Influence of raindrop size on rainfall intensity, kinetic energy, and erosivity in a sub-humid tropical area: a case study in the northern highlands of Ethiopia

2018 ◽  
Vol 136 (3-4) ◽  
pp. 1221-1231 ◽  
Author(s):  
Derege Tsegaye Meshesha ◽  
Atsushi Tsunekawa ◽  
Nigussie Haregeweyn
1984 ◽  
Vol 16 (8-9) ◽  
pp. 271-283
Author(s):  
Rafael G Quimpo ◽  
Ali-Bux Brohi

The washoff of pollutants from urban surfaces by storm events depends on the kinetic energy of storms. In order to determine the erosive power of rainfall, data on raindrop size distributions were analyzed and the kinetic energy expressed as a function of rainfall intensity. Results indicate that the regression equation that is currently used to determine storm erosive power from rainfall intensity needs to be revised.


2013 ◽  
Vol 772 ◽  
pp. 461-466
Author(s):  
Yi Jun Huang ◽  
Yu Yu Huang

Filter paper splash procedure is a kind of measuring means to raindrop size. It is used widely and operated briefly and its cost is low. The article mainly introduces the influence of different heights to the stain diameter and the relationship between stain diameter and the raindrops. According to the experiment, the relation between the stain diameter and the raindrops is d=0.478D0.610.it is the research foundation of filter paper stain method. According to the data from Fangxian area using the method of filter paper splash procedure, we can conclude that the raindrop kinetic energy has a positive relationship with rainfall intensity. The research is useful for measuring the water and soil loss.Water and soil loss is one of the global environment problems. The most important factor which can cause water and soil loss is rainfall. The research on raindrop kinetic energy is important for the further analysis of water and soil loss. A classical approach for the research on raindrop kinetic energy is paper splash procedure. The relationship between stain diameter and raindrop diameter shall be calibrated in this approach. In general, influences from titrated water drop height and stain diameter are not considered in the calibration process. In this experiment, influences of rain drop height on stain diameter are researched in the stain calibration, settling basis for the research on local volume of water and soil loss.


2002 ◽  
Vol 261 (1-4) ◽  
pp. 1-23 ◽  
Author(s):  
A.I.J.M van Dijk ◽  
L.A Bruijnzeel ◽  
C.J Rosewell

2021 ◽  
Vol 26 (5) ◽  
pp. 05021005
Author(s):  
Amin Mohebbi ◽  
Simin Akbariyeh ◽  
Montasir Maruf ◽  
Ziyan Wu ◽  
Juan Carlos Acuna ◽  
...  

2020 ◽  
Vol 5 (1) ◽  
pp. 56-60
Author(s):  
Wildan Gunawan ◽  
Suyitno Muslim ◽  
Imam Arif Rahardjo

This research is aimed to understand the effects of  rain fall and discharge rate towards hydro electric power plant productivity (case study at Kracak Sub Unit HPP, Bogor Regency Jawa Barat). Multiple regression tecnique analysis is used as research method with quantitative approach for describing the effects of rain fall and discharge rate towards hydro electric energy productivity. Based on Sub Unit PLTA Kracak during a highest down pour in June 2018 has gained electrical power about 173,583 kWh for 15,84 mm rain fall and the lowest rain fall in July 2018 is 0,86 mm only obtain 49,772 kWh electrical power with the average rain fall record in three stations is 8,9592 mm. Mean while, for the highest river discharge rate happened in February is 10,08 m3/detik which produce 198,296 kWh electrical power and the lowest in June that only gained 3,53 m3/detik which produce 49,772 kWh electrical power with the average of river discharge rate in 2018 is only 7,9858 m3/detik. The average of electrical power it self is only 156,0105 kWh for 8,9592 mm of rainfall and 7,9858 m3/detik river discharge rate record in 2018. The conclusion oh this research is the discharge rate in headwaters area is affected by rainfall intensity, but not necessarily affected to hydro electric energy productivity.   ABSTRAK Tujuan dari penelitian ini adalah untuk mengetahui pengaruh curah hujan dan debit air terhadap produktivitas energi listrik yang dihasilkan pada pembangkit listrik tenaga air (Studi Kasus: Sub Unit PLTA Kracak, Kabupaten Bogor Jawa Barat). Metode yang digunakan dalam penelitian ini adalah metode deskriptif dengan pendekatan kuantitatif teknik analisis data regresi berganda untuk mendiskripsikan data penelitian curah hujan dan debit air terhadap produktivitas energi listrik yang dihasilkan. Berdasarkan data hasil penelitian yang diperoleh di Sub Unit PLTA Kracak data curah hujan tertinggi pada tahun 2018 di Bulan Juni sebesar 15,84 mm dapat menghasilkan energi listrik sebesar 173,593 kWh dan terendah di Bulan Juli sebesar 0,86 mm dapat menghasilkan energi listrik sebesar  49,772 kWh dengan rata-rata pertahun 2018 yaitu sebesar 8,9592 mm di tiga stasiun. Sedangkan data debit air pada tahun 2018 tertinggi di Bulan Februari sebesar 10,08 m3/detik dapat menghasilkan energi listrik sebesar 198,296 kWh dan terendah di Bulan Juli sebesar 3,53 m3/detik dapat menghasilkan energi listrik sebesar 49,772 dengan rata-rata pertahun 2018 debit air sebesar 7,9858 m3/detik. Dengan rata-rata curah hujan 8,9592 mm dan debit air 7,9858 m3/detik dapat menghasilkan energi listrik rata-rata pertahun 2018 sebesar 156,0105 kWh selama tahun 2018. Dapat disimpulkan curah hujan tidak berpengaruh langsung terhadap produktivitas energi listrik yang dihasilkan sedangkan debit air berpengaruh terhadap produktivitas energi listrik.


2019 ◽  
Vol 23 (2) ◽  
pp. 163
Author(s):  
Syahri Syahri ◽  
Renny Utami Somantri ◽  
Priatna Sasmita

Burkholderia glumae, before mid-2018, is categorized as plant quarantine pest A2 Group 1 that its existence has been detected in Indonesia. B. glumae  has been known to spread in the central production of rice in Java, Sumatra, Borneo dan Sulawesi. This review aimed to explain the strategies for B. glumae detection through its characteristics and to prevent the divergence  of this bacterium in Indonesia. The previous studies reported that the bacteria could reduce yield up to 75% and caused the decrease  of weight-grain or the increase  of empty grain. The disease intensity is affected by environmental and physiological factors such as warm temperature at nighttime and high rainfall intensity. The optimum temperature for the development of the disease is 30–35°C. Moreover, the pathogen could survive at a temperature of 41°C. The tropical area of 32-36°C are suitable for B. glumae. Recently, the effective control of the disease in the field has not been found yet. Meanwhile, early detection of the disease is not yet determined,  even though  it is necessary  to prevent its spread in rice cultivation in Indonesia. Detection of the disease by Agricultural Quarantine Agency as a frontline is needed to check the entry of the disease carried by the import activities of the seed. Detection in the suspected field by protection institutes through frequent surveillance in central production areas of rice should be considered  as an important task.. The effective techniques to prevent B. glumae are the use of resistant varieties, the practice of seed treatments (using antibacterial, bactericide, heat treatment or plant extract), and  the application of oxolinic acid to the crops.


2018 ◽  
Author(s):  
Sandy Hardian Susanto Herho ◽  
Dasapta Erwin Irawan

Sonic anemometer observation was performed on 29 - 30 September 2014 in Ledeng, Bandung to see diurnal variations of Turbulence Kinetic Energy (TKE) that occurred in this area. The measured sonic anemometer was the wind velocity components u, v, and w. From the observation result, it can be seen that the diurnal variation that happened was quite significant. The maximum TKE occurs during the daytime when atmospheric conditions tend to be unstable. TKE values were small at night when atmospheric conditions are more stable than during the daytime.


2020 ◽  
Vol 24 (11) ◽  
pp. 5407-5422
Author(s):  
Qiang Dai ◽  
Jingxuan Zhu ◽  
Shuliang Zhang ◽  
Shaonan Zhu ◽  
Dawei Han ◽  
...  

Abstract. Soil erosion can cause various ecological problems, such as land degradation, soil fertility loss, and river siltation. Rainfall is the primary water-driven force for soil erosion, and its potential effect on soil erosion is reflected by rainfall erosivity that relates to the raindrop kinetic energy. As it is difficult to observe large-scale dynamic characteristics of raindrops, all the current rainfall erosivity models use the function based on rainfall amount to represent the raindrops' kinetic energy. With the development of global atmospheric re-analysis data, numerical weather prediction techniques become a promising way to estimate rainfall kinetic energy directly at regional and global scales with high spatial and temporal resolutions. This study proposed a novel method for large-scale and long-term rainfall erosivity investigations based on the Weather Research and Forecasting (WRF) model, avoiding errors caused by inappropriate rainfall–energy relationships and large-scale interpolation. We adopted three microphysical parameterizations schemes (Morrison, WDM6, and Thompson aerosol-aware) to obtain raindrop size distributions, rainfall kinetic energy, and rainfall erosivity, with validation by two disdrometers and 304 rain gauges around the United Kingdom. Among the three WRF schemes, Thompson aerosol-aware had the best performance compared with the disdrometers at a monthly scale. The results revealed that high rainfall erosivity occurred in the west coast area at the whole country scale during 2013–2017. The proposed methodology makes a significant contribution to improving large-scale soil erosion estimation and for better understanding microphysical rainfall–soil interactions to support the rational formulation of soil and water conservation planning.


Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 443 ◽  
Author(s):  
María Fernández-Raga ◽  
Roberto Fraile ◽  
Covadonga Palencia ◽  
Elena Marcos ◽  
Ana María Castañón ◽  
...  

This paper compares two different geographical sites, Aveiro and León, from different climatic regions, oceanic and continental, but which share the same type of weather (according to Lamb’s classification). The analysis was carried out over one year, and has revealed that rainfall in Aveiro is heavier and more abundant, with a higher number of raindrops and a longer duration of rain events (on average, 10 min longer than in Leon). Mean raindrop size is 0.45 mm in Aveiro and slightly smaller (0.37 mm) in Leon; in addition, the kinetic energy and linear momentum values in Aveiro are three times higher than those in Leon. A comparison of raindrop size distributions by weather type has shown that for both locations westerly weather presented a higher probability of rainfall, and the gamma distribution parameters for each weather type were independent of the study zone. When the analysis is done for the characteristics of rain related with erosion, the westerly cyclonic weather types (cyclonic west (CW) and cyclonic south-westerly (CSW)) are among the most energetic ones in both locations. However, comparing their five weather types with higher kinetic energy, in Aveiro a westerly component implies higher kinetic energy, while in Leon a southerly component involves more energy in the rain.


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