Compared with traditional real-time forecasting,this paper proposes a Grey Markov Model(GMM) to forecast the maximum water levels at hydrological stations in the estuary area.The GMM combines the Grey System and Marko...Compared with traditional real-time forecasting,this paper proposes a Grey Markov Model(GMM) to forecast the maximum water levels at hydrological stations in the estuary area.The GMM combines the Grey System and Markov theory into a higher precision model.The GMM takes advantage of the Grey System to predict the trend values and uses the Markov theory to forecast fluctuation values,and thus gives forecast results involving two aspects of information.The procedure for forecasting annul maximum water levels with the GMM contains five main steps:1) establish the GM(1,1) model based on the data series;2) estimate the trend values;3) establish a Markov Model based on relative error series;4) modify the relative errors caused in step 2,and then obtain the relative errors of the second order estimation;5) compare the results with measured data and estimate the accuracy.The historical water level records(from 1960 to 1992) at Yuqiao Hydrological Station in the estuary area of the Haihe River near Tianjin,China are utilized to calibrate and verify the proposed model according to the above steps.Every 25 years' data are regarded as a hydro-sequence.Eight groups of simulated results show reasonable agreement between the predicted values and the measured data.The GMM is also applied to the 10 other hydrological stations in the same estuary.The forecast results for all of the hydrological stations are good or acceptable.The feasibility and effectiveness of this new forecasting model have been proved in this paper.展开更多
Natural habitat ofHippophae salicifolia in Central Himalaya is continuously being degraded due to habitat destruction and harvesting. Although logging is prohibited, habitat destruction has increased because of regula...Natural habitat ofHippophae salicifolia in Central Himalaya is continuously being degraded due to habitat destruction and harvesting. Although logging is prohibited, habitat destruction has increased because of regular road construction, repairing and broadening activities. In addition, Hippophae resources are continuously being harvested by lopping （both partial and complete） for fuelwood, fodder and fruits in higher Himalayan region. This paper presents a detailed analysis of relationship between density, demographic structure, and harvesting of H. salicifolia growing pockets in the five major valleys （Gangotri, Yamunotri, Niti, Mana and Bhyundhar） of Uttarakhand in Central Himalaya, India. A total of 12o quadrats were laid randomly to study population structure, regeneration, sex ratio and lopping using quadrats of lOO m2 （a4 in each valley） in Hippophae growing patches. Our study shows that the density, size distribution, and regeneration of Hippophae vary considerably among the major valleys. Trees in the Yamunotri valley have the highest density of large trees but the lowest density of seedlings. In contrast, there are few large trees but many seedlings in the Mana valley. The number and size of lopped trees also varied among the valleys. Lopping was greatest in Bhyundhar （11.4%） and Yamunotri （19.7%） and least in Niti （3.9%）. The size of lopped trees differed substantially as well. In Bhyundhar, the largest trees were taken while saplings were taken in Yamunotri. Our study revealed that unsustainable harvesting from plants for fuel, fencing and fruits along with road broadening activities in Central Himalaya are the main cause ofhabitat destruction. Our research highlights the urgent need for in-situ and ex-situ conservation of Hippophae salicifolia so that it＇s potential can be harnessed sustainably by rural hill societies for their socio-economic development.展开更多
This paper examines the extent to which community radio has the empowering and transformation potential. It draws on Nkhotakota community radio station in Malawi to analyze how community radio can empower women especi...This paper examines the extent to which community radio has the empowering and transformation potential. It draws on Nkhotakota community radio station in Malawi to analyze how community radio can empower women especially in rural areas. Although the whole of the rural population can be considered as marginalized, women are the most affected as they face marginalization in the family and village setting. Based on the data drawn from semi-structured interviews, focus group discussions, document analysis, and participant observation, the paper observes that inequality and high illiteracy rate are the major hindrances among rural women which prevent them from accessing information necessary for their improvement. This paper argues that community radio has the potential to empower women in rural areas by providing them with access to information necessary to empower and transform their lives and enable them to participate in development activities.展开更多
基金supported by the National Natural Science Foundation of China (50879085)the Program for New Century Excellent Talents in University(NCET-07-0778)the Key Technology Research Project of Dynamic Environmental Flume for Ocean Monitoring Facilities (201005027-4)
文摘Compared with traditional real-time forecasting,this paper proposes a Grey Markov Model(GMM) to forecast the maximum water levels at hydrological stations in the estuary area.The GMM combines the Grey System and Markov theory into a higher precision model.The GMM takes advantage of the Grey System to predict the trend values and uses the Markov theory to forecast fluctuation values,and thus gives forecast results involving two aspects of information.The procedure for forecasting annul maximum water levels with the GMM contains five main steps:1) establish the GM(1,1) model based on the data series;2) estimate the trend values;3) establish a Markov Model based on relative error series;4) modify the relative errors caused in step 2,and then obtain the relative errors of the second order estimation;5) compare the results with measured data and estimate the accuracy.The historical water level records(from 1960 to 1992) at Yuqiao Hydrological Station in the estuary area of the Haihe River near Tianjin,China are utilized to calibrate and verify the proposed model according to the above steps.Every 25 years' data are regarded as a hydro-sequence.Eight groups of simulated results show reasonable agreement between the predicted values and the measured data.The GMM is also applied to the 10 other hydrological stations in the same estuary.The forecast results for all of the hydrological stations are good or acceptable.The feasibility and effectiveness of this new forecasting model have been proved in this paper.
基金Department of Science and Technology, New Delhi,India is thankfully acknowledged for financial support
文摘Natural habitat ofHippophae salicifolia in Central Himalaya is continuously being degraded due to habitat destruction and harvesting. Although logging is prohibited, habitat destruction has increased because of regular road construction, repairing and broadening activities. In addition, Hippophae resources are continuously being harvested by lopping （both partial and complete） for fuelwood, fodder and fruits in higher Himalayan region. This paper presents a detailed analysis of relationship between density, demographic structure, and harvesting of H. salicifolia growing pockets in the five major valleys （Gangotri, Yamunotri, Niti, Mana and Bhyundhar） of Uttarakhand in Central Himalaya, India. A total of 12o quadrats were laid randomly to study population structure, regeneration, sex ratio and lopping using quadrats of lOO m2 （a4 in each valley） in Hippophae growing patches. Our study shows that the density, size distribution, and regeneration of Hippophae vary considerably among the major valleys. Trees in the Yamunotri valley have the highest density of large trees but the lowest density of seedlings. In contrast, there are few large trees but many seedlings in the Mana valley. The number and size of lopped trees also varied among the valleys. Lopping was greatest in Bhyundhar （11.4%） and Yamunotri （19.7%） and least in Niti （3.9%）. The size of lopped trees differed substantially as well. In Bhyundhar, the largest trees were taken while saplings were taken in Yamunotri. Our study revealed that unsustainable harvesting from plants for fuel, fencing and fruits along with road broadening activities in Central Himalaya are the main cause ofhabitat destruction. Our research highlights the urgent need for in-situ and ex-situ conservation of Hippophae salicifolia so that it＇s potential can be harnessed sustainably by rural hill societies for their socio-economic development.
文摘This paper examines the extent to which community radio has the empowering and transformation potential. It draws on Nkhotakota community radio station in Malawi to analyze how community radio can empower women especially in rural areas. Although the whole of the rural population can be considered as marginalized, women are the most affected as they face marginalization in the family and village setting. Based on the data drawn from semi-structured interviews, focus group discussions, document analysis, and participant observation, the paper observes that inequality and high illiteracy rate are the major hindrances among rural women which prevent them from accessing information necessary for their improvement. This paper argues that community radio has the potential to empower women in rural areas by providing them with access to information necessary to empower and transform their lives and enable them to participate in development activities.
