Search

For the day-by-day evaporation observation data in the Yangtze River Basin from 1951 to 2019, the effects of the gradual shift of observation instruments from 20 cm diameter evaporation pan (D20) to E601 evaporation pan after 1980 are discussed, including inconsistent data series, and missing and anomalous data. This study proposes a governance and improvement method for dual-source evaporation data (GIME). The method can accomplish the homogenization of data from different observation series and solve the problem of inconsistent and missing data, and we applied it in practice on data of the Yangtze River Basin. Firstly, the primary and secondary periods of the data were obtained by wavelet periodicity analysis; secondly, we considered the first cycle of observations to be representative of the sample and calculated the conversion relationship between the primary and secondary periods; thirdly, the conversion coefficient between the dual-source observations was calculated, and the results were corrected for stations outside the main cycle; finally, the daily evaporation dataset of E601 pan was established through data fusion and interpolation technology. The study found that the annual average conversion coefficients of the D20 and E601 pans in the Yangtze River Basin are basically between 0.55 and 0.80, and there are obvious differences in different regions. The conversion coefficient is positively correlated with relative humidity, wind speed, minimum temperature and altitude; and negatively correlated with sunshine duration, average temperature and maximum temperature. Evaporation is high in the upper reaches of the basin and low in the middle and lower reaches; in particular, evaporation is highest in the southwest, which is associated with the drought hazards. In addition, the article presents the spatial distribution of the conversion coefficients of D20 and E601 pans in the Yangtze River Basin. The results can realize the rapid correction of the evaporation data of the local meteorological department, and can be extended to the processing of other types of data in similar areas. [ABSTRACT FROM AUTHOR]

• Introduce an evaluation approach for the Ecological Service Value of Water (ESV-W). • Improve the assessment of Ecosystem Services Value (ESV) by introducing the Agricultural Price Index (API) into the Equivalence Factor (EF). • Improve the Water Allocation and Simulation Model (WAS) to simulate and quantify the 'natural-artificial' soil water cycle. • Analysis of the ESV and ESV-W in the Yangtze River Basin from 2005 to 2020. This paper introduces an evaluation approach for the Ecological Service Value of Water (ESV-W) by coupling the assessment of Ecosystem Services Value (ESV) with the Water Allocation and Simulation Model (WAS). The proposed method is applied to evaluate ESV and ESV-W in the Yangtze River Basin from 2005 to 2020. Firstly, an improved Equivalence Factor (EF) method is employed to estimate ESV by considering different land use types and service categories. Then, the enhanced WAS model is used to quantify and identify the role of the 'natural-artificial' soil water cycle in supporting the ecological service functions. Finally, by integrating the ESV evaluation system with the WAS model, the evaluation method for ESV-W is established. The results indicated that from 2005 to 2020, the total ESV increased from 4.0 to 5.6 trillion US Dollars, with forests being the primary contributor among land use types (about 52%), and regulating services are dominating among service categories (about 70%). The spatial distribution of the ESV showed a decreasing trend from southeast to northwest in the Yangtze River Basin, while the ESV-W exhibited high values concentrated along the main stream of the upper reaches of the Yangtze River and lower in the middle. The ESV-W of the 'natural' soil water cycle still dominates (over 96%), but the ESV-W of the 'artificial' soil water cycle has been rapidly increasing in recent years. In 2020, the ESV-W per unit water of precipitation, irrigation, and ecological water were 4.0 Dollars/ m 3 , 0.7 Dollars/ m 3 , and 32.4 Dollars/ m 3 , respectively. This study aims to provide references for the protection of water ecosystems and the sustainable utilization of water resources. It also serves as a reference for improving the evaluation system of ESV. [ABSTRACT FROM AUTHOR]

Seismic hazards and risks around an individual fault can be assessed from complementary paleoseismic data. A high-resolution sediment core recovered from the Yileimu Lake revealed 11 potential paleoearthquakes around the Fuyun fault in northern Xinjiang. Among them, three events recorded by ductile deformation and turbidites or coseismic subsidence were possibly correlated with M s ≥ 7.0 earthquakes, and the others characterized by turbidites or coarse deposits were likely related to M s ≥ 5.8 or M s ≥ 5.5 earthquakes. Shaking intensities of 8.60 and 5.51 MMI were required to cause extensive landslides and turbidites, respectively; while 6.89, 6.35 and 5.34 MMI were likely to be required to cause coseismic subsidence, ductile deformation and coarse deposits related to landscape shattering in the catchment area, respectively. Absolute radiocarbon dating and historical earthquake-event markers disclosed a recurrence interval of 20–60 years for M s ≥ 5.5 earthquakes, and a potential interval of 100 years for M s ≥ 7.0 earthquakes during the last 450 years. A seismic quiescence of 89 years since the 1931/08/11 M s 8.0 Fuyun earthquake might have significantly increased the potential of a strong earthquake related to the fault in the near future. • Lake sediments recorded 11 potential paleoearthquakes around the Fuyun fault. • Intensities and magnitudes for distinct sedimentary events were distinguished. • Recurrence intervals for earthquakes with different magnitudes were proposed. [ABSTRACT FROM AUTHOR]

Ecological security (ES) can express the health and integrity of regional ecosystems; hence, a better understanding of regional ES levels and their influencing factors can help to specify sustainable ecological management policies. Levels of ES in the West Liao River Basin were computed for the years of 2000 to 2020 at both the grid and county scale by using the pressure–state–response model, with ecosystem services also included in the assessment system. From 2000 to 2020, the area of both the forests and grasslands increased, due to the Grain for Green Project, which augmented net primary productivity (NPP), an ecosystem production service, and enhanced the overall habitat quality of the basin and promoted improvements to the regional ecological environment. The ES levels in most areas of the West Liao River Basin were improved over time, in that >90% of its area was above the middle level in 2020. The coordinates of "very insecure" moved to the basin's southeast, while "very secure" moved to its northwest, which indicated serious ES problems in the southeast of the basin. When compared with the most economically developed areas or remote areas having societal progress and human activities, generally the moderately developed areas have better ES levels. Further, human factors are more important to ES than natural factors, though all driving factors had enhanced impacts on the change in ES via their interactive effects. By determining the ES levels of the basin, four ecological management zones were then derived for it. We identified the main environmental problems in each ecological management zones and put forward the corresponding management measures, which would make the results more useful for supporting resource management and ecological protection of ecologically fragile areas in the agriculture and pasture interlaced landscape of northern China. • Ecological security levels were improved in most areas of the West Liao River Basin. • Moderately developed areas have better ecological security levels. • From 2000 until 2020, the gravity center of ecological security changed. • Human factors are more important to ecological security than natural factors. • Including ecosystem services can better quantify the ecological security status. [ABSTRACT FROM AUTHOR]