Recording Rain Gauges Research Articles

Nutrient input by rainfall into secondary forests in East Kalimantan, Indonesia

Nutrient input by rainfall into secondary forests in East Kalimantan, Indonesia, was measured. Two investigation plots were installed, the first was situated at Lempake and the other one at Bukit Soeharto Protection Forest both close to Samarinda. Both sites are covered by secondary forests. The size of each plot was 50 x 50 m. In Table 1 some characteristics of the study sites are listed. Isolated rainfall events were measured and sampled under the forest canopy and in a nearby open area (100 m at Bukit Soeharto resp. 400 m distance at Lempake). For measuring throughfall, gutters (4 m long) were used. Each gutter discharged into its own measuring device (non recording). Rainfall in the open area was measured using a standard recording raingauge. The number of gutters used per measuring area depends on the heterogeneity of the crown canopy. The higher the variation in the canopy the more measuring devices are needed. In this case the heterogeneity was rather moderate and ten gutters were subjectively-randomly installed for measuring throughfall. Stemflow was measured by the standard method of collars running around the stem. The precipitation depth due to stemflow hn was estimated by the formula (DVWK 1992):

Hydrologic Response of a Karst Watershed

A ground water catchment was instrumented as a karst hydrology and water quality laboratory to develop long-term flow and water quality data. This catchment located in Woodford and Jessamine Counties in the Inner Bluegrass, Central Kentucky encompasses approximately 1620 ha, 40 water wells, over 400 sinkholes, 2 karst windows, and 1 sinking stream. The land uses consist of approximately 59% beef pasture, horse farm, and golf course; 16% row crops; 6% orchard; 13% forest; and 6% residential. The instrumentation consisted of a recording rain gage, an H-flume, a water stage recorder, and an automated water sampler. Flow data for 312 days were analyzed, and a peak flow rate prediction equation, specific to this catchment, was developed. Recession curves were analyzed and found to be of two distinct mathematical forms, log curves and exponential curves. Prediction equations were good for the log-type recession curve and fair for the exponential-type recession curve. For the exponential recessions, the peak flow rate was found to be bimodally distributed. The recession events were classified as either high flow or low flow, with the point of separation at 113 L/s. It was hypothesized that the flow system was controlled by pipe flow above 113 L/s and by open channel flow below 113 L/s. Subsequent analysis resulted in adequate prediction for the low flow events. Explained variation associated with the high flow events was low and attributed to storage in the karst system that was not incorporated into the predictor equation.

Comparative assessment of several rainfall erosivity indices in Southern Nigeria

Soil erosion, measured in field runoff plots, was correlated with several rainfall erosivity indices. Erosion was measured on field plots established on a Typic Paleudult in southeastern Nigeria. Several erosivity indices were computed from a daily recording rain gauge sited in vicinity of the runoff plots. Erosivity indices computed included EI30 (WISCHMEIER & SMITH 1978), KE>1 (HUDSON 1971) and AIm (LAL 1976). In addition, several new indices were computed including EkIm and EkI30, where, the new kinetic energy (Ek) factor was computed using an empirical relation developed by KOWAL & KASSAM (1976) in northern Nigeria. Two new indices were slightly better correlated with soil erosion than the conventionally used indices.

Quality of stormwater runoff from an urbanised watershed

A field monitoring network was set up within the Stamford canal watershed in 1989 to study both the quantitative and qualitative aspects of storm runoff from this urbanised catchment. The data acquisition equipment comprised a continuous recording rain gauge, a water level recorder and an automatic water sampler capable of sampling storm runoff at preset intervals during rainfall events. Water samples were collected after each storm and laboratory tests were carried out on the physical and chemical properties of the storm water. Preliminary findings on the temporal variations of stormwater quality during single storms and the effects of antecedent dry weather period on the quality are presented. The average ranges of some of the significant quality parameters found in the storm runoff were also established. The quality of storm runoff from the catchment under study was found to be of an acceptable level and could potentially be developed as a water catchment area.

Short‐Duration Rainfalls in Sicily

The Italian Hydrographic Service publishes yearly maximum rainfall depths with 1-, 3-, 6-, 12-, and 24-hr duration, recorded by recording rain gauges. It also publishes selected short-duration (t<1 hr) rainfall amounts. It is impossible to carry out a statistical analysis of the short-duration rainfalls for each recording rain gauge because the published data correspond to different record durations and to different recording rain gauges from year to year. Therefore, there is a practical need to derive empirical relationships between the 1-, 3-, 6-, 12-, and 24-hr duration amounts and shorter duration (t<1 hr) rainfall amounts. Such a relationship has been proposed by Bell and has been verified using rainfall data in the United States, South Africa, and Australia. In this technical note we study the applicability of Bell's rainfall-duration relationship in Sicily and Sardinia. Then, using mean values of the ratio between the depth of rainfall occurring in t min and that occurring in 60 min, we obtain, for...

Rainfall Intensities for Southeastern Arizona

Small watershed storm runoff in the southwestern United States is dominated by intense, short-duration convective rains of limited areal extent. Most commonly, flood peak estimates are based on rainfall predictions found in the National Oceanic and Atmospheric Administration (NOAA) Atlas 2, a precipitation-frequency atlas for the Western United States. Records of short-duration rainfall (5 to 30 min. duration) from a dense network of recording rain gauges in southeastern Arizona indicate that flood peaks based on NOAA Atlas 2 for less frequent events (50-yr. and 100-yr. frequencies) for small watersheds are underestimated.

Ground-Based, High-Resolution Measurements of the Spatial and Temporal Distribution of Rainfall

Abstract Preliminary data from ground-based measurements of rainfall using an optical disdrometer and high-resolution rain gage network are described. The recurrence of the rain period is shown to be non-Poisson with evidence of clustering, whereas a lognormal distribution is shown to be an approximate fit to the distribution of amount of rainfall in a rain period. About 40% of rain periods possess a total rainfall smaller than that resolvable by conventional recording rain gages; three-quarters of these were resolvable by the high-resolution rain gages used. Rapid fluctuations of rainfall intensity (∼1 mm h−1 s−1) are evident in individual rainfall intensity records and the distribution of duration of rainfall above a specified threshold intensity is shown to be approximately lognormal; these observations are consistent with a lognormal distribution of precipitation region sizes. An empirical fit to the average fractional duration of rainfall is given, although the curve is generally a poor fit to fracti...

Analysis of Recording Raingage Data for the Israeli II Experiment. Part II: Differential Day and Night Effects of Cloud Seeding

This paper reports separate analyses of daytime and nighttime precipitation based on data from recording raingages of the second Israeli randomized experiment. These analyses seemed important because there are a number of hypotheses on the differential effects of AgI seeding during the day and at night, and because about half of the seeding of this experiment was done at night. Our findings are unfortunately equivocal because of the large variability of the date which had to be broken down by categories of modal cloud-top temperatures and 12-b (day/night) periods. The increase of precipitation efficiency that had been noticed (on 24-h data) to occur in the −12° to −21°C window appears to have been larger at night, but the difference is not significant. The increase in the number of rain events for warmer clouds may have been only a daytime effect, but again, the present data are not conclusive.

Analysis of Recording Raingage Data for the Israeli II Experiment. Part I: Effects of Cloud Seeding on the Components of Daily Rainfall

Earlier Published analyses of the second Israeli randomized experiment (1969–75) were restricted to 24-h data; this paper provides more details which are based on continuous time data from recording raingages. The present analyses confirm that when cloud tops were warmer than −21°C, seeding increased the efficiency of precipitation. In the −21° to −11°C window, both amount and duration of rainfall increased by some 50%, but no extra rain events appeared. Extra rain events were apparently initiated by seeding when cloud-top temperatures were warmer (−11°C and above); however, this did not significantly increase the amount of rainfall. No effect of seeding was found when cloud tops were colder than −21°C. It appears that seeding makes the existing process of rain formation more effective and also inducts precipitation formation in some clouds that would not have precipitated naturally.

Rainfall intensity for local drainage design in Lucknow and its neighbouring area

The primary object of this study is to analyse rainfall data for working out design storm estimates for the design of urban drainage system. The probable rainfall has been statistically estimated by analysing the rainfall data recorded by 24 ordinary raingauge (ORG) stations and 3 self recording rain gauge (SRRG) stationi1 falling in and around the area enclosed by 0.50 latitude and 0.50 longitude around Lucknow. The various aspects studied are :&#x0D; (a) Temporal distribution of rainstorms over the said area and&#x0D; (b) Depth duration frequency analysis of rain storms for durations upto (6 hours anti for 2 and 5 years return periods.&#x0D;

Design and Performance of an Exposure System for Measuring the Response of Crops to Acid Rain and Gaseous Pollutants in the Field

During 1982-1984, experiments regarding the nature of crop responses to combinations of acid rain and gaseous pollutant treatments were conducted. Open-top field chambers were used in conjunction with an automatic rain exclusion-simulant distribution system to expose crops to controlled levels of gaseous pollutants and rain acidity in a field setting. Rain exclusion was achieved by automatically moving covers over the experimental plots at the onset of a rain event. The simulant distribution system was automatically activated after 0.25 mm of rain was collected in a recording rain gauge located adjacent to the experimental plots. Rain simulants were dispensed through nozzles until the amount deposited within the plot equaled that deposited by the natural rain outside the plot. The system was capable of dispensing rain simulants with three levels of acidity to ambient air plots and to charcoalfiltered and nonfiltered-air chambered plots. The ability to automatically dispense rain simulants during, and in e...

Surface Deposition of Lead and Cadmium from the Atmosphere in the Detroit River—Lake St. Clair Region

The research reported here forms part of a large multidisciplinary study of four toxic contaminants — lead, cadmium, PCBs, and octachlorostyrene in the Essex region of southwestern Ontario. The purpose of this part of the project is to quantify the atmospheric loading of the metallic contaminants. A bulk precipitation sampler, wet-only precipitation sampler, and recording rain gauge were installed at an urban and rural site. Results from 2 years of data indicate that atmospheric loading of lead is 40–50 times that of cadmium in the city and 16–40 times that of cadmium in the rural areas. Lead loadings in the city were found to be 2–4 times higher than in the rural areas, while cadmium loadings appeared to be similar in both areas. Concentrations of the metals are higher in winter than in summer, but because of higher summer precipitation surface loadings are similar in both seasons. Preliminary statistical analysis indicates that concentrations of the metals are related to intensity and amount of precipitation but not usually to wind direction.

Wetfall chemistry studies around a large coal‐fired power plant in the southeastern United States

A wetfall chemistry study was conducted within a 15‐km radius of a large coal‐fired power plant in the southeastern United States. The study was conducted during the winter of 1981 and included event precipitation sampling on a dense network of 31 stations, selected air chemistry monitoring at two sites, and extensive meteorological measurements. The precipitation samples were analyzed for all major inorganic ionic species, including dissolved sulfur dioxide. The meteorological network included a preexisting network of 49 recording rain gages and four surface windsets, the power plant's fully equipped meteorological station, and a bistatic acoustic sounder. This paper presents the results from five of the sampled storms. Plume washout is evident in most target area samples, and sulfur, hydrogen ion, and chloride ion were found to be the predominant plume‐related species. Concentrations in the affected regions exceeded the background levels by up to 100% in the case of sulfur and of hydrogen ion, and by up to 145% in the case of chloride ion. Two of the storms were characterized by excess dissolved SO2 amounts in the target samples; for these storms, scavenging model simulations of dissolved SO2 concentrations indicated that deposition of sulfur by SO2 scavenging within 12 km was probably less than 2% of the total emitted. Based on the measured Cl− in rainwater, an estimate of the source strength (coal Cl content) using conventional gas scavenging theory appears reasonable.

Estudo da interceptação da água de chuva em cobertura florestal amazônica do tipo terra firme

Resumo Em experimento conduzido junto à Reserva Florestal Ducke, situada a cerca de 26 km da cidade de Manaus, quantificou-se a parcela da água de chuva interceptada pela cobertura florestal. No seu desenvolvimento, foram empregados um pluviógrafo. localizado a 20 m da floresta e 20 pluviómetros instalados no interior da mata. Os resultados obtidos mostraram que. do total da chuva precipitada no período, cerca de 19,8%, em média foram interceptados pela cobertura florestal.

Évaluation de l'intensité de pluies des espaces à données manquantes

The results obtained by processing the data of conventional and recording rain gages are presented. These were used for deriving a relationship of general validity by which rain intensities can be estimated for certain regions with incomplete data. The data of rain gages with long (round 20 years) records available were examined to approximate the empirical distributions of annual greatest rainfalls of different (1, 2, ... 6, 12 days) durations by different distribution functions. Along with the observation data, the charts of recording rain gages were also processed and analysed, determining as accurate1y as the chart would permit the rain intensities by 30' time intervals for the period on record up to 1974. (During the last years the 30/ intervals could be resolved into 5 and 15 minutes) In the way, 10-20 years intensity time series were produced for round 10 stations. From the charts of the individual stations, we have determined the rain intensities of different probability during the annual maxima of 0.5, 1, 2 ... hours and 1, 2, ... 6, 12 days duration. In an intensity vs. time diagram these values plotted to a straight line (Fig. 1), implying that the rain intensities of short (few hours) and longer (few days) duration are described by a single function at a particular station. This result can be extended to rain gaging stations (having no recording gage), where a sufficient1y long observation record is availab1e. By extrapolating the function it is thus possible to estimate the intensity of rains shorter than one day for a particular station. The slope of the rain intensity functions was found to be related to the normal average annual rainfall at the station. The functions at stations with little annual rainfall were very steep relative to the fiat functions of the stations with abundant rainfall (Fig. 2).

Forage Plantings on Six Arizona Pinyon-Juniper Subtypes

Forage Plantings on Six Arizona Pinyon-Juniper Subtypes

A depth‐area‐duration model of storm rainfall in the Southern Great Plains

A depth‐area‐duration model for Oklahoma rainstorms was developed using 10 years of data from a dense network of recording rain gages covering a 3885‐km2 area. A nonlinear least squares procedure was used to fit the data to the model. The model developed can be used to convert storm center point rainfall amounts to mean rainfall in areas up to 3100 km2 and durations up to 24 hours. The model seems to have predictive value, especially for storms occurring in the Great Plains. Comparison of the model curves with actual depth‐area curves for two storms, Black Hills, South Dakota, and north central Oklahoma, showed that the model‐simulated depth‐area curves were within the experimental error of model development. Data from a network of gages located in the Chicago urban area were used to evaluate the model parameters with similar results.

Meteorological Analysis of an Oahu Flood

Abstract A detailed study has been made of the severe Oahu rainstorm 19 April 1974 and its implications for the Hawaii flood forecast problem. Data from Qahu's extensive recording raingage network were analyzed to determine the mesoscale structure of the precipitating cloud systems. Study of a special rain and stream gage network in Moanalua Valley showed that the current Hawaiian detection scheme based on one telemetered raingage per watershed is inadequate. Raingage data were incorporated with available conventional meteorological observations to construct a conceptual model of the flood-producing convective regime of 19 April. It was concluded that orography played an essential role in the persistence of major thunderstorm activity.

Study on the estimate of precipitation with the help of S-band at radar Calcutta

An attempt has been made to study the amount of rainfall associated with the severe cyclonic storm of 14-16 August 1974 with the help of the S-band radar installed at Calcutta. The first two modes of the gray scale, viz. gray and white shades were utilised in this study. It has been found that these modes correspond fairly well with the rates of rainfall recorded at these recording rain gauge stations, and rainfall reported by ordinary rain gauge stations within a radius of 200 km around Calcutta, Isogram analysis of the rates of rainfall at a particular time has also been made and the results compare fairly well with the radar photographs at the corresponding time.

Soil erosion on Alfisols in Western Nigeria: III. Effects of rainfall characteristics

The applicability of various erosivity indices was tested for runoff and soil loss from plowed bare-fallow field runoff plots of 25 × 4 m established on an Alfisol with natural slopes of 1, 5, 10 and 15%. The correlation coefficients of percent runoff from individual rainstorms with various indices such as kinetic energy ( E), EI 30, KE > 1, rainfall amount ( A), maximum intensity ( I m), and AI m, were generally low. The correlation coefficients of all these indices with soil loss per storm were high and did not differ significantly from one another. The use of an empirical relation (kinetic energy = 916 + 331 log 10, I is in inches/h) may underestimate the kinetic energy of tropical rainstorms. The kinetic energy of tropical rainstorms may be significantly influenced by other factors such as wind velocity, drop size distribution and high rainfall intensity. The index AI m has the advantage of simplicity of computation, and it incorporates one of the most important factors, peak intensity ( I m). Further improvements can be made in this index by incorporating a factor which accounts for the kinetic energy of a rainstorm. In the meantime, the index, AI m, may be used to prepare an “iso-erodant” map, i.e. places with equal erosion potential. There also exists a linear correlation between rainfall amount per storm and AI m. Such a relationship may be useful in estimating AI m for regions where data from recording rain gauges are not available.