Impact of Water Scarcity on the Fenhe River Basin and Mitigation Strategies

This study produced a drought map for the Fenhe River basin covering the period from 150 BC to 2012 using regional historical drought records. Based on meteorological and hydrological features, the characteristics and causes of water scarcity in the Fenhe River basin were examined, along with their impact on the national economy and ecological environment. The effects of water scarcity in the basin on the national economy were determined from agricultural, industrial, and domestic perspectives. The impact on aquatic ecosystems was ascertained through an evolution trend analysis of surface water systems, including rivers, wetlands, and slope ecosystems, and subterranean water systems, including groundwater and karst springs. As a result of these analyses, strategies are presented for coping with water scarcity in this basin, including engineering countermeasures, such as the construction of a water network in Shanxi, and the non-engineering approach of groundwater resource preservation. These comprehensive coping strategies are proposed with the aim of assisting the prevention and control of water scarcity in the arid and semi-arid areas of China

Cardiovascular mortality risk attributable to ambient temperature in China.

OBJECTIVE: To examine cardiovascular disease (CVD) mortality burden attributable to ambient temperature; to estimate effect modification of this burden by gender, age and education level. METHODS: We obtained daily data on temperature and CVD mortality from 15 Chinese megacities during 2007-2013, including 1,936,116 CVD deaths. A quasi-Poisson regression combined with a distributed lag non-linear model was used to estimate the temperature-mortality association for each city. Then, a multivariate meta-analysis was used to derive the overall effect estimates of temperature at the national level. Attributable fraction of deaths were calculated for cold and heat (ie, temperature below and above minimum-mortality temperatures, MMTs), respectively. The MMT was defined as the specific temperature associated to the lowest mortality risk. RESULTS: The MMT varied from the 70th percentile to the 99th percentile of temperature in 15 cities, centring at 78 at the national level. In total, 17.1% (95% empirical CI 14.4% to 19.1%) of CVD mortality (330,352 deaths) was attributable to ambient temperature, with substantial differences among cities, from 10.1% in Shanghai to 23.7% in Guangzhou. Most of the attributable deaths were due to cold, with a fraction of 15.8% (13.1% to 17.9%) corresponding to 305,902 deaths, compared with 1.3% (1.0% to 1.6%) and 24,450 deaths for heat. CONCLUSIONS: This study emphasises how cold weather is responsible for most part of the temperature-related CVD death burden. Our results may have important implications for the development of policies to reduce CVD mortality from extreme temperatures

The Optimal Concentration of KH2PO4 Enhances Nutrient Uptake and Flower Production in Rose Plants via Enhanced Root Growth

Monopotassium phosphate is a widely used phosphorus and potassium fertiliser for ornamental plants, but it is not known what concentration will result in optimal flower production, root growth and nutrient uptake of rose plants. We compared potted rose plants fertilised with six different concentrations (0.0 as a water-only control, 1.0, 2.0, 3.0, 4.0 and 5.0 g·L−1) of an aqueous monopotassium phosphate solution as a combination of foliar and soil applications over two consecutive flowering cycles. Rose growth, flower production and nutrient accumulation responded differently to fertilisation with different concentrations of monopotassium phosphate. During the first flowering cycle, shoot and root dry weight, leaf chlorophyll content, flower diameter, total root length and surface area, and total fine root length significantly increased in response to increased monopotassium phosphate concentrations from 0.0 to 3.0 g·L−1 but decreased in response to fertilisation with 4.0 or 5.0 g·L−1 monopotassium phosphate. Similar trends were observed in shoot dry weight, leaf chlorophyll content, flower diameter and number, phosphorus and potassium accumulation during the second flowering cycle. According to quadratic equations derived from both flowering cycles, the optimal concentration of monopotassium phosphate, based on flower diameter and dry weight, as well as total phosphorus and potassium accumulation, was 2.6–3.0 g·L−1. Furthermore, total root length was significantly correlated with flower diameter, flower dry weight, and total phosphorus and potassium accumulation (p < 0.05). These results indicated that fertilisation with optimal concentrations of monopotassium phosphate can increase rose growth, flower productivity and nutrient uptake through enhanced root growth

The Design and Check of Regional Typical Rainfall Processes: A Case Study of Yongnian District, China

Observing and analyzing runoff process is an important method to study the principle of runoff yield and concentration. However, natural rainfall is random and difficult to monitor the related runoff process timely, so most of the runoff processes analysis is based on the artificial rainfall experiments. In this study, the selected test site is located in Yongnian district, Hebei Province, China. Rainfall volume, rainfall peak, rainfall duration and peak ratio were considered as the key factors of designed rainfall type. Based on regional historical observed rainfall data from 1980 to 2012, the two mainly representative processes which was in flood season and non-flood season respectively, were calculated. The most typical rainfall process in each period was screened through two methods of characteristic frequency distribution. Furthermore, accuracy of rainfall intensity and uniformity of spatial and temporal distribution were selected as the criteria for correcting the artificial rainfall devices. This research is the foundation of the artificial runoff experiment and provide reference to regional climate change research and local water resources assessment

The Design and Check of Regional Typical Rainfall Processes: A Case Study of Yongnian District, China

Observing and analyzing runoff process is an important method to study the principle of runoff yield and concentration. However, natural rainfall is random and difficult to monitor the related runoff process timely, so most of the runoff processes analysis is based on the artificial rainfall experiments. In this study, the selected test site is located in Yongnian district, Hebei Province, China. Rainfall volume, rainfall peak, rainfall duration and peak ratio were considered as the key factors of designed rainfall type. Based on regional historical observed rainfall data from 1980 to 2012, the two mainly representative processes which was in flood season and non-flood season respectively, were calculated. The most typical rainfall process in each period was screened through two methods of characteristic frequency distribution. Furthermore, accuracy of rainfall intensity and uniformity of spatial and temporal distribution were selected as the criteria for correcting the artificial rainfall devices. This research is the foundation of the artificial runoff experiment and provide reference to regional climate change research and local water resources assessment

An Integrated Design and Optimization Approach for Radial Inflow Turbines—Part I: Automated Preliminary Design

An integrated design and optimization approach was developed for radial inflow turbines, which consists of two modules, an automated preliminary design module, and a flexible three-dimensional multidisciplinary optimization module. In this paper, the first module about the automated preliminary design approach was presented in detail and validated by the experimental data. The approach employs a genetic algorithm to explore the design space defined by the loading coefficient, flow coefficient, and rotational speed. The aim is to obtain the best design scheme with high aerodynamic performance under specified constraints and to reduce the dependency on human experiences when designing a radial inflow turbine. The validation results show that the present approach is able to get the optimal design and alleviate the dependence on the designer’s expertise under specified constraints at the preliminary design stage. Furthermore, the optimization results indicate that using the present optimization approach the total-to-static efficiency of the optimized T-100 radial inflow turbine can be increased by 1.0% under design condition and the rotor weight can be decreased by 0.35 kg (26.7%) as compared with that of the original case

An Integrated Design and Optimization Approach for Radial Inflow Turbines—Part II: Multidisciplinary Optimization Design

This paper proposes an integrated design and optimization approach for radial inflow turbines consisting of an automated preliminary design module and a flexible three-dimensional multidisciplinary optimization module. The latter was constructed by an evolution algorithm, a genetic algorithm-assisted self-learning artificial neural network and a dynamic sampling database. The 3-D multidisciplinary optimization approach was validated by the original T-100 turbine and the T-100re turbine obtained from the automated preliminary design approach, for maximizing the total-to-static efficiency and minimizing the rotor weight while keeping the mass flow rate constant and stress limitation satisfied. The validation results indicate that the total-to-static efficiency is 89.6%, increased by 1.3%, and the rotor weight is reduced by 0.14 kg (14.6%) based on the T-100re turbine, while the efficiency is 88.2%, increased by 2.2% and the weight is reduced by 0.49 kg (37.4%) based on the original T-100 turbine. Moreover, the T-100re turbine shows better performance at the preliminary design stage and conserves this advantage to the end, though both the aerodynamic performance of the T-100 and the T-100re turbine are improved after 3-D optimization. At the same time, it is implied that the preliminary design plays an essential role in the radial inflow turbine design process, and it is hard for only 3-D optimization to get a further performance improvement

Soil Moisture Contribution to Winter Wheat Water Consumption from Different Soil Layers under Straw Returning

To study the contribution of moisture from different straw-treated and irrigated soil layers to the water consumption of winter wheat in dry farming, a 2-year straw treatment and regulated deficit irrigation experiment was implemented. The field experiment was carried out with 0% (S0), 1% (S1), and 2% (S2) straw returning amounts, and 75 mm (V3), 60 mm (V2), and 45 mm (V1) irrigation volumes. This experiment involved nine treatments, used to quantitatively analyze the ratio and variation of soil water use from different soil layers via the direct contrast method (DCM) and the multiple linear mixed model (MLMM). The results show the following: (1) The distribution of precipitation isotope compositions displayed a repeated trend of first decreasing and then increasing during the study period. Regression analysis showed that the local meteoric water line (LMWL): δD = 6.37δ18O − 3.77 (R2 = 0.832). (2) With increasing soil depth, the δ18O value decreased gradually, and the maximum δ18O value of the soil water within each growth period was distributed at 10 cm. (3) Under the same irrigation amount, δ 18O increased with increasing straw return at 0–20 cm and decreased with increasing straw return at 20–80 cm. (4) The comparison results of the DCM and MLMM were consistent. During the jointing and flowering stages, 0–30 cm soil water was the main source of water for winter wheat. The contribution of soil water below 30 cm had a decreasing trend from the jointing stage to the flowering stage. The average contribution rates of the 0–30 cm soil layer during the jointing and flowering stages were 23.07% and 23.15%, respectively. These findings have important implications for studying the soil water cycle in the context of farming

Runoff Effect Evaluation of LID through SWMM in Typical Mountainous, Low-Lying Urban Areas: A Case Study in China

Urban flooding occurs frequently in many regions of China. To reduce the losses caused by urban flooding, sponge city (SPC) and low-impact development (LID) have been carried out in many Chinese cities. However, urban flooding is influenced by various factors, such as climate, land cover characteristics and nearby river networks, so it is necessary to evaluate the effectiveness of LID measures. In this study, the Storm Water Management Model (SWMM) was adopted to simulate historical urban storm processes in the mountainous Fragrance Hills region of Beijing, China. Subsequently, numerical simulations were performed to evaluate how various LID measures (concave greenbelt, permeable pavement, bio-retention, vegetative swales, and comprehensive measures) influenced urban runoff reduction. The results showed that the LID measures are effective in controlling the surface runoff of the storm events with return periods shorter than five years, in particular, for one-year events. Furthermore, the effectiveness on traffic congestion mitigation of several LID measures (concave greenbelt, vegetative swales, and comprehensive measures) was evaluated. However, the effective return periods of storm events are shorter than two years if the effectiveness on traffic congestion relief is considered. In all evaluated aspects, comprehensive measures and concave greenbelts are the most effective, and vegetative swale is the least effective. This indicated that LID measures are less effective for removing ponding from most storm events in a mountainous, low-lying and backward pipeline infrastructure region with pressures from interval flooding and urban waterlogging. The engineering measures including water conservancy projects and pipeline infrastructure construction combined with the non-engineering measures were suggested to effectively control severe urban storms