蓝藻水华严重威胁湖泊周围地区的饮用水安全,为了给决策部门提供良好的数据支持,利用MODIS Ter ra和Aqua影像,采用归一化植被指数法(N DVI)来提取湖泊蓝藻水华信息,并分析湖泊蓝藻水华覆盖面积、暴发频率等时空分布特征。以巢湖为例,提...蓝藻水华严重威胁湖泊周围地区的饮用水安全,为了给决策部门提供良好的数据支持,利用MODIS Ter ra和Aqua影像,采用归一化植被指数法(N DVI)来提取湖泊蓝藻水华信息,并分析湖泊蓝藻水华覆盖面积、暴发频率等时空分布特征。以巢湖为例,提取该湖泊2015年7月至2018年6月晴好天气下的蓝藻水华信息,结果显示:该湖泊蓝藻水华暴发时间主要集中于每年1月、5~6月及8~9月,水华暴发频率最大值出现在每年的8~10月。研究结果有助于掌握蓝藻水华的分布情况,为该湖泊应急治理工作提供数据支持,相关经验可以供类似河流湖泊管理单位借鉴。展开更多
In this paper,the relationship between a pair of low-frequency vortexes over the equatorial Indian Ocean and the South China Sea(SCS) summer monsoon onset is studied based on a multi-year(1980-2003) analysis.A pair of...In this paper,the relationship between a pair of low-frequency vortexes over the equatorial Indian Ocean and the South China Sea(SCS) summer monsoon onset is studied based on a multi-year(1980-2003) analysis.A pair of vortexes symmetric about the equator is an important feature prior to the SCS summer monsoon onset.A composite analysis shows that the life cycle of the pair of vortexes is closely associated with the SCS summer monsoon onset.The westerly between the twin cyclones is an important factor to the SCS summer monsoon onset process.展开更多
This study is a review of existing reports and summary of some field experiences aiming at building of a resilient wheat seed system to resist rust risks in Ethiopia. Practical gaps in the wheat seed system were ident...This study is a review of existing reports and summary of some field experiences aiming at building of a resilient wheat seed system to resist rust risks in Ethiopia. Practical gaps in the wheat seed system were identified with regard to understanding of seed system factors that build, or undermine resilience to rust risks. The study has recognized that the formal seed multiplication schemes are too slow to respond to the ever increasing frequencies of wheat rust outbreaks. Therefore, it is indicated that new approaches such as pre-release and farmer based seed multiplication schemes are helpful in insuring availability of seed of rust resistant wheat varieties to the small farmers.展开更多
文摘蓝藻水华严重威胁湖泊周围地区的饮用水安全,为了给决策部门提供良好的数据支持,利用MODIS Ter ra和Aqua影像,采用归一化植被指数法(N DVI)来提取湖泊蓝藻水华信息,并分析湖泊蓝藻水华覆盖面积、暴发频率等时空分布特征。以巢湖为例,提取该湖泊2015年7月至2018年6月晴好天气下的蓝藻水华信息,结果显示:该湖泊蓝藻水华暴发时间主要集中于每年1月、5~6月及8~9月,水华暴发频率最大值出现在每年的8~10月。研究结果有助于掌握蓝藻水华的分布情况,为该湖泊应急治理工作提供数据支持,相关经验可以供类似河流湖泊管理单位借鉴。
基金financed by the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No. KZCX2-YW-Q11-03)the National Basic Research Program of China(Grant No.2010CB950401)
文摘In this paper,the relationship between a pair of low-frequency vortexes over the equatorial Indian Ocean and the South China Sea(SCS) summer monsoon onset is studied based on a multi-year(1980-2003) analysis.A pair of vortexes symmetric about the equator is an important feature prior to the SCS summer monsoon onset.A composite analysis shows that the life cycle of the pair of vortexes is closely associated with the SCS summer monsoon onset.The westerly between the twin cyclones is an important factor to the SCS summer monsoon onset process.
文摘This study is a review of existing reports and summary of some field experiences aiming at building of a resilient wheat seed system to resist rust risks in Ethiopia. Practical gaps in the wheat seed system were identified with regard to understanding of seed system factors that build, or undermine resilience to rust risks. The study has recognized that the formal seed multiplication schemes are too slow to respond to the ever increasing frequencies of wheat rust outbreaks. Therefore, it is indicated that new approaches such as pre-release and farmer based seed multiplication schemes are helpful in insuring availability of seed of rust resistant wheat varieties to the small farmers.