Soil erosion by water
(Monitoring frequency: twice a year).
To monitor the full set of soil erosion process in whole the catchment will require a survey oriented to the following processes:
- Gully erosion
- Rill erosion
- Sheet and splash erosion indicators (as pavement formation by and crusting and sealing, depositional pavement and splash pedestals etc.)
The Maps with the main areas affected and their degree of severity will produced.
The evidence of main erosion processes will be identified as related to their typical association land use- soil - management that are hydrological basic Unit (HBU) : (e.g. oliveyard - volcanic soils- continuous fallow - bare soil) in the basin. Inside the principal type of hydrologic units will be identified a representative sample of survey sites to evaluate the rate of soil erosion (Mg/ha) developed during the two seasons in which the main erosion events develop: end of winter (frontal precipitations- medium intensity long time duration) and end of summer (convective storms - high intensity short /time duration). This survey will allow identification of details the main hot spots for soil erosion processes, to quantify it and to indentify the main drivers. The quantification of soil erosion rate will be realized with measurement of rill density and their geometrical characteristics (with - depth ), splash pedestal height as well by the measurement of soil erosion evidence or monuments as the emerging part of root system in oliveyards and - vineyards in order to evaluate in these HBU the long term average soil erosion rate. In the latter case the knowing year form plantation (vineyards)or the year from the given management practices (oliveyards) the average erosion rate (mg/ha/yr) may derived by direct measurement of depth of eroded layer.
Furthermore, a person living in the area will add observations in between main periodic surveys and will alert us in case of intense events where detailed surveys may be advisable and feasible. In this case the person living in the area , that has technical agronomical skills and is trained to make observations related soil erosion processes ( ephemeral gullies, rill and sheet erosion and sedimentation) will perform in these period the documentation of the effects of single storms. Indicating eventually new hot spot areas for soil erosion and a quick survey of soil erosion landforms like ephemeral gullies and rills (position in UTM coordinates, land use, depth, width, slope gradient etc.).
The map produced will be linked to the soil erosion modelling approach used for other WBs (PESERA -WB5). The data available during the monitoring will be used to validate the reliability of some results obtained by modelling.
