Recent changes in precipitation regime in South-East Asia are a subject of ongoing discussion. In this article, for the first time, evidence of a precipitation regime shift during the mid-1970s in the Northern Hemispheric part of South-East Asia is demonstrated. The detection of regime shifts is made possible by using a new comprehensive dataset of daily precipitation records (South-East Asian Climate Assessment and Dataset) and applying a novel Bayesian approach for regime shift detection. After the detected regime shift event in the mid-1970s, significant changes in precipitation distribution occurred in the Northern Hemispheric regions—Indochina Peninsula and the Philippines. More specifically, dry days became up to 10% more frequent in some regions. However, no precipitation regime shift is detected in Southern Hemisphere regions—Java and Northern Australia, were the number of observed dry days increased gradually.
{"title":"Precipitation Regime Shift Associated with the Pacific Decadal Oscillation in the Maritime Continent","authors":"V. Kokorev, J. Ettema, P. Siegmund, G. Schrier","doi":"10.4236/ajcc.2020.92009","DOIUrl":"https://doi.org/10.4236/ajcc.2020.92009","url":null,"abstract":"Recent changes in precipitation regime in South-East Asia are a subject of ongoing discussion. In this article, for the first time, evidence of a precipitation regime shift during the mid-1970s in the Northern Hemispheric part of South-East Asia is demonstrated. The detection of regime shifts is made possible by using a new comprehensive dataset of daily precipitation records (South-East Asian Climate Assessment and Dataset) and applying a novel Bayesian approach for regime shift detection. After the detected regime shift event in the mid-1970s, significant changes in precipitation distribution occurred in the Northern Hemispheric regions—Indochina Peninsula and the Philippines. More specifically, dry days became up to 10% more frequent in some regions. However, no precipitation regime shift is detected in Southern Hemisphere regions—Java and Northern Australia, were the number of observed dry days increased gradually.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47385547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lowland rice production is highly vulnerable to extreme temperature as a result of climate change. The study analyses farmer’s perception about climate change, management practice and their on-farm adoption strategies at the rice fields of Sapu and Kuntaur study location. The selected villages were the main rice production area, where rice is a monoculture crop. Focus group discussion was held with twenty rice growing farmers at Sapuand Kuntaur, and these were divided into five groups. Personal interview and key informant involves the two village head, two youth development chairpersons (VDC) and the extension worker overseeing both villages. This was done to gain in-depth knowledge on the subject matter. The analysis results indicated that more than 50% of the rice growing farmers were female and do not undergo formal education. More than 70% of them having perceived knowledge on the causes of climate change, inorganic fertilizer use, transplanting of rice seedlings, use of improved rice varieties, and on-farm coping strategies such as changing of cropping calendar and the use of pesticides to cope with current and future climate situation.
{"title":"Farmers Perceptions about Climate Change, Management Practice and Their On-Farm Adoption Strategies at Rice Fields in Sapu and Kuntaur of the Gambia, West Africa","authors":"F. Bojang, S. Traoré, A. Togola, Y. Diallo","doi":"10.4236/ajcc.2020.91001","DOIUrl":"https://doi.org/10.4236/ajcc.2020.91001","url":null,"abstract":"Lowland rice production is highly vulnerable to extreme temperature as a result of climate change. The study analyses farmer’s perception about climate change, management practice and their on-farm adoption strategies at the rice fields of Sapu and Kuntaur study location. The selected villages were the main rice production area, where rice is a monoculture crop. Focus group discussion was held with twenty rice growing farmers at Sapuand Kuntaur, and these were divided into five groups. Personal interview and key informant involves the two village head, two youth development chairpersons (VDC) and the extension worker overseeing both villages. This was done to gain in-depth knowledge on the subject matter. The analysis results indicated that more than 50% of the rice growing farmers were female and do not undergo formal education. More than 70% of them having perceived knowledge on the causes of climate change, inorganic fertilizer use, transplanting of rice seedlings, use of improved rice varieties, and on-farm coping strategies such as changing of cropping calendar and the use of pesticides to cope with current and future climate situation.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49412258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Neya, Tiga Neya, A. Abunyewa, B. J. Zoungrana, Hypolite Tiendrebeogo, K. Dimobe, Joel Korahire
Sahel zone has been reported as one of the most vulnerable regions to climate change, so serious attention must be paid to this zone by researchers and development actors who are interested in environmental-human dynamics and interactions. The aim of this study was to bring more insight into the impact of actions aiming at reducing land degradation, regreening the Sahel, stopping population migration and reducing the pressure on land in the Sahelian zone. The study focused on farmland dynamic in Ouahigouya municipality based on remote sensing data from 1986 to 2016 using intensity analysis. The annual time interval change was 0.77% and 2.46% for 1986-2001 and 2001-2016, respectively. Farmlands gained from mixt vegetation, water bodies and from bar lands. Mixed vegetation and water bodies were both active during both intervals while the other land use such as woodland and bar land were dormant. Combining land use land cover analysis and intensity analysis was found to be effective for assessing the differentiated impact of the various land restoration actions.
{"title":"Land Use Land Cover Dynamics and Farmland Intensity Analysis at Ouahigouya Municipality of Burkina Faso, West Africa","authors":"O. Neya, Tiga Neya, A. Abunyewa, B. J. Zoungrana, Hypolite Tiendrebeogo, K. Dimobe, Joel Korahire","doi":"10.4236/ajcc.2020.91003","DOIUrl":"https://doi.org/10.4236/ajcc.2020.91003","url":null,"abstract":"Sahel zone has been reported as one of the most vulnerable regions to climate change, so serious attention must be paid to this zone by researchers and development actors who are interested in environmental-human dynamics and interactions. The aim of this study was to bring more insight into the impact of actions aiming at reducing land degradation, regreening the Sahel, stopping population migration and reducing the pressure on land in the Sahelian zone. The study focused on farmland dynamic in Ouahigouya municipality based on remote sensing data from 1986 to 2016 using intensity analysis. The annual time interval change was 0.77% and 2.46% for 1986-2001 and 2001-2016, respectively. Farmlands gained from mixt vegetation, water bodies and from bar lands. Mixed vegetation and water bodies were both active during both intervals while the other land use such as woodland and bar land were dormant. Combining land use land cover analysis and intensity analysis was found to be effective for assessing the differentiated impact of the various land restoration actions.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45343684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study analyzed relationships between soil properties and food crop production in Ebonyi State of southeast Nigeria. Free survey was conducted after three zones (Agbaja, Akaeze and Ikwo) in the state were purposely selected for representation of the soil sampling. Two types of sampling were conducted; Auger sampling at 0 - 20 and 20 - 40 cm depths and soil profile sampling. Annual crop yield data on maize and cassava for the state from 1988 to 2017 were collected from Agriculture Development Program. Variations in properties among soil horizons were obtained using coefficient of variations while soil parameters were regressed against crop yields to establish their relationships. Results showed that fine sand, total sand, bulk density, total porosity, soil pH, and available phosphorus significantly (p = 0.05) differ from 0 - 20 cm and 20 - 40 cm depths. Also, cassava yield correlated negatively with base saturation, and organic matter at 0.05 probability level; with exchangeable Ca and Na at 0.01 probabilities level but correlated positively with bulk density and available water capacity at 0.01 and 0.05 probability levels, respectively. Similarly, maize yield correlated negatively with available phosphorus and total nitrogen at 0.05 probability level; and with total porosity and exchangeable Ca at 0.01 probability level; and then correlated positively with available water capacity, and bulk density, at 0.01 probability level; with coarse sand at 0.05 probability level. However, soils of Ebonyi State are fertile but some of the chemical properties are still low, therefore, it is paramount to improve the quality of the soil to achieve improved food security in the state.
{"title":"Physico-Chemical Soil Properties and Their Correlations with Maize and Cassava Production in Ebonyi, Nigeria","authors":"F. Okorie, J. Njoku, E. Onweremadu, M. Iwuji","doi":"10.4236/ajcc.2020.91004","DOIUrl":"https://doi.org/10.4236/ajcc.2020.91004","url":null,"abstract":"This study analyzed relationships between soil properties and food crop production in Ebonyi State of southeast Nigeria. Free survey was conducted after three zones (Agbaja, Akaeze and Ikwo) in the state were purposely selected for representation of the soil sampling. Two types of sampling were conducted; Auger sampling at 0 - 20 and 20 - 40 cm depths and soil profile sampling. Annual crop yield data on maize and cassava for the state from 1988 to 2017 were collected from Agriculture Development Program. Variations in properties among soil horizons were obtained using coefficient of variations while soil parameters were regressed against crop yields to establish their relationships. Results showed that fine sand, total sand, bulk density, total porosity, soil pH, and available phosphorus significantly (p = 0.05) differ from 0 - 20 cm and 20 - 40 cm depths. Also, cassava yield correlated negatively with base saturation, and organic matter at 0.05 probability level; with exchangeable Ca and Na at 0.01 probabilities level but correlated positively with bulk density and available water capacity at 0.01 and 0.05 probability levels, respectively. Similarly, maize yield correlated negatively with available phosphorus and total nitrogen at 0.05 probability level; and with total porosity and exchangeable Ca at 0.01 probability level; and then correlated positively with available water capacity, and bulk density, at 0.01 probability level; with coarse sand at 0.05 probability level. However, soils of Ebonyi State are fertile but some of the chemical properties are still low, therefore, it is paramount to improve the quality of the soil to achieve improved food security in the state.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48441764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lori Petrauski, S. Owen, G. Constantz, James T. Anderson
There has been an increased effort to utilize untapped sources of historical phenological data such as museum specimens, journals written by nature-minded citizens, and dated photographs through local phenology projects for climate change research. Local phenology projects have contributed greatly to our current understanding of phenological changes over time and have an important role in the public’s engagement with natural history, but there are also significant challenges in finding and analyzing historical data. The West Virginia Climate History Project collected historical phenology data (1890-2015) from citizens in West Virginia with scientific and cultural results. We discuss the development of the project, issues we overcame, recommendations for future projects, and the conservation value of local phenology projects. Local phenology projects lend value to climate change research and conservation education. Policy directed towards supporting humanities grants and museum collections, including herbariums, is crucial in the success of these projects.
{"title":"Developing a Historical Phenology Dataset through Community Involvement for Climate Change Research","authors":"Lori Petrauski, S. Owen, G. Constantz, James T. Anderson","doi":"10.4236/ajcc.2020.91002","DOIUrl":"https://doi.org/10.4236/ajcc.2020.91002","url":null,"abstract":"There has been an increased effort to utilize untapped sources of historical phenological data such as museum specimens, journals written by nature-minded citizens, and dated photographs through local phenology projects for climate change research. Local phenology projects have contributed greatly to our current understanding of phenological changes over time and have an important role in the public’s engagement with natural history, but there are also significant challenges in finding and analyzing historical data. The West Virginia Climate History Project collected historical phenology data (1890-2015) from citizens in West Virginia with scientific and cultural results. We discuss the development of the project, issues we overcame, recommendations for future projects, and the conservation value of local phenology projects. Local phenology projects lend value to climate change research and conservation education. Policy directed towards supporting humanities grants and museum collections, including herbariums, is crucial in the success of these projects.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44026058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The AJCC Most Influential Paper Award recognizes papers that had significant impacts in the scientific community (e.g. cited by Nature, Science) or had more than 15 citations based on the Web of knowledge. Each year, the editorial board of American Journal of Climate Change (AJCC) reviews the papers published by AJCC to select the papers they consider to have had the most influence on the research of climate change and related fields since their original publication. The AJCC Most Influential Paper Award recognizes papers that had significant impacts in the scientific community (e.g. cited by Nature, Science) or had more than 15 citations based on the Web of knowledge. This award consists of a certificate listing the paper, the author’s name and the author’s affiliation and carries a financial prize of $599 to cover the article processing charge of their future paper published by AJCC.
{"title":"Recipients of 2020 AJCC Most Influential Paper Award","authors":"Ajcc Editorial Board","doi":"10.4236/ajcc.2018.71001","DOIUrl":"https://doi.org/10.4236/ajcc.2018.71001","url":null,"abstract":"The AJCC Most Influential Paper Award recognizes papers that had significant impacts in the scientific community (e.g. cited by Nature, Science) or had more than 15 citations based on the Web of knowledge. Each year, the editorial board of American Journal of Climate Change (AJCC) reviews the papers published by AJCC to select the papers they consider to have had the most influence on the research of climate change and related fields since their original publication. The AJCC Most Influential Paper Award recognizes papers that had significant impacts in the scientific community (e.g. cited by Nature, Science) or had more than 15 citations based on the Web of knowledge. This award consists of a certificate listing the paper, the author’s name and the author’s affiliation and carries a financial prize of $599 to cover the article processing charge of their future paper published by AJCC.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70503292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Existing limited understanding on the teleconnections between ocean-atmosphere coupled phenomena and drought occurrences in Ethiopia has been undermining the decisions and interventions related to climate change adaptation and mitigation. The two drought indices Standardized Precipitation Index and Reconnaissance Drought Index were used for correlation and lag correlation with global indices El-Nino Southern Oscillation, Oceanic Nino, Indian Ocean Dipole and Pacific Decadal Oscillation. The indices were obtained from their respective database websites of the National Center for Environmental Prediction. Historical EL-Nino and La-Nina years and Ethiopian drought years were collected from literatures. Meteorological data on seasonal mean rainfall, maximum and minimum temperatures from 1916-2016 were collected from Tigray regional meteorology agency. In addition, the Cru/ Model data were collected from KNMI climate explorer. The analysis results the strong correlations of global indices Nino3.4, IOD and PDO with local indices for April to June rainy season while SOI and IOD indices for July-Sep. The positive correlation of indices weakened and/or dislocated the rain-producing components for main rainy season, while those systems enhanced in low rain season. This shows global indices alter rain fall distribution & conveys Meteorological and Agricultural drought. The study revealed that, in addition to El Nino impacts, other events such as PDO, SOI and IOD are important factors for triggering meteorological and agricultural droughts in Tigray region of Ethiopia. This information has multiple implications, among others, improves seasonal forecast to make informed decisions.
{"title":"Teleconnections between Ocean-Atmosphere Coupled Phenomenon and Droughts in Tigray Region: Northern Ethiopia","authors":"M. Molla","doi":"10.4236/ajcc.2020.93018","DOIUrl":"https://doi.org/10.4236/ajcc.2020.93018","url":null,"abstract":"Existing limited understanding on the teleconnections between ocean-atmosphere coupled phenomena and drought occurrences in Ethiopia has been undermining the decisions and interventions related to climate change adaptation and mitigation. The two drought indices Standardized Precipitation Index and Reconnaissance Drought Index were used for correlation and lag correlation with global indices El-Nino Southern Oscillation, Oceanic Nino, Indian Ocean Dipole and Pacific Decadal Oscillation. The indices were obtained from their respective database websites of the National Center for Environmental Prediction. Historical EL-Nino and La-Nina years and Ethiopian drought years were collected from literatures. Meteorological data on seasonal mean rainfall, maximum and minimum temperatures from 1916-2016 were collected from Tigray regional meteorology agency. In addition, the Cru/ Model data were collected from KNMI climate explorer. The analysis results the strong correlations of global indices Nino3.4, IOD and PDO with local indices for April to June rainy season while SOI and IOD indices for July-Sep. The positive correlation of indices weakened and/or dislocated the rain-producing components for main rainy season, while those systems enhanced in low rain season. This shows global indices alter rain fall distribution & conveys Meteorological and Agricultural drought. The study revealed that, in addition to El Nino impacts, other events such as PDO, SOI and IOD are important factors for triggering meteorological and agricultural droughts in Tigray region of Ethiopia. This information has multiple implications, among others, improves seasonal forecast to make informed decisions.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70503160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Mwangi, Anthony M. Musili, Viola A. Otieno, H. S. Endris, G. Sabiiti, M. Hassan, A. T. Tsehayu, Artan Guleid, Z. Atheru, A. C. Guzha, Thomas De Meo, N. Smith, D. Makanji, J. Kerkering, B. Doud, E. Kanyanya
Recent trends show that in the coming decades, Kenya’s natural resources will continue to face significant pressure due to both anthropogenic and natural stressors, and this will have greater negative impacts on socio-economic development including food security and livelihoods. Understanding the impacts of these stressors is an important step to developing coping and adaptation strategies at every level. The Water Towers of Kenya play a critical role in supplying ecosystems services such as water supply, timber and non-timber forest products and regulating services such as climate and water quantity and quality. To assess the vulnerability of the Water Towers to climate change, the study adopted the IPCC AR4 framework that defines vulnerability as a function of exposure, sensitivity, and adaptive capacity. The historical trends in rainfall indicate that the three Water Towers show a declining rainfall trend during the March-April-May (MAM) main rainy season, while the October-November-December (OND) short rainy season shows an increase. The temperature patterns are consistent with the domain having a common rising trend with a rate in the range of 0.3°C to 0.5°C per decade. Projection analysis considered three emissions scenarios: low-emission (mitigation) scenario (RCP2.6), a medium-level emission scenario (RCP4.5), and a high-emission (business as usual) scenario (RCP8.5). The results of the high-emission scenario show that the annual temperature over the Water Towers could rise by 3.0°C to 3.5°C by the 2050s (2036-2065) and 3.6°C to 4.8°C by the 2070s (2055-2085 results not presented), relative to the baseline period 1970-2000. The findings indicate that exposure, sensitivity, and adaptive capacity vary in magnitude, as well as spatially across the Water Towers. This is reflected in the spatially variable vulnerability index across the Water Towers. Overall vulnerability will increase in the water towers leading to erosion of the resilience of the exposed ecosystems and the communities that rely on ecosystem services these landscapes provide.
{"title":"Vulnerability of Kenya’s Water Towers to Future Climate Change: An Assessment to Inform Decision Making in Watershed Management","authors":"K. Mwangi, Anthony M. Musili, Viola A. Otieno, H. S. Endris, G. Sabiiti, M. Hassan, A. T. Tsehayu, Artan Guleid, Z. Atheru, A. C. Guzha, Thomas De Meo, N. Smith, D. Makanji, J. Kerkering, B. Doud, E. Kanyanya","doi":"10.4236/ajcc.2020.93020","DOIUrl":"https://doi.org/10.4236/ajcc.2020.93020","url":null,"abstract":"Recent trends show that in the coming decades, Kenya’s natural resources will continue to face significant pressure due to both anthropogenic and natural stressors, and this will have greater negative impacts on socio-economic development including food security and livelihoods. Understanding the impacts of these stressors is an important step to developing coping and adaptation strategies at every level. The Water Towers of Kenya play a critical role in supplying ecosystems services such as water supply, timber and non-timber forest products and regulating services such as climate and water quantity and quality. To assess the vulnerability of the Water Towers to climate change, the study adopted the IPCC AR4 framework that defines vulnerability as a function of exposure, sensitivity, and adaptive capacity. The historical trends in rainfall indicate that the three Water Towers show a declining rainfall trend during the March-April-May (MAM) main rainy season, while the October-November-December (OND) short rainy season shows an increase. The temperature patterns are consistent with the domain having a common rising trend with a rate in the range of 0.3°C to 0.5°C per decade. Projection analysis considered three emissions scenarios: low-emission (mitigation) scenario (RCP2.6), a medium-level emission scenario (RCP4.5), and a high-emission (business as usual) scenario (RCP8.5). The results of the high-emission scenario show that the annual temperature over the Water Towers could rise by 3.0°C to 3.5°C by the 2050s (2036-2065) and 3.6°C to 4.8°C by the 2070s (2055-2085 results not presented), relative to the baseline period 1970-2000. The findings indicate that exposure, sensitivity, and adaptive capacity vary in magnitude, as well as spatially across the Water Towers. This is reflected in the spatially variable vulnerability index across the Water Towers. Overall vulnerability will increase in the water towers leading to erosion of the resilience of the exposed ecosystems and the communities that rely on ecosystem services these landscapes provide.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70503235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Quansah, P. Welikhe, G. E. Afandi, S. Fall, D. Mortley, R. Ankumah
Process-based crop simulation models are useful for simulating the impacts of climate change on crop yields. Currently, estimation of spatially calibrated soil parameters for crop models can be challenging, as it requires the availability of long-term and detailed input data from several sentinel sites. The use of aggregated regional data for model calibrations has been proposed but not been employed in regional climate change studies. The study: 1) employed the use of county-level data to estimate spatial soil parameters for the calibration of CROPGRO-Soybean model and 2) used the calibrated model, assimilated with future climate data, in assessing the impacts of climate change on soybean yields. The CROPGRO-Soybean model was calibrated using major agricultural soil types, crop yield and current climate data at county level, for selected counties in Alabama for the period 1981-2010. The calibrated model simulations were acceptable with performance indicators showing Root Mean Square Error percent of between 27 - 43 and Index of Agreement ranging from 0.51 to 0.76. Projected soybean yield decreased by an average of 29% and 23% in 2045, and 19% and 43% in 2075, under Representative Concentration Pathways 4.5 and 8.5, respectively. Results showed that late-maturing soybean cultivars were most resilient to heat, while late-maturing cultivators needed optimized irrigation to maintain appropriate soil moisture to sustain soybean yields. The CROPGRO-Soybean phenological and yield simulations suggested that the negative effects of increasing temperatures could be counterbalanced by increasing rainfall, optimized irrigation, and cultivating late-maturing soybean cultivars.
{"title":"CROPGRO-Soybean Model Calibration and Assessment of Soybean Yield Responses to Climate Change","authors":"J. Quansah, P. Welikhe, G. E. Afandi, S. Fall, D. Mortley, R. Ankumah","doi":"10.4236/ajcc.2020.93019","DOIUrl":"https://doi.org/10.4236/ajcc.2020.93019","url":null,"abstract":"Process-based crop simulation models are useful for simulating the impacts of climate change on crop yields. Currently, estimation of spatially calibrated soil parameters for crop models can be challenging, as it requires the availability of long-term and detailed input data from several sentinel sites. The use of aggregated regional data for model calibrations has been proposed but not been employed in regional climate change studies. The study: 1) employed the use of county-level data to estimate spatial soil parameters for the calibration of CROPGRO-Soybean model and 2) used the calibrated model, assimilated with future climate data, in assessing the impacts of climate change on soybean yields. The CROPGRO-Soybean model was calibrated using major agricultural soil types, crop yield and current climate data at county level, for selected counties in Alabama for the period 1981-2010. The calibrated model simulations were acceptable with performance indicators showing Root Mean Square Error percent of between 27 - 43 and Index of Agreement ranging from 0.51 to 0.76. Projected soybean yield decreased by an average of 29% and 23% in 2045, and 19% and 43% in 2075, under Representative Concentration Pathways 4.5 and 8.5, respectively. Results showed that late-maturing soybean cultivars were most resilient to heat, while late-maturing cultivators needed optimized irrigation to maintain appropriate soil moisture to sustain soybean yields. The CROPGRO-Soybean phenological and yield simulations suggested that the negative effects of increasing temperatures could be counterbalanced by increasing rainfall, optimized irrigation, and cultivating late-maturing soybean cultivars.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70503223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vegetation resources in Nigeria are of vital importance for the sustainable development of the country. However, this essential resource is in danger due to the effect of anthropogenic and climate induced impacts. Currently desert encroachment which cuts across the Sahel is affecting most of the states in the northern part of the country particularly the eleven states considered by the Federal Ministry of Environment in Nigeria as the frontline states. Several studies on the Nigerian environment have shown that there are serious threats to the general environment particularly vegetation. Due to population growth and the need for housing as well as the expansion of the over-utilised farmlands across these states, places considered as reserved areas across the country are being exploited to the detriment of the vegetal resources particularly the forest and rangeland areas. This study utilized Idrisi TerrSet (version 18) raster-based remote sensing and GIS software to analyse seventy two (72) dekadal Normalised Vegetation Index (NDVI) imageries from SPOT satellite covering Nigeria in order to assess the anthropogenic and likely climatic impacts on the vegetal resources using the forward t-mode Principal Component Analysis (PCA) with standardised principal components. Results indicated that Component 1 which explains about 69% of the 72 time-series NDVI imageries shows typical vegetation cover over the study area within the time period under study. While component two indicated a cyclic trend differentiating the ENSO events of 1999 and 2009; component three indicated positive anomaly pattern of vegetation NDVI mostly within Sokoto, Kebbi, Kano, Jigawa and the northern parts of Bauchi, Yobe and Borno states. However, Component four imagery indicated a likely link to the 2009 flood that affected Kainji dam and rivers Niger and Benue. For a better result, the integration of socio-economic and high spatial resolution data into an assessment of this kind in future studies is encouraged.
{"title":"Spatio-Temporal Assessment of Vegetation Resource Dynamics in Nigeria from SPOT Satellite Imageries","authors":"S. Yelwa, A. B. Sanda, U. Usman","doi":"10.4236/ajcc.2019.84027","DOIUrl":"https://doi.org/10.4236/ajcc.2019.84027","url":null,"abstract":"Vegetation resources in Nigeria are of vital importance for the sustainable development of the country. However, this essential resource is in danger due to the effect of anthropogenic and climate induced impacts. Currently desert encroachment which cuts across the Sahel is affecting most of the states in the northern part of the country particularly the eleven states considered by the Federal Ministry of Environment in Nigeria as the frontline states. Several studies on the Nigerian environment have shown that there are serious threats to the general environment particularly vegetation. Due to population growth and the need for housing as well as the expansion of the over-utilised farmlands across these states, places considered as reserved areas across the country are being exploited to the detriment of the vegetal resources particularly the forest and rangeland areas. This study utilized Idrisi TerrSet (version 18) raster-based remote sensing and GIS software to analyse seventy two (72) dekadal Normalised Vegetation Index (NDVI) imageries from SPOT satellite covering Nigeria in order to assess the anthropogenic and likely climatic impacts on the vegetal resources using the forward t-mode Principal Component Analysis (PCA) with standardised principal components. Results indicated that Component 1 which explains about 69% of the 72 time-series NDVI imageries shows typical vegetation cover over the study area within the time period under study. While component two indicated a cyclic trend differentiating the ENSO events of 1999 and 2009; component three indicated positive anomaly pattern of vegetation NDVI mostly within Sokoto, Kebbi, Kano, Jigawa and the northern parts of Bauchi, Yobe and Borno states. However, Component four imagery indicated a likely link to the 2009 flood that affected Kainji dam and rivers Niger and Benue. For a better result, the integration of socio-economic and high spatial resolution data into an assessment of this kind in future studies is encouraged.","PeriodicalId":69702,"journal":{"name":"美国气候变化期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48844390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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