Special issue  

NDVI and EVI vegetation indexes, estimated from satellite images, can been used to estimate root zone soil moisture. However, depending on the spatial and radiometric resolution of the sensors used, estimations could change. In this work, images taken by satellites IKONOS-2 and LANDSAT-7 of the same location are compared on the four bands involved in these vegetation indexes. The results show that spatial resolution has a similar scaling effect in the four bands, but not radiometric resolution.

Melon crop got different levels of N that constituted a contribution to the variation of soil N at mainly larger scales. During its development a proportion of the N was taken up, adding a second factor of variability at smaller scales. After the melon harvest, the wheat was sown across the plots and harvested at the end of the season. Wheat was used as a N sink crop and allowed us to evaluate the soil N residual. Multiscale and relative entropy were applied to study N scale dependencies.

In this paper, we present the results of a heavy metal soil geochemical survey in Hefei city and use three multifractal parameters to indicate the overall amount of multifractality within the soil geochemical data. The results show all of the elements barring Hg have larger multifractal parameters in the Daxing area compared to the Yicheng area. The degree of multifractality suggests that the differing economic activities in Daxing and Yicheng generate very different heavy metal pollution loads.

The current study aimed to describe the dynamics of soil water content at three depths in a vineyard under rain-fed and irrigation conditions and to assess the multifractality of these time data series. Soil water content data series obeyed power laws and tended to behave as multifractals. Our results suggest that singularity spectra were useful for characterising temporal variability of soil water content, distinguishing patterns among series registered under rain-fed and irrigation treatments.

We measure soil water at points (point scale) and try to understand how they vary over the landscape. Previous studies identified a statistical relationship between these scales only at the surface and not at depths. This study found that the relationship stands at different depths. The relationship was very similar at different depths in drier season or in late summer and fall. A less similar relationship was observed between surface and subsurface layers in spring or in wetter seasons.