ABSTRACT
Alleviating water scarcity is at the core of Sustainable Development Goal 6. Yet the timing of water scarcity in its onset and possible relief in different regions of the world due to climate change and changing human population dynamics remains poorly investigated. Here we assess the timing of the first emergence of water scarcity (FirstWS) and disappearance of water scarcity (EndWS), by using ensembles of simulations with six Global Hydrological Models under two representative concentration pathways (i.e., RCP2.6, RCP6.0) combined with two shared socioeconomic pathways (i.e., SSP2, SSP3) for 1901-2090. Historically (1901-2020), FirstWS occurred predominantly in Asia (e.g., China and India) and Africa (e.g., East Africa); the peak time of emerging water scarcity began around the 1980s. Under all the four future RCPs-SSPs scenarios (2021-2090), FirstWS will likely occur mainly in some regions of Africa, for which the newly added area is double that in Asia. On the other hand, EndWS will mostly occur in China after 2050, primarily due to the projected declining population. We, therefore, call for specific attention and effort to adapt to the looming water scarcity in Africa.
ABSTRACT
Given that it was a once-in-a-century emergency event, the confinement measures related to the coronavirus disease 2019 (COVID-19) pandemic caused diverse disruptions and changes in life and work patterns. These changes significantly affected water consumption both during and after the pandemic, with direct and indirect consequences on biodiversity. However, there has been a lack of holistic evaluation of these responses. Here, we propose a novel framework to study the impacts of this unique global emergency event by embedding an environmentally extended supply-constrained global multi-regional input-output model (MRIO) into the drivers-pressure-state-impact-response (DPSIR) framework. This framework allowed us to develop scenarios related to COVID-19 confinement measures to quantify country-sector-specific changes in freshwater consumption and the associated changes in biodiversity for the period of 2020-2025. The results suggest progressively diminishing impacts due to the implementation of COVID-19 vaccines and the socio-economic system's self-adjustment to the new normal. In 2020, the confinement measures were estimated to decrease global water consumption by about 5.7% on average across all scenarios when compared with the baseline level with no confinement measures. Further, such a decrease is estimated to lead to a reduction of around 5% in the related pressure on biodiversity. Given the interdependencies and interactions across global supply chains, even those countries and sectors that were not directly affected by the COVID-19 shocks experienced significant impacts: Our results indicate that the supply chain propagations contributed to 79% of the total estimated decrease in water consumption and 84% of the reduction in biodiversity loss on average. Our study demonstrates that the MRIO-enhanced DSPIR framework can help quantify resource pressures and the resultant environmental impacts across supply chains when facing a global emergency event. Further, we recommend the development of more locally based water conservation measures-to mitigate the effects of trade disruptions-and the explicit inclusion of water resources in post-pandemic recovery schemes. In addition, innovations that help conserve natural resources are essential for maintaining environmental gains in the post-pandemic world.
Subject(s)
Biodiversity , COVID-19 , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Pandemics , Water Supply , SARS-CoV-2 , Fresh WaterABSTRACT
In the context of China's freshwater crisis high-resolution data are critical for sustainable water management and economic growth. Yet there is a dearth of data on water withdrawal and scarcity regardless of whether total or subsector amount, for prefectural cities. In administrative and territorial scope, we accounted for water withdrawal of all 63 economic-socio-environmental sectors for all 343 prefectural cities in China, based on a general framework and 2015 data. Spatial and economic-sector resolution is improved compared with previous studies by partitioning general sectors into industrial and agricultural sub-sectors. Construction of these datasets was based on selection of 16 driving forces. We connected a size indicator with corresponding water-withdrawal efficiency. We further accounted for total blue-water withdrawal and quantitative water scarcity status. Then we compared different scopes and methods of official accounts and statistics from various water datasets. These disaggregated and complete data could be used in input-output models for municipal design and governmental planning to help gain in-depth insights into subsector water-saving priorities from local economic activities.
ABSTRACT
In recent decades, climate change and other anthropogenic activities have substantially affected groundwater systems worldwide. These impacts include changes in groundwater recharge, discharge, flow, storage, and distribution. Climate-induced shifts are evident in altered recharge rates, greater groundwater contribution to streamflow in glacierized catchments, and enhanced groundwater flow in permafrost areas. Direct anthropogenic changes include groundwater withdrawal and injection, regional flow regime modification, water table and storage alterations, and redistribution of embedded groundwater in foods globally. Notably, groundwater extraction contributes to sea level rise, increasing the risk of groundwater inundation in coastal areas. The role of groundwater in the global water cycle is becoming more dynamic and complex. Quantifying these changes is essential to ensure sustainable supply of fresh groundwater resources for people and ecosystems.
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Riverine ecosystems have adapted to natural discharge variations across seasons. However, evidence suggesting that climate change has already impacted magnitudes of river flow seasonality is limited to local studies, mainly focusing on changes of mean or extreme flows. This study introduces the use of apportionment entropy as a robust measure to assess flow-volume nonuniformity across seasons, enabling a global analysis. We found that ~21% of long-term river gauging stations exhibit significant alterations in seasonal flow distributions, but two-thirds of these are unrelated to trends in annual mean discharge. By combining a data-driven runoff reconstruction with state-of-the-art hydrological simulations, we identified a discernible weakening of river flow seasonality in northern high latitudes (above 50°N), a phenomenon directly linked to anthropogenic climate forcing.
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Despite the progress made in understanding relevant carbon dynamics under grazing exclusion, previous studies have underestimated the role of soil bulk density (BD), and its implications for potential accumulation of soil organic carbon (SOC), especially at regional scale over long term. In this study, we first constructed a database covering a vast majority of the grasslands in northwestern China based on 131 published literatures. A synthesis was then conducted by analyzing the experimental data to comprehensively investigate the mechanisms of vegetation recovery, carbon-nitrogen coupling, and the importance of changed soil BD in evaluating SOC sequestration potential. The results showed that although the recovery of vegetation height and cover were both critical for improving vegetation biomass, vegetation height required a longer recovery period. While the SOC accumulation was found to be greater in surface layers than deeper ones, it exhibited a reduced capacity for carbon sequestration and an increased risk of SOC loss. Grazing exclusion significantly reduced soil BD across different soil profiles, with the rate of change influenced by soil depth, time, geographical and climatic conditions. The potential for SOC accumulation in the top 30 cm of soil based on data of 2003-2022 was 0.78 Mg ha-1 yr-1 without considering BD effects, which was significantly underestimated compared to that of 1.16 Mg ha-1 yr-1 when BD changes were considered properly. This suggests that the efficiency of grazing exclusion in carbon sequestration and climate mitigation may have been previously underreported. Furthermore, mean annual precipitation represented the most relevant environmental factor that positively correlated to SOC accumulation, and a wetter climate may offer greater potential for carbon accumulation. Overall, this study implies grazing exclusion may play an even more critical role in carbon sequestration and climate change mitigation over long-term than previously recognized, which provides essential scientific evidence for implementing stepwise ecological restoration in grasslands.
Subject(s)
Carbon , Soil , Carbon/analysis , Grassland , Biomass , China , Carbon SequestrationABSTRACT
Background: The momentum of robotic surgery is increasing, and it has great prospects in pancreatic surgery. It has been widely accepted and expanding to more and more centers. Robotic distal pancreatectomy (RDP) is the most recent advanced minimally invasive approach for pancreatic lesions and malignancies. However, laparoscopic distal pancreatectomy (LDP) also showed good efficacy. We compared the effect of RDP with LDP using a meta-analysis. Methods: From January 2010 to June 2023, clinical trials of RDP versus LDP were determined by searching PubMed, Medline, and EMBASE. A meta-analysis was conducted to compare the effect of RDP with LDP. This meta-analysis evaluated the R0 resection rate, lymph node metastasis rate, conversion to open surgery rate, spleen preservation rate, intraoperative blood loss, postoperative pancreatic fistula, postoperative hospital stay, 90-day mortality rate, surgical cost, and total cost. Results: This meta-analysis included 38 studies. Conversion to open surgery, blood loss, and 90-day mortality in the RDP group were all significantly less than that in the LDP group (P < .05). There was no difference in lymph node resection rate, R0 resection rate, or postoperative pancreatic fistula between the two groups (P > .05). Spleen preservation rate in the LDP group was higher than that in the RDP group (P < .05). Operation cost and total cost in the RDP group were both more than that in the LDP group (P < .05). It is uncertain which group has an advantage in postoperative hospital stay. Conclusions: To some degree, RDP and LDP were indeed worth comparing in clinical practice. However, it may be difficult to determine which is absolute advantage according to current data. Large sample randomized controlled trials are needed to confirm which is better treatment. PROSPERO ID: CRD4202345576.
Subject(s)
Laparoscopy , Pancreatectomy , Robotic Surgical Procedures , Humans , Length of Stay , Pancreatectomy/methods , Pancreatic Fistula , Pancreatic Neoplasms/surgery , Pancreatic Neoplasms/pathology , Postoperative Complications/epidemiology , Postoperative Complications/surgery , Retrospective Studies , Robotics , Treatment Outcome , Pancreatic Diseases/pathology , Pancreatic Diseases/surgery , Pancreas/pathology , Pancreas/surgeryABSTRACT
Applying the planetary boundary for the freshwater framework at the regional level is important in supporting local water management but is subject to substantial uncertainty. Previous estimates have not fully investigated the potential of trade in mitigating regional freshwater boundary (RFB) exceedance. Here, we estimate RFB based on the average results of 15 different hydrological models to reduce uncertainty. We then propose a framework to divide the RFB exceedance/maintenance into contributions from both consumption and trade and further identify trade contribution into six types. We applied the framework to China's provinces, which are characterized by intensive interprovincial trade and a significant mismatch in water resource supply and demand. We found that the current trade pattern limits the role of trade to mitigate RFB exceedance. For the importing provinces exceeding RFBs, 78% of their imported goods and services came from other RFB exceeding provinces. Scenario analysis showed that relying on increased imports alone, even to its greatest extent, will not reverse RFB exceedance in most importing provinces. Increased imports, however, will have an aggregate effect on the trade partners, leading to the exceedance of the national freshwater boundary. We also found that promoting export of goods and services from non-RFB exceeding provinces and reducing their water intensity will help address the imbalance both locally and, in the aggregate, nationally.
Subject(s)
Fresh Water , Water Supply , Water , ChinaABSTRACT
Shallow groundwater nitrate nitrogen (NO3--N) concentrations in agricultural areas usually show high spatial and intra-annual variability. It is hard to predict such concentrations due to the complexity of influencing factors (e.g., different forms of N in soil, vadose zone characteristics, and groundwater physiochemical conditions). Here, a large number of groundwater and soil samples were collected monthly over two years at 14 sites to analyze the soil and groundwater physiochemical properties and the stable isotopes of δ15N and δ18O of groundwater NO3--N in agricultural areas. Based on field observations, a random forest (RF) model was used to predict the groundwater NO3--N concentrations and reveal the importance of effect factors. The results show that there are large spatiotemporal variations in NO3--N, δ15N-NO3-, and δ18O-NO3- in groundwater. NO3--N is the major dominant specie of inorganic N in groundwater, and the groundwater NO3--N concentration in 24 % of the samples failed to meet the drinking water standard of the WHO (10 mg L-1). The RF model satisfactorily predicted groundwater NO3--N concentrations with R2 of 0.90-0.94, RMSE of 4.54-5.07, and MAE of 2.17-3.38. Groundwater nitrite and ammonium are the most important factors related to NO3--N consumption and production, respectively, in groundwater. Denitrification and nitrification were further identified by the relationships among δ15N-NO3-, δ18O-NO3-, and NO3--N, and by the ranges of δ15N-NO3-, δ18O-NO3-, temperature, pH, DO, and ORP in groundwater. Soil-soluble organic nitrogen (S-SON) and the depth of groundwater table were identified as vital factors related to N sourcing and leaching. Overall, as a first approach to adopting a RF model for high spatiotemporal-resolution prediction of groundwater NO3--N variations, the findings of this study enable a better understanding of groundwater N pollution in agricultural areas. Optimizing management of irrigation and N inputs is anticipated to reduce S-SON accumulation and mitigate the threat to groundwater quality in agricultural areas.
ABSTRACT
The Mekong River basin (MRB) is a transboundary basin that supports livelihoods of over 70 million inhabitants and diverse terrestrial-aquatic ecosystems. This critical lifeline for people and ecosystems is under transformation due to climatic stressors and human activities (e.g., land use change and dam construction). Thus, there is an urgent need to better understand the changing hydrological and ecological systems in the MRB and develop improved adaptation strategies. This, however, is hampered partly by lack of sufficient, reliable, and accessible observational data across the basin. Here, we fill this long-standing gap for MRB by synthesizing climate, hydrological, ecological, and socioeconomic data from various disparate sources. The data- including groundwater records digitized from the literature-provide crucial insights into surface water systems, groundwater dynamics, land use patterns, and socioeconomic changes. The analyses presented also shed light on uncertainties associated with various datasets and the most appropriate choices. These datasets are expected to advance socio-hydrological research and inform science-based management decisions and policymaking for sustainable food-energy-water, livelihood, and ecological systems in the MRB.
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The complex formation mechanism and numerous influencing factors of urban waterlogging disasters make the identification of their risk an essential matter. This paper proposes a framework for identifying urban waterlogging risk that combines multi-source data fusion with hydrodynamics (MDF-H). The framework consists of a source data layer, a model parameter layer, and a calculation layer. Using multi-source data fusion technology, we processed urban meteorological information, geographic information, and municipal engineering information in a unified computation-oriented manner to form a deep fusion of a globalized multi-data layer. In conjunction with the hydrological analysis results, the irregular sub-catchment regions are divided and utilized as calculating containers for the localized runoff yield and flow concentration. Four categories of source data, meteorological data, topographic data, urban underlying surface data, and municipal and traffic data, with a total of 12 factors, are considered the model input variables to define a real-time and comprehensive runoff coefficient. The computational layer consists of three calculating levels: total study area, sub-catchment, and grid. The surface runoff inter-regional connectivity is realized at all levels of the urban road network when combined with hydrodynamic theory. A two-level drainage capacity assessment model is proposed based on the drainage pipe volume density. The final result is the extent and depth of waterlogging in the study area, and a real-time waterlogging distribution map is formed. It demonstrates a mathematical study and an effective simulation of the horizontal transition of rainfall into the surface runoff in a large-scale urban area. The proposed method was validated by the sudden rainstorm event in Futian District, Shenzhen, on 11 April 2019. The average accuracy for identifying waterlogging depth was greater than 95%. The MDF-H framework has the advantages of precise prediction, rapid calculation speed, and wide applicability to large-scale regions.
Subject(s)
Biological Products , Disasters , Hydrodynamics , Rain , Water Movements , Cities , ChinaABSTRACT
Since the "Belt and Road" initiative was put forward, the trade of crops between China and the countries have increased markedly. Agriculture is the most water-consuming sector, the trade of crops could influence national water availability via virtual water embodied in the products. In order to gain an in-depth understanding of the water use of crops traded in countries along the "Belt and Road", from the perspective of import and export of China's crops, based on the characteristics and driving factors of virtual water trade, we proposed the Water Use Potential Index (WUPI) to assess sustainability of countries and their crops, and constructed a more comprehensive virtual water trade research framework. Results showed that the import and export of virtual water in 64 countries was dominated by green virtual water content from 2001 to 2017, and China was in a virtual water trade surplus. The Association of South-East Asian Nations was China's leading importer and exporter. The level of agricultural available water resources, the proportion of the agricultural population, the scale of agricultural production and the virtual water intensity could promote the growth of virtual water trade in crops between China and countries along the "Belt and Road", while economic model and the population structure played a restraining role. In terms of water use potential, China and Kazakhstan had great sustainable water use potential for crops, and the trade structure of other countries still needed to be further optimized. Understanding the virtual water trade in crops can provide a reference for the rational planning of crop cultivation and water resource conservation.
Subject(s)
Water Supply , Water , Water Resources , Crops, Agricultural , ChinaABSTRACT
Lakes are important natural resources and carbon gas emitters and are undergoing rapid changes worldwide in response to climate change and human activities. A detailed global characterization of lakes and their long-term dynamics does not exist, which is however crucial for evaluating the associated impacts on water availability and carbon emissions. Here, we map 3.4 million lakes on a global scale, including their explicit maximum extents and probability-weighted area changes over the past four decades. From the beginning period (1984-1999) to the end (2010-2019), the lake area increased across all six continents analyzed, with a net change of +46,278 km2, and 56% of the expansion was attributed to reservoirs. Interestingly, although small lakes (<1 km2) accounted for just 15% of the global lake area, they dominated the variability in total lake size in half of the global inland lake regions. The identified lake area increase over time led to higher lacustrine carbon emissions, mostly attributed to small lakes. Our findings illustrate the emerging roles of small lakes in regulating not only local inland water variability, but also the global trends of surface water extent and carbon emissions.
Subject(s)
Climate Change , Lakes , Carbon , Humans , WaterABSTRACT
Ecosystem services (ESs) have been widely used for ecological protection and land spatial planning. Natural and anthropogenic drivers exhibit a strong dynamic coupling relationship with ESs. However, current ESs-related research focused on mapping the ESs spatially or investing the trade-offs and synergies relationship between ES, ignoring the nonlinear response of ESs to natural and anthropogenic drivers. Here we aimed to investigate the nonlinear effect of 14 potential drivers (8 natural and 6 anthropogenic) on the total value of six typical ESs (ESV). Taking Beijing-Tianjin-Hebei urban agglomeration (BTH) in China as an example, we established 14 constrain lines and identified critical thresholds through the restricted cubic splines (RCS) regression. We found strong non-linear impacts of natural and anthropogenic drivers on ESV and critical thresholds existed among all the 14 constrain lines. The RCS plots showed that the overall ESV was kept at a high level before or after certain thresholds (e.g., altitude >687 m, slope >13.4°, NDVI >0.7, distance from water <31.2 km, etc.). We categorized these threshold combinations and found the potentially high ES delivery areas were mainly distributed in the Yanshan Mountian, accounting for approximately 5% of the total BTH region. These critical thresholds offer a new method to delineate conservation and restoration priority areas.
Subject(s)
Conservation of Natural Resources , Ecosystem , Altitude , Beijing , ChinaABSTRACT
Although cultural ecosystem services (CES) are greatly valued by diverse stakeholders, the full range of CES provided by a landscape is notoriously difficult to estimate. The resulting lack of objective norms for CES may lead to the loss of the multiple non-material factors that contribute to how a landscape is valued and experienced. This is especially true under ecological restoration, which could sharply change how people experience landscapes. Therefore, our aim in this study was to identify and analyze the CES that arise from people's interaction with their landscape, focusing specifically on the influences of different ecological restoration strategies. We carried out semi-structured interviews with the residents of villages in the Xilin Gol League, Inner Mongolia, China. Regarding the implementation of ecological restoration measures, the people living in typical pastoral zones would be most affected by these measures because their main livelihood (animal husbandry) depends strongly on grasslands. Our results demonstrated that human perception of the CES provided by landscapes is affected not only by the factors related to an individual's cultural worldview (e.g., ethnicity, age, education) but also by the utility of landscape features, which are reflected in the individual's landscape dependence (occupation). Our research provides a cultural perspective for aspects of local well-being in addition to ecological and economic targets. Understanding these other aspects is critical for implementing sustainable ecological restoration.
Subject(s)
Conservation of Natural Resources , Ecosystem , China , HumansABSTRACT
BACKGROUND: Hepatic arterial infusion chemotherapy (HAIC) and Transarterial chemoembolization (TACE) both showed good local efficacy in advanced or unresectable hepatocellular carcinoma (HCC). We performed a systematic review and meta-analysis to compare the effect of HAIC with TACE in patients with unresectable HCC. METHODS: Clinical trials, which were about HAIC or TACE in Patients with unresectable HCC, were identified by searching PubMed, Medline, and EMBASE from January 2010 to March 2022. A meta-analysis was performed to analyze HAIC in comparison with TACE. Treatment response, 1-year overall survival (OS), 2-year OS and serious adverse events were evaluated in this meta-analysis. RESULTS: This meta-analysis included 6 studies. Objective response rate or Partial response in the HAIC group was significantly more than that in the TACE group (Pâ <â .05). But, stable disease showed no difference between the 2 groups (Pâ =â .52). Disease control rate in the HAIC group was better than that in the TACE group (Pâ <â .05). Progressive disease in the HAIC group was less than that in the TACE group (Pâ <â .05). In 1-year OS, there was no significant deterioration between the 2 groups (Pâ =â .53). There was not significant difference in 2-year OS between the 2 groups (Pâ =â .05). serious adverse events in the HAIC group was significantly less than that in the TACE group (Pâ <â .05). CONCLUSION: To some degree, HAIC may be a better therapeutic method in patients with unresectable HCC than TACE.
Subject(s)
Carcinoma, Hepatocellular , Chemoembolization, Therapeutic , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/pathology , Chemoembolization, Therapeutic/adverse effects , Treatment Outcome , Infusions, Intra-Arterial/methodsABSTRACT
CoQ10, which has been widely applied in medicine by dietary supplement, possesses important functions in antioxidant process and bioenergy generation. Iterative mutagenesis introduced by atmospheric and room temperature plasma (ARTP) treatment was studied to improve the coenzyme Q10 (CoQ10) production of Rhodobacter sphaeroides (R. sphaeroides), and multiple selection pressures including vitamin K3 (VK3), Na2S and benzoic acid (BA) were adopted for the first time. After two rounds of mutation and screening, a mutant strain R.S 17 was obtained, and the product titer was increased by 80.37%. The CoQ10 titer and cell density reached 236.7 mg L-1 and 57.09 g L-1, respectively, in the fed-batch fermentation, and the CoQ10 content was 22.1% higher than that of the parent strain. In addition, the spectral scanning results indicated the metabolic flux improvement contributing to the CoQ10 production in R.S 17, and the genetic stability was validated. Based on the iterative mutagenesis introduced by ARTP under multiple selection pressures, the promotion of CoQ10 production by R. sphaeroides was achieved. The significant improvement in fermentation performances and the good genetic stability of R.S 17 indicate a potential way for the efficient biosynthesis of CoQ10.