Impact of climate change on regional irrigation water demand in Baojixia irrigation district of China

Water scarcity in China would possibly be aggravated by rapid increase in water demand for irrigation due to climate change. This paper focuses on the mechanism of climate change impact on regional irrigation water demand by considering the dynamic feedback relationships among climate change, irrigation water demand and adaptation measures. The model in implemented using system dynamics approach and employed in Baojixia irrigation district located in Shaanxi Province of China to analyses the changes in irrigation water demand under different climate change scenarios. Obtained results revealed that temperature will be the dominant factor to determine irrigation water demand in the area. An increase of temperature by 1 °C will result in net irrigation water demand to increase by about 12,050?×?10⁴ m³ and gross water demand by about 20,080?×?10⁴ m³ in the area. However, irrigation water demand will not increase at the same rate of temperature rise as the adaptation measures will eventually reduce the water demand increased by temperature rise. It is expected that the modeling approach presented in this study can be used in adopting policy responses to reduce climate change impacts on water resources.     

Forecasting industrial water demand in Huaihe River Basin due to environmental changes

A framework is proposed for forecasting industrial water demand in the context of climate change, economic growth, and technological development. The framework was tested in five sub-basins of Huaihe River of China, namely Upstream of Huaihe River (UH), Middlestream of Huaihe River (MH), Downstream of Huaihe River (DH), Yishusi River (YSSR), and Coastal River of Shandong Peninsula (CSP) to project future changes in industrial water demand under different environment change scenarios. Results showed that industrial water demand in Huaihe River basin will increase in the range of 10 to 44.6% due to economic development, water-saving technological advances, and climate change. The highest increase was projected by general circulation model (GCM) BCC-CSM1–1 (179.16 × 108 m³) and the lowest by GCM GISS-E2-R (132.4 × 10⁸ m³) in 2020, while the GCM BNU-ESM projected the highest increase (190.57 × 10⁸ m³) and GCM CNRM-CM5 the lowest (160.41 × 10⁸ m³) in 2030. Among the different sub-basins, the highest increase was projected in MH sub-basin where industrial water demand is already very high. On the other hand, the lowest increase in industrial water demand was projected in UH sub-basin. The rapid growth of high water-consuming industries and increased water demand for cooling due to temperature rise are the major causes of the sharp increase in industrial water demand in the basin. The framework developed in the study can be used for reliable forecasting of industrial water demand which in turn can help in selection of an appropriate water management strategy for adaptation to global environmental changes.     

Assessment of the Risks for Human Health of Adenoviruses,Hepatitis A Virus,Rotaviruses and Enteroviruses in the Buffalo River and Three Source Water Dams in the Eastern Cape

Buffalo River is an important water resource in the Eastern Cape Province of South Africa. The potential risks of infection constituted by exposure to human enteric viruses in the Buffalo River and three source water dams along its course were assessed using mean values and static quantitative microbial risk assessment (QMRA). The daily risks of infection determined by the exponential model [for human adenovirus (HAdV) and enterovirus (EnV)] and the beta-Poisson model (for hepatitis A virus (HAV) and rotavirus (RoV)) varied with sites and exposure scenario. The estimated daily risks of infection values at the sites where the respective viruses were detected, ranged from 7.31 × 10^?3 to 1 (for HAdV), 4.23 × 10^?2 to 6.54 × 10^?1 (RoV), 2.32 × 10^?4 to 1.73 × 10^?1 (HAV) and 1.32 × 10^?4 to 5.70 × 10^?2 (EnV). The yearly risks of infection in individuals exposed to the river/dam water via drinking, recreational, domestic or irrigational activities were unacceptably high, exceeding the acceptable risk of 0.01 % (10^?4 infection/person/year), and the guideline value used as by several nations for drinking water. The risks of illness and death from infection ranged from 6.58 × 10^?5 to 5.0 × 10^?1 and 6.58 × 10^?9 to 5.0 × 10^?5, respectively. The threats here are heightened by the high mortality rates for HAV, and its endemicity in South Africa. Therefore, we conclude that the Buffalo River and its source water dams are a public health hazard. The QMRA presented here is the first of its kinds in the Eastern Cape Province and provides the building block for a quantitatively oriented local guideline for water quality management in the Province.     

Using activated biochar for greenhouse gas mitigation and industrial water treatment

This study explored the feasibility of using residual biomass to both mitigate greenhouse gas (GHG) emissions and remediate water contaminated by hydrocarbons. Using produced (process-affected) water from Canada’s oil sands operations as a case study, activated biochar (ACB) was found to have a higher affinity to organics than activated coal and removed 75 % of total organic carbon (TOC) from produced water in steam-assisted gravity drainage (SAGD) operations or 90 % of the TOC from synthetic tailings (ST) water sample. Up to 6 Tg dry biomass year^?1 would be required to treat the waters associated with the 93?×?10⁶-m³ of bitumen recovered per year. Landfilling the spent ACB and flaring any biogas produced were estimated to provide a greater GHG benefit than the combustion of the biochar + organics for heat to offset natural gas demand. Net costs for the ACB were about 13.84?$?m^?3 bitumen for SAGD operations and 1.76?$?m^?3 bitumen for mining operations. The values for mining operations justify further work to create a value chain that will integrate bioprocesses into the fossil fuel industry.     

Quantitative Detection and Characterization of Human Adenoviruses in the Buffalo River in the Eastern Cape Province of South Africa

Buffalo River is an important water resource in the Eastern Cape Province of South Africa. Over a 1-year period (August 2010?CJuly 2011), we assessed the prevalence of human adenoviruses (HAdVs) at a total of 6 sites on the river and three dams along its course. HAdVs were detected by real-time quantitative PCR in about 35?% of the samples with concentrations ranging from 1.2?×?10¹ genome copies (GC)/l to 4.71?×?10³ GC/l. HAdVs were detected at 5 of the 6 sampling sites with the detection rate ranging from 8.3?% at Rooikrantz Dam to 92?% at Parkside. The HAdV concentrations across the sampling sites were as follows: Parkside (3.25?×?10²?C4.71?×?10³?GC/); King William??s Town (1.02?×?10²?C4.56?×?10³?GC/l); and Eluxolzweni (1.17?×?10²?C3.97?×?10² GC/l). Significantly (P?<?0.05) higher concentrations were detected at the non-dam sites compared to the dam sites. A very low mean concentration of 1.86?×?10¹ HAdV GC/l was observed at Bridle Drift Dam. While HAdVs were detected only once at Rooikrantz Dam (1.74?×?10¹?GC/l), no HAdV was detected at Maden Dam. Epidemiologically important serotypes, Ad40/41, constituted 83.3?%, while Ad21 made up 16.7?% of the all HAdVs detected and were characterized by qualitative PCR. The Buffalo River presents a public health risk heightened by the presence of Ad 40/41 and Ad21. Our results make imperative the need for assessing water sources for viral contamination in the interest of public health. This work is a significant contribution to the molecular epidemiology of adenoviruses and to the best of our knowledge this is the first report on detection of enteric virus from surface waters in the Eastern Cape.     

白洋淀湿地不同时空水生植物生态需水规律研究

在对白洋淀典型水生植物的蒸腾量实地监测的基础上,确定了不同时间和空间下水生植物的蒸散系数,对白洋淀湿地基于现状和恢复目标下的植物生态需水量进行了等级划分和计算.研究结果表明,6～9月综合蒸散系数为3.21、6.24、6.02和1.86.水生植物需水量的时间分布规律为7月>8月>6月>9月,空间分布规律为陆地>水陆过渡带>水中.现状条件下,白洋淀水生植物6～9月的最小需水量分别为0.49×108m3、0.80×108m3、0.60×108m3、0.16×108m3,分别占湿地最小生态需水量的44%、56%、49%、50%(未包含湿地土壤需水量),与湿地最小生态需水量对应的最低生态水位为7.50m、7.50m、7.50m、6.30m.基于生态恢复目标,计算得到6～9月的水生植物最小生态需水量分别为0 56×108m3、0.91×108m3、0.69×108m3、0.19×108m3,为湿地最小生态需水量的30%、41%、35%、21%.对比白洋淀水生植物生态需水量的实际值和计算值发现,白洋淀水生植物的生态需水量在6～9月间分别是计算值的5.75倍、6.42倍、5.00倍和2.29倍.     

CH4 emission model from the waste of Sus Domesticus and Gallus Domesticus in Nigerian local farms: environmental implications and prospects

The potential of CH₄ (methane) greenhouse gas (GHG) emissions based on a model of prevailing behavioural pattern of livestock waste management in Nigerian local farms was investigated in this paper. Livestock waste, from Sus domesticus, pig, and Gallus domesticus, poultry, were employed as substrates in the study which uses water from a fish rearing farm as the matrix medium to simulate wastewater pool/river environment. A substrate to fish-water ratio of 1:3 by mass was used in developed laboratory-size digesting reactor system with U-tube water displacement, to facilitate volumetric readings of gas production, for each mix of the livestock waste. Volumetric readings from these, at ambient temperature conditions in the retention time of 32 days, follow the Normal probability density function, in accordance with Kolmogorov-Smirnov goodness-of-fit criteria. These readings showed that CH₄-containing gas as high as 67.3?×?10^?3 dm³ was produced on the 14th day from the pig and 86.8?×?10^?3 dm³ on the 13th day from the poultry substrates. The overall CH₄-containing gas productions of 255.4?×?10^?3 dm³/kg and 323.58?×?10^?3 dm³/kg were observed for the pig and the poultry substrates, respectively. A 70% scale-up analysis, modelled from these results, for the nation yield potential emission of about 4 kg CH₄ (that could be as potent as 84 kg CO₂-equivalent) annually. The environmental implications on global warming and possible prospects of recoverable domestic benefits from the waste through the adoption of sustainable policy of livestock waste managements for mitigating the CH₄ emissions in Nigerian local farms are presented.     

Impacts of climate change on savannah woodland biomass carbon density and water-use: a modelling study of the Sudanese gum belt region

This paper analyzes potential impacts of climate change on biomass carbon (C) density and water-use (actual evapotranspiration, AET) of savannah woodlands in Sudan. Climate change scenarios were developed from five General Circulation Models (GCMs; CGCM2, CSIRO2, ECHam4, HadCM3 and PCM) under two IPCC (Intergovernmental Panel on Climate Change) emission scenarios (A1FI and B1). Baseline (1961-90) climate and climate change scenarios for 2080s for eight map sheet grids (1° latitude x 1.5° longitude) were constructed. Compared to baseline values, mean annual precipitation (MAP) showed both increases (+112 to +221 mm) and decreases (?13 to ?188 mm) but mean annual temperature (MAT) only showed increases (+1.2 to +8.3 °C). Baseline biomass C densities showed an exponential relationship with MAP (y?=?6.798 e ^0.0054x, R²?=?0.70). Depending on climate change MAP, biomass C densities increased (+14 to +241 g C m^?2) or decreased (?1 to ?148 g?C m^?2). However, because of uncertainty in biomass C density estimates, the changes were only significant (P <0.05) for some of the climate change scenarios and for grids with MAP >260 mm. Under A1FI emission scenarios, only HadCM3 did not have a significant effect while under B1 emission scenarios, only CGCM2 and ECHam4 had a significant effect on biomass C density. AET also showed both increases (+100 to +145 mm for vertisols and +82 to +197 mm for arenosols) and decreases (?12 to ?178 mm for vertisols and ?12 to ?132 mm for arenosols). The largest relative changes in AET (up to 31 %) were associated with grids receiving the lowest rainfall. Thus, even if MAP increases across the study region, the increase will have little impact on biomass levels in the driest areas of the region, emphasizing the need for improved management and use of savannah woodlands.     

三江源区水源涵养功能评估

为实现三江源区水源涵养功能评估,服务区域生态服务价值估算,从水源涵养的概念出发,解析水源涵养功能的内涵特征和表征指标,提出了三江源区水源涵养功能评估技术框架,并基于SWAT模型建立三江源区水文模型,通过年尺度、月尺度和日尺度的水文模拟,完成三江源区水源涵养功能定量评估.从水文模型校准结果来看,直门达、唐乃亥和香达3个验证站日径流量最大相对误差不超过17.0%,月径流量最大相对误差不超过13.0%;日尺度模型中直门达站模拟效率系数超过了0.6,其他两个站也超过了0.5,月尺度模型中3个验证站模拟效率系数均超过0.6以上;日尺度模型和月尺度模型验证结果均可接受,在一定程度上较好地揭示出了三江源区的水量输出过程、趋势和规律.应用该模型对水源涵养功能进行定量评估,长江流域、黄河流域、澜沧江流域水资源供给量分别可达到158.8×108、326.2×108、72.6×108 m3;考虑土地利用和植被变化对流域径流输出的影响作用,植被破坏可能导致长江流域、黄河流域和澜沧江流域地下径流量分别可能减少98.6×108、200.1×108和44.5×108 m3;在相同降水条件下,低植被覆盖会导致长江流域、黄河流域和澜沧江流域年最大流量的平均值、最大值、最小值分别增加了约80%、60%和30%.研究显示,三江源区在保障下游用水、提升径流调节能力和缓解防洪压力等方面具有突出的作用.      

黄河下游影响带地下水资源评价及合理开发利用

论文研究黄河下游影响带(河南段)地下水资源评价及合理开发利用问题。在概要介绍河南省黄河影响带水文地质条件基础上,运用FEFLOW建立研究区三维地下水流模型,计算出地下水多年平均补给资源28.35×10⁸m³/a和可开采资源量19.43×10⁸m³/a。重点阐述新增9个水源地的开采条件,并通过地下水模型预测新增133×10⁴m³/d开采量条件下,浅层地下水位最大降深小于20m,开采5～10年后地下水趋于稳定,新增开采量的62.58%来自黄河水的补给。研究表明,黄河对研究区地下水具有重要的补给作用,新增地下水开采量是有保证的。同时阐述了研究区地下水可持续开发利用的对策。     

Natural ecological water demand in the lower Heihe River

The ecological environment in the lower Heihe River has been deteriorating due to large water consumption in the upper and middle reaches, and less available water downstream. To restore the ecological environment in the lower Heihe River, the ecological water demand should be guaranteed. The natural vegetation area in the lower Heihe River was first obtained through the interpretation of remote sensing images taken in 1998. Based on the analysis for the Quota of the natural ecological water demand in the lower Heihe River and the determination of the natural ecological water demand calculation method, the ecological water demand in the lower Heihe River was calculated. Finally, the natural ecological water demand in the lower Heihe River under the current situation was calculated with the groundwater storage volume change method, Aweliyongrufe method and the measured water volume method. In comparison, the natural ecological water demand in the lower Heihe River is 3.91−4.05 × 10⁸ m³.     

Modeling and simulation of industrial water demand of Beijing municipality in China

Statistic and econometric regression models were established in this study to analyze and predict industrial water demand, water deficits, and their future uncertainty in Beijing—a Chinese city with a severe water stress problem. A forecasting model was selected based on a modeling evaluation by comparing predictions with observations. Four scenarios were designed to simulate and analyze the future uncertainty of industrial water demand and the water deficit of Beijing. The modeling results for industrial water demand suggested that Beijing industry would face a water deficit between 3.06 × 10⁸ m³ in 2008 and 2.77×10⁸ m³ in 2015, though its industrial water demand would decrease from 6.31×10⁸ m³ to 4.84 ×10⁸ m³ during this period of time. Results from simulated scenario illustrated that, due to the extreme water scarcity situation, industry in Beijing would still face a serious water deficit problem even with a very optimistic scenario for the future.     

内蒙古乌海热电厂水源地地下水资源量评价

在分析勘察区水文地质条件的基础上,用水量均衡法计算了该区地下水的补给量和排泄量,结果为负均衡。水源地开采后水源主要来源于黄河激发补给量,抽水试验和数值模拟表明黄河激发补给量为3.45×10⁴m³/d。根据水位预测,水源地开采20年后和不利水文、气象条件下连续开采2年,水位下降值均不及含水层厚度的1/10,说明水源地开采量3×10⁴m³/d是有保证的,可以满足电厂供水要求。     

基于生态保护目标的太子河下游河道生态需水量计算

河流生态需水量计算是进行生态水权分配的一项基础性工作,是生态环境保护和水资源配置的依据.随着社会经济的发展,流域水资源短缺和生态环境问题日益突出.针对太子河下游河段水资源开发利用现状及存在的生态环境问题,在确定生态保护目标的基础上,采用月保证率法和生态水力学法计算下游河道不同等级生态需水量,既可以从各月角度反映河道生态需水是一个与自然径流相适应的过程,又注重水生生物的关键期和生境需求.通过Tennant法验证月保证率法和生态水力学法计算结果可靠,最终确定太子河下游河道最小、适宜和理想等级年生态需水量分别为:5.31×108m3、8.52×108m3和12.17×108m3,而且现状流量可以满足最小生态需水量的要求.     

Impacts of climate change on water resources in the Yellow River basin and identification of global adaptation strategies

Climate change is a global environmental issue, which is challenging water resources management and practices. This study investigates the impact of climate change on water resources of the Yellow River basin, a major grain-producing area in China, and provides recommendations on strategies to increase adaptive capacity and resilience in the basin region. Results show that the recorded stream flows of the Yellow River declined from 1951 to 2010 and have decreased significantly in the middle and lower reaches. The variable infiltration capacity (VIC) model performs well as a tool to simulate monthly discharge of both the tributary catchments and the whole Yellow River basin. Temperature across the Yellow River basin over 2021–2050 is expected to continue to rise with an average rates of approximately 0.039–0.056 °C/annum. The average annual precipitation in the basin is projected to increase by 1.28–3.29 % compared with the 1991–2010 baseline. Runoff during 2021–2050 is projected to decrease by 0.53–9.67 % relative to 1991–2010 with high decadal and spatial variability. This is likely due to the model’s projections of a significant rise in temperature and changes in precipitation patterns. Climate change will likely aggravate the severity and frequency of both water shortages and flooding in the basin region. It is therefore essential to devote sufficient attention on structural and non-structural measures for the Yellow River basin to cope with climate change. At the global level, strategies to increase adaptive capacity and build resilience to climate change focus on public education to improve awareness of climate risks, implementing the integrated water resources management and planning based on impact assessments.     

珠江广州河段员村段的底泥耗氧

探讨广州珠江员村段底泥的耗氧特点及总底泥耗氧中生物耗氧和非耗氧所占比例。结果表明,在实验期间内平水期底泥只出现前６ｈ的持续耗氧过程,而丰水期泥除出现前６ｈ的快速耗氧外,还表现出相对较缓慢的耗氧过程。两水期底泥耗氧中化学耗氧起主导作用。同温、同流量条件下,平水期的底泥耗氧速率略低于丰水期。由实验推导出两水期底泥耗氧速率与温度及流量之间的关系为：ＳＯＤ丰＝０．４９４５×１．００５８＾（Ｔ－２０）（Ｔ≤     

An assessment of carbon stock for various land use system in Aravally mountains, Western India

Reducing carbon emissions from deforestation and degradation in developing countries is of the central importance in efforts to combat climate change. A study was conducted to measure carbon stocks in various land-use systems including forms and reliably estimates the impact of land use on carbon (C) stocks in the forest of Rajasthan, western India (23°3′–30°12′N longitude and 69°30′–78°17′E). 22.8% of India is forested and 0.04% is the deforestation rate of India. In Indian forest sector of western India of Aravally mountain range covered large area of deciduous forest and it’s very helpful in carbon sequestration at global level. The carbon stocks of forest, plantation (reforestation) and agricultural land in aboveground, soil organic and fine root within forest were estimated through field data collection. Results revealed that the amount of total carbon stock of forests (533.64?±?37.54 Mg·ha^?1, simplified expression of Mg (carbon) ·ha^?1) was significantly greater (P?<?0.05) than the plantation (324.37?±?15.0 Mg·ha^?1) and the agricultural land (120.50?±?2.17 Mg·ha^?1). Soil organic carbon in the forests (172.84?±?3.78 Mg·ha^?1) was also significantly greater (P?<?0.05) than the plantation (153.20?±?7.48 Mg·ha^?1) and the agricultural land (108.71?±?1.68 Mg·ha^?1). The differences in carbon stocks across land-use types are the primary consequence of variations in the vegetation biomass and the soil organic matter. Fine root carbon was a small fraction of carbon stocks in all land-use types. Most of the soil organic carbon and fine root carbon content was found in the upper 30-cm layer and decreased with soil depth. The aboveground carbon (ABGC): soil organic carbon (SOC): fine root carbon ratios (FRC), was 8:4:1, 4:5:1, and 3:37:1 for the forest, plantation and agricultural land, respectively. These results indicate that a relatively large proportion of the C loss is due to forest conversion to agricultural land.     

Assessment of trophic change and its probable impact on tropical estuarine environment (the Kodungallur-Azhikode estuary, India)

The cumulative effects of global change, including climate change, increased population density and domestic waste disposal, effluent discharges from industrial processes, agriculture and aquaculture will likely continue and increases the process of eutrophication in estuarine environments. Eutrophication is one of the leading causes of degraded water quality, water column hypoxia/anoxia, harmful algal bloom (HAB) and loss of habitat and species diversity in the estuarine environment. The present study attempts to characterize the trophic condition of coastal estuary using a simple tool; trophic index (TRIX) based on a linear combination of the log of four state variables with supplementary index Efficiency Coefficient (Eff. Coeff.) as a discriminating tool. Numerically, the index TRIX is scaled from 0 to10, covering a wide range of trophic conditions from oligotrophic to eutrophic. Study area Kodungallur-Azhikode Estuary (KAE) was comparatively shallow in nature with average depth of 3.6?±?0.2?m. Dissolve oxygen regime in the water column was ranged from 4.7?±?1.3?mgL^?1 in Station I to 5.9?±?1.4?mgL^?1 in Station IV. The average nitrate-nitrogen (NO₃-N) of KAE water was 470?mg?m^?3; values ranged from Av. 364.4?mg?m^?3 at Station II to Av. 626.6?mg?m^?3at Station VII. The mean ammonium-nitrogen (NH ₄ ⁺ -N) varied from 54.1?mg?m^?3 at Station VII to 101?mg?m^?3 at Station III. The average Chl-a for the seven stations of KAE was 6.42?±?3.91?mg?m^?3. Comparisons over different spatial and temporal scales in the KAE and study observed that, estuary experiencing high productivity by the influence of high degree of eutrophication; an annual average of 6.91 TRIX was noticed in the KAE and seasonal highest was observed during pre monsoon period (7.15) and lowest during post monsoon period (6.51). In the spatial scale station V showed high value 7.37 and comparatively low values in the station VI (6.93) and station VII (6.96) and which indicates eutrophication was predominant in land cover area with comparatively high water residence time. Eff. Coeff. values in the KAE ranges from ?2.74 during monsoon period to the lowest of ?1.98 in pre monsoon period. Present study revealed that trophic state of the estuary under severe stress and the restriction of autochthonous and allochthonous nutrient loading should be keystone in mitigate from eutrophication process.     

河道最小环境需水量确定方法及其应用研究(Ⅱ)--应用

以黄河支流渭河为例，概算了河河4个断面及其干流现状及不同水文年的河道最小环境需水量，结果表明，在多年平均状况下，渭河最小环境需水量为19．8亿m^3/a，占年轻流量的12．9％，占基流量的64．9％，考虑河道环境用水后渭河的水资源利用率应为14．2％，比未考虑环境用水的利用率降低约14％，为满足最小环境需水量的要求，渭河废污水排放量必须低于1998年水平。     

A holistic approach for evaluating ecological water allocation in the Yellow River Basin of China

The characteristics and sustainable management of water resources on a basin scale require that they should be managed using a holistic approach. In this study, a holistic methodology called the holistic approach in a basin scale (HABS) is proposed to determine the ecological water requirements of a whole basin. There are three principles in HABS. First, ecological water requirements in a basin scale indicate not only the coupling of hydrological and ecological systems, but also the exchange of matter and energy between each ecological type through all kinds of physical geography processes. Second, ecological water requirements can be divided into different types according to their functions, and water requirements of different types are compatible. Third, ecological water requirements are related to a multiple system including water quality, water quantity, and time and space, which interact with each other. The holistic approach in a basin scale was then used in the Yellow River Basin and it suggested that 265.0 × 10⁸ m³ of water, 45% of the total surface water resources, should be allocated to ecological systems, such as rivers, lakes, wetlands and cities, to sustain its function and health. The ecological water requirements of inside river systems and outside river systems were respectively 261.0 × 10⁸ and 3.65 × 10⁸ m³.