A hydrologic balance approach to saline seep remediation design
2000
Mankin, K.R. | Koelliker, J.K.
Concern about saline seeps is increasing in the dryland production regions of Kansas and the North American Great Plains. To reclaim salt-affected seep areas, site hydrologic factors must be modified to reduce seep recharge. A simple method is needed to help design effective remediation treatments. A hydrologic balance model, POTYLDR (Potential Yield Model, Revised), was modified and used to estimate the water balance in a saline seep recharge area and to estimate the effectiveness of various acreages of alfalfa treatments in reducing seep recharge. This model uses readily available data, such as daily rainfall and temperature, NRCS runoff curve numbers, NRCS soil irrigation classes, Penman evapotranspiration parameters and Blaney-Criddle crop coefficients, to determine runoff, evapotranspiration, soil moisture, and percolation from the root zone. According to the assumed seep mechanism, deep percolation from the local recharge area was used to estimate seep recharge. Various percentages of the seep recharge area were shifted from the current wheat cropping to alfalfa to determine the reductions in total recharge and number of months contributing to recharge. A 50% reduction in total recharge required 14 to 32% alfalfa acreage depending upon site-specific factors of five targeted fields. A given alfalfa acreage reduced total recharge volume more effectively than it reduced the number of months contributing to recharge. The major limitation in application of these results is selection of the percentage seepage reduction needed to provide seep control. The modeling approach provides an important indication of a system's responsiveness to changes in vegetation and quantifies this response in a way that is useful for designing bioremediation treatments that require control of seepage or shallow groundwater recharge.
显示更多 [+] 显示较少 [-]