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AbstractThis article explores the use of a negative pollution tax to control erosion in semiarid agriculture. This tax operates on the setting of either one or two threshold levels. With two threshold levels, T‐max identifies the maximum acceptable limit of pollution and T‐min identifies the desirable or target level. Above T‐max, fines or penalties are imposed; below T‐min, the farm, county, or state is paid for their superior achievement. Although from a theoretical perspective the negative pollution tax has several attractive features, from an operational and political point of view many obstacles to its implementation must be surmounted.

Abstract. In Hungary, wind erosion is one of the most serious natural hazards. Spatial and temporal variation in the factors that determine the location and intensity of wind erosion damage are not well known, nor are the regional and local sensitivities to erosion. Because of methodological challenges, no multi-factor, regional wind erosion sensitivity map is available for Hungary. The aim of this study was to develop a method to estimate the regional differences in wind erosion sensitivity and exposure in Hungary. Wind erosion sensitivity was modelled using the key factors of soil sensitivity, vegetation cover and wind erodibility as proxies. These factors were first estimated separately by factor sensitivity maps and later combined by fuzzy logic into a regional-scale wind erosion sensitivity map. Large areas were evaluated by using publicly available data sets of remotely sensed vegetation information, soil maps and meteorological data on wind speed. The resulting estimates were verified by field studies and examining the economic losses from wind erosion as compensated by the state insurance company. The spatial resolution of the resulting sensitivity map is suitable for regional applications, as identifying sensitive areas is the foundation for diverse land development control measures and implementing management activities.

Abstract. Wind erosion susceptibility of Hungarian soils was mapped on the national level integrating three factors of the complex phenomenon of deflation (physical soil features, wind characteristics, and land use and land cover). Results of wind tunnel experiments on erodibility of representative soil samples were used for the parametrization of a countrywide map of soil texture compiled for the upper 5 cm layer of soil, which resulted in a map representing threshold wind velocity exceedance. Average wind velocity was spatially estimated with 0.5′ resolution using the Meteorological Interpolation based on Surface Homogenised Data Basis (MISH) method elaborated for the spatial interpolation of surface meteorological elements. The probability of threshold wind velocity exceedance was determined based on values predicted by the soil texture map at the grid locations. Ratio values were further interpolated to a finer 1 ha resolution using sand and silt content of the uppermost (0–5 cm) layer of soil as spatial co-variables. Land cover was also taken into account, excluding areas that are not relevant to wind erosion (forests, water bodies, settlements, etc.), to spatially assess the risk of wind erosion. According to the resulting map of wind erosion susceptibility, about 10 % of the total area of Hungary can be identified as susceptible to wind erosion. The map gives more detailed insight into the spatial distribution of wind-affected areas in Hungary compared to previous studies.

Soil degradation is one of the most serious ecological problems in the world. In arid and semi-arid northern China, soil degradation predominantly arises from wind erosion. Trends in soil degradation caused by wind erosion in northern China frequently change with human activities and climatic change. To decrease soil loss by wind erosion and enhance local ecosystems, the Chinese government has been encouraging residents to reduce wind-induced soil degradation through a series of national policies and several ecological projects, such as the Natural Forest Protection Program, the National Action Program to Combat Desertification, the "Three Norths" Shelter Forest System, the Beijing-Tianjin Sand Source Control Engineering Project, and the Grain for Green Project. All these were implemented a number of decades ago, and have thus created many land management practices and control techniques across different landscapes. These measures include conservation tillage, windbreak networks, checkerboard barriers, the Non-Watering and Tube-Protecting Planting Technique, afforestation, grassland enclosures, etc. As a result, the aeolian degradation of land has been controlled in many regions of arid and semiarid northern China. However, the challenge of mitigating and further reversing soil degradation caused by wind erosion still remains.

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<0.05) decrease (-0.007 m s-1 year-1) of near-surface wind speed was observed annually, with significant declining trends in spring (-0.010 m s-1 year-1 )and autumn (-0.009 m s-1 year-1). At the same time, wind erosion simulations reveal a negative trend for the annual soil loss from wind erosion (SLWE,-6.20 t hectare-2 year-1 , p<0.05; affecting 99.8% of the study region), with significant declining trends in all seasons, particularly in spring (-3.49 t hectare-2 year-1) and autumn (-1.26 hectare-2 year-1). Further, we isolate the effects of wind variability on wind erosion (SLWED) from 1982 to 2016 by the model variable control method. This shows that wind speed variability strongly weakens wind erosion at-8.14 t hectare-2 year-1 (p<0.05) annually, with the strongest stilling recorded in spring leading to major decreases of wind erosion in spring (-4.77 t hectare-2 year-1 , p<0.05). Meanwhile, the weakest stilling in summer had the opposite influence on wind erosion (+0.40 t hectare-2 year-1 , p<0.10). To summarize, our findings have shown a significant impact of wind stilling on the decline of soil erosion rates in Northern China. ; This research is funded by the National Natural Science Foundation of China (Grant No. 41621061), and funding from the European Union's Horizon 2020 research and innovation ...

The definitive version is available at: http://www.sciencedirect.com/science/journal/11610301 ; In Central Aragón (NE Spain), where strong and dry winds are frequent all year round, fallow lands are susceptible to wind erosion due to insufficient crop residues on the surface and loose, finely divided soils by multiple tillage operations. Effects of conventional tillage (mouldboard ploughing followed by a compacting roller) and reduced tillage (chisel ploughing) on soil surface properties affecting wind erosion were studied during three experimental campaigns in a dryland field of Central Aragón. Reduced tillage provided higher soil protection than conventional tillage through a lower wind erodible fraction of soil surface (on average, 10% less) and a significantly higher percentage of soil cover with crop residues and clods (30% higher). Random roughness was also higher after reduced tillage than after conventional tillage (15% vs. 4%). These results indicate that reduced tillage can be an effective soil management practice for wind erosion prevention during the fallow period in semiarid Aragón. The study shows, likewise, that significant changes in soil aggregate size distribution associated with wind erosion processes may occur in short periods of time. Thus, temporal variability of soil surface properties, including crust and clods stability, needs to be considered in wind erosion research in agricultural soils. ; This work was supported by the WELSONS project funded by the European Union (Contract No. ENV4-CT95-0182). The first author is grateful to the Spanish Ministry of Education and Culture for her PNFPI contract. ; Peer reviewed