Ecosystem health evaluation based on land use change-case study of the riparian zone of the Yangtze River in Jiangsu Province, China.

Evaluating the ecosystem health of riparian zones is helpful for decision-makers to formulate appropriate management measures. However, there are few methods for such evaluation which account for both the human requirements and ecological aspects of riparian zones. To address this, we created a Pressure-State(Vigor-Organization-Resilience)-Response framework for evaluating the ecosystem health of the riparian zone of the Yangtze River in Jiangsu Province, a region experiencing intense land use changes. Evaluation indicators, including land use change and ecosystem services, were selected. The comprehensive index method was used to calculate the evaluation indicators of ecosystem health, namely pressure, state, and response, and the comprehensive evaluation indicator itself. Using the cold and hot spot analysis, we also analyzed the spatial heterogeneity of ecosystem health in the riparian zone, constructed an ecological management pattern, and proposed corresponding management and protection measures. The results show that (1) from 2010 to 2020, construction land in the study area increased by more than 20%, and all studied land types underwent some degree of conversion to construction land, with cultivated land and water bodies being the main focus of conversion. (2) In 2020, the average ecosystem health in the riparian zone was normal, with a spatial distribution characterized by "high dispersion and low clustering"; and (3) according to the results of the ecosystem health evaluation and cold and hot spot analysis, key areas for stronger ecological protection were identified and, based on this, a number of management recommendations were proposed.

A study on urban household water consumption behavior under drought conditions.

The increasing frequency of drought events has intensified the risk of water scarcity, posing significant challenges for urban domestic water supply. Reducing urban household water consumption is an important way to alleviate water stress during drought periods. However, due to various factors, it is difficult to determine a water-saving target that is within the residents' capacity. Here, taking Beijing, China as an example, we explored the socio-psychological factors behind urban household water use behaviors under drought conditions, and further quantified the compressible ratio of water quotas for flexible water use behaviors. Therefore, the present study was based on the theory of planned behavior (TPB) and extended TPB (ETPB) by adding drought risk perception as a variable to the theoretical framework. With the help of questionnaire method and structural equation modeling (SEM), the explanatory power of TPB and ETPB in predicting people's water saving intention and behavior was compared. Meanwhile, mathematical statistical analysis methods were employed to calculate the water quota for elastic water consumption behavior and the compressible proportion of urban residents' elastic water consumption under drought conditions. The results showed that drought risk perception has a significant positive correlation with subject norms and water reduction behavior under drought conditions. Furthermore, ETPB was more effective in analyzing water use intentions and behaviors. The predictive explanatory power of SEM for reducing water use increased from 44% to 50% after adding drought risk perception variable. In terms of quantification of elastic water use behavior, the average total water consumption in summer and winter were 71.3L/(p.d) and 52.9L/(p.d) under drought conditions, while it were 124.3 L/(p.d) and 108.9 L/(p.d) under normal conditions. And the compressible proportions of the total water quota for summer and winter elastic water use were 46.7% and 56.8%, respectively. The calculation results can provide a reference for the government to make emergency water supply decisions against drought.

Improved indicators of hydrological alteration for quantifying the dam-induced impacts on flow regimes in small and medium-sized rivers.

Dam construction is the main factor altering the flow regimes, while few studies have described that in small and medium-sized rivers (SMRs). The universal indicators of hydrological alteration (IHA) that are widely used in large rivers calculate the parameters just on the annual scale and omit the intra-annual seasonal differences of the flow regimes in SMRs. To fully quantify dam-induced impacts on the flow regimes in SMRs, this paper proposes the improved IHA (IIHA) based on the universal IHA. Then two methods of range of variable approach (RVA) and histogram matching approach (HMA) are used to assess the flow regime alteration. Finally, two indicators of water quantity level (WQL)/hydrological alteration (HA) defined by the parameters in IIHA are employed to evaluate the influence of flow regime alteration on the riverine ecosystem. The case study of a typical SMR named Liujiaping River in Hunan Province, China, verifies the necessity of improving IHA where more hydrological parameters calculated in different periods can comprehensively reflect the flow regime alteration. We find that the integrated hydrological alteration of Liujiaping River assessed by RVA and HMA are both at a high level, and the flow regimes have been significantly altered after the dam construction. Also, the indicators of WQL and HA have higher correlation coefficients with 77 of IIHA parameters and thus can retain as much information of the flow regimes as possible to evaluate the influence of its alteration on the riverine ecosystem.

Identifying how future climate and land use/cover changes impact streamflow in Xinanjiang Basin, East China.

Climate and land use/cover changes are the main factors altering hydrological regimes. To understand the impacts of climate and land use/cover changes on streamflow within a specific catchment, it is essential to accurately quantify their changes given many possibilities. We propose an integrated framework to assess how individual and combined climate and land use/cover changes impact the streamflow of Xinanjiang Basin, in East China, in the future. Five bias-corrected and downscaled General Circulation Model (GCM) projections are used to indicate the inter-model uncertainties under three Representative Concentration Pathways (RCPs). Additionally, three land use/cover change scenarios representing a range of tradeoffs between ecological protection (EP) and urban development (UD) are projected by Cellular Automata - Markov (CA-Markov). The streamflow in 2021-2050 is then assessed using the calibrated Soil and Water Assessment Tool (SWAT) with 15 scenarios and 75 possibilities. Finally, the uncertainty and attribution of streamflow changes to climate and land use/cover changes at monthly and annual scale are analyzed. Results show that while both land use/cover change alone and combined changes project an increase in streamflow, there is a disagreement on the direction of streamflow change under climate change alone. Future streamflow may undergo a more blurred boundary between the flood and non-flood seasons, potentially easing the operation stress of Xinanjiang Reservoir for water supply or hydropower generation. We find that the impacts of climate and land use/cover changes on monthly mean streamflow are sensitive to the impermeable area (IA). The impacts of climate change are stronger than those induced by land use/cover change under EP (i.e., lower IA); and land use/cover change has a greater impact in case of UD (i.e., higher IA). However, changes in annual mean streamflow are mainly driven by land use/cover change, and climate change may decrease the influence attributed to land use/cover change.

Future changes in Yuan River ecohydrology: Individual and cumulative impacts of climates change and cascade hydropower development on runoff and aquatic habitat quality.

The eco-hydrological system in southwestern China is undergoing great changes in recent decades owing to climate change and extensive cascading hydropower exploitation. With a growing recognition that multiple drivers often interact in complex and nonadditive ways, the purpose of this study is to predict the potential future changes in streamflow and fish habitat quality in the Yuan River and quantify the individual and cumulative effect of cascade damming and climate change. The bias corrected and spatial downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5) General Circulation Model (GCM) projections are employed to drive the Soil and Water Assessment Tool (SWAT) hydrological model and to simulate and predict runoff responses under diverse scenarios. Physical habitat simulation model is established to quantify the relationship between river hydrology and fish habitat, and the relative change rate is used to assess the individual and combined effects of cascade damming and climate change. Mean annual temperature, precipitation and runoff in 2015-2100 show an increasing trend compared with that in 1951-2010, with a particularly pronounced difference between dry and wet years. The ecological habitat quality is improved under cascade hydropower development since that ecological requirement has been incorporated in the reservoir operation policy. As for middle reach, the runoff change from January to August is determined mainly by damming, and climate change influence becomes more pronounced in dry seasons from September to December. Cascade development has an effect on runoff of lower reach only in dry seasons due to the limited regulation capacity of reservoirs, and climate changes have an effect on runoff in wet seasons. Climate changes have a less significant effect on fish habitat quality in middle reach than damming, but a more significant effect in lower reach. In addition, the effect of climate changes on fish habitat quality in lower reach is high in dry seasons but low in flood seasons.

[Treatment of patella fractures of 164 patients with 5 methods].

OBJECTIVE: To investigate the effects of different treatments for different patella fractures, and analyze the clinical outcome. METHODS: One hundred and sixty-four patients with patella fracture were treated between July 2005 and December 2009, 113 males and 51 females with an average age of 38.5 years old, ranging from 21 to 72 years. There were 21 cases of linear fracture or separation of the patella < 0.5 cm, 63 of patella separation > 0.5 cm and for the pure horizontal type or vertical-type fractures, 34 cases were separated into three block, 46 cases were separated into four and above. Of 164 cases, 21 patients accepted traditional treatment, 39 patients were fixed with cerclage wire and tension band wire, 43 with cannulated screws and tension band wire fixation, 29 with cannulated screws for the minimally invasive treatment, 32 patients with fixation of NT-PC RESULTS: One hundred and sixty-four cases were followed up with a mean period of 14 months (3 to 36 months). By Lysholm knee score criteria: 19 cases in traditional treatment were excellent and good, 36 cases in cerclage wire and tension band wire technique cases were excellent and good, 40 cases in cannulated screws and tension band wire fixation, 27 cases in cannulated screws for the minimally invasive treatment were excellent and good, 30 cases in NT-PC were excellent and good. CONCLUSION: The surgery should be avoided if the patients can be treated with manipulation and fixation. Those who need surgical treatment should be based on the type of fracture to select a different surgical operation. Percutaneous reduction can be fixed, and try to minimally invasive surgery. Whether traditional treatment or internal fixation, the appropriate functional exercise need to make as early as possible.

Palladium-catalyzed cross-coupling of stereospecific potassium cyclopropyl trifluoroborates with aryl bromides.

[reaction: see text] Stereospecific cyclopropanation of alkenylboronic esters of pinacol followed by in situ treatment with excess KHF(2) afforded the corresponding potassium cyclopropyl trifluoroborates in high yields, which then underwent Suzuki-Miyaura cross-coupling reactions with aryl bromides to give cyclopropyl-substituted arenes in good yields with retention of configuration. This promises to be a useful method for the synthesis of enantiomerically pure cyclopropanes.