北方农牧交错带生态用水现状及优化配置分析——以河北沽源县为例

Ecological Water Use and Optimization Analysis of Northern Ecotone——Taking Guyuan County of Hebei Province As a Example

生态用水研究是分析流域水利用不可缺少的一部分,而水科学中关注更多的是社会经济系统的水资源供需平衡问题,对生态用水的忽视带来了严重的生态退化和环境恶化。本研究选取北方农牧交错带的典型地区河北沽源县,采用桑斯维特公式(Thornthwaite)来计算潜在蒸散量,计算出沽源县各项生态用水类型的用水量。结果表明:沽源县生态用水总量为4.183×108 m3.a-1,其中耕地农作物生态用水1.506×108 m3.a-1,林地植被生态用水1.539×108 m3.a-1,草地生态用水0.705×108 m3.a-1,园地生态用水0.026×108 m3.a-1,水域生态用水0.407×108 m3.a-1。从生态用水角度考虑,该县土地利用规划中,应适当退耕,且采取还草比还林更适宜;在保证经济效益的同时应降低蔬菜和土豆的种植面积。

Ecological water use is indispensable in area water utilization analysis.However,water hydrologists are always concerned with integral water resource balances for social and economic systems and sometimes ignore ecological water use in water utilization analyses.It is the neglect of ecological water use that has caused serious ecological and environment degradation.Therefore,Guyuan county of Hebei province is selected as a typical area of northern ecotone for the survey of ecological water use in this paper.The amounts of potential evapotranspiration and ecological water use are calculated using Thornthwaite formula.Results show that the total amount of ecological water use at Guyuan county is 4.183×108 m3·a-1,in which the average annual amounts of ecological water use are 1.506×108 m3·a-1 in arable lands,1.539×108 m3·a-1 in forests,0.705×108 m3·a-1 in grasslands,0.026×108 m3·a-1 in garden plots and 0.407×108 m3·a-1 in water areas.