Dakar area landscape is mainly characterized by the existence of the ＂niaye＂-or agricultural depressions located in the sand dunes system. In these depressions, the top-table of quaternary sand groundwater reaches o...Dakar area landscape is mainly characterized by the existence of the ＂niaye＂-or agricultural depressions located in the sand dunes system. In these depressions, the top-table of quaternary sand groundwater reaches or overflows the soil surface. Because of a recent groundwater level drop, some of the niayes have become runoff-gathering sites. This water ensures various economical, environmental and social services, i.e. urban agriculture, drinking water supply of Dakar and formation of ecosystems supporting biodiversity. Given that rainwater infiltration is the only natural ＂input＂, conception and implemention of rainwater management PPP （Politics, Plan and Program） must necessarily take into account this interrelationl Nowadays, two acute problems are observed in the Dakar area. On the one hand, the niayes are threatened by a hydrological drying process due to the insufficiency of rainwater refill. On the other hand, the dramatic social pressure on the environment has led to the urbanization of these bottom-lands. Furthermore, because of the pluviometry decrease, a worsening of the nuisances （floods and malaria） related to surface waters occurs. Consequently, an appropriate runoff management should integrate both the ＂risk＂ and ＂resource＂ dimensions, thus allowing the protection of natural resources and a secure living environment. According to the limits of＂classicai＂ solutions, this paper provides approach elements for building a sustainability plan focusing on emergent concerns, which would control rainwater in urbanized zones.展开更多
Social imbalance and obsolescence of the built environment has emerged in large sized housing estates in metropolises. In particular, the requirement of such planned housing areas has not matched public service provid...Social imbalance and obsolescence of the built environment has emerged in large sized housing estates in metropolises. In particular, the requirement of such planned housing areas has not matched public service provided by the infrastructure. On not only physical but also social aspect of local communities of this kind of housing area have a lot of problems while it also has a lot of good characteristics. A representative one is that age of the tenants is rising very swiftly and it makes the local community imbalanced. Nowadays many countries including Japan have tackled problems concerning housing estates constructed during the mass housing era and try to search for ways to reactivate so-called new town areas by utilisation of existing environmental resources such as building stock and ample green open space. In Japan many elemental technologies have been developed in order to utilise existing building stock. However, how to combine these technologies and new holistic methods for reactivation are still underdeveloped. Therefore, it is very important to fred these ways and to make a comprehensive plan for rehabilitation of these areas. The first purpose of our study is to develop and clarify how to organise and integrate many kinds of elemental techniques and the holistic measures for the improvement of both social and physical environment in suburban mass housing estates. Subsequently we try to reorganise proper relations between human settlements and the various service provision for those regions. Our last focus is put on searching for new ways to raise the value of existing housing environment. Our conclusion intends to indicate important of the master plan and its execution, where mass housing estates progress for the physical and social improvement.展开更多
Abuse of chemical fertilizer and pesticide will not only impair the quality of agricultural products,but also damage the agricultural ecological environment.From the perspective of cooperatives’socialized services,th...Abuse of chemical fertilizer and pesticide will not only impair the quality of agricultural products,but also damage the agricultural ecological environment.From the perspective of cooperatives’socialized services,this paper studies agricultural households’chemical fertilizer and pesticide use behavior,attempting to provide references for the government’s formulation of relevant policies and cooperatives’adjustment of their operation strategies.The survey data of 518 agricultural households in Zigui County and Badong County,Hubei Province,China are used to examine the influence of cooperatives and their socialized services on agricultural households’chemical fertilizer and pesticide use intensity via propensity score matching.Research reveals that:(1)Joining cooperatives has a significantly negative influence on agricultural households’chemical fertilizer and pesticide use intensity,and the average treatment effect is-341.505 yuan mu^(-1).(2)Agricultural materials supply services and technical support services can significantly bring down agricultural households’chemical fertilizer and pesticide use intensity,and the average treatment effect is-225.966 yuan mu^(-1)and-163.580 yuan mu^(-1),respectively.While the influence of agricultural products sale services on chemical fertilizer and pesticide use intensity is not significant.(3)Grouped investigation is carried out by age,education years and planting scale,and the influence of socialized services on agricultural householders’chemical fertilizer and pesticide use intensity is obviously varied among different groups.The influence of agricultural materials supply services on agricultural households who are elder,with smaller education years and small planting scale is significant;the influence of technical support services on agricultural households who are younger,with higher education years and small planting scale is significant;the influence of agricultural products sale services on agricultural households who are elder is significant.It is necessary to improve the percentage of agricultural households joining cooperatives,increase the supply level of cooperatives’socialized services,and make socialized services of cooperatives more targeted.All this can contribute to further reduction of agricultural households’chemical fertilizer and pesticide use intensity.展开更多
文摘Dakar area landscape is mainly characterized by the existence of the ＂niaye＂-or agricultural depressions located in the sand dunes system. In these depressions, the top-table of quaternary sand groundwater reaches or overflows the soil surface. Because of a recent groundwater level drop, some of the niayes have become runoff-gathering sites. This water ensures various economical, environmental and social services, i.e. urban agriculture, drinking water supply of Dakar and formation of ecosystems supporting biodiversity. Given that rainwater infiltration is the only natural ＂input＂, conception and implemention of rainwater management PPP （Politics, Plan and Program） must necessarily take into account this interrelationl Nowadays, two acute problems are observed in the Dakar area. On the one hand, the niayes are threatened by a hydrological drying process due to the insufficiency of rainwater refill. On the other hand, the dramatic social pressure on the environment has led to the urbanization of these bottom-lands. Furthermore, because of the pluviometry decrease, a worsening of the nuisances （floods and malaria） related to surface waters occurs. Consequently, an appropriate runoff management should integrate both the ＂risk＂ and ＂resource＂ dimensions, thus allowing the protection of natural resources and a secure living environment. According to the limits of＂classicai＂ solutions, this paper provides approach elements for building a sustainability plan focusing on emergent concerns, which would control rainwater in urbanized zones.
文摘Social imbalance and obsolescence of the built environment has emerged in large sized housing estates in metropolises. In particular, the requirement of such planned housing areas has not matched public service provided by the infrastructure. On not only physical but also social aspect of local communities of this kind of housing area have a lot of problems while it also has a lot of good characteristics. A representative one is that age of the tenants is rising very swiftly and it makes the local community imbalanced. Nowadays many countries including Japan have tackled problems concerning housing estates constructed during the mass housing era and try to search for ways to reactivate so-called new town areas by utilisation of existing environmental resources such as building stock and ample green open space. In Japan many elemental technologies have been developed in order to utilise existing building stock. However, how to combine these technologies and new holistic methods for reactivation are still underdeveloped. Therefore, it is very important to fred these ways and to make a comprehensive plan for rehabilitation of these areas. The first purpose of our study is to develop and clarify how to organise and integrate many kinds of elemental techniques and the holistic measures for the improvement of both social and physical environment in suburban mass housing estates. Subsequently we try to reorganise proper relations between human settlements and the various service provision for those regions. Our last focus is put on searching for new ways to raise the value of existing housing environment. Our conclusion intends to indicate important of the master plan and its execution, where mass housing estates progress for the physical and social improvement.
基金The Australian Research Council(DP180100519)The National Natural Science Foundation of China(72004116)The Openof the Reservoir Resettlement Research Center of Hubei Province University Humanities and Social Sciences Key Research Base(2022KFJJ01)。
文摘Abuse of chemical fertilizer and pesticide will not only impair the quality of agricultural products,but also damage the agricultural ecological environment.From the perspective of cooperatives’socialized services,this paper studies agricultural households’chemical fertilizer and pesticide use behavior,attempting to provide references for the government’s formulation of relevant policies and cooperatives’adjustment of their operation strategies.The survey data of 518 agricultural households in Zigui County and Badong County,Hubei Province,China are used to examine the influence of cooperatives and their socialized services on agricultural households’chemical fertilizer and pesticide use intensity via propensity score matching.Research reveals that:(1)Joining cooperatives has a significantly negative influence on agricultural households’chemical fertilizer and pesticide use intensity,and the average treatment effect is-341.505 yuan mu^(-1).(2)Agricultural materials supply services and technical support services can significantly bring down agricultural households’chemical fertilizer and pesticide use intensity,and the average treatment effect is-225.966 yuan mu^(-1)and-163.580 yuan mu^(-1),respectively.While the influence of agricultural products sale services on chemical fertilizer and pesticide use intensity is not significant.(3)Grouped investigation is carried out by age,education years and planting scale,and the influence of socialized services on agricultural householders’chemical fertilizer and pesticide use intensity is obviously varied among different groups.The influence of agricultural materials supply services on agricultural households who are elder,with smaller education years and small planting scale is significant;the influence of technical support services on agricultural households who are younger,with higher education years and small planting scale is significant;the influence of agricultural products sale services on agricultural households who are elder is significant.It is necessary to improve the percentage of agricultural households joining cooperatives,increase the supply level of cooperatives’socialized services,and make socialized services of cooperatives more targeted.All this can contribute to further reduction of agricultural households’chemical fertilizer and pesticide use intensity.
