Maize Suitability in the Lowlands of Lesotho

Kabelo Lebohang Donald - Nanjing University of Information Science & Technology, 2019

The Food and Agriculture Organization (FAO) defined that the suitability is a function of crop climate requirements and land characteristics and it is a measure of how will the qualities of land unit matches the requirements of a particular form of land use. The aim of this research is to improve maize production in the lowlands of Lesotho, this is one of the agro-ecological zones with the most arable land and good soils so it is best to determine the suitability of each crop across this region. This will be achieved by quantitatively and qualitatively looking at the climate conditions require ...

English

 Maize Suitability in the Lowlands of Lesotho

Lebohang Donald Kabelo

Published by: Nanjing University of Information Science & Technology ; 2019

The Food and Agriculture Organization (FAO) defined that the suitability is a function of crop climate requirements and land characteristics and it is a measure of how will the qualities of land unit matches the requirements of a particular form of land use. The aim of this research is to improve maize production in the lowlands of Lesotho, this is one of the agro-ecological zones with the most arable land and good soils so it is best to determine the suitability of each crop across this region. This will be achieved by quantitatively and qualitatively looking at the climate conditions required by maize and also looking at the physio-chemical soil properties that suffices for the maximum production of the crop.
Climatic potential of maize under dryland farming in the lowlands of Lesotho was investigated using five climatic suitability indices namely: probability of receiving heat units of greater than 1320GDD, probability of a frost-free growing season, probability of seasonal rainfall of more than 650mm and the slope of an area. Also the physio-chemical properties of the soils found in the area of study were investigated looking at 6 soil parameters (pH, porosity, permeability, infiltration, organic matter, moisture equivalence) which are crucial to maize growth. For each of the above parameters a coverage layer was prepared in GIS environment and the layers were overlaid to obtain the agro-climatic suitability map of maize in the lowlands of Lesotho. Weighted overlay method is used for suitability analysis. The spatial analysis show that suitable soils are distributed throughout the whole lowlands but they are highly concentrated in the middle parts of the lowlands and with water requirement, the north-most part of the lowlands is highly suitable while the central part is moderately suitable.
The overall maize suitability in the lowlands of Lesotho indicate that 45.7% of the area is moderately suitable and this are concentrated in the middle to northern lowlands. 49.3% of the lowlands are found to be suitable for maize growth and are distributed throughout the whole lowlands but with the highest concentration in the north-most parts. Of the 5% remaining only 4.3% is highly suitable and it some area in the central part of Maseru near Moshoeshoe-I station.
Future projections show that there will be an improvement of growing degree days across the whole lowlands due to an increase in temperature but as of water requirement satisfaction there is a notable change of reduction especially in Mafeteng and Moshoeshoe-I this is due to reduction in annual accumulated rainfall, this is the case for both two (RCP 4.5, RCP 4.5) scenarios undertaken in this study.

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Language(s): English

Format: Digital (Available online for logged-in users)

Tags: Agroclimatology ; Scenario ; Lesotho ; Suitability ; Weighted overlay method ; spatial analysis ; physio-chemical ; RCP 4.5 Add tag

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Study of interannual variability of October-December rainfall season over Djibouti

Houda Youssouf Houssein - Nanjing University of Information Science & Technology, 2017

Rainfall is a very important weather and climate parameter that affects social and economic activities in Djibouti. This leads to droughts, floods and humanitarian disasters over the country. The rainfall climatology of the country has some changes which need to be taken into account while planning for economic activities such as civil and structural engineering. The whole country receives significant rains in the months of (October – December) and (March – April) as known except for the southern parts of the country. The southern part of the country gets its rains in the months of (June to Au ...

English

 Study of interannual variability of October-December rainfall season over Djibouti

Youssouf Houssein Houda

Published by: Nanjing University of Information Science & Technology ; 2017

Rainfall is a very important weather and climate parameter that affects social and economic activities in Djibouti. This leads to droughts, floods and humanitarian disasters over the country. The rainfall climatology of the country has some changes which need to be taken into account while planning for economic activities such as civil and structural engineering. The whole country receives significant rains in the months of (October – December) and (March – April) as known except for the southern parts of the country. The southern part of the country gets its rains in the months of (June to August). Djibouti is located in the Eastern Africa it is believed that OND rainfall over the Eastern Africa is strongly caused by IOD and ENSO events. The roles of Indian-Pacific Ocean SSTs in climate variability over Eastern Africa have been discussed in a number of studies, and since most of previous studies focused on the entire region of eastern Africa. But less concerns remained on the analysis of specific countries like Djibouti. To explain it is OND season over Djibouti strongly caused by IOD and ENSO? This study will try to cover this gap by study inter-annual variability of October-December rainfall season over Djibouti.
The study inter-annual variability of OND rainfall over Djibouti focuses on analyzing by using different methods such as EOF, composite analysis and correlation analysis, the study tried to assess the spatial and temporal distribution of OND season rainfall over Djibouti and its associate circulating weather system covering a period of 1971 – 2010. The first EOF mode analysis is referred to be a dominant mode and was taken into consideration in this study. The identification of dry and wet years was based on the interannual standardized rainfall anomaly, we have identified the five wettest (1972, 1982, 1994, 1997, 2000) and three driest years (1974, 1975, 1978). The Mann–Kendall test statistics for abrupt change in rainfall was using there was observed abrupt change throughout the study period occurred 1979. The composite analysis of the wet and dry years with respect to the different variables including, wind, velocity potential/divergence (convergence) reveals that the wet (dry) years were associated with convergence (divergence) at 850hpa and
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divergence (convergence) at the upper level (200hpa), implying rising (sinking) motion, especially over the study area and western Indian Ocean. During wet years the sea level pressure is weakens over the West Indian Ocean and the eastern African coast due to the presence of low pressure in that region. Because of low pressure at the coast (Djibouti coastal area), the area experience a lot of activities (convection) favored for rain formation. The results of correlation analysis show that there exists a significant correlation between OND rainfall, Nino 3.4 and DMI over the country. The correlation coefficient of OND rainfall and DMI is 0.66 while that of Nino 3.4 and OND rainfall is 0.51. It was found that IOD exerts significant influence on Djibouti OND rainfall such that rainfall is enhanced (suppressed) during warm cold events in the events Indian Ocean dipole. Although IOD is the dominant mode over the country but Djibouti’s rainfall pattern seemed to be stronger when the large positive IOD indices matched with El Niño events. This these aims to investigate how Indo-Pacific Oceans modulate Djibouti rainfall and provide us with a physical basis to consider IOD as a predictor for variations of the OND season. It was found significant relationship between the anomalous SST in the Indian Ocean and enhanced rainfall intensity over Djibouti especially the coastal, south-eastern and center parts of the country where the positive correlation. Therefore the previous climate events must be well understood so as to make reliable and accurate forecasts that will enable to improve planning and management of climate sensitive activities.

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Language(s): English

Format: Digital (Available online for logged-in users)

Tags: Precipitation ; Djibouti ; Thesis - WMO Fellowship Division ; Interannual variability ; IOD Add tag

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Diagnosis of floods/drought and their associated circulation anomaly over Malawi

Alexander Francis - Nanjing University of Information Science & Technology, 2017

Floods and droughts are one of extreme weather climatic events that result in loss of life and property in Malawi. However, a well detailed knowledge of understanding of previous extreme climatic events and their associated impacts can be a precautionary in reducing their impacts, as it will help to project future events timely. Therefore this paper presents an analysis of Dec-Feb seasonal flood/drought events and their associated circulation anomalies over Malawi. The DJF seasonal flood/drought was studied using monthly data from 9 selected stations for the period of 1978-2010. A set of regio ...

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 Diagnosis of floods/drought and their associated circulation anomaly over Malawi

Francis Alexander

Published by: Nanjing University of Information Science & Technology ; 2017

Floods and droughts are one of extreme weather climatic events that result in loss of life and property in Malawi. However, a well detailed knowledge of understanding of previous extreme climatic events and their associated impacts can be a precautionary in reducing their impacts, as it will help to project future events timely. Therefore this paper presents an analysis of Dec-Feb seasonal flood/drought events and their associated circulation anomalies over Malawi. The DJF seasonal flood/drought was studied using monthly data from 9 selected stations for the period of 1978-2010. A set of regional flood drought indices with a scheme of classifying their severity was employed to classify the flood/drought into seven different grades using the Z-Index. The results revealed that 2 years 1997 and 2007 the area experienced severe floods, while extreme drought years were 1992 and 2000 . Wet years were associated with convergence at low level and divergence at upper level mostly over the equatorial western Indian Ocean as well as over the area of study. Dry years had divergence at low level and convergence at upper level especially western Indian ocean and the area of study .The SST showed that dry years were manifested with negative anomalies over equatorial western Indian ocean and the equatorial Atlantic ocean, while a strong positive anomaly in equatorial pacific Ocean. Wet years were characterized by positive anomaly south of Madagascar in the Indian Ocean, and a negative anomaly in the Pacific Ocean. The EOF1 showed that the spatial distribution of rainfall during DJF is relatively uniform, positive loadings dominate all over the area with strong positive loading in the southern region and a weak positive loading over northern region and south of Lake Malawi.

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Language(s): English

Format: Digital (Available online for logged-in users)

Tags: Flood ; Drought ; Malawi ; Thesis - WMO Fellowship Division Add tag

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Change of diurnal precipitation in different phases of Bsiso

Sitchanukrist Worapon - Nanjing University of Information Science & Technology, 2017

As we know tropical intraseasonal oscillation (ISO) was described as 2 modes such as Boreal summer intraseasonal oscillation (BSISO) during boreal summer and Madden-Julian Oscillation (MJO) dominates during boreal winter. In summer time, Thailand where located at the coastal region at the Equator which is effected by BSISO. Some week there is strong diurnal cycle but some week is opposite. The purpose of this work is to study the evolution of BSISO and to study the change of diurnal precipitation in different phases of BSISO. Tropical Rainfall Measuring Mission (TRMM) version 3B42 data on 0.25 ...

English

 Change of diurnal precipitation in different phases of Bsiso

Worapon Sitchanukrist

Published by: Nanjing University of Information Science & Technology ; 2017

As we know tropical intraseasonal oscillation (ISO) was described as 2 modes such as Boreal summer intraseasonal oscillation (BSISO) during boreal summer and Madden-Julian Oscillation (MJO) dominates during boreal winter. In summer time, Thailand where located at the coastal region at the Equator which is effected by BSISO. Some week there is strong diurnal cycle but some week is opposite. The purpose of this work is to study the evolution of BSISO and to study the change of diurnal precipitation in different phases of BSISO. Tropical Rainfall Measuring Mission (TRMM) version 3B42 data on 0.25° X 0.25° grid for JJA 1998-2010 and EOF analysis are used to answer how BSISO modulates the global diurnal precipitation cycle.
This study displays the spatial pattern to show daily mean precipitation, diurnal range and also EOF analysis in different phases of BSISO for summer from 1998-2010. All figures from this study can explain that the effect of BSISO on the diurnal cycle is depended on location. For example in BSISO1 phase 2 (wet phase) over Maritime Continent both ocean and land area have enhance diurnal cycle but over South Asia is different. Over South Asia only the diurnal cycle over land enhances but over ocean at Bay of Bengal the diurnal cycle is depress. On the other hand, in BSISO 1 phase 6 (dry phase) over ocean area such as Bay of Bengal and Philippines Sea have enhance diurnal cycle but over Maritime Continent the diurnal cycle is depress.

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Language(s): English

Format: Digital (Available online for logged-in users)

Tags: Precipitation ; Tropical meteorology ; Thailand ; Thesis - WMO Fellowship Division ; Boreal summer intraseasonal oscillation (BSISO) Add tag

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Analysis inter decadal of climate variability facing projections of the CMIP5 models and its involvement in the agricultural production of Venezuela

Cudemus Leila - Nanjing University of Information Science & Technology, 2017

Agriculture is the largest employer in the world and is probably the most dependent on the climate of all human activities. In recent years there have been events that have put in evidence the vulnerability of global food security to major meteorological phenomena, both in global agricultural markets and the world economy. The food price crisis and the subsequent economic crisis reduced the purchasing power of large segments of the population in many developing countries, which seriously reduced their access to food and thus undermined their food security. During the years 2009 and 2010 in Ven ...

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 Analysis inter decadal of climate variability facing projections of the CMIP5 models and its involvement in the agricultural production of Venezuela

Leila Cudemus

Published by: Nanjing University of Information Science & Technology ; 2017

Agriculture is the largest employer in the world and is probably the most dependent on the climate of all human activities. In recent years there have been events that have put in evidence the vulnerability of global food security to major meteorological phenomena, both in global agricultural markets and the world economy. The food price crisis and the subsequent economic crisis reduced the purchasing power of large segments of the population in many developing countries, which seriously reduced their access to food and thus undermined their food security. During the years 2009 and 2010 in Venezuela there were strong weather anomalies, drought in the first case and the second extreme rains, caused mainly by the effect of the El Niño-Southern Oscillation (ENSO) event, with warm phase (El Niño) in 2009 and cold phase (La Niña) in 2010, affecting farming, mostly in Monagas, Anzoátegui and Guárico States negatively influencing its economy. The planning of agricultural production based on the use of agricultural information, as calendars of sowing, as well as the monitoring of the conditions during the crop cycle and the use of agrometeorological forecasting, then is of great importance for the development of the agricultural sector, because it minimizes the effects on food production which might be affected by climate variability, making it less vulnerable. Model results confirm the importance of known key physiological processes, such as the shortening of the time to maturity of a crop with increasing mean temperature, decline in grain set when high temperatures occur during flowering, and increased water stress at high temperatures throughout the growing cycle. Temperature responses are generally well understood for temperatures up to the optimum temperature for crop development. The impacts of prolonged periods of temperatures beyond the optimum for development are not as well understood. For this study the agro meteorological stations selected have daily records of all climatic elements, so it held a summary monthly apart from daily data (with prior quality control) for the accumulated monthly rainfall and temperature maximum and minimum for the 1971-2010 series. Therefore, Inter decadal rainfall and temperature analysis and the use of the cropwat 8.0 to model future scenarios can be estimated water requirements of main crops, allowing some adaptation measures to help mitigate the effects of climate change in the country's agricultural production. In selected stations were determined significant changes on ETc when the temperature increase and the availability of water is a key factor to reach the harvest. Adaptation measurements involve reducing risk and vulnerability; for developing countries rely heavily on climate-dependent agriculture and especially in conjunction with poverty and rapid increase in population they are vulnerable to climate change.

Notes: If you wish to download the full text, please contact the author (leilacudemus(at)hotmail.com) or library(at)wmo.int (Please replace (at) by @).

Language(s): English

Format: Digital (Free)

Tags: Climatic variation ; Agroclimatology ; Water management ; Climate model ; Climate change ; Venezuela, Bolivarian Republic of ; Thesis - WMO Fellowship Division Add tag

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Climate change effect on wheat production over Ethiopia by model simulation and prediction

Muleta Dereba - Nanjing University of Information Science & Technology, 2017

Climate is one of the key factors that affect agriculture. Climate change and climate variability have been observed, typically shown as global warming due to the increased greenhouse gases. The change in climate is even predicted to be rapped and sharp in recent future and the impacts of extreme climate condition associated with climate change will be high on agriculture. Studying the impacts of climate change, especially the effects of temperature and precipitation on agriculture, is important for food safety, agricultural management, and sustainable development.

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Variability of the West African summer Monsoon and its relation to the SSTA over the Atlantic Ocean

Kanko Defoke Joel Sylvain - Nanjing University of Information Science & Technology, 2016

This study investigates spatial and temporal features of the West African Summer Monsoon (WASM) and its relation to the Sea Surface Temperature Anomaly (SSTA). The variability of the WASM from June to September was analyzed during the period 1960-2013, with methods including EOF analysis of the precipitation anomaly and SSTA and the associated large scale circulation pattern. The result from the first EOF-Mode of the precipitation anomaly which has the highest positive loadings over the region shows that during the summer, the precipitation anomalies are positives in the Sahel and the Sahara. ...

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Drought Assessment Using SPEI and NDVI : Case of Lesotho

Monnapula Mookho - Nanjing University of Information Science & Technology, 2016

While drought conditions are generally a common and recurring phenomenon of the climate in Southern Africa especially Lesotho, the frequency of droughts in Lesotho has increased significantly over the past few years. Lesotho has suffered the devastating impacts of drought during the past several decades resulting in poor harvests and large livestock losses to rural farmers. The majority of the population in Lesotho engages with rain- fed agriculture and is dependent to some degree on own production for household food supply and/or cash income (Dejene, Midgley, & Marake, 2011). Any negative cha ...

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Diagnosis Of Extreme Rainfall And Temperature Event Over Rwanda (1961-2010)

Uwimbabazi Jacqueline - Nanjing University of Information Science & Technology, 2016

This study attempted to investigate the variability of extreme rainfall and temperature over Rwanda and the associated circulation anomalies forecasting on wet and dry rainfall events between 1961 and 2010. The datasets used to achieve the objectives includes Temperature, the rainfall dataset, wind vector, pressure vertical velocity (omega) and the Indian Ocean sea surface temperature (SST). The methods used include correlation analysis, Standardized anomaly, composite analysis, and Empirical Orthogonal Functions (EOF) analysis. The results show that the mean annual cycle depict two rainy Seas ...

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The Sahel Drought Mechanism: insights from two contrasting extreme events

Ceesay Abdoulie O. - Nanjing University of Information Science & Technology, 2016

The Sahel drought mechanism: insights from two contrasting extreme events during boreal summer July-August-September (JAS) is investigated in this study using the standardized precipitation index (SPI). Empirical orthogonal function (EOF) and composite analyses were deployed in this study, where the global precipitation climatology center (GPCC) rainfall data is used. The SPI shows large widespread decreasing rainfall trend in the Sahel in the mid-1980s; thereafter, Sahel rainfall have recovered somewhat through the late 1990s, even though the drought conditions have not ended in the region. A ...

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Projection of Future Streamflow Changes in the Pearl River Basin

San Yin Yin - Nanjing University of Information Science & Technology, 2016

Global climate change is remarkably changing the climatic patterns of the Pearl River basin and are significantly impacting the hydrological processes. Projection of future climate change impacts on steamflow variation is potential to provide scientific guidelines for sustainable water resources management and effective prevention and control for flood and drought disasters. In this study, a hydrological modeling system for assessing climate change impacts on runoffin the Pearl River basin was established and were used to simulate historical hydrological process and to project future streamflo ...

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Study on the Dynamical and Thermodynamical Process Intensifying the Squall Lines over Guinea

Sory Diallo Ibrahima - Nanjing University of Information Science & Technology, 2016

This research investigates the dynamical and thermodynamical process of mesoscale convective system that intensifies squall lines wind speed propagation. The generation of African Easterly Waves (AEWs) and its lifecycle. The characteristics of squall lines (SLs) over West Africa (WA) which occurred In Guinea for two cases periods June 01-02 and June 13-14, 2015. In all six (6) AEWs have been tracked using reanalysis data from European Centre for Medium-Range Weather Forecasts (ECMWF). European Meteorological Satellite images (EUMETSAT) and Earth Networks WeatherBug StreamerRT were also used to ...

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Analysis of aerosol optical depth (AOD) retrieved from light detection and ranging (LIDAR) and sunphotometer measurements

Salah Waiss Mahado - Nanjing University of Information Science & Technology, 2016

Aerosols are small, micrometer-sized particles, whose optical effects coupled with their impact on cloud properties is a source of large uncertainty in climate models. Aerosols when inhaled are believed to have significant and detrimental effects on human health. Their presence also affects photosynthesis and agricultural production. Aerosol measurements are urgently required for the complete understanding and modeling their role in the climate system. This study builds on the analysis of Aerosol Optical depth (AOD) using Light Detection and Ranging (LIDAR) and sun photometer measurements then ...

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Aerosol Measurement by Raman Lidar

Telou Taro Dadja - Nanjing University of Information Science & Technology, 2016

This paper examines the aerosol extinction coefficient profiles measured by Rayleigh-Raman-Mie-Lidar (RRML) system in Nanjing, China. I introduced two lidars methods (Raman and Fernald) and detection principle, and two lidars data Using Raman analysis method and Fernald analysis method to obtained aerosol extinction coefficient. Aerosol profiles at 607 nm and 532 nm over ranges from 6 km to 10 km were obtained using respectively Raman lidar and Rayleigh lidar in Nanjing.

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Variability of Benin JJAS Precipitation associated with MAM SST Anomaly in the Atlantic Ocean

Zekpete Raphael Fustel Djaou - Nanjing University of Information Science & Technology, 2016

Precipitations vary consistently in Benin from 1981 to 2010. The present study reveals that the variation of Benin JJAS precipitation is positively correlated to MAM Sea Surface Temperature (SST) in Atlantic Ocean with correlation coefficient more than 0.7. When the SST is higher (lower) in the Atlantic Ocean, precipitation over Benin tends to be above (below) normal. The years 1988, 1989, 2003, 2007 and 2008, were wet with 1988, 2003, 2008 high SST over Tropical Southern Atlantic Ocean (STAO) while the years 1982, 1983, 1992 and 1997 formed the dry years with low SST over Tropical Southern At ...

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