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Land degradation induced by soil erosion is widespread in semiarid regions globally and is common in the agro–pastoral ecotone of northern China. Most researchers identify soil erosion by wind and water as independent processes, and there is a lack of research regarding the relative contributions of wind and water erosion and the interactions between them in what is referred to here as compound soil erosion (CSE). CSE may occur in situations where wind more effectively erodes a surface already subject to water erosion, where rainfall impacts a surface previously exposed by wind erosion, or where material already deposited by wind is subject to water erosion. In this paper, we use the Chinese Soil Loss Equation (CSLE) and the Revised Wind Erosion Equation (RWEQ) to calculate the rate of soil erosion and map the distribution of three types of soil erosion classified as (i) wind (wind-erod), (ii) water (water-erod), and (iii) CSE (CSE-erod) for the study area that spans more than 400,000 km2 of sand- and loess-covered northern China. According to minimum threshold values for mild erosion, we identify water-erod, wind-erod, and CSE-erod land as occurring across 41.41%, 13.39%, and 27.69% of the total area, while mean soil erosion rates for water-erod, wind-erod, and CSE-erod land were calculated as 6877.65 t km−2 yr−1, 1481.47 t km−2 yr−1, and 5989.49 t km−2 yr−1, respectively. Land subject to CSE-erod is predominantly distributed around the margins of those areas that experience wind erosion and water erosion independently. The CSLE and RWEQ do not facilitate a direct assessment of the interactions between wind and water erosion, so we use these equations here only to derive estimates of the relative contributions of wind erosion and water erosion to total soil erosion and the actual mechanisms controlling the interactions between wind and water erosion require further field investigation. It is concluded that CSE is an important but underappreciated process in semiarid regions and needs to be accounted for in land degradation assessments as it has substantial impacts on agricultural productivity and sustainable development in regions with sandy and/or loess-covered surfaces.

Additional file 3. List of 58 published papers from which the data used in this study were derived.

Additional file 1. Supplemental figures and tables.

Additional file 4. Supplementary environmental data description.

This chapter illustrates disaster and risk management. The disaster management includes hazard management and disaster issue management. Disaster risk management relies on the institution, policy, and scientific and technological progress for disaster reduction. Improving disaster risk management capacity is the key point to improving the utilization efficiency and effectiveness of disaster reduction resources, which is also an important guarantee for disaster risk reduction.

In this chapter, we will elaborate on three basic terms in the field of disaster risk science: hazards, disasters, and risks. We will also discuss the classification, indexes, temporal and spatial patterns, and some other fundamental scientific problems that are related to these three terms.

Deep-rooted fruit trees mine more water from deep soils than their shallow-rooted counterparts. Understanding how deep soil water (DSW) is replenished and subsequently depleted by deep-rooted fruit trees, therefore, are important for informing sustainable water resources management particularly in arid regions. In this study, we collected soil samples from the surface down to 20 m under four land use types (farmland, 8-year apple orchard, 12-year peach orchard, and 25-year apple orchard) in China's Loess Plateau. We then measured the soil water content, stable (δ2H and δ18O) and radioactive (3H) isotopic compositions. The radioactive isotope was used to constrain the age of soil water while the stable isotopes were used to determine the types of storms that would have contributed to recharging the DSW. We then implemented a soil water balance model to identify the mechanisms underlying the changes in DSW. Mechanistically, our results show that water movement in these soils was predominantly via piston flow. The age of DSW below 8 m was determined to be older than 55 years. Altogether, these results support an interpretation that DSW may have only been recharged by high-intensity, low-frequency rainfall events during the wet season (July to September), but that the magnitude of DSW recharge was likely to be influenced by subsequent water mining by deep-rooted fruit trees. The deep-rooted fruit trees consumed more DSW than farmland vegetation, substantially limiting the magnitude of DSW recharge under the orchards. Our simple soil water balance model, informed by water stable isotopes and supplemented with information from tritium, provides a technique for partitioning soil water balance (SWB) and insights into the long-term effects of land use change on water resources in arid regions.

Póster presentado en: EGU General Assembly 2019 celebrada del 7 al 12 de abril en Viena, Austria. The Wind erosion in arid and semi-arid areas is an important global environmental issue, and changes in wind speed trends over time play a key role in wind erosion dynamics. In a warming climate, scientists have recently observed a widespread decline in wind speed, termed "stilling". Here, we apply the Revised Wind Erosion Equation Model (RWEQ) to simulate the variability of wind erosion and quantify the impact of wind speed changes on soil degradation dynamics over the eastern agro-pastoral transitional zone of Northern China (EANC) from 1982 to 2016. Our results show that a significant (i.e., p

Deep-rooted fruit trees mine more water from deep soils than their shallow-rooted counterparts. Understanding how deep soil water (DSW) is replenished and subsequently depleted by deep-rooted fruit trees, therefore, are important for informing sustainable water resources management particularly in arid regions. In this study, we collected soil samples from the surface down to 20 m under four land use types (farmland, 8-year apple orchard, 12-year peach orchard, and 25-year apple orchard) in China's Loess Plateau. We then measured the soil water content, stable (δ2H and δ18O) and radioactive (3H) isotopic compositions. The radioactive isotope was used to constrain the age of soil water while the stable isotopes were used to determine the types of storms that would have contributed to recharging the DSW. We then implemented a soil water balance model to identify the mechanisms underlying the changes in DSW. Mechanistically, our results show that water movement in these soils was predominantly via piston flow. The age of DSW below 8 m was determined to be older than 55 years. Altogether, these results support an interpretation that DSW may have only been recharged by high-intensity, low-frequency rainfall events during the wet season (July to September), but that the magnitude of DSW recharge was likely to be influenced by subsequent water mining by deep-rooted fruit trees. The deep-rooted fruit trees consumed more DSW than farmland vegetation, substantially limiting the magnitude of DSW recharge under the orchards. Our simple soil water balance model, informed by water stable isotopes and supplemented with information from tritium, provides a technique for partitioning soil water balance (SWB) and insights into the long-term effects of land use change on water resources in arid regions.

Póster presentado en: EGU General Assembly 2018 celebrada del 8 al 13 de abril en Viena, Austria. The current global climate research has traditionally focused on changes in air temperature and precipitation. As a key climate parameter, changes of winds have a very significant impact on the environment, such as soil wind erosion, air pollution diffusion, wind power energy, etc. In particular, changes of extreme wind speed (i.e., wind gusts) are poorly analyzed and deserve further investigation. In this study we assess trends in máximum wind speed (MWS) across China for 1975-2016, using observed daily wind datasets, and also analyze its relationship with the East Asian monsoon. The raw observed MWS dataset was subject to aquality control and robust homogenization protocol using the Climatol package. The results reveal a statistically significant (p0.10). Even though MWS declines dominated across much of the country through out the year, only as mal number of stations showed statistically significant negative trends in summer (37.7 %) and spring (29.0 %). Our preliminary analyses show that the weakened East Asian monsoon, particularly in winter, positively correlates with the observed changes in MWS. However, statistical significant correlations are too few and further attribution analyses are strongly needed. This research is funded by (i) the National Natural Science Foundation of China (Grant No.41621061); (ii) the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant (Grant No. 703733); and (iii) the Swedish Research Council by the project “Detection and attribution of changes in extreme wind gusts over land” (2017-03780).

Póster presentado en: EMS Annual Meeting - European Conference for Applied Meteorology and Climatology 2018, celebrado en Budapest del 3 al 7 de septiembre de 2018. This study analyzes the variability of winter haze days and visibility in the Beijing-Tianjin-Hebei (BTH) region in relation to wind speed changes in the lower troposphere and emissions for 1961-2014. Daily surface meteorological data, NCEP/NCAR atmospheric reanalysis data, and fossil fuel emission data are used in this research. The results reveal a significant increase in winter haze days of +0.8 days decade-1 (p

On the basis of introducing the principle of path analysis, this paper positively analyzes the influence factors of cultivated land change from 1978 to 2002 in Hubei Province. The relationship between the influence factors and cultivated land change is studied by means of the path analysis. The results show that the construction rearrangement of agriculture, grain security and market mechanism are the main factors that decide the cultivated land change. Meanwhile, the impact of investment, urbanization and benefit gap among the different utilizing ways also leads to the change of cultivated land. The result means that though some factors have less direct influence on the change of cultivated land, their indirect influence is significant or vice versa.

Reviewing some concepts of fuzzy risk, we give a new definition of fuzzy risk. To improve probability-risk analysis, we propose the concept of possibility-probability distribution. Fuzzy sets are employed to show the imprecision of probability estimation. We use the information distribution method to calculate a possibility-probability distribution instead of expert experience. With a flood example, we show how to calculate a fuzzy risk, where the probability of exceeding losses is not one value but a fuzzy number. The benefit of this result is that one can easily understand the imprecision of risk assessment of natural disasters when data is lacking.

The ubiquitin ligase Nedd4 has been proposed to regulate a number of signaling pathways, but its physiological role in mammals has not been characterized. Here we present an analysis of Nedd4-null mice to show that loss of Nedd4 results in reduced insulin-like growth factor 1 (IGF-1) and insulin signaling, delayed embryonic development, reduced growth and body weight, and neonatal lethality. In mouse embryonic fibroblasts, mitogenic activity was reduced, the abundance of the adaptor protein Grb10 was increased, and the IGF-1 receptor, which is normally present on the plasma membrane, was mislocalized. However, surface expression of IGF-1 receptor was restored in homozygous mutant mouse embryonic fibroblasts after knockdown of Grb10, and Nedd4(-/-) lethality was rescued by maternal inheritance of a disrupted Grb10 allele. Thus, in vivo, Nedd4 appears to positively control IGF-1 and insulin signaling partly through the regulation of Grb10 function.