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Analysis of Rainfall and Temperature Trends and Variability in Semi-arid North-eastern Ethiopia
Abate Getachew Feleke,
Mulualem Abera
Issue:
Volume 8, Issue 4, August 2020
Pages:
75-87
Received:
31 March 2020
Accepted:
23 April 2020
Published:
27 August 2020
Abstract: Northeast Ethiopia is a semi-arid region that exhibits high rainfall and temperature variability. The impact of climate change has received a great deal of attention worldwide. This study focused on detecting trends in in rainfall (1983-2013) and temperature (1981-2010) at annual, seasonal and monthly time scales for six weather stations in semi-arid north eastern Ethiopia. The study also aimed to determine dry spell length, number of rainy days, onset and cessation dates, and length of growing period. The non-parametric tests such as Mann-Kendall and Sen’s Slope were used to determine climatic trends. The results indicated that both the annual maximum and minimum temperature in the study region showed an increasing trend, but only the trend for maximum temperature was significant. In the same manner, both the Belg and Kiremt seasons maximum and minimum temperature also showed an increasing trend but only trend of maximum temperature during Belg season and trend of minimum and maximum temperature during Kiremt seasons was significant. The annual and Belg season rainfall in the region showed a decreasing trend and its trend was significant. The coefficient of rainfall variability for annual and Belg season was very high which could affect agricultural production in the region. In the contrary, the trend for Kiremt season rainfall was increasing without significant trend. On the other hand, the average length of dry spell during the Kiremt season in the region was generally long that ranged from 27 days to 39 days and showed both decreasing and increasing but with no significant trend in most stations. The number of annual rainy days also showed both increasing and decreasing trends but its trend was not significant. The length of growing period in the region was relatively stable at all stations during the last 30 years period without non-significant trend. In general, from the analysis of annual, seasonal and monthly rainfall and temperature data series it can be concluded that rainfall and temperature characteristics of the study area is changing, even though some of the trends on both parameters were not statistically significant.
Abstract: Northeast Ethiopia is a semi-arid region that exhibits high rainfall and temperature variability. The impact of climate change has received a great deal of attention worldwide. This study focused on detecting trends in in rainfall (1983-2013) and temperature (1981-2010) at annual, seasonal and monthly time scales for six weather stations in semi-ar...
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Effect of Rainfall and Temperature on Crop Production in Quarit District
Abdi Yirdew,
Yimenu Yeshiwas
Issue:
Volume 8, Issue 4, August 2020
Pages:
88-95
Received:
19 February 2020
Accepted:
12 March 2020
Published:
27 August 2020
Abstract: In this research, we have investigated the effects of rainfall and temperature variability on wheat, Teff, Maize and Barley yield in Quarit district of West Gojjam zone. The data used in this study were temperature, rainfall and (Wheat, teff, maize and barley) yield for the period 1997 to 2016 and Origin 07 and Matlab software were used for the analyses purpose. The weather parameters were correlated with selected crop yield (descriptive and inferential analysis techniques were used). Trend of crop yield and climatic parameters were developed and plotted against time. From this study, there was positive correlation between maximum temperature and all selected crop production (Maize, teff, wheat and barley) and there was correlation between these selected crop yields and rainfall. There has been variability and none stability of temperature and rainfall in the study area, leads to high variability of crop yields from year to year in the study area. This finding has demonstrated that, there was an increasing trend of temperature and very slightly decreasing trend of rainfall in Quarit district. Teff production was the most sensitive and affected by climate variability. Results showed that crop yield varied regularly with climate parameters. It was concluded that climate parameters (temperature and rainfall) vary in time whose effects given high variability of crop yield.
Abstract: In this research, we have investigated the effects of rainfall and temperature variability on wheat, Teff, Maize and Barley yield in Quarit district of West Gojjam zone. The data used in this study were temperature, rainfall and (Wheat, teff, maize and barley) yield for the period 1997 to 2016 and Origin 07 and Matlab software were used for the ana...
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Conservation Constraints and Strategies of the Arba Minch Forest Nech Sar National Park: Arba Minch, Ethiopia
Selemon Thomas Fakana,
Debebe Dana Feleha
Issue:
Volume 8, Issue 4, August 2020
Pages:
96-110
Received:
19 May 2020
Accepted:
28 May 2020
Published:
27 August 2020
Abstract: Human beings are utterly dependent on nature particularly on the forest ecosystem services. Our health, economy, prosperity, and development are all connected to the forest ecosystem services. Forest ecosystems afford variety of the ecosystem services that human beings depend up on them. Ecosystem services are base for the survival of mankind and play significant role in economic development, prosperity, health, etc. Arba Minch Forest ecosystem is a crucial asset that maintains the continuity and survival of the Arba Minch town and its environs. Despite its tangible and worthy ecosystem services, it has been exposed to the conservation constraints due to the anthropogenic activities. However, limited studies have been conducted on its conservation constraints and strategies. Hence, this study focuses on identifying conservation constraints and finding out conservation strategies. Accordingly, the study was carried out using four sample categories (Arba Minch town residents households (n=151), key informants (n=21), accommodations delivers (n=9) and peoples entering into the forest (n=21)) besides to field observation. Altogether (n=199) peoples involved in this study. Collected raw data were chosen, refined, categorized edited, coded and entered to SPSS version 20 software. Descriptive statistics were computed for relevant variables and information obtained from the key informants was described in meaningful content. Findings of this study revealed that in spite of its undeniable ecosystem services, conservation constraints are ongoing like deforestation, dependence of households and accommodation delivers, lack of alternative livelihood generation, and so on. Hence, to overcome the stated constraints; putting into practice variety of the identified conservation strategies like enhancing public awareness, stakeholders’ participation, providing alternative livelihood generation, ensuring alternative energy sources, etc. are core activities to save the forest and sustain its ecosystem services.
Abstract: Human beings are utterly dependent on nature particularly on the forest ecosystem services. Our health, economy, prosperity, and development are all connected to the forest ecosystem services. Forest ecosystems afford variety of the ecosystem services that human beings depend up on them. Ecosystem services are base for the survival of mankind and p...
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A Wavelet-based Algorithm for the Computation of Intraseasonal Oscillations Intensity and Frequency Indices and Application to Central Africa
Alain Tchakoutio Sandjon,
Armand Nzeukou Takougang
Issue:
Volume 8, Issue 4, August 2020
Pages:
111-116
Received:
19 May 2020
Accepted:
7 July 2020
Published:
31 August 2020
Abstract: The rainfall modeling at regional scale remains a great challenge in the tropics because of the complexity of the processes that induce rainfall variability. Then the good parameterization of some atmospheric processes will be of great contribution towards the improvement of regional models. In this paper we applied wavelet transform on 2.5°×2.5° daily Outgoing Long-wave Radiation (OLR) datasets for the period 1981-2015 (35 years) to extract Intraseasonal Intensity (ISOI) and intraseasonal Period (ISOP), with application to Central Africa (CA). In fact for each grid point in the study area, the wavelet transform was applied to the 25-70-day filtered daily OLR time series and the wavelet spectrum is obtained. In the resulting spectrum, the maximum variance for each day is taken as ISOI and the period exhibiting that maximum variance is the ISOP. The plots of seasonal mean ISOI and ISOP obtained showed that the ISO characteristics (amplitude, frequency) strongly vary from season to another. The ISO amplitude is extremely high during December-February (DJF) and March-May (MAM) and lower during JJA and SON seasons. As for the period of oscillations, the ISOP peaks during MAM and JJA seasons. But for the four seasons, the period is predominantly contained between 40-50 days, suggesting the dominance of Madden-Julian Oscillation (MJO) signal.
Abstract: The rainfall modeling at regional scale remains a great challenge in the tropics because of the complexity of the processes that induce rainfall variability. Then the good parameterization of some atmospheric processes will be of great contribution towards the improvement of regional models. In this paper we applied wavelet transform on 2.5°×2.5° d...
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