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The frequent occurrence of extreme climate events has a significant impact on people's lives. Heavy rainfall can lead to an increase of regional Terrestrial Water Storage (TWS), which will cause land subsidence due to the influence of hydrological load. At present, regional TWS is mostly obtained from Gravity Recovery and Climate Experiment (GRACE) data, but the method has limitations for small areas. This paper used water level and flow data as hydrological signals to study the land subsidence caused by heavy rainfall in the Chaohu Lake area of East China (June 2016–August 2016). Pearson's correlation coefficient was used to study the interconnection between water resource changes and Global Navigation Satellites System (GNSS) vertical displacement. Meanwhile, to address the reliability of the research results, combined with the Coefficient of determination method, the research findings were validated by using different institutional models. The results showed that: (1) During heavy rainfall, the vertical displacement caused by atmospheric load was larger than non-tidal oceanic load, and the influence trends of the two were opposite. (2) The rapidly increasing hydrologic load in the Chaohu Lake area resulted in greater subsidence displacement at the closer CORS station (CHCH station) than the more distant CORS station (LALA station). The Pearson correlation coefficients between the vertical displacement and water level were as high as −0.80 and −0.64, respectively. The phenomenon confirmed the elastic deformation principle of disc load. (3) Although there was a systematic bias between the different environmental load deformation models, the deformation trends were generally consistent with the GNSS monitoring results. The average Coefficients of determination between the different models and the GNSS results were 0.63 and 0.77, respectively. The results demonstrated the effectiveness of GNSS in monitoring short-term hydrological load. This study reveals the spatial-temporal evolution of land deformation during heavy rainfall around Chaohu Lake, which is of reference significance for water resource management and infrastructure maintenance in this area. [ABSTRACT FROM AUTHOR]

Sedum plumbizincicola has been widely employed to remove cadmium (Cd) and zinc (Zn) from contaminated soils and harvested biomass is used to recover valuable metals. While chopping and compacting are efficient methods to rapidly reduce the volume and moisture of fresh biomass, the resulting waste liquor containing metals needs treatment. Two types of contaminated soils were cropped with S. plumbizincicola and top-dressed with this liquor to study metals migration in soil profile and their uptake by plants. There were three treatments: planting and adding liquor (PL), planting without liquor (P) and adding liquor without planting (L). The results showed that Cd and Zn from liquor were mainly retained at top soil 0–10 cm under L treatment. Compared with L treatment, soil Cd and Zn under PL treatment decreased significantly in soil profile due to the extraction of S. plumbizincicola. Moreover, the amount of Cd and Zn extracted by plants was greater than that applied in soils. The metal removal rate by S. plumbizincicola in acid clay loam soil was higher than that in neutral sandy soil. To sum up, metal retaining in soil and uptake by S. plumbizincicola can be used to treat waste liquor from its fresh biomass. Novelty Statement Rapid and efficient treatment of harvested fresh biomass is still a challenge although phytoextraction using hyperaccumulator Sedum plumbizincicola has been widely employed. Chopping and compacting fresh biomass are efficient methods for rapid dehydration, however, a large amount of waste liquor that contains of Cd and Zn is produced and needs treatment. In the present study, a simple and low-cost method was tested to dispose the liquor, i. e. irrigating it onto the surface of contaminated soils where grown S. plumbizincicola. It was found that Cd and Zn applied in soils from liquor were mainly retained at top 0–10 cm soil depth where S. plumbizincicola root system was widespread, and the amount of Cd and Zn extracted by plants was greater than that applied in soils. Therefore, it is technically feasible to dispose the waste liquor dewatering from fresh biomass of S. plumbizincicola in its phytoextraction process. This study is helpful for the rapid, efficient and low-cost treatment of harvested fresh biomass in the large-scale application of phytoremediation. [ABSTRACT FROM AUTHOR]

Lake sediments are subjected to intensive anthropogenic activities such as dumping of industrial waste water and leakage of P fertilisation from agricultural lands. There has a great body of research focusing on examining phosphorus fractions, which provide fundamental data that facilitate understanding the risk of P-induced eutrophication. Here, we have extracted the data of P fractions from 484 sediment samples residing in 48 lakes mainly in EU, China and USA. NH4Cl-P and total phosphorus (TP) displayed a well linear relationship, but not applicable to all lakes. Six groups were categorised as per the slope and intercept by using the clustering analysis. Specific measures were recommended to curb P release risk by considering the characteristics of each group. For instance, TP controlling is deemed as a priority in group with steep linear dependence of NH4Cl-P on TP. A significant correlation was determined between TP and NaOH-P (r2 = 0.63). Among other findings, larger lake area significantly contributes to lower all P pools. Deeper depth could only pronouncedly influence the BD-P, HCl-P. Additionally, we found lakes in Germany have pronounced higher averaged P pools than other regions. Furthermore, this paper creates awareness of the present status of lake eutrophication for researchers and policy-makers. [ABSTRACT FROM AUTHOR]