Research Article
Flood Frequency Analysis Using Gumbel Distribution Method: A Case of Robigumero River, Abay Basin, Ethiopia
Issue:
Volume 12, Issue 1, March 2024
Pages:
1-7
Received:
16 January 2024
Accepted:
8 February 2024
Published:
27 February 2024
Abstract: Hydraulic structures like weirs, dams, spillways, and bridges require precise estimation of flood peaks at the intended return period in order to be planned, built, and maintained. In this paper, the findings of a study conducted on the Robigumoro River and the flow measurements taken are presented. The flood frequency analysis of the Robigumoro River was performed using the Gumbel distribution, which is a probability distribution commonly used for modeling river flows. This analysis is crucial as it aims to safeguard the lives and properties located downstream from the catchment area. The Gumbel distribution was employed to model the highest annual river flow over a span of 20 years (1990-2009). The investigation was carried out by the Ethiopian water and energy office, Abay Basin Development Authority. The Robigumoro River's maximum annual discharge over a 20-year period (1990–2009) was modeled using Gumbel distribution technique. From the trend line equation, R2 value of 0.935 which shows that Gumbel’s distribution is suitable for predicting expected flow in the river. It can be concluded that the Gumbel distribution can accurately forecast expected river flow. The flood peak values were calculated using the same procedure for various return times. This helps with storm management in the research region. The estimated discharges obtained using the Gumbel's distribution and return periods (T) of 2 years, 10 years, 50 years, 100 years, 150 years, 200 years, 300 years and 400 years are 177.327m3/s, 320.784m3/s, 446.553m3/s, 499.722m3/s, 530.727m3/s, 552.698m3/s, 583.38m3/s, and 605.577m3/s respectively. The accuracy of flood forecasts in the basin indicates their potential use in various applications such as the design of crucial hydraulic structures, river reach planning, construction of bridges, and conservation efforts for Robigumoro watershed.
Abstract: Hydraulic structures like weirs, dams, spillways, and bridges require precise estimation of flood peaks at the intended return period in order to be planned, built, and maintained. In this paper, the findings of a study conducted on the Robigumoro River and the flow measurements taken are presented. The flood frequency analysis of the Robigumoro Ri...
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Research Article
Effect of Deficit Irrigation and Mulch on Field and Water Productivity of Tomato Under Drip Irrigation at Ambo Agricultural Research Center, West Shewa, Ethiopia
Oli Frrisa*,
Selamawit Bekele
Issue:
Volume 12, Issue 1, March 2024
Pages:
8-16
Received:
1 February 2024
Accepted:
14 February 2024
Published:
7 March 2024
Abstract: Ethiopia produces far fewer tomatoes than the world average due to poor management techniques. It was found that the soil moisture and agroclimatic conditions affected how tomatoes reacted to water management during irrigation. In order to assess the impacts of irrigation level and mulch types on the yield, yield components, water productivity, and economic return of drip irrigated tomato production, a field experiment was carried out at the Ambo Agricultural Research Center Farm Site in 2021–2023. The experiment was a two-factor factorial experiment arranged in a randomized complete block design. The two factors were the four irrigation levels (55%ETc, 85%Etc, 70%ETc and 100%ETc) and three mulch types (no mulch, wheat straw mulch, and white plastic mulch). The two-year data on fruit yield, yield components, and water productivity were subjected to analysis of variance using SAS 9.4 software with a significance level (p≤ 0.05). least significant difference test was applied for statistically significant parameters to compare means among the treatments. The best soil moisture depletion levels, as determined by statistical analysis, are 100% ETc, 85% ETc, and 70% ETc, with marketable fruit yields of 56,405 kg/ha, 45,331 kg/ha, and 41,769 kg/ha, respectively. As for mulch types, the best practices are wheat straw mulch and white plastic mulch, with marketable fruit yields of 45,721 kg/ha and 44,514 kg/ha, respectively, for the study area. However, the results of the partial budget analysis results showed that, with net incomes for onion production in the research region of 1,350,930 ETB/ha and 1,367,071 ETB/ha, respectively, 85% ETc and wheat straw mulch are the economically optimal methods.
Abstract: Ethiopia produces far fewer tomatoes than the world average due to poor management techniques. It was found that the soil moisture and agroclimatic conditions affected how tomatoes reacted to water management during irrigation. In order to assess the impacts of irrigation level and mulch types on the yield, yield components, water productivity, and...
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