Monitoring and prediction of agricultural drought are paramount to food security at the global and regional scales, particularly under the influence of climate change and anthropogenic activities. Soil moisture is an effective indicator for monitoring and characterizing agricultural drought. Soil moisture (agricultural drought) is mainly affected by precipitation (meteorological drought) and temperature (hot conditions). Owing to the flexibility of vine copulas in handling multidimensional variables by decomposing them into pair copula constructions (PCCs), we propose a novel drought prediction method using three predictors, namely antecedent meteorological drought, previous hot conditions, and persistent agricultural drought, based on the conditional distributions of C‐vine copulas in a four‐dimensional scenario. The proposed model was applied to agricultural drought (characterized by the standardized soil moisture index (SSI)) prediction with 1–2‐months lead time for the summer season (i.e., August at a 6‐months timescale) in China. Taking two severe agricultural drought events that occurred in many regions across China in August of 2006 and 2014 as validation cases, the SSI predictions with 1–2‐months lead time using the conditional C‐vine copulas model were found to be generally consistent with the corresponding historical SSI observations in most parts of China. Performance evaluation using the Nash‐Sutcliffe efficiency (NSE), coefficient of determination (R2), and F1 score (F1S) for different climate regions also indicated that this model provided a reliable prediction of agricultural drought for most areas of China. The outcome of this study can serve as a guidance for drought prediction, early warning, and drought mitigation.

this paper calculated the weights using EFAST method, which considers the coupling relationship between indicators. The connection entropy model that can overcome the uncertainty of evaluation was carried out to evaluate comprehensive water resources carrying capacity. By taking the Yellow River Basin as an example, the weights of the carrying capacity indices were calculated using EFAST method and weight entropy method respectively and made a comparison between the two methods. Finally, the water resources carrying capacity of 61 cities in this basin in 2015 was comprehensively evaluated. The results showed that: EFAST method was more reasonable than entropy weight method in identifying important indicators.Cities whose water resources carrying capacity were at grade I (very high), grade II (higher), grade III (medium), grade IV (lower) and grade V (very low) levels accounted for 0%, 4.9%, 18.1%, 63.9% and 13.1% respectively of the number of cities in the Yellow River Basin. The cities of grades IV and V were distributed in provinces except Qinghai.

This study investigated the effects of soil crust development on the underlying soil properties. The field sampling work was conducted in June 2016 in the Hobq Desert in Inner Mongolia, North China. Soil crust samples and 0-6, 6-12, 12-18, 18-24, and 24-30 cm deep underlying soil samples were taken from five representative areas of different soil crust development stages. All samples were analyzed for physicochemical properties, including water content, bulk density, aggregate content, organic matter content, enzyme activities, and microbial biomass carbon and nitrogen. The results showed that the thickness, water content, macro-aggregate (>250 µm) content, organic matter content, microbial biomass, and enzyme activities of the soil crusts gradually increased along the soil crust development gradient, while the bulk density of the soil crusts decreased. Meanwhile, the physicochemical and biological properties of the soils below the algal and moss crusts were significantly ameliorated when compared to the physical crust. Moreover, the amelioration effects were significant in the upper horizons (∼0-12 cm deep) and diminished quickly in the deeper soil layers.

Drought/wetness conditions are fundamental not only for agricultural production but also ecology, human health, and economic activity. Dryness/wetness is a function of precipitation, temperature, vegetation and potential evapotranspiration. Regions with low moisture are often characterized by aridity which, in turn, reflects the degree of meteorological drought. Observed climatic data from eleven meteorological stations in and around Shiyang River basin, China, were used to calculate the aridity index (AI) which was defined as the ratio of potential evapotranspiration (ET 0 ) to precipitation (P). ET 0 was calculated using the Penman-Monteith method. The ordinary kriging method was used to interpolate the spatial variability of ET 0 , P and AI. The Mann-Kendall test with a pre-whitening method was employed using the Yue and Wang autocorrelation correction to detect temporal trends. The Theil-Sen estimator was used to estimate the slopes of trend lines. Results showed a higher AI in the north basin and a lower AI in the Qilian Mountain region. Annual ET 0 and P had increasing trends with a slope of 0.672 and 0.459 mm per year, respectively, but trends were not statistically significant for most stations. While annual AI had a slight decreasing trend with a slope of -0.01 per year, the trend was not statistically significant for all stations. The decreasing trends in winter AI (at a rate of -0.313/a) was more significant than that in other seasons. The study indicates that the Shiyang River basin is getting slightly wetter, especially in winter.

Sun (2020) The effect of π-Conjugation on the self-assembly of micelles and controlled cargo release, Artificial Cells, Nanomedicine, and Biotechnology, 48:1, 525-532, ABSTRACTHere we presented a novel micelle self-assembled from amphiphiles with p-conjugated moieties (OEG-DPH). The p-conjugated structural integrity of the micelles enabled stable encapsulation of Nile Red (NR, model drug). The self-assembly behaviour of the amphiphiles and the release profile of NR loaded micelles were investigated. Spherical core-shell structured NR loaded micelles with low CMC of 57 lg/mL and the efficient intracellular delivery process was monitored. This research provided a way to fabricate stable polymeric micelles and develop a practical nanocarrier for therapeutics delivery. ARTICLE HISTORY