collectors spaced 3 m to 30 km apart; network operation was on an event basis. The chief objective was an accurate determination of atmospheric inputs into the three watersheds and an assessment of intra- and interbasin variability. Approximately 96% of all possible events were captured. One of the watersheds, Sagamore, received from 6 to 36% less precipitation on a seasonal basis. The capture efficiency relationship between volume collected and standard rain gauge was quantified and shown to be a function of precipitation quantity, type, and sampler location.

Observations on the Geomorphic Significance of Tunnel Erosion in a Semi-Arid Ephemeral Drainage System

Observations on the Geomorphic Significance of Tunnel Erosion in a Semi-Arid Ephemeral Drainage System

Real-Time Estimation and Forecasting of Spatially Distributed Areal Rainfall

After a short demonstration about the need for operational rainfall forecasts, a literature survey, constraints for model development and definition of criteria of model performance a simple multi-variate autoregressive model is presented that forecasts point rainfall spatially distributed, for short lead times, quantitatively and automatically. For model operation only remotely transmitted standard raingage data is necessary. The model is expanded to forecast and estimate also areal rainfall from point measurements using the Kaiman filter technique and the theory of regionalized variables. It is demonstrated that the Kaiman filter model is superior for areal rainfall estimation (compared to the Thiessen procedure) as well as for areal rainfall forecasting compared to trivial forecasts and the point forecasting model mentioned above.

DISCUSSION1: “Sampling Accuracy of Pit vs. Standard Rain Gages on the Fernow Experimental Forest,”

JAWRA Journal of the American Water Resources AssociationVolume 20, Issue 2 p. 275-276 DISCUSSION1: “Sampling Accuracy of Pit vs. Standard Rain Gages on the Fernow Experimental Forest,” J. D. Helvey, J. D. HelveySearch for more papers by this authorJ. H. Patric, J. H. Patric Paper No. 82079 of the Water Resources Bulletin 19(1):87-89.Search for more papers by this authorJohn A. Kay, John A. Kay Senior Hydrologist, Dames & Moore, The Limes, 123 Mortiake High Street, London SW14 8SN, United Kingdom.Search for more papers by this author J. D. Helvey, J. D. HelveySearch for more papers by this authorJ. H. Patric, J. H. Patric Paper No. 82079 of the Water Resources Bulletin 19(1):87-89.Search for more papers by this authorJohn A. Kay, John A. Kay Senior Hydrologist, Dames & Moore, The Limes, 123 Mortiake High Street, London SW14 8SN, United Kingdom.Search for more papers by this author First published: April 1984 https://doi.org/10.1111/j.1752-1688.1984.tb04684.x 1 Discussion No. 83208D of the Water Resources Bulletin. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume20, Issue2April 1984Pages 275-276 RelatedInformation

DISCUSSION: “Sampling Accuracy of Pit vs. Standard Rain Gages on the Fernow Experimental Forest”2

JAWRA Journal of the American Water Resources AssociationVolume 20, Issue 2 p. 277-278 DISCUSSION: “Sampling Accuracy of Pit vs. Standard Rain Gages on the Fernow Experimental Forest”2 John A. Kay, John A. Kay Discussion No. 83208D of the Water Resources Bulletin 20(2):275-276.Search for more papers by this authorJ. D. Helvey, J. D. Helvey Project Leader, Watershed Management Research, Northeastern Forest Experiment Station, Timber and Watershed Laboratory, Box 404, Parsons, West Virginia 26287.Search for more papers by this author John A. Kay, John A. Kay Discussion No. 83208D of the Water Resources Bulletin 20(2):275-276.Search for more papers by this authorJ. D. Helvey, J. D. Helvey Project Leader, Watershed Management Research, Northeastern Forest Experiment Station, Timber and Watershed Laboratory, Box 404, Parsons, West Virginia 26287.Search for more papers by this author First published: April 1984 https://doi.org/10.1111/j.1752-1688.1984.tb04685.xCitations: 1 2 Paper No. 82079 of the Water Resources Bulletin 19(1):87-89. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume20, Issue2April 1984Pages 277-278 RelatedInformation

SAMPLING ACCURACY OF PIT VS. STANDARD RAIN GAGES ON THE FERNOW EXPERIMENTAL FOREST1

ABSTRACT: Catch in standard (unshielded) rain gages exposed 3 feet above the land surface was compared with catch in pit (buried) gages exposed 1 inch above the land surface. These tests confirmed that catch in standard gages under estimates point rainfall in forest openings, as well as in conventional weather stations. Pit gages caught significantly (P=0.05) more rain than did standard gages at each of four locations tested. Catch increases ranged from 2.3 to 3.4 percent.

FOG DRIP IN THE BULL RUN MUNICIPAL WATERSHED, OREGON1

ABSTRACT: Net precipitation under old growth Douglas fir forest in the Bull Run Municipal Watershed (Portland, Oregon) totaled 1739 mm during a 4Cbweek period, 387 mm more than in adjacent clearcut areas. Expressing data on a full water year basis and adjusting gross precipitation for losses due to rainfall interception suggest fog drip could have added 882 mm (35 in) of water to total precipitation during a year when precipitation measured 2160 mm in a rain gage in a nearby clearing. Standard rain gages installed in open areas where fog is common may be collecting up to 30 percent less precipitation than would be collected in the forest. Long term forest management (Le., timber harvest) in the watershed could reduce annual water yield and, more importantly, summer stream flow by reducing fog drip.

Prediction of throughfall quantities under different forest stands

The quantitative distribution of throughfall in fertilizer-treated and control plots under six softwood and three hardwood stands and rainfall in open areas close to these stands were intensively measured during 1977–1978. Standard rain gauges and improvised funnel-type collectors were used for measuring both throughfall and rainfall in the open. The improvised funnel-type collectors with an orifice smaller than that of the standard rain gauges were found to be suitable for accurately measuring quantities of both open rainfall and throughfall. Simple linear regression models of the form Y = b − a were sufficient to predict throughfall quantities (Y) based on rainfall (X) measurements. The relationship between the quantities of throughfall and rainfall was highly significant in each case. Application of urea at a rate of 225 kg N ha−1 did not affect either the slope (b) or the elevation (a) of the relationship. No significant differences were found between the relationships calculated for 1977 and 1978 for any species except balsam fir (Abiesbalsamea (L.) Mill) and larch (Lurixlaricina (Du Roi) K. Koch). The difference for balsam fir was probably a result of extensive defoliation by the spruce budworm (Choristoneurafumiferana (Clem.)). In most cases, values of the slopes (b) of the models for the different species were not significantly different. The nine species did, however, differ significantly from one another in terms of the minimum quantity of rain (a/b) that must fall before throughfall was measurable in the collectors.

Regional water balance on the Arctic Tundra in summer

The regional distributions of evaporation and precipitation were investigated on the arctic tundra on Axel Heiberg Island, Northwest Territory, Canada, during the summers of 1969 and 1970. The measurements were made using small weighing lysimeters and Canadian standard rain gauges installed at eight locations ranging in altitude from the sea level to 800 m above mean sea level. The mean evaporation rate for the snow‐free period increases slightly with altitude. The total evaporation for the snow‐free period at high altitudes, however, is cut short due to the longer duration of the snow cover. Consequently, the total summer evaporation shows a maximum value in the altitude zone between 100 and 600 m. Summer total precipitation increases steadily with altitude, exceeding evaporation at about 500 m. Below this altitude, most of the annual runoff takes place during and immediately after the melt of the winter snow cover. At higher altitudes, runoff is observed throughout summer.

Forage Plantings on Six Arizona Pinyon-Juniper Subtypes

Forage Plantings on Six Arizona Pinyon-Juniper Subtypes

A field evaluation of the Hasl wet-dry deposition collector

Samples of precipitation, dry deposition and total deposition have been obtained from Tutuila Island, American Samoa, since April 1976. These collections are part of a study of global levels of pollutants. The volume of rain water collected by a HASL wet/dry collector has averaged within 4% of the volume expected based on data obtained using a standard rain gauge. The deposition of Cl−, SO 4 −2 , NA+. Mg−2 and K+ in the total collector, which is exposed continuously to the atmosphere, is about 10% greater than the deposition in the wet plus dry sides of the HASL collector.

Development of a self‐sealing rain sampler for arid zones

Owing to evaporation from standard rain gauges in arid zones the natural isotopic abundance of deuterium and oxygen 18 in rainwater may not have been correctly determined in the past. A single‐stage rain sampler has been developed involving the use of a hermetic seal to help eliminate the evaporation problem. This gauge provides a suitable sample for isotopic analysis. A multiple‐stage rain sampler has been developed to enable the collection of successive rainfall fractions within a particular storm. Instruments of both types were distributed throughout the Negev Desert in Israel. Results from 2 years of observations involving 20 storms indicate the efficiency and reliability of the instruments developed.

Use of a Standard Raingage as a Precipitation Chemistry Collector (Comments on “The Effect of Some Meteorological Parameters on the Chemical Composition of Precipitation at the University Field Station, Trinidad, West Indies”)

Use of a Standard Raingage as a Precipitation Chemistry Collector (Comments on “The Effect of Some Meteorological Parameters on the Chemical Composition of Precipitation at the University Field Station, Trinidad, West Indies”)

Experimental Results with a Rain Analyzer

Abstract The rain analyzer is an instrument with which the main part of the raindrop size spectrum can be determined. During measurements of the rain attenuation of millimeter waves, rainfall was recorded both with rain analyzers and with standard rain gages. The observed millimeter-wave attenuation is somewhat more directly related to rainfall rates obtained with the analyzer than to those measured with rain gages. The average drop-size distribution measured during the experiment is similar to that of Laws and Parsons.