Demonstrating Effects of Current and Projected Rainfall Characteristics on Wheat yield has been investigated in Sinana district for the period 1995-2016. Data on rainfall and crop yield for the period 1995-2016 were o...Demonstrating Effects of Current and Projected Rainfall Characteristics on Wheat yield has been investigated in Sinana district for the period 1995-2016. Data on rainfall and crop yield for the period 1995-2016 were obtained from National Meteorological Agency and Sinana District Agricultural Offices, respectively. Following data quality checking, rainfall data (current and future), correlation and regression studies were analyzed using Statistical software like Instat V3.36 and SPSS V20. Downscaling the output of CSIRO-Mk3.6.0 GCM model (daily rainfall data) for RCP8.5 emission scenario using a web based software tool (Marksim GCM) for the period 2020-2049 were used to determine seasonal total rainfall and ascertain its impact on yield. This study used mean, coefficient of variation, correlation and regression analysis to ascertain the relation, cause and effect relationship between rainfall characteristics and wheat yields. The results indicated that the mean onset date of the main rainy season (JJAS) for Robe and Sinana station was June 30 and July 3. Furthermore, the results of Pearson Correlation Coefficients indicated that kiremt rainfall total (JJAS) had moderate positive relationship (r = 0.499) with wheat yield in the study area. It was also observed that nearly fifty percent of total variance of crop yield is explained jointly by kiremt rainfall total and rainy day (R2 value was 47.9%). The result of projected wheat yield indicated that there will be a slight decrease in wheat yield (qt/ha) after 2030 years due to the impact of expected weakening of kiremt rainfall total. Taking in to account the above findings, it could be suggested that the farmers’ community will be encouraged encouraged to utilize timely climate information issued from National Meteorological Agency of Ethiopia (NMA) and other centers for farm level decision to enhance their crop production.展开更多
Introduction:Rangeland ecosystems provide multiple ecosystem services,including feed resources for wild and domestic herbivores in semi-arid areas.However,under the ever increasing environmental changes,the impact of ...Introduction:Rangeland ecosystems provide multiple ecosystem services,including feed resources for wild and domestic herbivores in semi-arid areas.However,under the ever increasing environmental changes,the impact of rainfall variability on the productivity and vegetation dynamics of rangelands are the great challenges that pastoral community are facing today.As a result,the potentials of most rangelands in semi-arid ecosystems affect the livestockproduction.Therefore,we studied the interconnections between the long-term rainfall variation and the rangeland Water Requirement and Satisfaction Index(WRSI)in Mieso,Jigjiga,and Shinile districts under pastoral conditions of Ethiopia.Methods:The base period rainfall data(1984–2015)was obtained from the National Meteorological Agency of Ethiopia,whereas the future rainfall trend was predicted using MarkSim software(Representative Concentration Pathways 4.5 GHG concentration trajectory).Mann-Kendall’s statistical tests,coefficient of variation,LEAP software(version 2.61),and Minitab Software(version 15)were used to assess the relationship between rangeland WRSI and long-term rainfall variability.Results:The result indicated that mean annual rainfall anomaly had strong positive correlation with rangeland WRSI in Mieso(P<0.05),Jigjiga(P<0.001),and Shinile(P<0.001)pastoral areas.Similarly,short and long rainy seasons had positive association(P<0.001)with rangeland WRSI,especially in Jigjiga and Shinile pastoral districts.The base period rainfall as well as the predicted annual rainfall showed variability in amount and distribution in all studied districts in pastoral areas of Ethiopia.Conclusions:The mean annual rainfall anomaly is correlated with the rangeland WRSI.Moreover,the future rainfall trend analysis indicated that variability of rainfall would be expected in between the years 2020–2049,2040–2069,and 2070–2099.Thus,the future rainfall variability would limit future rangeland WRSI under pastoral conditions of Ethiopia.Based on our study,we suggested establishment and implementation of early warning systems to reduce the likely impact of rainfall variability on future rangeland potential in dry lands under the pastoral production systems in eastern Ethiopia.展开更多
文摘Demonstrating Effects of Current and Projected Rainfall Characteristics on Wheat yield has been investigated in Sinana district for the period 1995-2016. Data on rainfall and crop yield for the period 1995-2016 were obtained from National Meteorological Agency and Sinana District Agricultural Offices, respectively. Following data quality checking, rainfall data (current and future), correlation and regression studies were analyzed using Statistical software like Instat V3.36 and SPSS V20. Downscaling the output of CSIRO-Mk3.6.0 GCM model (daily rainfall data) for RCP8.5 emission scenario using a web based software tool (Marksim GCM) for the period 2020-2049 were used to determine seasonal total rainfall and ascertain its impact on yield. This study used mean, coefficient of variation, correlation and regression analysis to ascertain the relation, cause and effect relationship between rainfall characteristics and wheat yields. The results indicated that the mean onset date of the main rainy season (JJAS) for Robe and Sinana station was June 30 and July 3. Furthermore, the results of Pearson Correlation Coefficients indicated that kiremt rainfall total (JJAS) had moderate positive relationship (r = 0.499) with wheat yield in the study area. It was also observed that nearly fifty percent of total variance of crop yield is explained jointly by kiremt rainfall total and rainy day (R2 value was 47.9%). The result of projected wheat yield indicated that there will be a slight decrease in wheat yield (qt/ha) after 2030 years due to the impact of expected weakening of kiremt rainfall total. Taking in to account the above findings, it could be suggested that the farmers’ community will be encouraged encouraged to utilize timely climate information issued from National Meteorological Agency of Ethiopia (NMA) and other centers for farm level decision to enhance their crop production.
文摘Introduction:Rangeland ecosystems provide multiple ecosystem services,including feed resources for wild and domestic herbivores in semi-arid areas.However,under the ever increasing environmental changes,the impact of rainfall variability on the productivity and vegetation dynamics of rangelands are the great challenges that pastoral community are facing today.As a result,the potentials of most rangelands in semi-arid ecosystems affect the livestockproduction.Therefore,we studied the interconnections between the long-term rainfall variation and the rangeland Water Requirement and Satisfaction Index(WRSI)in Mieso,Jigjiga,and Shinile districts under pastoral conditions of Ethiopia.Methods:The base period rainfall data(1984–2015)was obtained from the National Meteorological Agency of Ethiopia,whereas the future rainfall trend was predicted using MarkSim software(Representative Concentration Pathways 4.5 GHG concentration trajectory).Mann-Kendall’s statistical tests,coefficient of variation,LEAP software(version 2.61),and Minitab Software(version 15)were used to assess the relationship between rangeland WRSI and long-term rainfall variability.Results:The result indicated that mean annual rainfall anomaly had strong positive correlation with rangeland WRSI in Mieso(P<0.05),Jigjiga(P<0.001),and Shinile(P<0.001)pastoral areas.Similarly,short and long rainy seasons had positive association(P<0.001)with rangeland WRSI,especially in Jigjiga and Shinile pastoral districts.The base period rainfall as well as the predicted annual rainfall showed variability in amount and distribution in all studied districts in pastoral areas of Ethiopia.Conclusions:The mean annual rainfall anomaly is correlated with the rangeland WRSI.Moreover,the future rainfall trend analysis indicated that variability of rainfall would be expected in between the years 2020–2049,2040–2069,and 2070–2099.Thus,the future rainfall variability would limit future rangeland WRSI under pastoral conditions of Ethiopia.Based on our study,we suggested establishment and implementation of early warning systems to reduce the likely impact of rainfall variability on future rangeland potential in dry lands under the pastoral production systems in eastern Ethiopia.
