Soil water dynamics: hydrologic and management interactions

封盖材料（如覆盖在库存上的表土）通常用于保护环境（通常是土壤、空气和水）免受潜在危险废物的影响。封盖材料作为植被的基质，进一步保护环境。在许多填海方案中，适当的封顶深度是一个具有深远环境和经济影响的关键问题。监管机构通常希望最大封顶深度以减少潜在的环境影响，而工业界则希望最小深度以降低回收成本。监管机构和科学界普遍认为，深度越大越好。我的初步研究表明，情况并非如此；深度太大会减少植物可利用的土壤水量，因为它可能会越过根区。

Capping materials (such as topsoil placed over stockpiles) are often used to protect the environment (usually soil, air and water) from exposure to potentially hazardous waste materials. Capping materials serve as a substrate for revegetation, to further protect the environment. In numerous reclamation scenarios, appropriate capping depth is a key question that has profound environmental and economic implications. Regulators generally desire maximum capping depths to reduce potential environmental impacts while industry desires minimum depths to reduce reclamation costs. There is a general perception among regulators and the scientific community that greater depths are better. My preliminary research indicates that this is not the case; depths too great can diminish the amount of soil water available to plants as it may pass beyond the root zone.