Journal of Irrigation and Drainage Engineering

Maximization of infiltration and seepage rates is important to better control the quantity of stormwater to foster sustainable urban stormwater management. In this study, the effect of the cross-sectional flow area of a permeable channel on seepage rate was investigated to improve the efficiency of permeable stormwater channels. Physical models under ponding were used to examine seepage of earthen trapezoidal channels with various initial water levels, base widths, and side slopes. Regression analysis was used to develop an equation for predicting the rate of the unsteady seepage over time, and the equation was used to examine several cases of different flow cross-sectional areas and channel dimensions. The results showed that the channel side slope significantly affected the cumulative seepage volume. For a given top width, decreasing the base width and increasing the side slope resulted in an increase in the unsteady seepage rate.

The productivity of the peanut in salinity-prone areas has sharply declined and needs an immediate solution to meet the ever increasing demand of oilseed. It is hypothesized in this paper that the reuse of peanut seeds harvested from salinity-prone areas is a possible reason for this decline in peanut productivity. To investigate, the seed of two cultivars (TG 37A and GG 2) were grown under three different irrigation-water salinity levels (2, 4, and $6{\mathrm{dSm}}^{-1}$) and under normal soil conditions. All plant biometric parameters, including pod and haulm yield, decreased with increasing salinity levels for both seed types (normally grown and salinity-grown) and both cultivars. However, biometric parameters were higher in Cultivar GG 2 than in TG 37A except days to 50% flowering, number of immature pods, 100-pod mass, and 100-seed mass. Furthermore, the performance of salinity-grown seed was poor compared with normally grown seed, as indicated by a decrease in real value of seed, germination percentage, germination velocity, plant stand, number of mature pods, 100-pod mass, and 100-seed mass. Therefore, reuse of salinity-grown seed reduced pod yield of up to 46% under different irrigation-water salinity levels compared with seed grown under normal-water conditions. Kernel quality was also affected by salinity stress, with lower oil and higher protein and sugar content. The content of phenol, free amino acid, and moisture was slightly affected as well. Alterations in quality traits were higher in GG 2 than in TG 37A, suggesting the former’s better elasticity under salinity stress. For these reasons, use of peanut seed harvested from saline conditions should be avoided to ensure better peanut production under saline and nonsaline conditions.

In this paper, the flow-process of a slit weir was analyzed on the basis of a theorem of dimensional analysis and incomplete self-similarity theory. The theoretically deduced stage-discharge formula then was calibrated using experimental data obtained for a ratio between the weir and the channel width, ranging from 0.05 to 0.25. The deduced stage-discharge relationship allowed measuring discharge values characterized by errors that, for 98% of the measured values, were less than or equal to $\pm 5\%$. The performance of the proposed theoretical stage-discharge formula also was improved by introducing the Reynolds number (for 98.5% of the measured values the error was less than or equal to $\pm 5\%$, and the error for 74% of the measured values was less than or equal to $\pm 2\%$).