Water resource access in the Nouhao sub-basin, assessed based on the availability of drinking water mobilization facilities, the availability of water for uses and the quality of drinking water, revealed that in 2017 ...Water resource access in the Nouhao sub-basin, assessed based on the availability of drinking water mobilization facilities, the availability of water for uses and the quality of drinking water, revealed that in 2017 the basin was covered by 1249 modern water point, main drinking water sources. On average, the sub-basin shows a ratio of 271 users per drinking water point. Communal level shows some disparity with Bittou recording the highest number of people per drinking water point, i.e., around 537. Water that can be captured in the entire sub-basin meets only 42% of the total water needs from the three mains uses: irrigation, domestic consumption and livestock. The highest demander among these uses is Irrigation with 75% of the need, i.e., approximately 12,859,995 m<sup>3</sup>. Water in 33% drinking sources of this sub basin is of poor quality. Arsenic, one of the quality parameters studied, is found in some communes of the sub-basin. 11% of the water points in Bissiga are arsenic polluted making this commune the most arsenic contaminated location. The vulnerability maps deducted from lack of water for uses;lack of drinking water works and poor water quality shows so, the exposure level of the sub-basin’ communes to some potential risks related to low water resources access.展开更多
In 2000, the United Nations (UN) developed Millennium Development Goals (MDG) with one of its aim being to improve access of potable water supply by 2015 in developing countries. This study thus focused on Kenya’s Gi...In 2000, the United Nations (UN) developed Millennium Development Goals (MDG) with one of its aim being to improve access of potable water supply by 2015 in developing countries. This study thus focused on Kenya’s Gilgil constituency which lies in both arid and semi-arid zones and experiences bimodal rains which are neither heavy nor reliable. With persistent shortages, water management and monitoring became essential and in current times the use of Geographic Information Systems (GIS) is being incorporated due to its capability as an effective tool in water resources management. The study’s aim was to provide knowledge about accessible areas and gaps using cost surface analysis as well as identify other factors that influence settlement. The study utilized walk speeds as an impedance to determine cost surfaces followed by creation of service areas from water facilities using time as a measurement of access. The study established that surface friction may not have major influence on accessibility and service areas while logistic regression established that other factors strongly influence settlement apart from water availability. The study also reveals that 77% of the semi-permanent households in Gilgil have a hard time accessing water as they are outside the 30-minute walk time.展开更多
This paper is premised on the hypothesis that the amount of rainfall in Nigeria decreases with increasing distance from the coastal areas to the north semi arid lands. This belief widely held in some circles does not ...This paper is premised on the hypothesis that the amount of rainfall in Nigeria decreases with increasing distance from the coastal areas to the north semi arid lands. This belief widely held in some circles does not really follow this pattern due to other climatic factors. This paper examined rainfall pattern and its variability in northeastern Nigeria and its impacts on access to water supply. Data on the mean monthly rainfall over a period of 33 years (1970-2002) were collected from the Nigeria Meteorological Agency (NIMET) in Abuja, Nigeria. The result of the analysis indicates that the mean annual rainfall in the study area is not dependent on distance but some other climatic factors such as relief, solar radiation, temperature, winds, and nature of soil among others. Thus, the amount of rainfall received in Taraba and Borno states which are located in the southern most and extreme end of the study area respectively were higher than that of Gombe state which lies in between them.展开更多
The study examined climate influenced challenges of accessibility to water by households downstream of the Upper Benue River Basin, Nigeria. Literatures related to the topic being investigated were reviewed. The study...The study examined climate influenced challenges of accessibility to water by households downstream of the Upper Benue River Basin, Nigeria. Literatures related to the topic being investigated were reviewed. The study adopted a descriptive survey design. The population of the study consisted of communities in Adamawa, Gombe, Bauchi and Taraba states. Eight different communities, two in each local government were sampled for the study. Simple random and purposive samplings were used for the study. A total of 351 respondents were selected for the study using Krejcie and Morgan sample size determination. Data analysis was done using frequency tables percentages and mean statistics. The findings of the study showed that climate variability has great impact on water stress and threats to households’ downstream in Upper Benue River basin represented with a mean 3.85 (decrease in the quality and quantity of surface water) as well as 3.43 (drying up of rivers and lakes). The study also revealed that water stress induced by climate variability has a significant effect on household livelihoods represented by 87% of the respondents in the study area. It was also revealed that that households downstream the basin are vulnerable to climate change and households in the study area have development strategies to contend with water stress so as to better their livelihood among which is surface water harvesting (2.78), reducing the number of times dishes are washed (2.96), reducing the quantity of water used for bathing (3.0) among others. The study recommended that stakeholders and the government should make proactive efforts to ensuring that alternative water sources are established in the study area to reduce water stress among the rural populace.展开更多
A stable surface to move manpower and equipment is a key for the construction operations. To create a stable road surface, the road construction techniques are time-consuming and expensive for a traditional constructi...A stable surface to move manpower and equipment is a key for the construction operations. To create a stable road surface, the road construction techniques are time-consuming and expensive for a traditional construction which requires compaction of soil, aggregate base, sub-base and asphaltic layers. A Geosynthetic Access Mat (GAM) system can serve as an alternative to other traditional construction techniques to accommodate temporary construction. Due to its rigidity, the mat system can provide substantial vertical resistance to the applied load under a large deflection subject to soil conditions. This paper provides details of GAM specifications, soil conditions, applications, installation procedure, comparison with other soil stabilization methods and Aramco experience for deployments of these mats.展开更多
The number of interurban and urban-rural travelers in the city of Yaounde has recently exceeded one hundred thousand per year, yet surprisingly few studies have assessed travelers’ behavior, illness, and risk factors...The number of interurban and urban-rural travelers in the city of Yaounde has recently exceeded one hundred thousand per year, yet surprisingly few studies have assessed travelers’ behavior, illness, and risk factors in a sanitary risks setting. Particularly scarce are surveys of data spanning travel, return, and follow-up of the same cohort in traveling agencies and parks. This study examines behavior and illness among travelers moving from Yaounde to other urban and rural areas of Cameroon and beyond. Patterns of behavior connected to a type of travel and illness are characterized in this study so as to identify risks factors and provide background data for pre-travel advice in our traveling agencies. Assessing the susceptibility that imported cases could pose to the national response to infectious diseases depends both on public health, health services and infrastructures. The six agencies assessed: Nvan, Mokolo, Tongolo, Biyem Assi, Mimbowman and Etoudi reveal that the sanitary infrastructures for faecal and urinary disposal are not sufficient and more so, some agencies do not keep enough cleanliness, let alone provide adequate hand washing material as prescribed by national and international concerns to combat the global health challenges. This could be an impediment to travellers going out or inside of the city, and could be a preponderant mechanism for the spread of infectious disease as presented by the infectious diseases isolated and identified in the health districts around the travelling agencies.展开更多
Background: Kinshasa’s peri-urban settings have a low rate of water access, which has significant consequences for the WASH infrastructures in schools and preventative measures against the spread of waterborne diseas...Background: Kinshasa’s peri-urban settings have a low rate of water access, which has significant consequences for the WASH infrastructures in schools and preventative measures against the spread of waterborne diseases and pathogens. This study aimed to assess the availability, functionality, and gender sensitivity of WASH infrastructures of Kinshasa’s peri-urban schools. Methods: A cross-sectional study was performed in three of the four educational provinces of Kinshasa, targeting 165 peri-urban schools. Data were collected using a questionnaire and an observation grid. Results: An overall proportion of 10.9% of schools possessed a water point, and therefore time-consuming water chores are a necessity in 89.1% of schools. Girl students provided 30% of the labor collecting water during punishments. A total of 98.2% of schools had functional latrines of which 3.6% were found hygienic, associated with water reserve next to the latrines (P = 0.040). Only 2.4% of schools displayed posters raising awareness of latrine hygiene, and 3.6% displayed posters on hand hygiene. The ratios of latrines units for girls were 58:1 for toilets and 115:1 for urinals, justifying open defecation and urination reported in 62.4% of schools. Also, 43% of schools had hand-washing facilities whose functionality was significantly associated with the presence of water points in the school’s inner courtyard (P = 0.032), with water (P P Conclusion: The majority of schools had limited drinking water services, which negatively impact the functionality and gender sensitivity of other WASH provisions. The current evidence as a public health concern would raise government and school authorities’ attention to address these environmental threats.展开更多
Mountain water, which contributes 50% to 90% to the lower reaches of the watershed, has a considerably low utility efficiency. The water accessibility could be a quantitative measure of water scarcity in the mountains...Mountain water, which contributes 50% to 90% to the lower reaches of the watershed, has a considerably low utility efficiency. The water accessibility could be a quantitative measure of water scarcity in the mountains. It can be used effectively for emergency water shortage planning and water resource management. In the present study, Dongchuan District, a typical county in the Hengduan Mountains in Yunnan province of Southwest China, was selected as the study area, and the minimal cumulative resistance(MCR) model was used to simulate the least-cost path(LCP) from 1255 point features of natural villages, as well as 12,368 dryfield centroids, to their respective surrounding river systems, which serve as a source for emergency drinking water and irrigation during droughts. The average length of the LCP for each administrative village was calculated to represent the accessibility to water sources for agricultural production and daily life in these mountain villages. The distribution of population and dryfields, as well as other geographic elements, were analyzed to classify the degree of water scarcity in these villages. The results indicate that the area facing the highest risk of water shortage for agricultural irrigation is located in northern Dongchuan, in particular along the two sides of the Xiaojiang Valley, and that the area with the highest risk of water shortage for daily life needs is located along the Xiaojiang Valley.展开更多
The river Niger is the 3rd longest river in Africa, with a stream length of 4200 km, a drainage basin of 2,170,500 km2 of which 1,500,000 km2 is an active basin, and an average discharge of about 6000 m3/s. The natura...The river Niger is the 3rd longest river in Africa, with a stream length of 4200 km, a drainage basin of 2,170,500 km2 of which 1,500,000 km2 is an active basin, and an average discharge of about 6000 m3/s. The natural variability of its rainfall and discharge is analyzed for several major sub-basins, in the context of the West African drought which has lasted for nearly 40 years, showing two paradoxes: the increase of Sahelian runoff since the beginning of the drought due to land degradation, and the steep decrease of sudanian runoff over the same period, substantiated by the long-lasting decrease of the groundwater tables. Much information about the water resources available in the basin is collected and analysed by the NBA1, which is summarized in this paper including surface water resources, rainfall over the basin, existing and projected dams. The river Niger is deficient in dams to control water, especially in its upper and middle basins. Nigeria has many dams, including large dams, while Burkina Faso has many small dams, but there are only a few dams upstream of the river Niger in Mali/Guinea/Ivory Coast. It is therefore likely that several dams will be built in the Niger basin in the coming years, and several are in the project phase. All of these will have a large impact on the river Niger regime and the environment, especially the Fomi dam which will change significantly the river regime upstream of the inner Delta, inducing an important reduction of the flooded area, and the Tossaye dam on the Saharan border of Mali which could promote a very significant level of evaporation. It is very important before building these dams to take into account the past years variability of climate and river regime.展开更多
Populations in urban centers of developing countries have increased very significantly during the post-1960 period,primarily due to urbanization.Rates of population growth during this period simply overwhelmed theirfi...Populations in urban centers of developing countries have increased very significantly during the post-1960 period,primarily due to urbanization.Rates of population growth during this period simply overwhelmed theirfinancial,institutional,and technical capacities to manage all types of basic services,including the provision of clean water and proper wastewater management.Surprisingly,issues of access to clean water and sanitation at major international forums of very senior policymakers werefirst raised during the United Nations Conference,in Vancouver,in 1976.It recommended that everyone should have access to clean water by 1990.Subsequently,Millennium Development Goals set the target that,by 2015,the number of people not having access to clean water should be reduced by half,compared to 1990.The United Nations claimed that this target was met in 2010.However,this is not true.Thereafter,the Sustainable Development Goals stipulated that everyone should have access to clean water by 2030.Current developments indicate that this goal is highly unlikely to be reached.This paper objectively reviews the progress of urban water security in developing countries from the post-1960 period,analyses why international targets were missed in the past,and what can be done to ensure urban water security in developing countries in the future.展开更多
文摘Water resource access in the Nouhao sub-basin, assessed based on the availability of drinking water mobilization facilities, the availability of water for uses and the quality of drinking water, revealed that in 2017 the basin was covered by 1249 modern water point, main drinking water sources. On average, the sub-basin shows a ratio of 271 users per drinking water point. Communal level shows some disparity with Bittou recording the highest number of people per drinking water point, i.e., around 537. Water that can be captured in the entire sub-basin meets only 42% of the total water needs from the three mains uses: irrigation, domestic consumption and livestock. The highest demander among these uses is Irrigation with 75% of the need, i.e., approximately 12,859,995 m<sup>3</sup>. Water in 33% drinking sources of this sub basin is of poor quality. Arsenic, one of the quality parameters studied, is found in some communes of the sub-basin. 11% of the water points in Bissiga are arsenic polluted making this commune the most arsenic contaminated location. The vulnerability maps deducted from lack of water for uses;lack of drinking water works and poor water quality shows so, the exposure level of the sub-basin’ communes to some potential risks related to low water resources access.
文摘In 2000, the United Nations (UN) developed Millennium Development Goals (MDG) with one of its aim being to improve access of potable water supply by 2015 in developing countries. This study thus focused on Kenya’s Gilgil constituency which lies in both arid and semi-arid zones and experiences bimodal rains which are neither heavy nor reliable. With persistent shortages, water management and monitoring became essential and in current times the use of Geographic Information Systems (GIS) is being incorporated due to its capability as an effective tool in water resources management. The study’s aim was to provide knowledge about accessible areas and gaps using cost surface analysis as well as identify other factors that influence settlement. The study utilized walk speeds as an impedance to determine cost surfaces followed by creation of service areas from water facilities using time as a measurement of access. The study established that surface friction may not have major influence on accessibility and service areas while logistic regression established that other factors strongly influence settlement apart from water availability. The study also reveals that 77% of the semi-permanent households in Gilgil have a hard time accessing water as they are outside the 30-minute walk time.
文摘This paper is premised on the hypothesis that the amount of rainfall in Nigeria decreases with increasing distance from the coastal areas to the north semi arid lands. This belief widely held in some circles does not really follow this pattern due to other climatic factors. This paper examined rainfall pattern and its variability in northeastern Nigeria and its impacts on access to water supply. Data on the mean monthly rainfall over a period of 33 years (1970-2002) were collected from the Nigeria Meteorological Agency (NIMET) in Abuja, Nigeria. The result of the analysis indicates that the mean annual rainfall in the study area is not dependent on distance but some other climatic factors such as relief, solar radiation, temperature, winds, and nature of soil among others. Thus, the amount of rainfall received in Taraba and Borno states which are located in the southern most and extreme end of the study area respectively were higher than that of Gombe state which lies in between them.
文摘The study examined climate influenced challenges of accessibility to water by households downstream of the Upper Benue River Basin, Nigeria. Literatures related to the topic being investigated were reviewed. The study adopted a descriptive survey design. The population of the study consisted of communities in Adamawa, Gombe, Bauchi and Taraba states. Eight different communities, two in each local government were sampled for the study. Simple random and purposive samplings were used for the study. A total of 351 respondents were selected for the study using Krejcie and Morgan sample size determination. Data analysis was done using frequency tables percentages and mean statistics. The findings of the study showed that climate variability has great impact on water stress and threats to households’ downstream in Upper Benue River basin represented with a mean 3.85 (decrease in the quality and quantity of surface water) as well as 3.43 (drying up of rivers and lakes). The study also revealed that water stress induced by climate variability has a significant effect on household livelihoods represented by 87% of the respondents in the study area. It was also revealed that that households downstream the basin are vulnerable to climate change and households in the study area have development strategies to contend with water stress so as to better their livelihood among which is surface water harvesting (2.78), reducing the number of times dishes are washed (2.96), reducing the quantity of water used for bathing (3.0) among others. The study recommended that stakeholders and the government should make proactive efforts to ensuring that alternative water sources are established in the study area to reduce water stress among the rural populace.
文摘A stable surface to move manpower and equipment is a key for the construction operations. To create a stable road surface, the road construction techniques are time-consuming and expensive for a traditional construction which requires compaction of soil, aggregate base, sub-base and asphaltic layers. A Geosynthetic Access Mat (GAM) system can serve as an alternative to other traditional construction techniques to accommodate temporary construction. Due to its rigidity, the mat system can provide substantial vertical resistance to the applied load under a large deflection subject to soil conditions. This paper provides details of GAM specifications, soil conditions, applications, installation procedure, comparison with other soil stabilization methods and Aramco experience for deployments of these mats.
文摘The number of interurban and urban-rural travelers in the city of Yaounde has recently exceeded one hundred thousand per year, yet surprisingly few studies have assessed travelers’ behavior, illness, and risk factors in a sanitary risks setting. Particularly scarce are surveys of data spanning travel, return, and follow-up of the same cohort in traveling agencies and parks. This study examines behavior and illness among travelers moving from Yaounde to other urban and rural areas of Cameroon and beyond. Patterns of behavior connected to a type of travel and illness are characterized in this study so as to identify risks factors and provide background data for pre-travel advice in our traveling agencies. Assessing the susceptibility that imported cases could pose to the national response to infectious diseases depends both on public health, health services and infrastructures. The six agencies assessed: Nvan, Mokolo, Tongolo, Biyem Assi, Mimbowman and Etoudi reveal that the sanitary infrastructures for faecal and urinary disposal are not sufficient and more so, some agencies do not keep enough cleanliness, let alone provide adequate hand washing material as prescribed by national and international concerns to combat the global health challenges. This could be an impediment to travellers going out or inside of the city, and could be a preponderant mechanism for the spread of infectious disease as presented by the infectious diseases isolated and identified in the health districts around the travelling agencies.
文摘Background: Kinshasa’s peri-urban settings have a low rate of water access, which has significant consequences for the WASH infrastructures in schools and preventative measures against the spread of waterborne diseases and pathogens. This study aimed to assess the availability, functionality, and gender sensitivity of WASH infrastructures of Kinshasa’s peri-urban schools. Methods: A cross-sectional study was performed in three of the four educational provinces of Kinshasa, targeting 165 peri-urban schools. Data were collected using a questionnaire and an observation grid. Results: An overall proportion of 10.9% of schools possessed a water point, and therefore time-consuming water chores are a necessity in 89.1% of schools. Girl students provided 30% of the labor collecting water during punishments. A total of 98.2% of schools had functional latrines of which 3.6% were found hygienic, associated with water reserve next to the latrines (P = 0.040). Only 2.4% of schools displayed posters raising awareness of latrine hygiene, and 3.6% displayed posters on hand hygiene. The ratios of latrines units for girls were 58:1 for toilets and 115:1 for urinals, justifying open defecation and urination reported in 62.4% of schools. Also, 43% of schools had hand-washing facilities whose functionality was significantly associated with the presence of water points in the school’s inner courtyard (P = 0.032), with water (P P Conclusion: The majority of schools had limited drinking water services, which negatively impact the functionality and gender sensitivity of other WASH provisions. The current evidence as a public health concern would raise government and school authorities’ attention to address these environmental threats.
基金financially supported by the National Program on Key Basic Research Project (973 Program) (Grant No. 2015CB452706)
文摘Mountain water, which contributes 50% to 90% to the lower reaches of the watershed, has a considerably low utility efficiency. The water accessibility could be a quantitative measure of water scarcity in the mountains. It can be used effectively for emergency water shortage planning and water resource management. In the present study, Dongchuan District, a typical county in the Hengduan Mountains in Yunnan province of Southwest China, was selected as the study area, and the minimal cumulative resistance(MCR) model was used to simulate the least-cost path(LCP) from 1255 point features of natural villages, as well as 12,368 dryfield centroids, to their respective surrounding river systems, which serve as a source for emergency drinking water and irrigation during droughts. The average length of the LCP for each administrative village was calculated to represent the accessibility to water sources for agricultural production and daily life in these mountain villages. The distribution of population and dryfields, as well as other geographic elements, were analyzed to classify the degree of water scarcity in these villages. The results indicate that the area facing the highest risk of water shortage for agricultural irrigation is located in northern Dongchuan, in particular along the two sides of the Xiaojiang Valley, and that the area with the highest risk of water shortage for daily life needs is located along the Xiaojiang Valley.
文摘The river Niger is the 3rd longest river in Africa, with a stream length of 4200 km, a drainage basin of 2,170,500 km2 of which 1,500,000 km2 is an active basin, and an average discharge of about 6000 m3/s. The natural variability of its rainfall and discharge is analyzed for several major sub-basins, in the context of the West African drought which has lasted for nearly 40 years, showing two paradoxes: the increase of Sahelian runoff since the beginning of the drought due to land degradation, and the steep decrease of sudanian runoff over the same period, substantiated by the long-lasting decrease of the groundwater tables. Much information about the water resources available in the basin is collected and analysed by the NBA1, which is summarized in this paper including surface water resources, rainfall over the basin, existing and projected dams. The river Niger is deficient in dams to control water, especially in its upper and middle basins. Nigeria has many dams, including large dams, while Burkina Faso has many small dams, but there are only a few dams upstream of the river Niger in Mali/Guinea/Ivory Coast. It is therefore likely that several dams will be built in the Niger basin in the coming years, and several are in the project phase. All of these will have a large impact on the river Niger regime and the environment, especially the Fomi dam which will change significantly the river regime upstream of the inner Delta, inducing an important reduction of the flooded area, and the Tossaye dam on the Saharan border of Mali which could promote a very significant level of evaporation. It is very important before building these dams to take into account the past years variability of climate and river regime.
文摘Populations in urban centers of developing countries have increased very significantly during the post-1960 period,primarily due to urbanization.Rates of population growth during this period simply overwhelmed theirfinancial,institutional,and technical capacities to manage all types of basic services,including the provision of clean water and proper wastewater management.Surprisingly,issues of access to clean water and sanitation at major international forums of very senior policymakers werefirst raised during the United Nations Conference,in Vancouver,in 1976.It recommended that everyone should have access to clean water by 1990.Subsequently,Millennium Development Goals set the target that,by 2015,the number of people not having access to clean water should be reduced by half,compared to 1990.The United Nations claimed that this target was met in 2010.However,this is not true.Thereafter,the Sustainable Development Goals stipulated that everyone should have access to clean water by 2030.Current developments indicate that this goal is highly unlikely to be reached.This paper objectively reviews the progress of urban water security in developing countries from the post-1960 period,analyses why international targets were missed in the past,and what can be done to ensure urban water security in developing countries in the future.
