Real time crop coefficient from SEBAL method for estimating the evapotranspiration

Crop coefficients (Kc) are defined as the ratio of actual crop evapotranspiration to the evapotranspiration (Eto) of a grass reference crop, often taken from Penman/Monteith"s methodology. They are used to estimate theoretical crop evapotranspiration (Etc). Actual evapotranspiration is measured in field lysimeters but this lacks acceptability when applied to the field or large irrigation schemes where conditions are very variable. This paper uses the SEBAL method (Bastiaanssen et al., 1998) to determine actual evapotranspiration from satellite images. This is compared with estimated Eto from both Penman/Monteiths methodology and Eto estimated from a SEBAL estimation of reference crop evaporation within a project. The range of Kc values for the cotton crop were then calculated. Crop coefficient Kc maps were made for two irrigation projects. The methodology was applied on a large cotton irrigation scheme (Starikan) southern Kazakhstan. The estimated mean real time Kc value of 1.16 (±1-3% error) was higher than the standard Kc value of 1.1 identified by FAO-56. The methodology was validated on a different date and different irrigation schemes (Chardara) 200 km south Starikan. The methodology is discussed

Evaluation of kaolin clay as natural material for

Copper sulfide formation is one of the possible corrosion mechanisms involving the corrosive sulfur of copper. EDX scans of copper strip before and after immersing in aged transformer oils containing sulfur without copper passivator at 100 °C for 3 h indicated that copper sulfide was formed on the copper strip surface. The reclaimed oil by using kaolin clay reduced the sulfur content of all tested aged oils reducing the corrosion on copper strips in all samples investigated. In every case studied, the oil after reclamation by kaolin clay showed no sign at all of corrosive sulfur on the surface of copper strips. Nevertheless the atomic absorption analysis of copper ions in oil samples showed that the dissolution of copper was increased with increasing the sulfur content in the oil at different times of immersed copper strip in the oil

Water Quality Observations in the Marine Aquaculture Complex of the Deeba Triangle, Lake Manzala, Egyptian Mediterranean Coast

Coastal aquaculture is faced with extreme variation in water quality. The Deeba Triangle on Lake Manzala is the largest marine coastal aquaculture-producing area on the Egyptian Mediterranean. Samples from 16 ponds were taken during four seasons (2014–2015), to investigate the variation of 12 water quality parameters at that region. We tested the hypothesis that there is no spatial or temporal variation in water quality of the fish ponds. Fish ponds were statistically clustered into three groups (p = 0.0005) coincident with their geographical location. Hypersaline and transparent waters characterized the western ponds; higher dissolved oxygen and higher nutrients characterized the central region. These spatial differences were principally due to variations in salinity and nutrients of the water sources used for irrigation of the ponds and to differences in the aeration management styles. Strong seasonality was seen in water temperature (following air temperature), nutrients, and turbidity (following the seasonal cycles of various water sources from the Lake Manzala and the seasonality of the petrochemical plants effluents close to these ponds). We conclude that municipal effluents significantly affected, spatially and temporally, the quality of the irrigation water used for coastal aquaculture purposes, which consequently might affect fish yield