Effects of climate change and land-use changes on spatiotemporal distributions of blue water and green water in Ningxia, Northwest China

Water resources are a crucial factor that determines the health of ecosystems and socio-economic development;however,they are under threat due to climate change and human activities.The quantitative assessment of water resources using the concept of blue water and green water can improve regional water resources management.In this study,spatiotemporal distributions of blue water and green water were simulated and analyzed under scenarios of climate change and land-use changes using the Soil and Water Assessment Tool(SWAT)in Ningxia Hui Autonomous Region,Northwest China,between 2009 and 2014.Green water,a leading component of water resources,accounted for more than 69.00%of the total water resources in Ningxia.Blue water and green water showed a single peak trend on the monthly and annual scales during the study period.On the spatial scale,the southern region of Ningxia showed higher blue water and green water resources than the northern region.The spatiotemporal distribution features of blue water,green water,and green water flow had strong correlations with precipitation.Furthermore,the simulation identified the climate change in Ningxia to be more influential on blue water and green water than land-use changes.This study provides a specific scientific foundation to manage water resources in Ningxia when encountered with climate change together with human activities.

Agricultural Water Footprint of Southern Highbush Blueberry Produced Commercially with Drip Irrigation and Sprinkler Frost Protection

A study was conducted from 2010 to 2017 to determine the water footprint for producing blueberries in the Entre Ríos province of Argentina. Three cultivars of southern highbush blueberry (hybrid cross of Vaccinium sp.) were evaluated in the study, including “Star”, “Emerald”, and “Snowchaser”. In each case, the plants were irrigated by drip and protected from frost using overhead sprinklers. Water requirements for irrigation and frost protection varied among the cultivars due to differences in the timing of flowering and fruit development. The annual water footprint for fruit production in each cultivar is expressed in units of cubic meters of water used to produce one ton of fresh fruit and ranged from 212 - 578 m3∙t−1 for “Star”, 296 - 985 m3∙t−1 for “Emerald”, and 536 - 4066 m3∙t−1 for “Snowchaser”. “Snowchaser” flowered earlier than the other cultivars and, therefore, needed more water for frost protection. “Star”, on the other hand, ripened the latest among the cultivars and required little to no water for frost protection. Frost protection required a minimum of 30 m3∙h−1 of water per hectare and in addition to drip irrigation was a major component of the water footprint.

Blue and Grey Water Footprints of Dairy Farms in Kuwait

In Kuwait, dairy farming faces challenges due to its significant water demands. The current study assessed seasonal patterns of water use to estimate the blue water footprint (WF) and grey WF per kg of fat protein corrected milk (FPCM) for confined dairy farming systems in Kuwait. Blue and grey WFs were evaluated using data from three operational farms. The average blue WF (L·kg-1 FPCM) was estimated to be 54.5 ± 4.0 L·kg-1 in summer and 19.2 ± 0.8 L·kg-1 in winter. The average grey WF (generated from milk house wastewater) was assessed on bimonthly basis and determined based on its phosphate (PO4) concentration (82.2 ± 14.3 mg·L-1) which is the most limiting factor to be 23.0 ± 9.0 L·kg-1 FPCM d-1. The outcomes indicate that enhancing the performance of dairy cows and adopting alternative water management strategies can play a role in minimizing the impacts of confined dairy farming systems in Kuwait on water quality and quantity.

Virtual Water Trade and Food Security for Iraq

Iraq depends on its water resources from the water of the Tigris and Euphrates Rivers and their tributaries. Now, the flow of these rivers is decreasing, and Iraq is experiencing a water shortage problem. The situation is expected to be graver in the future if no action is considered. It is expected that the population will be about 70 million in 2050 and about 90 million in 2070. In such a case, thus, the quantities of water available in the future will not be sufficient to produce most of the requirements of food security, whether that be from agricultural or animal products. To overcome this problem, water management planning should be based on scientific background to overcome the present and expected problems. One of the main factors to be considered should be based on scientific studies of the virtual water footprint of different food crops to provide the largest possible amount of virtual water and avoid the acute shortage of its national water from surface and ground irrigation water (blue water) and rainwater (green water), in addition to working hard to provide the largest possible amount of desalinated water and refined sewage (gray water). In addition, any strategic plan for sustainable development in the country must be comprehensive so that it is not satisfied with improving the situation in the field of food security related to water security, but rather among its other elements is community development that directly affects food security, including setting policies to reduce consumption by reducing the steady increase in population where the population rate is 2.97% now. Collective awareness and guidance programs in all the fields of water and food security are very important to be adopted, so that everyone knows that the issue of food security and what derives from it are an existential issue related to the survival of Iraq as a state and people. In this research, facts are stated so that action is to be considered to minimize the water shortage problem. The new strategic water resources management plan is to be adopted that considers existing and future expected problems.

Recharge to Blue Lake and Strategies for Water Security Planning, Mount Gambier, South Australia

Blue Lake, a volcanic crater provides municipal water supply to the city of Mount Gambier, population of 26,000. Current average annual pumping from the lake is 3.6 × 106 m3. The lake is fed by karstic unconfined Gambier Limestone aquifer. Storm water of the city discharges to the aquifer via about 400 drainage wells and three large sinkholes. Average annual storm water discharge is estimated at approximately 6.6 × 106 m3 through drainage wells and sinkholes within 16.8 km2 of the central part of the city. Chemical mass balance for calcium was used to estimate groundwater inflow to the lake at 6.3 × 106 m3, almost equal to the volume of storm water discharge and slightly higher than the previous estimates using environmental isotopes (4.8 - 6.0 × 106 m3). Considering the lake outflow volume of 2.7 × 106 m3, the net inflow to the lake equates to the current annual pumping and therefore it is considered that the current pumping rate is at the upper limit. For meeting the short-term future demand, confined aquifer water may be used and in the longerterm, an additional well field is required outside the Blue Lake capture zone, preferably to the north-east of the city. For water supply security, inflow to the lake along with water quality has to be maintained within the city. Current annual private abstraction within the capture zone is about 4.4 × 106 m3 and in order to maintain aquifer water levels, no additional allocation should be allowed.

中国燃煤发电水足迹时空特征研究

中国燃煤发电行业需要消耗大量水资源。基于生命周期方法,建立了中国燃煤发电水足迹评估模型。该模型包括煤炭开采、煤炭加工、煤炭运输、燃煤发电和电力输送五个阶段,水足迹不仅考虑了直接水足迹,还有间接水足迹。基于该模型,定量分析了2000—2020年中国燃煤发电整个生命周期的用水量和废水排放对环境的影响,中国各省份燃煤发电的水足迹以及跨省煤电运输所产生的虚拟水的时空变化特征。结果显示:从时间上看,2000—2020年,中国燃煤发电总水足迹逐年上升,从160亿立方米增加到661亿立方米。单位水足迹处于先上升后下降的趋势,2015年达到最大值15.6 m3/MW·h。期间,灰水足迹占比较大,为76%~83%。整个生命周期中,间接水足迹占总水足迹的36%~45%。从空间上看,2020年,内蒙古、安徽、宁夏、陕西和新疆是主要虚拟水输出省份,而内蒙古、山西、山东和新疆是2000—2020年水足迹增长最多的省份。研究结果以期为我国煤炭和水资源高效利用以及水环境管理提供重要借鉴。

基于集对分析的清流河流域蓝绿水分类分析

运用SWAT模型模拟厄尔尼诺和拉尼娜事件影响时段内清流河流域蓝绿水资源的时空分布规律,并利用集对分析法解析了多时间尺度下清流河流域蓝绿水资源丰枯演变特性。结果表明:厄尔尼诺和拉尼娜事件影响时段内清流河流域绿水资源分别比多年平均值高12.0 mm和69.7 mm,蓝水资源分别比多年平均值低115.7 mm和138.2 mm,绿水系数分别比多年平均值高9.3%和12.9%;厄尔尼诺和拉尼娜事件影响时段内清流河流域蓝水资源均属于枯类,绿水资源属于丰类和平类;清流河流域蓝水资源在1967—1979年、1980—1992年、1993—2005年、2006—2018年4个阶段分别属于枯、平、枯、平类,绿水资源分别属于丰、平、丰、平类,蓝绿水资源丰枯演变具有一定的波动性。

基于SWAT模型的黑河中游蓝绿水安全时空变化分析

蓝水和绿水是淡水资源循环的两个组成部分,反映了人类活动和生态系统可利用水资源,用来评估区域水资源的安全状况,优化区域水资源管理。然而,目前对于同时揭示蓝绿水资源安全之间潜在联系的空间规律的研究还较为缺乏。地处西北内陆干旱区的黑河中游的生态环境保护和社会经济发展之间的用水矛盾日益加剧,导致水资源供需关系渐趋紧张,影响区域可持续发展。以黑河中游为研究区,采取多源地理数据,基于SWAT模型分析了黑河中游2000—2020年期间子流域尺度上蓝水和绿水资源的可用性,进而结合用水需求,定量评估了蓝水资源和绿水资源安全的时空变化。结果表明:(1)率定期和验证期R2与NSE均>0.7,说明观测径流与模拟径流之间一致性较好,构建的SWAT模型在蓝绿水安全研究中较为可靠。(2)黑河中游的年平均绿水资源量是蓝水资源量的4倍,是该地区的主要水资源。从空间分布来看,蓝绿水资源的空间分布具有较大的差异性,蓝水资源大多分布于南部林草地和干流两侧的农田灌区,而绿水从南部向北部呈现递减趋势(2)由于水资源供给和需求的空间不匹配,蓝水资源的安全性较低,不安全地区位于中部农田集中区,而绿水资源安全性较高且整体较为稳定,空间差异不大。研究结果可为区域水资源持续管理提供参考。

水量-水质-生态需水综合视角下黄河流域水稀缺评估

基于水足迹方法从水量水质生态需水综合视角下对黄河流域的水稀缺进行评估。结果表明:2021年黄河流域的蓝水足迹和灰水足迹分别为526.5亿m^(3)和3056.2亿m^(3);仅考虑水量和生态需水时,黄河流域的缺水压力较小,其中85.4%的地级市为低缺水压力,仅10.1%的地级市处于极端缺水压力;纳入水质因素后,仅15.7%的地级市为低缺水压力,而64.0%的地级市处于极端缺水压力,水质因素显著加剧了流域的缺水压力。建议协同推进水资源管理和保护,推广节水技术和水资源循环利用,重点提高农业水资源利用效率和强化农业污染治理,以缓解黄河流域经济发展与水资源限制之间的矛盾。

Cropping Pattern Modifications Change Water Resource Demands in the Beijing Metropolitan Area

Adequate freshwater supply has become an issue of increasing local and international concern. Reducing water use in agriculture, which is the largest water using sector of the economy, is both important and urgent. The aim of this paper was to quantify how recent cropping pattern changes have influenced water resources in the great Beijing metropolitan area, an expanding megacity which also includes rural counties. Crop production affects blue water use through water consumption and water pollution, the latter assessed here using a critical dilution method. From 1990 to 2010, the total blue water used by crop production declined due to a decrease in overall cropped area, initially in response to local government policies favouring urban development. However, the average blue water use per hectare increased from 2 112 m3 ha-~ yr-~ in 1990 to 2 764 m3 ha-1 yr-1 in 2003, largely as the result of a transition from cereal to vegetable crops, and in particular an increase in intensively managed plastic and glass covered vegetable production systems. Current policies aim to conserve agricultural land, in the interests of food security, and to stimulate cereal production systems with higher ecosystem services provision. As such, in 2010 the average blue water use was 2 425 m3 ha-~ yr-l. These results demonstrate that cropping pattern changes in peri-urban regions and rural communities surrounding the Beijing metropolitan area can have a substantial impact on water resources. They also highlight the tradeoffs between food production and urban and industrial water supply and the need for integrated policy development.

‘蓝鸟’睡莲花色苷W/O皮克林乳液的制备及稳定性分析

由于睡莲中所提取的活性成分具有不稳定性,对活性成分的包埋技术有待探索。该文以热带睡莲中的‘蓝鸟’睡莲(Nymphaea'Blue Bird')作为研究对象,通过制备W/O皮克林乳液将睡莲花色苷包埋,目的在于构建一个稳定的食品级体系,并研究该技术对花色苷的包埋稳定性与释放效果。以花色苷溶液作为水相(W),大豆油为油相(O),乳化剂选取亲脂性乳化剂聚甘油蓖麻醇酸酯(PGPR),制备不同水相体积分数的W/O乳液。研究发现,水相体积分数为30%和50%时制备的W/O乳液,在不同温度下贮藏15 d后体系稳定,对花色苷的包封率分别为75.97%和78.12%,且15 d内的包埋稳定性较好。以不同剪切速率制备W/O乳液考察其稳定性,当剪切速率为28000 r/min时,W/O乳液的表观稳定,保存120 min之后离心保留率达到97.40%。综合研究,该论文制备的W/O皮克林乳液体系平衡,且对花色苷有较好的包封效果。

Environmental Sustainability of Water Footprint in China' Mainland

Water footprint(WF)measures human appropriation of water resources for consumptive use of surface and ground water(blue WF)and soil water(green WF)and for assimilating polluted water(grey WF).Questions have been often asked about the exact meaning behind the numbers from WF accounting.However,to date environmental sustainability of WF has never been assessed at the sub-national level over time.This study evaluated the environmental sustainability of blue,green and grey WF for China’s 31 mainland provinces in 2002,2007 and 2012,and identified the unsustainable hotspots.Overall,the total WF increased by 30%between 2002 and 2012.The growth can be attributed to the increase of grey WF because the green and blue WF showed only a slight rise.Among all provinces investigated in 2012,eleven showed unsustainable blue WF(sustainability index SI<0),which were mainly located in the North China Plain.There were 12 provinces that displayed unsustainable green WF,and they were distributed in China’s southern and southeastern areas.The grey WF was not sustainable in approximately two third of provinces(19),which were mainly located in China’s middle and northern regions and Guangdong province.More than half of China’s provinces showed trends of improved SI of green and blue WF from 2002 to 2012.However,the SI of grey WF decreased in almost two third of provinces.Poor levels of WF sustainability were due to water scarcity and pollution,which intensify the degradation of local rivers and ecosystems and make restoration more difficult.The results shed light on the policy making needed to improve sustainable water management,and ecological restoration of hotspot regions.

苏南水网地区蓝绿空间格局多情景模拟预测

【目的】模拟预测苏南水网地区蓝绿空间格局多情景发展趋势,探究促进地区可持续发展的情景方案。【方法】以江苏省苏州市吴江南片区为例,设置自然发展、生态保护优先和城镇发展优先等3种情景,借助CA-Markov模型,对2030年蓝绿空间格局变化趋势进行多情景模拟分析,并运用形态学空间格局分析(MSPA)和景观连通性评价解读蓝绿空间景观生态结构与生态格局特征。【结果】不同发展情景下蓝绿空间规模与格局变化差异显著。自然发展和城镇发展优先情景下,蓝绿空间面积呈现加速减少趋势,分别减少了3626.37、7145.74 hm^(2)。蓝绿空间核心区、孔隙等形态类型负向变化剧烈,蓝绿空间破碎度增加,连通性降低。生态保护优先情景与自然发展和城镇发展优先情景相比,蓝绿空间面积分别增加了2904.30、6423.67 hm^(2),蓝绿空间核心区等形态类型增幅明显,孔隙率显著降低,蓝绿空间破碎度降低,连通性增强。【结论】自然发展和城镇发展优先情景对水网地区蓝绿空间呈现负向影响趋势,生态保护优先情景在维持蓝绿空间面积与格局稳定,改善蓝绿空间连通性方面效果显著。

NBs-GO膜的渗透性能及其对染料截留性能

氧化石墨烯(GO)膜因其优异的物化特性、独特的水通道,被广泛应用于复杂废水中的染料分离。通过将纳米气泡(NBs)吸附到GO上,形成纳米气泡-氧化石墨烯(NBs-GO)膜,有望提高膜的染料分离性能。以NBs-GO膜处理亚甲基蓝溶液模拟的染料废水,测定了该膜的水渗透率、截留率和稳定性等指标,并探究了染料种类与浓度、膜厚度和GO的制备条件等因素对膜性能的影响。结果表明:NBs-GO膜的水渗透率相比传统GO膜高出50.8%,并且能够将亚甲基蓝的截留率维持在99.88%,具有更优的染料分离性能。此外,NBs-GO膜在72 h内展现出了良好的稳定性,截留率始终保持在90%以上。即使在改变染料种类、浓度及膜厚度等条件下,NBs-GO膜依然保持了优异的水渗透性能。纳米气泡的引入为提高GO膜的染料分离效率提供了新的思路,在染料废水的处理方面展现出巨大的发展潜力,这一研究在染料废水处理领域具有广泛的应用前景。

Impacts of Climate Change on Water Resources in Diyala River Basin, Iraq

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.

黄河中游河口-龙门区间蓝绿水资源对气候与土地利用变化的响应

气候变化和土地利用变化会改变蓝绿水资源的时空分布,量化二者变化所带来的影响对水资源管理具有重要意义。黄河中游的河龙区间(河口镇至龙门)社会经济的迅速发展和大规模生态修复工程的实施改变了流域的土地利用格局,蓝绿水资源时空分布受到影响。研究基于遥感数据,分析河龙区间近40年土地利用的变化特征;结合VIC模型和四种情景设置,定量分析气候与土地利用变化对流域内蓝绿水的时空影响。进一步分析了生产性绿水流及非生产性绿水流对气候及土地利用变化的响应规律,以便开发绿水资源的生产潜力。结果表明:(1)河龙区间平均最高气温和平均最低气温在1997年发生突变,变化趋势由减小转为增大;降水量在2006年发生突变,变化趋势由减少转为增加。草地和耕地是河龙区间的主要土地利用类型,1980-2020年间耕地减少了3 407 km^(2),林地、草地和灌木林的面积均呈现增加趋势,与退耕还林还草工程的实施密切相关。(2)气候变化和土地利用变化对蓝水流的贡献率分别为90.89%和9.11%,对绿水流的贡献率分别为103.13%、-3.13%,对绿水储的贡献率分别为89.07%、10.93%,气候变化对河龙区间蓝绿水变化起主导作用。4种情景下,河龙区间的蓝水流、绿水流、绿水储均呈现从西北到东南逐渐增加的趋势。(3)植被恢复下,植被蒸腾作为生产性绿水流占总绿水流的比例由71.63%增大到72.93%。4种情景下,植被冠层截留蒸发量、植被蒸腾量的空间分布呈现从西北到东南地区增加的趋势,而裸土蒸发量呈现相反的空间分布格局。气候变化下,植被冠层截留蒸发量、植被蒸腾量呈增加趋势,土地利用变化对裸土蒸发量的影响更大。

A dynamic analysis of water footprint of Jinghe River basin

Water footprint in a region is defined as the volume of water needed for the production of goods and services consumed by the local people, Ecosystem services are a kind of important services, so ecological water use is one necessary component in water footprint. Water footprint is divided into green water footprint and blue water footprint but the former one is often ignored.In this paper waterJootprint includes blue water needed by agricultural irrigation, industrial and domestic water demand, and green water needed by crops, economic forests, livestock prochtcts, forestlalands and grasslands. The study calculates the footprint of the Jinghe River basin in 1990, 1995, 2000 and 2005 with quarto methods. Results of research show that water footprints reached 164.1 ×10^8m3, 175. 69 ×10^8m3 and 178. 45 ×10^8m3 respectively in 1990, 1995 and 2000 including that of ecological water use, but reached 77.68×10^8m3, 94.24×10^8m3, 92.92×10^8m3 and 111.36 ×10^8m3 respectively excluding that of ecological water use. Green water.footprint is much more than blue water footprint; thereby, green water plays an important role in economic development and ecological construction The dynamic change of water footprints shows that blue water use increases rapidly and that the ecological water use is occupied by economie and domestic water use. The change also shows that water use is transferred from primary industry to secondary industry In primary industry, it is transferred from crops farming to forestry, and animal agriculture. The factors impelling the change include development anticipation on econonomy; government policies, readjustment of the industrial structure, population growth, the raise of urbanization level, and structurul change of consumption, low level of waler-saving and poor ability of waste water treatment.With blue water use per unit, green water use per unit, blue water use structure and green water use structure, we analyzed the difference of the six ecologieal function districts of the Jinghe River basin. Future ecological construction may influence on blue water use of District V and District Ⅵ at middle and lower reaches. At last some suggestions are given for effective water resouree use.

基于SWAT模型的蓝绿水短缺指数计算与风险评价

为了降低沁河流域水资源短缺风险,以沁河流域为研究对象,基于所构建SWAT模型的输出结果,估算2010—2016年沁河流域蓝绿水资源量,利用蓝绿水足迹和可利用蓝绿水资源量计算蓝绿水短缺指数,并划分4个蓝绿水短缺风险等级,定量评估沁河流域蓝绿水短缺状况。结果显示:1)沁河流域多年平均蓝水资源量为9.1亿m^(3),占水资源总量的12.0%;多年平均绿水资源量为66.9亿m^(3),占水资源总量的88.0%,说明沁河流域水资源大部分为绿水资源;2)年尺度下沁河大部分子流域的蓝水短缺指数大于1.0,蓝水短缺风险等级为较大风险,其中下游地区的焦作市蓝水短缺问题尤为严重;3)年尺度下沁河各子流域的绿水短缺指数呈现一定差异性,大部分子流域多年平均绿水短缺指数在0.5~1.0范围内,绿水短缺面临中度风险,总体而言,绿水短缺风险低于蓝水短缺风险。基于蓝绿水短缺指数分析,提出应对沁河流域水安全风险的措施建议。

Climate Change Impacts on Water Resources of Greater Zab River, Iraq

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.

Effect of future climate change on the water footprint of major crops in southern Tajikistan

Danghara,a major food production area in southern Tajikistan,is currently suffering from the impact of rapid climate change and intensive human activities.Assessing the future impact of climate change on crop water requirements(CWRs)for the current growing period and defining the optimal sowing date to reduce future crop water demand are essential for local/regional water and food planning.Therefore,this study attempted to analyze possible future climate change effects on the water requirements of major crops using the statistical downscaling method in the Danghara District to simulate the future temperature and precipitation for two future periods(2021-2050 and 2051-2080),under three representative concentration pathways(RCP2.6,RCP4.5,and RCP8.5)according to the CanESM2 global climate model.The water footprint(WFP)of major crops was calculated as a measure of their CWRs.The increased projection of precipitation and temperature probably caused an increase in the main crop’s WFP for the current growing period,which was mainly due to the green water(GW)component in the long term and a decrease in the blue water(BW)component during the second future period,except for cotton,where all components were predicted to remain stable.Under three scenarios for the two future potato and winter wheat decreased from 5.7%to 4.8%and 3.4%to 2.2%,respectively.Although the WFP of cotton demonstrated a stable increase,according to the optimal sowing date,adecrease in irrigation demand or Bw was expected.The results of our study might be useful fordeveloping a new strategy related to irrigation systems and could help to find a balance betweenwater and food for environmental water demands and human use.