scholarly journals Bivariate EMD-Based Data Adaptive Approach to the Analysis of Climate Variability

2011 ◽  
Vol 2011 ◽  
pp. 1-21 ◽  
Author(s):  
Md. Khademul Islam Molla ◽  
Poly Rani Ghosh ◽  
Keikichi Hirose
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Reference Signal ◽  
Complex Signal ◽  
Intrinsic Mode Functions ◽  
Climate Data ◽  
Climate Signal ◽  
Adaptive Approach ◽  
Climate Change And Variability ◽  
Data Adaptive

This paper presents a data adaptive approach for the analysis of climate variability using bivariate empirical mode decomposition (BEMD). The time series of climate factors: daily evaporation, maximum and minimum temperatures are taken into consideration in variability analysis. All climate data are collected from a specific area of Bihar in India. Fractional Gaussian noise (fGn) is used here as the reference signal. The climate signal and fGn (of same length) are combined to produce bivariate (complex) signal which is decomposed using BEMD into a finite number of sub-band signals named intrinsic mode functions (IMFs). Both of climate signal as well as fGn are decomposed together into IMFs. The instantaneous frequencies and Fourier spectrum of IMFs are observed to illustrate the property of BEMD. The lowest frequency oscillation of climate signal represents the annual cycle (AC) which is an important factor in analyzing climate change and variability. The energies of the fGn's IMFs are used to define the data adaptive threshold to separate AC. The IMFs of climate signal with energy exceeding such threshold are summed up to separate the AC. The interannual distance of climate signal is also illustrated for better understanding of climate change and variability.

scholarly journals Compound Vulnerabilities: The Intersection of Climate Variability and HIV/AIDS in Northwestern Tanzania

2014 ◽  
Vol 6 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Valerie Githinji ◽  
Todd A. Crane
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Social Dynamics ◽  
Lake Victoria ◽  
Rural Livelihoods ◽  
Climate Change And Variability ◽  
Northwestern Tanzania ◽  
Food And Nutrition ◽  
Agricultural Yields ◽  
Hiv Aids

Abstract Drawing on ethnographic research conducted in Nsisha, a rural village located close to the shores of Lake Victoria in northwestern Tanzania, this article analyzes how climate change and variability intersect with other stressors that affect rural livelihoods, particularly HIV/AIDS. The analysis integrates theories of vulnerability from both climate and HIV/AIDS literatures to show how these intersecting stressors compound livelihood vulnerability in complex ways. Climate change and variability are linked to declining agricultural yields and an increase in food and nutrition insecurity and poor health in this region. This situation heightens poverty and susceptibility to HIV/AIDS, compromising people’s abilities to cope and adapt. Because of social dynamics, single mothers and their children are particularly affected by these compound vulnerabilities. Climate change and variability are significant contributing vulnerability factors that sustain and exacerbate asymmetrical poverty, food and nutrition insecurity, and HIV/AIDS. By describing the links between vulnerability to HIV/AIDS and climate variability, findings highlight the importance of holistic and localized approaches to adaptation, instead of trying to isolate single issues. Prioritization of multidisciplinary research focusing on the socially differentiated and gendered distribution of vulnerability specifically in regard to poverty, food and nutrition insecurity, and HIV/AIDS is recommended as a means to enrich the understanding of climate change vulnerability. Adaptation strategies should address how climatic shifts interact with generalized poverty, food and nutrition insecurity, health, and gendered vulnerability in areas most affected.

scholarly journals Climate change impacts on cattle production: analysis of cattle herders’ climate variability/change adaptation strategies in Nigeria

2019 ◽  
Vol 5 (1) ◽  
pp. 12-23
Author(s):  
Ayansina Ayanlade ◽  
Stephen M. Ojebisi
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Extreme Weather ◽  
Adaptation Strategies ◽  
Extreme Weather Events ◽  
Climate Data ◽  
Cattle Production ◽  
Study Region ◽  
Qualitative Approaches ◽  
Weather Events

Abstract The study examines the seasonality in climate and extreme weather events, and its effect on cattle production in the Guinea Savannah ecological zone of Nigeria. The study uses both quantitative and qualitative approaches. Climate data of 34 years were used to examine the trends in rainfall pattern and climate variability while household survey was used to appraise the herders’ awareness of climate variability/change impacts and adaptation strategies. Cumulative Departure Index (CDI) method was used to assess the extreme weather events while descriptive statistics and multinomial logistic (MNL) regression model were used to identify the factors that determined herders’ adaptation strategies to climate change. The results revealed a significant spatiotemporal variation in both rainfall and temperature with CDI ranging from -1.39 to 3.3 and -2.3 to 1.81 respectively. The results revealed a reduction in the amount of water available for cattle production. From survey results, 97.5% of the herders identified drought as the major extreme weather event affecting livestock productivities in the study region. In the herder’s perception, the droughts are more severe in recent years than 34 years ago. The results from MNL revealed that extreme weather events, such as drought, has a positive likelihood on migration, at a 10% level of significance, the events has led to migration of cattle herders from the northern part of the study area toward the southern part in recent years.

scholarly journals Analyzing Climate Variability in Malaysia Using Association Rule Mining

2018 ◽  
Vol 7 (4.34) ◽  
pp. 394
Author(s):  
Rabiatul A. A. Rashid ◽  
Puteri N. E. Nohuddin ◽  
Zuraini Zainol
Keyword(s):  
Climate Change ◽  
Data Mining ◽  
Climate Variability ◽  
Association Rule ◽  
Association Rule Mining ◽  
Climate Data ◽  
Rule Mining ◽  
Clustering And Classification ◽  
Change Climate ◽  
Climate Uncertainty

Previous surveys proved that data mining is one of the methods that can be utilized for climate prediction, predominantly clustering and classification are the most applied methods in data mining to build a model to predict changes in the climate. Unlike the climate change, climate variability is a phenomenon where the occurrence of climate uncertainty is according to the changes year to year basis. This study is focusing to look at the effectiveness of the Association Rule Mining (ARM) techniques in predicting climate variability events in Malaysia. In this report, it explained how the patterns that exist within climate data is discovered using ARM and how the extracted pattern is used to predict climate variability. In this report also, a framework is developed to explain how ARM can generate rules and extract patterns from the data and how the extracted rules and patterns is used to develop a model for predicting climate variability event.  

scholarly journals Strategi Peningkatan Produktivitas Kopi serta Adaptasi terhadap Variabilitas dan Perubahan Iklim melalui Kalender Budidaya

2020 ◽  
Vol 14 (2) ◽  
pp. 65
Author(s):  
Yeli Sarvina ◽  
Tania June ◽  
Elza Surmaini ◽  
Rita Nurmalina ◽  
Sutjahjo Surjono Hadi
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Adaptation Strategy ◽  
Climate Forecast ◽  
Climate Variability And Change ◽  
Coffee Production ◽  
Climate Change And Variability ◽  
Potential Strategy ◽  
Coffee Cultivation ◽  
The Impact

<p><strong>Abstrak</strong>. Rendahnya produktivitas kopi merupakan salah satu permasalahan utama dalam sistem produksi kopi Indonesia. Hal ini diantaranya disebabkan tidak adanya perawatan kopi yang optimal dengan memperhatikan fase fenologi kopi, serta dampak variabilitas dan perubahan iklim. Berbagai teknologi adaptasi kopi sudah banyak dihasilkan namun langkah adaptasi dengan memanfaatkan prakiraan iklim dalam bentuk penyesuian kegiatan budidaya dengan fase fenologi atau disebut sebagai kalender budidaya belum dikembangkan. Tulisan ini memaparkan tentang dampak variabilitas dan perubahan iklim pada tanaman kopi, teknologi adaptasi kopi yang sudah tersedia, perlunya pengembangan kalender budidaya kopi sebagai bentuk strategi adaptasi dan peningkatan produktivitas serta potensi dan tantangan pengembangan kalender budidaya kopi di Indonesia. Hasil review ini menunjukkan kalender budidaya kopi berpotensi dikembangkan sebagai strategi peningkatan produktivitas serta adaptasi terhadap variabilitas dan perubahan iklim.</p><p> </p><p><strong>Abstract</strong>. Low productivity is one of the main challenges in Indonesia's coffee production system .It is low due to cultivation management; most of the coffee farmer does not manage their plantation base on the coffee phenology phase.  Moreover climate variability and change also have important effect on coffee productivity. Various technologies on adaptation and measurement to climate change and variability have been identified. Unfortunately, the technology which use climate forecast through adjusting cultivation activity and coffee phenology called as cultivation calendar do not exist yet. This paper provides an overview on the impact of climate variability and change to coffee production, the existing adaptation strategy, and the importance of cultivation calendar as a strategy for adapting and increasing productivity, and the potential and challenges to develop cultivation calendar in Indonesia. This review reveals that coffee cultivation calendar is a potential strategy for increaseing productivity and adapting climate change and variability.</p>

scholarly journals Modeling the Impact of Climate Change on Hydrological Responses in the Lake Tana Basin, Ethiopia

2020 ◽  
Author(s):  
Achenafi Teklay ◽  
Yihun T. Dile ◽  
Dereje H. Asfaw ◽  
Haimanote K Bayabil ◽  
Kibruyesfa Sisay
Keyword(s):  
Climate Change ◽  
Swat Model ◽  
Climate Data ◽  
Lake Tana ◽  
Impact Of Climate Change ◽  
Climate Change And Variability ◽  
The Future ◽  
The Impact ◽  
Lake Tana Basin ◽  
Impacts Of Climate Change

Abstract BackgroundHydrologic systems have been changing due to the impact of climate change and climate variability. The impacts of climate change are set to increase in the future due to the rise of global warming. Quantifying the impact of climate change on the spatial and temporal hydrological processes is important for integrated water resource management. The Lake Tana basin, which is the source of the Upper Blue Nile, is vulnerable to climate change and variability. This study was carried out in the four major tributary watersheds of the Lake Tana basin: Gilgel Abay, Gumara, Ribb, and Megech. The climate model and hydrological model was used to (i) to evaluate the performance of the Soil and Water Assessment Tool for study watershed, (ii) to assess the future rainfall and temperature variability and change in the study watershed, and (iii) to examine the impact of climate change on future watershed hydrology. The study used dynamically downscaled climate data for the baseline (2010–2015) and future period (2046–2051) under two Representative Concentration Pathways (RCP4.5 and RCP8.5). The climate scenarios were simulated using the Weather Research and Forecasting (WRF) model, with a 4-km horizontal resolution. A linear scaling method was applied to minimize model biases. The SWAT model was used to estimate the baseline and future hydrology using the bias-corrected climate data. ResultsThe performance of the SWAT model was ‘good’ to ‘very good’ for both the calibration and validation periods, with the Nash–Sutcliffe efficiency values between 0.71 to 0.92. The projected changes in rainfall vary with seasons and watershed under both scenarios. On average, annual rainfall may increase by 9.8% and 21.2% under RCP4.5 and RCP8.5 scenarios, respectively. Minimum temperature may rise by 1.68 °C and 2.26 °C while maximum temperature may increase by 1.65 °C and 2.75 °C under RCP4.5 and RCP8.5 scenarios, respectively. The changes in climate may cause an increase in surface runoff by 20.9% and 46.5% under RCP4.5 and RCP8.5 scenarios, respectively, while the evapotranspiration increase by 4.7% and 12.2% under RCP4.5 and RCP8.5, respectively. ConclusionThe findings provide valuable insights to implement appropriate water management strategies to mitigate and adapt to the negative impacts of climate change and variability on the Lake Tana basin, and other regions which have similar agro-ecology.

scholarly journals Adaptation Measures to Mitigate the Impacts of Climate Variability among Pastoralists in Kajiado, Kenya

2020 ◽  
pp. 156-166
Author(s):  
Jacktone Achola Yala ◽  
Joshua Orungo Onono ◽  
William Okelo Ogara ◽  
Gilbert Ongisa Ouma ◽  
Sam Oyieke Okuthe
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Cross Sectional Study ◽  
Livestock Production ◽  
Primary Data ◽  
Adaptation Measures ◽  
Cross Sectional ◽  
Climate Change And Variability ◽  
Negative Impacts ◽  
Village Elders

Climate change and variability has direct and indirect effects on pastoralism through its effect on natural resources including water and pastures that support livestock production in pastoral areas. This study was conducted in Kajiado County where pastoralism is the main source of livelihood. The objective was to identify challenges facing pastoralism and adaptation measures applied by Maasai pastoralists to mitigate impacts of adverse climate events including flooding and drought. A cross-sectional study design was used and primary data collected through focus group discussions (FGDs), key informant interviews (KIIs) and expert opinion interviews (EOIs). A total of 10 FGDs (114 respondents within 10 wards, out of which 81 were men and 33 women), 25 KIIs (6 opinion leaders, 5 village elders, 6 chiefs, 6 government staff and 2 non-governmental organisation) and 12 EOIs (1 Department of Meteorological Services, 1 National Drought Management Authority (NDMA), 2 Department of Agriculture and 8 Departments of Veterinary Services and Livestock Production) were conducted during the data collection period. The findings showed that drought and flooding were the main climate related challenges that were often experienced by the pastoralists. The adaptation measure which were frequently implemented by pastoralist during flooding was livestock vaccination and mass treatment of sick livestock (Z >1.96) while the most frequently implemented adaptation measures during drought periods included migration with livestock to search for water and pasture (Z=1.51) and livestock vaccination and treatment of sick livestock (Z=1.08). Other climate variability related-challenges included increased incidences of livestock diseases, increased livestock deaths, increased cases of community conflicts, unavailability of veterinary vaccines and medicines, high cost of livestock vaccines and drugs and inadequate number of technical staff within the county. The study has shown that climate variability has significant impact on sources of livelihood for pastoralists who in turn are implementing several adaptation measures to mitigate the effects of climate change and variability. The study recommends formulation and implementation of appropriate plans and policies that are focussed on supporting resilience of the vulnerable pastoral communities and that could further assist in fighting the negative impacts of climate change and variability.

Climate Variability and Urban Agricultural Activities in Ibadan, Nigeria

2022 ◽  
pp. 1175-1194
Author(s):  
Ayobami Abayomi Popoola
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Urban Poverty ◽  
Agricultural Activities ◽  
Urban Farming ◽  
Global Literature ◽  
Climate Change And Variability ◽  
Main Activity ◽  
Farm Livestock ◽  
Livestock Rearing

Two terms that are enjoying increasing overwhelming global literature advocacy and discussion are urban farming and climate change. While there is increasing advocacy towards the relevance of urban agriculture for urban dwellers and how it translates into a mitigation strategy against climate change variability and adaptation to urban poverty, the effect of some urban farming activities and how it serves as a driver to climate change needs to be investigated. In most of the urban periphery where there is availability of a large expanse of land areas, farming activities are usually practised in form of settlement farm, livestock rearing, or plantation agriculture. The study based on quantitative and qualitative data from urban farmers in Ibadan argues that the location of urban farmlands is dependent on climatic factor such as access to land. The study identified that climate variability as reported by the urban farmers has resulted in the increased use of fertilizer for farming by urban farmers, and the main activity that is pro-climate change and variability is bush burning.

Climate Variability and Urban Agricultural Activities in Ibadan, Nigeria

2020 ◽  
pp. 11-30
Author(s):  
Ayobami Abayomi Popoola
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Urban Poverty ◽  
Agricultural Activities ◽  
Urban Farming ◽  
Global Literature ◽  
Climate Change And Variability ◽  
Main Activity ◽  
Farm Livestock ◽  
Livestock Rearing

Two terms that are enjoying increasing overwhelming global literature advocacy and discussion are urban farming and climate change. While there is increasing advocacy towards the relevance of urban agriculture for urban dwellers and how it translates into a mitigation strategy against climate change variability and adaptation to urban poverty, the effect of some urban farming activities and how it serves as a driver to climate change needs to be investigated. In most of the urban periphery where there is availability of a large expanse of land areas, farming activities are usually practised in form of settlement farm, livestock rearing, or plantation agriculture. The study based on quantitative and qualitative data from urban farmers in Ibadan argues that the location of urban farmlands is dependent on climatic factor such as access to land. The study identified that climate variability as reported by the urban farmers has resulted in the increased use of fertilizer for farming by urban farmers, and the main activity that is pro-climate change and variability is bush burning.

scholarly journals Single Channel Speech Enhancement Using Adaptive Soft-Thresholding with Bivariate EMD

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Md. Ekramul Hamid ◽  
Md. Khademul Islam Molla ◽  
Xin Dang ◽  
Takayoshi Nakai
Keyword(s):  
Speech Enhancement ◽  
Speech Signal ◽  
Single Channel ◽  
Complex Signal ◽  
Intrinsic Mode Functions ◽  
Noisy Speech ◽  
Mode Decomposition ◽  
Data Adaptive ◽  
Improved Performance ◽  
Short Time

This paper presents a novel data adaptive thresholding approach to single channel speech enhancement. The noisy speech signal and fractional Gaussian noise (fGn) are combined to produce the complex signal. The fGn is generated using the noise variance roughly estimated from the noisy speech signal. Bivariate empirical mode decomposition (bEMD) is employed to decompose the complex signal into a finite number of complex-valued intrinsic mode functions (IMFs). The real and imaginary parts of the IMFs represent the IMFs of observed speech and fGn, respectively. Each IMF is divided into short time frames for local processing. The variance of IMF of fGn calculated within a frame is used as the reference term to classify corresponding noisy speech frame into noise and signal dominant frames. Only the noise dominant frames are soft-thresholded to reduce the noise effects. Then, all the frames as well as IMFs of speech are combined, yielding the enhanced speech signal. The experimental results show the improved performance of the proposed algorithm compared to the recently reported methods.

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