Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain (NCP), where the shortage of water is currently disturbing the stability and...Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain (NCP), where the shortage of water is currently disturbing the stability and sustainability of agricultural production with respect to the drying tendency since the 1950s. However, although potential evapotranspiration (ET) has shown a decreasing trend under climate change, actual ET has slightly increased with an acceleration in hydrological cycling. Global climate model (GCM) ensemble projections predict that by the 2050s, the increased crop water demand and intensified ET resulting from global warming will reduce water resources surplus (Precipitation-ET) about 4%-24% and increase significantly the irrigation water demand in crop growth periods. This study assesses possible mitigation and adaptation measures for enabling agricultural sustainability. It is revealed that reducing the sowing area of winter wheat (3.0%-15.9%) in water-limited basins, together with improvement in crop water-use efficiency would effectively mitigate water shortages and intensify the resilience of agricultural systems to climate change.展开更多
Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alt...Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alternative option to fossil diesel as it is renewable and environmentally friendly. Nevertheless, this alternative fuel that is usually derived from terrestrial oil crops will cause shortage in food supply and deforestation if mass production is realized. In recent years, cultivation of aquatic microorganism(particularly microalgae) to produce biodiesel is considered as a practical solution due to their high growth rate and ability to synthesize large quantity of lipid within their cell. However, the development of energy and cost-efficiency of microalgae cultivation system are the main issues in producing renewable microalgae biodiesel. Of late, wastewater or organic compost has been used as the cultivation medium as it can provide sufficient nutrients to sustain microalgae growth.Microalgae cultivation method and system are vitally important as these factors undoubtedly affect the final microalgae biomass and lipid yield. In this review, the cultivation system of microalgae, nutrients demanded for microalgae production, cell harvesting and drying, microalgae oil extraction, and utilization of microalgae biomass for biodiesel production are introduced and discussed. It is anticipated to convey clearer perspectives in upstream and downstream processes in microalgae-derived biodiesel production.展开更多
Climate change is an inevitable trend,which challenges security of water resources in China,especially in cities.Assessing vulnerability of water resource to climate change in cities has important role for policy make...Climate change is an inevitable trend,which challenges security of water resources in China,especially in cities.Assessing vulnerability of water resource to climate change in cities has important role for policy makers. The paper constructs a vulnerability function,including exposure,sensitivity and adaptive capacity,according to the vulnerability concept proposed by IPCC,establishes an assessment indicators system of water resources to climate change in cities,and analyzes vulnerability features of Chinese cites based on 655 cities'data in 2006.The vulnerability assessment results show that there are distinctive differences among all the cities,between east,central and west cities,between ordinary,big and mega cities,while there is no statistical significant difference between north and south cities.Based on the research,the paper suggests that strategic emphasis should focus on the central cities and ordinary cities展开更多
On the basis of analyzing the importance of cryospheric researches in China and current status of cryospheric sciences in the world, this paper addresses key issues and main contents of present cryospheric sciences in...On the basis of analyzing the importance of cryospheric researches in China and current status of cryospheric sciences in the world, this paper addresses key issues and main contents of present cryospheric sciences in China. The key issues currently addressed are: i) mechanisms of different types of glaciers in response to climate change and the scale-conversion in water resources assessments; ii) modeling of water and heat exchanges between frozen soil and vegetation; iii) parameterization of physical processes in cryosphere as well as coupling with climate models. To gain full clarification of these key issues, works of the following three aspects should be highlighted, i.e., cryospheric processes and responses to climate change, influences of cryospheric changes, and adaptation strategies for cryospheric changes.展开更多
Diyala River is the third largest tributary of the Tigris River running 445 km length and draining an area of 32,600 km2. The river is the major source of water supply for Diyala City for municipal, domestic, agricult...Diyala River is the third largest tributary of the Tigris River running 445 km length and draining an area of 32,600 km2. The river is the major source of water supply for Diyala City for municipal, domestic, agriculture and other purposes. Diyala River Basin currently is suffering from water scarcity and contamination problems. Up-to-date studies have shown that blue and green waters of a basin have been demonstrating increasing variability contributing to more severe droughts and floods seemingly due to climate change. To obtain better understanding of the impacts of climate change on water resources in Diyala River Basin in near 2046-2064 and distant future 2080~2100, SWAT (soil and water assessment tool) was used. The model is first examined for its capability of capturing the basin characteristics, and then, projections from six GCMs (general circulation models) are incorporated to assess the impacts of climate change on water resources under three emission scenarios: A2, AIB and B1. The results showed deteriorating water resources regime into the future.展开更多
This paper addresses the impact of climate change on the water cycle and resource changes in the Eastern Monsoon Region of China (EMRC). It also represents a summary of the achievements made by the National Key Basi...This paper addresses the impact of climate change on the water cycle and resource changes in the Eastern Monsoon Region of China (EMRC). It also represents a summary of the achievements made by the National Key Basic Research and Development Program (2010CB428400), where the major research focuses are detection and attribution, extreme floods and droughts, and adaptation of water resources management. Preliminary conclusions can be summarized into four points: 1) Water cycling and water resource changes in the EMRC are rather complicated as the region is impacted by natural changes relating to the strong monsoon influence and also by climate change impacts caused by CO2 emissions due to anthropogenic forcing; 2) the rate of natural variability contributing to the influence on precipitation accounts for about 70%, and the rate from anthropogenic forcing accounts for 30% on average in the EMRC. However, with future scenarios of increasing CO2 emissions, the contribution rate from anthropogenic forcing will increase and water resources management will experience greater issues related to the climate change impact; 3) Extreme floods and droughts in the EMRC will be an increasing trend, based on IPCC-AR5 scenarios; 4) Along with rising temperatures of 1 ~C in North China, the agricultural water consumption will increase to about 4% of total water consumption. Therefore, climate change is making a significant impact and will be a risk to the EMRC, which covers almost all of the eight major river basins, such as the Yangtze River, Yellow River, Huaihe River, Haihe River, and Pearl River, and to the South-to-North Water Diversion Project (middle line). To ensure water security, it is urgently necessary to take adaptive countermeasures and reduce the vulnerability of water resources and associated risks.展开更多
Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or...Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or socio-economic drought. Among the different categories of drought, hydrological drought, especially streamflow drought, has been given more attention by local governments, researchers and the public in recent years. Identifying the occurrence of streamflow drought and issuing early warning can provide timely information for effective water resources management. In this study, streamflow drought is detected by using the Standardized Runoff Index, whereas meteorological drought is detected by the Standardized Precipitation Index. Comparative analyses of frequency, magnitude, onset and duration are conducted to identify the impact of meteorological drought on streamflow drought. This study focuses on the Jinghe River Basin in Northwest China, mainly providing the following findings. 1) Eleven meteorological droughts and six streamflow droughts were indicated during 1970 and 1990 after pooling using Inter-event time and volume Criterion method. 2) Streamflow drought in the Jinghe River Basin lagged meteorological drought for about 127 days. 3) The frequency of streamflow drought in Jinghe River Basin was less than meteorological drought. However, the average duration of streamflow drought is longer. 4) The magnitude of streamflow drought is greater than meteorological drought. These results not only play an important theoretical role in understanding relationships between different drought categories, but also have practical implications for streamflow drought mitigation and regional water resources management.展开更多
Climate change impacts on water resources are expected to be significant in Yemen. Efforts have been made to understand the expected changes and develop mitigation possibilities for the expected scenarios for a future...Climate change impacts on water resources are expected to be significant in Yemen. Efforts have been made to understand the expected changes and develop mitigation possibilities for the expected scenarios for a future sustainable use of resources and mitigation of expected impacts. The paper describes the development of a detailed baseline database and the assessment of climate change and variability impacts on water resources over the 2030, 2050 and 2080 time horizon on a Yemen-wide scale. Based on downscaled Global Climate Model data, a range of scenarios were established, representing potential Mean, Warm & Wet and Hot & Dry conditions as derived by evaluating worst case scenarios from the ensemble of the global models for the specified years. The results of the model include an estimated runoff coefficient, monthly rainfall, runoff, infiltration and evaporation representing the water balance in the different catchments. Analysis of the different evaluated scenarios shows that in the Mid, Warm and Wet scenario the hydrological components are generally higher than in the baseline scenario. For the Hot & Dry scenario, runoff, infiltration and evapotranspiration are decreasing due to the decreasing precipitation and increase in temperature. The relative changes in runoff are strongest.展开更多
Greater Zab is the largest tributary of the Tigris River in lraq where the catchment area is currently being plagued by water scarcity and pollution problems. Contemporary studies have revealed that blue and green wat...Greater Zab is the largest tributary of the Tigris River in lraq where the catchment area is currently being plagued by water scarcity and pollution problems. Contemporary studies have revealed that blue and green waters of the basin have been manifesting increasing variability contributing to more severe droughts and floods apparently due to climate change. In order to gain greater appreciation of the impacts of climate change on water resources in the study area in near and distant future, SWAT (Soil and Water Assessment Tool) has been used. The model is first tested for its suitability in capturing the basin characteristics, and then, forecasts from six GCMs (general circulation models) with about half-a-century lead time to 2046-2064 and one-century lead time to 2080-2100 are incorporated to evaluate the impacts of climate change on water resources under three emission scenarios: A 1 B, A2 and BI. The results showed worsening water resources regime into the future.展开更多
Poor countries are prone to climate change effects due to lack of mechanisms to mitigation. As such, they are most vulnerable to effects of climate changes which are floods, drought, deforestation, environmental degra...Poor countries are prone to climate change effects due to lack of mechanisms to mitigation. As such, they are most vulnerable to effects of climate changes which are floods, drought, deforestation, environmental degradation and so on. Many of affected communities particularly in rural areas and urban poor have resorted to migration to viable agricultural lands and urban areas increasing pressure on available social services. This situation has led to depletion of natural resources in the fringes of the cities in search for shelter, food, water, energy etc.. Dares Salaam city is highly prone to environmental degradation by being highly populated and closer to the Kazimzumbwi Forest National Reserve, which has been a resource of logging at the guise of sustainable livelihood of Dares Salaam city residents. This paper is reporting on a study undertaken in ENVI & ARCGIS software environment to evaluate the extent of environmental degradation in the forest reserve for the period of 16 years i.e. 1995-201 l, firstly, for purpose of informing policy makers and administrators to determine the extent of the problem and secondly to provide evidence for development of effective mitigation measures. Results revealed a considerable environmental degradation within the forest reserve over the study period. This was attested by a decrease of forests by 42%, grass land, as well as increase of bare land and grass land by 26% and 42% respectively. This is a testimony that there was a significant environmental degradation and loss of natural resources during the study period which should be addressed by relevant authorities.展开更多
Rainfall and air temperature data from six meteorological stations above the Bengbu Sluice and hydrological and water resources evaluation data from the Bengbu Hydrological Station in the Huai River Basin from 1961 to...Rainfall and air temperature data from six meteorological stations above the Bengbu Sluice and hydrological and water resources evaluation data from the Bengbu Hydrological Station in the Huai River Basin from 1961 to 2008 are used to analyze the impact of changes in climatic factors on the amount of water resources in the Basin. There was a general trend of rise in its average annual air temperature, with the highest increase of 0.289℃/10a recorded at Bengbu in Anhui Province. Rising rainfall was mainly observed in the western part of the study area, while rainfall actually declined in the eastern part, i.e. the middle reaches of the Huai River. The Average rainfall in the study area was in a vaguely declining trend. In other words, the rainfall in the Basin is still much affected by natural fluctuations. On the whole, there was a trend of gradual decrease in the quantity of the Basin's water resources for the period under study. Water resources quantity is found to fall with decreasing rainfall and rising air temperature. Regression analysis is used to establish a mathematical model between water resources quantity and climatic factors (i.e. air temperature and rainfall) in order to explore the impact of climate change on water resources in the Basin. Moreover, various scenarios are set to quantitatively analyze the response of water resources to climate change. Sensitivity analysis shows that changes in rainfall have a much bigger impact on its water resources quantity than changes in its air temperature.展开更多
This study is a rapid appraisal procedure (RAP) of two forms of agriculture water delivery systems comprising two canal irrigation schemes and 26 Zimbabwean bush pumps in the Midlands and Masvingo Provinces. A longi...This study is a rapid appraisal procedure (RAP) of two forms of agriculture water delivery systems comprising two canal irrigation schemes and 26 Zimbabwean bush pumps in the Midlands and Masvingo Provinces. A longitudinal multiple data collection technique employed involved various primary and secondary sources including site visits, literature review, observation, interviews with key personnel and group discussions. General findings of this study indicate: (1) the available coping mechanisms in smallholder farming in a climate change context and (2) the challenges faced in the actual delivery of water in terms of design, management, physical and institutional factors. The study provides pragmatic recommendations for overall improvement and performance in a local, technical and socio-economic context through evaluation of the current situation, practices and processes. An integrated approach to addressing climate change impacts should include water management, rehabilitation, complete overhaul and introduction of other relevant water systems and water saving farming techniques. Yet, ownership of these technologies by communities remains instrumental. Rural development and agricultural policies that ensure maximum and full capacity utilisation of water systems to improve rural livelihoods, mitigation and adaptation to climate change are recommended.展开更多
In this secondary research, published works on effect of climate change on water resources in other countries and in Australia were reviewed critically. Research question, objectives and assumptions were made to facil...In this secondary research, published works on effect of climate change on water resources in other countries and in Australia were reviewed critically. Research question, objectives and assumptions were made to facilitate this study. First, methods used for such studies and their results at global level were reviewed. Then Australian specific methods of study and findings were reviewed. More commonly, both globally and in Australia, simulations using long-term real data on selected climatic scenarios of global climatic models are projected for long-term future trends. The validity and certainty of predicted occurrences depend upon the closeness of real time data with scenarios to which they are projected. Even with these limitations, projections of already rising temperatures and declining rainfall on surface water and ground water availabilities show gradual decline in water availability leading to water stress both for human communities and ecosystems The role of human-induced emissions in hastening the degradation process has also been investigated. Conserving all available water, practising efficient water consumption and prudent water policies only can provide some relief from what is inevitable.展开更多
Based on a high-resolution regional climate model (RegCM3) simulation over East Asia, future climate changes over the Miyun Reservoir in the 21st century under the Intergovernmental Panel on Climate Change (IPCC) Spec...Based on a high-resolution regional climate model (RegCM3) simulation over East Asia, future climate changes over the Miyun Reservoir in the 21st century under the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A1B scenario are analyzed. The model simulation extends from 1951 to 2100 at a grid spacing of 25 km and is one-way nested within a global model of MIROC3.2_ hires (the Model for Interdisciplinary Research on Climate). The focus of the analysis is on the Watershed of Miyun Reservoir, the main water supply for Beijing in northern China. The results show that RegCM3 reproduces the observed temperature well but it overestimates precipitation over the region. Significant warming in the 21st century is simulated in the annual mean, December-January-February (DJF) and June-July-August (JJA), although with differences concerning the spatial distribution and magnitude. Changes in precipitation for the annual mean, DJF, and JJA also show differences. A prevailing increase of precipitation in DJF and a decrease of it in JJA is projected over the region, while little change in the annual mean is projected. Changes of the difference between precipitation and evapotranspiration to measure the potential water availability are also presented in the paper.展开更多
Sustainable development indicators, aim to measure sustainable development over longer periods of time. The sustainable development indicators are grouped into 10 subject categories: socioeconomic development, sustai...Sustainable development indicators, aim to measure sustainable development over longer periods of time. The sustainable development indicators are grouped into 10 subject categories: socioeconomic development, sustainable consumption and production, social inclusion, demographic changes, public health, climate change and energy, sustainable transport, natural resources, global partnership and finally good governance. In this paper, the authors examined a number of researches and compared the methods they used in order to determine the advantages and disadvantages of each method. The methods used a large number of different indicators. The comparison of the indicators could be made through mathematical models and also through theoretical approach.展开更多
The combined surface and groundwater allocation practice by wells and canals had contributed to the safety of groundwater environment and agriculture sustainable production. The typical area in the People's Victory C...The combined surface and groundwater allocation practice by wells and canals had contributed to the safety of groundwater environment and agriculture sustainable production. The typical area in the People's Victory Canal irrigation district was taken as a case, drawing together the irrigation district agriculture water consumption and precipitation from 1954 to 2014 in the People's Victory Canal irrigation district, ratios of surface to groundwater irrigation amount, dynamic of groundwater depth and hydrochemical characteristic of groundwater from 2008 to 2014 in the research area, the relationship between groundwater depth and ratio of surface to groundwater irrigation amount was analyzed, in order to ascertain the influence of precipitation on ratios of surface to groundwater irrigation amount and its effect on soil and groundwater environment. The results indicated that positive correlation between the ratios of surface to groundwater irrigation amount and annual precipitation was appeared, affected by climate change, average irrigation amount from surface in the recent 5 years was 2.90 x 108 cubic meters, accounted for 75.52% of total irrigation amount, on the other hand, decreasing tendency of precipitation was obvious, and groundwater depth dynamic in upstream of the branch canals was more dramatic than downstream because of surface water irrigation infiltration, under the unified condition of water use efficiency, ratio of surface to groundwater irrigation amount was negative correlation with area of the groundwater depth beyond 11 m, meanwhile, groundwater depth demonstrated negative correlation with the ratio of surface to groundwater irrigation amount, moreover, alkaline trend of groundwater hydrochemistry during the normal season in the research area was obvious because of phreatic evaporation and the agricultural irrigation from wells, along with irrigation from surface inflow of Yellow River, quality of groundwater hydrochemistry during the dry season was ameliorative greatly. Consequently, it was very important to the agriculture sustainable production that well-canal combined irrigation patterns alleviated extremely alkaline trend of the groundwater hydrochemistry and played a positive role of root layer soil salinity leaching.展开更多
基金Acknowledgment This work was supported by the State's Key Project of Research and Development Plan (2010CB428404) and the Natural Science Foundation of China (41471026).
文摘Climate change is having a considerable impact on the availability of water resources for agricultural production on the North China Plain (NCP), where the shortage of water is currently disturbing the stability and sustainability of agricultural production with respect to the drying tendency since the 1950s. However, although potential evapotranspiration (ET) has shown a decreasing trend under climate change, actual ET has slightly increased with an acceleration in hydrological cycling. Global climate model (GCM) ensemble projections predict that by the 2050s, the increased crop water demand and intensified ET resulting from global warming will reduce water resources surplus (Precipitation-ET) about 4%-24% and increase significantly the irrigation water demand in crop growth periods. This study assesses possible mitigation and adaptation measures for enabling agricultural sustainability. It is revealed that reducing the sowing area of winter wheat (3.0%-15.9%) in water-limited basins, together with improvement in crop water-use efficiency would effectively mitigate water shortages and intensify the resilience of agricultural systems to climate change.
基金Supported by the Ministry of Higher Education,Malaysia(FRGS with cost center015AB-L25)Universiti Teknologi PETRONAS(YUTP-FRG with cost center 0153AAH46)
文摘Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alternative option to fossil diesel as it is renewable and environmentally friendly. Nevertheless, this alternative fuel that is usually derived from terrestrial oil crops will cause shortage in food supply and deforestation if mass production is realized. In recent years, cultivation of aquatic microorganism(particularly microalgae) to produce biodiesel is considered as a practical solution due to their high growth rate and ability to synthesize large quantity of lipid within their cell. However, the development of energy and cost-efficiency of microalgae cultivation system are the main issues in producing renewable microalgae biodiesel. Of late, wastewater or organic compost has been used as the cultivation medium as it can provide sufficient nutrients to sustain microalgae growth.Microalgae cultivation method and system are vitally important as these factors undoubtedly affect the final microalgae biomass and lipid yield. In this review, the cultivation system of microalgae, nutrients demanded for microalgae production, cell harvesting and drying, microalgae oil extraction, and utilization of microalgae biomass for biodiesel production are introduced and discussed. It is anticipated to convey clearer perspectives in upstream and downstream processes in microalgae-derived biodiesel production.
基金a part of research result of the CLIMA Project,supported by the European Union AsiaLink Programme
文摘Climate change is an inevitable trend,which challenges security of water resources in China,especially in cities.Assessing vulnerability of water resource to climate change in cities has important role for policy makers. The paper constructs a vulnerability function,including exposure,sensitivity and adaptive capacity,according to the vulnerability concept proposed by IPCC,establishes an assessment indicators system of water resources to climate change in cities,and analyzes vulnerability features of Chinese cites based on 655 cities'data in 2006.The vulnerability assessment results show that there are distinctive differences among all the cities,between east,central and west cities,between ordinary,big and mega cities,while there is no statistical significant difference between north and south cities.Based on the research,the paper suggests that strategic emphasis should focus on the central cities and ordinary cities
基金the Nation Basic Research Program of China(973 Program,Research No.2007CB411500)
文摘On the basis of analyzing the importance of cryospheric researches in China and current status of cryospheric sciences in the world, this paper addresses key issues and main contents of present cryospheric sciences in China. The key issues currently addressed are: i) mechanisms of different types of glaciers in response to climate change and the scale-conversion in water resources assessments; ii) modeling of water and heat exchanges between frozen soil and vegetation; iii) parameterization of physical processes in cryosphere as well as coupling with climate models. To gain full clarification of these key issues, works of the following three aspects should be highlighted, i.e., cryospheric processes and responses to climate change, influences of cryospheric changes, and adaptation strategies for cryospheric changes.
文摘Diyala River is the third largest tributary of the Tigris River running 445 km length and draining an area of 32,600 km2. The river is the major source of water supply for Diyala City for municipal, domestic, agriculture and other purposes. Diyala River Basin currently is suffering from water scarcity and contamination problems. Up-to-date studies have shown that blue and green waters of a basin have been demonstrating increasing variability contributing to more severe droughts and floods seemingly due to climate change. To obtain better understanding of the impacts of climate change on water resources in Diyala River Basin in near 2046-2064 and distant future 2080~2100, SWAT (soil and water assessment tool) was used. The model is first examined for its capability of capturing the basin characteristics, and then, projections from six GCMs (general circulation models) are incorporated to assess the impacts of climate change on water resources under three emission scenarios: A2, AIB and B1. The results showed deteriorating water resources regime into the future.
基金Acknowledgment This study was supported by the National Key Basic Research Development Program Project (2010CB428400) and the Natural Science Foundation of China (51279140).
文摘This paper addresses the impact of climate change on the water cycle and resource changes in the Eastern Monsoon Region of China (EMRC). It also represents a summary of the achievements made by the National Key Basic Research and Development Program (2010CB428400), where the major research focuses are detection and attribution, extreme floods and droughts, and adaptation of water resources management. Preliminary conclusions can be summarized into four points: 1) Water cycling and water resource changes in the EMRC are rather complicated as the region is impacted by natural changes relating to the strong monsoon influence and also by climate change impacts caused by CO2 emissions due to anthropogenic forcing; 2) the rate of natural variability contributing to the influence on precipitation accounts for about 70%, and the rate from anthropogenic forcing accounts for 30% on average in the EMRC. However, with future scenarios of increasing CO2 emissions, the contribution rate from anthropogenic forcing will increase and water resources management will experience greater issues related to the climate change impact; 3) Extreme floods and droughts in the EMRC will be an increasing trend, based on IPCC-AR5 scenarios; 4) Along with rising temperatures of 1 ~C in North China, the agricultural water consumption will increase to about 4% of total water consumption. Therefore, climate change is making a significant impact and will be a risk to the EMRC, which covers almost all of the eight major river basins, such as the Yangtze River, Yellow River, Huaihe River, Haihe River, and Pearl River, and to the South-to-North Water Diversion Project (middle line). To ensure water security, it is urgently necessary to take adaptive countermeasures and reduce the vulnerability of water resources and associated risks.
基金Under the auspices of National Natural Science Foundation of China(No.41171403,41301586)China Postdoctoral Science Foundation(No.2013M540599,2014T70731)Program for New Century Excellent Talents in University(No.NCET-08-0057)
文摘Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or socio-economic drought. Among the different categories of drought, hydrological drought, especially streamflow drought, has been given more attention by local governments, researchers and the public in recent years. Identifying the occurrence of streamflow drought and issuing early warning can provide timely information for effective water resources management. In this study, streamflow drought is detected by using the Standardized Runoff Index, whereas meteorological drought is detected by the Standardized Precipitation Index. Comparative analyses of frequency, magnitude, onset and duration are conducted to identify the impact of meteorological drought on streamflow drought. This study focuses on the Jinghe River Basin in Northwest China, mainly providing the following findings. 1) Eleven meteorological droughts and six streamflow droughts were indicated during 1970 and 1990 after pooling using Inter-event time and volume Criterion method. 2) Streamflow drought in the Jinghe River Basin lagged meteorological drought for about 127 days. 3) The frequency of streamflow drought in Jinghe River Basin was less than meteorological drought. However, the average duration of streamflow drought is longer. 4) The magnitude of streamflow drought is greater than meteorological drought. These results not only play an important theoretical role in understanding relationships between different drought categories, but also have practical implications for streamflow drought mitigation and regional water resources management.
文摘Climate change impacts on water resources are expected to be significant in Yemen. Efforts have been made to understand the expected changes and develop mitigation possibilities for the expected scenarios for a future sustainable use of resources and mitigation of expected impacts. The paper describes the development of a detailed baseline database and the assessment of climate change and variability impacts on water resources over the 2030, 2050 and 2080 time horizon on a Yemen-wide scale. Based on downscaled Global Climate Model data, a range of scenarios were established, representing potential Mean, Warm & Wet and Hot & Dry conditions as derived by evaluating worst case scenarios from the ensemble of the global models for the specified years. The results of the model include an estimated runoff coefficient, monthly rainfall, runoff, infiltration and evaporation representing the water balance in the different catchments. Analysis of the different evaluated scenarios shows that in the Mid, Warm and Wet scenario the hydrological components are generally higher than in the baseline scenario. For the Hot & Dry scenario, runoff, infiltration and evapotranspiration are decreasing due to the decreasing precipitation and increase in temperature. The relative changes in runoff are strongest.
文摘Greater Zab is the largest tributary of the Tigris River in lraq where the catchment area is currently being plagued by water scarcity and pollution problems. Contemporary studies have revealed that blue and green waters of the basin have been manifesting increasing variability contributing to more severe droughts and floods apparently due to climate change. In order to gain greater appreciation of the impacts of climate change on water resources in the study area in near and distant future, SWAT (Soil and Water Assessment Tool) has been used. The model is first tested for its suitability in capturing the basin characteristics, and then, forecasts from six GCMs (general circulation models) with about half-a-century lead time to 2046-2064 and one-century lead time to 2080-2100 are incorporated to evaluate the impacts of climate change on water resources under three emission scenarios: A 1 B, A2 and BI. The results showed worsening water resources regime into the future.
文摘Poor countries are prone to climate change effects due to lack of mechanisms to mitigation. As such, they are most vulnerable to effects of climate changes which are floods, drought, deforestation, environmental degradation and so on. Many of affected communities particularly in rural areas and urban poor have resorted to migration to viable agricultural lands and urban areas increasing pressure on available social services. This situation has led to depletion of natural resources in the fringes of the cities in search for shelter, food, water, energy etc.. Dares Salaam city is highly prone to environmental degradation by being highly populated and closer to the Kazimzumbwi Forest National Reserve, which has been a resource of logging at the guise of sustainable livelihood of Dares Salaam city residents. This paper is reporting on a study undertaken in ENVI & ARCGIS software environment to evaluate the extent of environmental degradation in the forest reserve for the period of 16 years i.e. 1995-201 l, firstly, for purpose of informing policy makers and administrators to determine the extent of the problem and secondly to provide evidence for development of effective mitigation measures. Results revealed a considerable environmental degradation within the forest reserve over the study period. This was attested by a decrease of forests by 42%, grass land, as well as increase of bare land and grass land by 26% and 42% respectively. This is a testimony that there was a significant environmental degradation and loss of natural resources during the study period which should be addressed by relevant authorities.
基金supported by the National Natural Sciences Foundation of China (Project Nos. 51079132 and 50679075)the Special Research Fund Project of the Chinese Ministry of Water Resources (Grant No. 200801001)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20094101110002)the National Key Scientific and Technological Project on Water Pollution Control and Treatment of China (Project No. 2009ZX07210-006)
文摘Rainfall and air temperature data from six meteorological stations above the Bengbu Sluice and hydrological and water resources evaluation data from the Bengbu Hydrological Station in the Huai River Basin from 1961 to 2008 are used to analyze the impact of changes in climatic factors on the amount of water resources in the Basin. There was a general trend of rise in its average annual air temperature, with the highest increase of 0.289℃/10a recorded at Bengbu in Anhui Province. Rising rainfall was mainly observed in the western part of the study area, while rainfall actually declined in the eastern part, i.e. the middle reaches of the Huai River. The Average rainfall in the study area was in a vaguely declining trend. In other words, the rainfall in the Basin is still much affected by natural fluctuations. On the whole, there was a trend of gradual decrease in the quantity of the Basin's water resources for the period under study. Water resources quantity is found to fall with decreasing rainfall and rising air temperature. Regression analysis is used to establish a mathematical model between water resources quantity and climatic factors (i.e. air temperature and rainfall) in order to explore the impact of climate change on water resources in the Basin. Moreover, various scenarios are set to quantitatively analyze the response of water resources to climate change. Sensitivity analysis shows that changes in rainfall have a much bigger impact on its water resources quantity than changes in its air temperature.
文摘This study is a rapid appraisal procedure (RAP) of two forms of agriculture water delivery systems comprising two canal irrigation schemes and 26 Zimbabwean bush pumps in the Midlands and Masvingo Provinces. A longitudinal multiple data collection technique employed involved various primary and secondary sources including site visits, literature review, observation, interviews with key personnel and group discussions. General findings of this study indicate: (1) the available coping mechanisms in smallholder farming in a climate change context and (2) the challenges faced in the actual delivery of water in terms of design, management, physical and institutional factors. The study provides pragmatic recommendations for overall improvement and performance in a local, technical and socio-economic context through evaluation of the current situation, practices and processes. An integrated approach to addressing climate change impacts should include water management, rehabilitation, complete overhaul and introduction of other relevant water systems and water saving farming techniques. Yet, ownership of these technologies by communities remains instrumental. Rural development and agricultural policies that ensure maximum and full capacity utilisation of water systems to improve rural livelihoods, mitigation and adaptation to climate change are recommended.
文摘In this secondary research, published works on effect of climate change on water resources in other countries and in Australia were reviewed critically. Research question, objectives and assumptions were made to facilitate this study. First, methods used for such studies and their results at global level were reviewed. Then Australian specific methods of study and findings were reviewed. More commonly, both globally and in Australia, simulations using long-term real data on selected climatic scenarios of global climatic models are projected for long-term future trends. The validity and certainty of predicted occurrences depend upon the closeness of real time data with scenarios to which they are projected. Even with these limitations, projections of already rising temperatures and declining rainfall on surface water and ground water availabilities show gradual decline in water availability leading to water stress both for human communities and ecosystems The role of human-induced emissions in hastening the degradation process has also been investigated. Conserving all available water, practising efficient water consumption and prudent water policies only can provide some relief from what is inevitable.
基金supported by the National Natural Science Foundation of China under Grant 40975041the National Basic Research Program of China under Grant 2009CB421407
文摘Based on a high-resolution regional climate model (RegCM3) simulation over East Asia, future climate changes over the Miyun Reservoir in the 21st century under the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A1B scenario are analyzed. The model simulation extends from 1951 to 2100 at a grid spacing of 25 km and is one-way nested within a global model of MIROC3.2_ hires (the Model for Interdisciplinary Research on Climate). The focus of the analysis is on the Watershed of Miyun Reservoir, the main water supply for Beijing in northern China. The results show that RegCM3 reproduces the observed temperature well but it overestimates precipitation over the region. Significant warming in the 21st century is simulated in the annual mean, December-January-February (DJF) and June-July-August (JJA), although with differences concerning the spatial distribution and magnitude. Changes in precipitation for the annual mean, DJF, and JJA also show differences. A prevailing increase of precipitation in DJF and a decrease of it in JJA is projected over the region, while little change in the annual mean is projected. Changes of the difference between precipitation and evapotranspiration to measure the potential water availability are also presented in the paper.
文摘Sustainable development indicators, aim to measure sustainable development over longer periods of time. The sustainable development indicators are grouped into 10 subject categories: socioeconomic development, sustainable consumption and production, social inclusion, demographic changes, public health, climate change and energy, sustainable transport, natural resources, global partnership and finally good governance. In this paper, the authors examined a number of researches and compared the methods they used in order to determine the advantages and disadvantages of each method. The methods used a large number of different indicators. The comparison of the indicators could be made through mathematical models and also through theoretical approach.
文摘The combined surface and groundwater allocation practice by wells and canals had contributed to the safety of groundwater environment and agriculture sustainable production. The typical area in the People's Victory Canal irrigation district was taken as a case, drawing together the irrigation district agriculture water consumption and precipitation from 1954 to 2014 in the People's Victory Canal irrigation district, ratios of surface to groundwater irrigation amount, dynamic of groundwater depth and hydrochemical characteristic of groundwater from 2008 to 2014 in the research area, the relationship between groundwater depth and ratio of surface to groundwater irrigation amount was analyzed, in order to ascertain the influence of precipitation on ratios of surface to groundwater irrigation amount and its effect on soil and groundwater environment. The results indicated that positive correlation between the ratios of surface to groundwater irrigation amount and annual precipitation was appeared, affected by climate change, average irrigation amount from surface in the recent 5 years was 2.90 x 108 cubic meters, accounted for 75.52% of total irrigation amount, on the other hand, decreasing tendency of precipitation was obvious, and groundwater depth dynamic in upstream of the branch canals was more dramatic than downstream because of surface water irrigation infiltration, under the unified condition of water use efficiency, ratio of surface to groundwater irrigation amount was negative correlation with area of the groundwater depth beyond 11 m, meanwhile, groundwater depth demonstrated negative correlation with the ratio of surface to groundwater irrigation amount, moreover, alkaline trend of groundwater hydrochemistry during the normal season in the research area was obvious because of phreatic evaporation and the agricultural irrigation from wells, along with irrigation from surface inflow of Yellow River, quality of groundwater hydrochemistry during the dry season was ameliorative greatly. Consequently, it was very important to the agriculture sustainable production that well-canal combined irrigation patterns alleviated extremely alkaline trend of the groundwater hydrochemistry and played a positive role of root layer soil salinity leaching.