黄土高原农、林、草地水量平衡异同比较分析

Similarities and differences of water balance among cropland, grassland and woodland in the Loess Plateau

水量平衡是说明生态系统功能和特征的重要指标之一。在黄土高原,降水通常是土壤水分的唯一来源,农、林、草地等不同土地利用类型在对土壤水分的利用时段、深度、利用率、水分的收支比以及土壤干燥化特征等方面存在着较大差异。水量平衡计算时,土壤深度农地通常需取到2m,多年生草地取到5m,林地则需到5m以下。

The water balance is one of the important indicators to describe the characteristics and function of an ecosystem. The rainwater is usually the only source of soil water in the Loess Pateau. There are marked differences of water balance among various types of land use, including cropland, grassland and woodland, in the aspects of the time phase, depth and ratio of soil water use, as well as the ratio of water income to consumption and the characteristics of soil desiccation. The soil depth should reach to 2 m for cropland, 5 m for perennial grassland, deeper than 5 m for woodland in calculating the water balance.