The southern regions of Madagascar have the country’s lowest water supply coverage and are highly vulnerable to drought.Access to potable drinking water is a major challenge for the local population.Chronic droughts ...The southern regions of Madagascar have the country’s lowest water supply coverage and are highly vulnerable to drought.Access to potable drinking water is a major challenge for the local population.Chronic droughts lead to annual emergency appeals to save the lives of acute malnourished children.UNICEF’s response consisting in providing potable drinking water through the drilling of boreholes has been challenged by the complex hydrogeology,the low yield of boreholes and high-level salinity of water,the lack of reliable groundwater data and the weak capacity of the drilling sector.These constraints result in a high rate of drilling failure.To improve drilling success and provide more potable drinking water to local communities,it is vital to undertake reliable groundwater investigation.UNICEF Madagascar and the European Union delegation in Madagascar collaborated on the use of satellite imagery to improve sector knowledge and access to safe and clean water for local communities in southern Madagascar.The methodology relies on produce thematic layers of groundwater potential areas.Later,these thematic layers were overlaid with ground-based hydrogeological data to map the groundwater potential zones(GWP) and identify the most suitable sites for borehole siting and drilling.Findings of this study are very encouraging,and the integrated approach used has proven its applicability in mapping groundwater potential areas in the eight drought-affected areas of south Madagascar.The groundwater potential zone map is being used by UNICEF and partners to plan water supply projects and identify the best sites for positioning new boreholes and reduce the likelihood of drilling failure.Additionally,the project developed a database of groundwater resources,which will improve knowledge of the regional hydrogeological context and strengthen the capacity of the water sector.Lessons learnt from this study show that an integration of the groundwater potential zone map with demographics and water demand information will help identifying priority areas for detailed studies.Moreover,a capacity building activity is required for knowledge/technology transfer to the Ministry of Energy,Water and Hydrocarbons(MEEH),allowing the possibility of scaling-up this integrated approach to the rest of Madagascar.Finally,strengthening the capacity of the MEEH and refining this approach as suggested above will certainly help in the pursuit to improve equitable access to safe and clean water for households located in the drought-affected areas of southern Madagascar,allowing them to be more resilient to the effects of climate change.展开更多
以华北农田冬小麦-夏玉米轮作体系连续6a施用生物炭和秸秆还田的土壤为研究对象,于2013年10月—2014年9月,采用静态暗箱-气相色谱法,对CO_2、N_2O通量进行了整个轮作周期的连续观测,探究施用生物炭与秸秆还田对其排放通量的影响。试验共...以华北农田冬小麦-夏玉米轮作体系连续6a施用生物炭和秸秆还田的土壤为研究对象,于2013年10月—2014年9月,采用静态暗箱-气相色谱法,对CO_2、N_2O通量进行了整个轮作周期的连续观测,探究施用生物炭与秸秆还田对其排放通量的影响。试验共设4个处理:CK(对照)、C1(低量生物炭4.5 t hm^(-2)a^(-1))、C2(高量生物炭9.0 t hm^(-2)a^(-1))和SR(秸秆还田straw return)。结果表明:在整个轮作周期内,各处理CO_2、N_2O通量随时间的变化趋势基本一致。随着生物炭施用量的增加,CO_2排放通量分别增加了0.3%—90.3%(C1)、1.0%—334.2%(C2)和0.4%—156.3%(SR)。其中,C2处理对CO_2累积排放量影响最大,增幅为42.9%。对N_2O而言,C2处理显著降低了N_2O累积排放量,但增加了CO_2和N_2O排放的综合增温潜势,C1和SR处理对N_2O累积排放量及综合增温潜势均没有显著影响。相关分析表明,土壤温度和土壤含水量是影响CO_2通量最主要的因素,两者之间呈极显著的正相关关系;N_2O通量与土壤温度、土壤含水量、NO_3^--N和NH_4^+-N均表现出极显著的正相关关系,而与土壤p H值表现出极显著的负相关关系。由此可见,添加生物炭对于减少氮素的气体损失具有较大的潜力。展开更多
基金the support of the Delegation of the European Union of the Republic of Madagascarthe Management of UNICEF Madagascar
文摘The southern regions of Madagascar have the country’s lowest water supply coverage and are highly vulnerable to drought.Access to potable drinking water is a major challenge for the local population.Chronic droughts lead to annual emergency appeals to save the lives of acute malnourished children.UNICEF’s response consisting in providing potable drinking water through the drilling of boreholes has been challenged by the complex hydrogeology,the low yield of boreholes and high-level salinity of water,the lack of reliable groundwater data and the weak capacity of the drilling sector.These constraints result in a high rate of drilling failure.To improve drilling success and provide more potable drinking water to local communities,it is vital to undertake reliable groundwater investigation.UNICEF Madagascar and the European Union delegation in Madagascar collaborated on the use of satellite imagery to improve sector knowledge and access to safe and clean water for local communities in southern Madagascar.The methodology relies on produce thematic layers of groundwater potential areas.Later,these thematic layers were overlaid with ground-based hydrogeological data to map the groundwater potential zones(GWP) and identify the most suitable sites for borehole siting and drilling.Findings of this study are very encouraging,and the integrated approach used has proven its applicability in mapping groundwater potential areas in the eight drought-affected areas of south Madagascar.The groundwater potential zone map is being used by UNICEF and partners to plan water supply projects and identify the best sites for positioning new boreholes and reduce the likelihood of drilling failure.Additionally,the project developed a database of groundwater resources,which will improve knowledge of the regional hydrogeological context and strengthen the capacity of the water sector.Lessons learnt from this study show that an integration of the groundwater potential zone map with demographics and water demand information will help identifying priority areas for detailed studies.Moreover,a capacity building activity is required for knowledge/technology transfer to the Ministry of Energy,Water and Hydrocarbons(MEEH),allowing the possibility of scaling-up this integrated approach to the rest of Madagascar.Finally,strengthening the capacity of the MEEH and refining this approach as suggested above will certainly help in the pursuit to improve equitable access to safe and clean water for households located in the drought-affected areas of southern Madagascar,allowing them to be more resilient to the effects of climate change.
文摘以华北农田冬小麦-夏玉米轮作体系连续6a施用生物炭和秸秆还田的土壤为研究对象,于2013年10月—2014年9月,采用静态暗箱-气相色谱法,对CO_2、N_2O通量进行了整个轮作周期的连续观测,探究施用生物炭与秸秆还田对其排放通量的影响。试验共设4个处理:CK(对照)、C1(低量生物炭4.5 t hm^(-2)a^(-1))、C2(高量生物炭9.0 t hm^(-2)a^(-1))和SR(秸秆还田straw return)。结果表明:在整个轮作周期内,各处理CO_2、N_2O通量随时间的变化趋势基本一致。随着生物炭施用量的增加,CO_2排放通量分别增加了0.3%—90.3%(C1)、1.0%—334.2%(C2)和0.4%—156.3%(SR)。其中,C2处理对CO_2累积排放量影响最大,增幅为42.9%。对N_2O而言,C2处理显著降低了N_2O累积排放量,但增加了CO_2和N_2O排放的综合增温潜势,C1和SR处理对N_2O累积排放量及综合增温潜势均没有显著影响。相关分析表明,土壤温度和土壤含水量是影响CO_2通量最主要的因素,两者之间呈极显著的正相关关系;N_2O通量与土壤温度、土壤含水量、NO_3^--N和NH_4^+-N均表现出极显著的正相关关系,而与土壤p H值表现出极显著的负相关关系。由此可见,添加生物炭对于减少氮素的气体损失具有较大的潜力。
