潮河流域不同水土保持措施配置方案对年径流量的影响

Impacts of Different Allocation Plans as Soil and Water Conservation Measures on Annual Runoff in the Chaohe River Basin

结合潮河流域2005年的水土流失状况,基于水土保持的生态、经济、社会三大目标以及保证粮食生产区域自给和增加植被覆盖率两项原则,建立了粮食保障方案、生态优先方案、综合水保方案3种水土保持措施配置方案。基于不同降水水平年潮河流域水平梯田和林地的减水定额,模拟分析了不同水土保持措施配置方案下流域年径流量的变化。结果表明,若流域水土流失面积全部造林,丰、平、枯水平年减水量分别占流域多年平均径流量的8.27%,8.28%和11.13%,对流域年径流量的影响程度较大;若按综合水保方案,丰、平、枯水平年减水量分别占流域多年平均径流量的11.42%,8.38%和13.21%,对流域年径流量的影响程度最大;粮食保障方案下,丰、平、枯水平年减水量分别占流域多年平均径流量的7.59%,6.03%及9.11%,对流域年径流量的影响程度较小。

By considering the three objectives of ecology, economy, and society in soil and water conservation, the two principles of guaranteeing regional grain self-sufficiency and increasing vegetation coverage, as well as the current status of soil and water loss in the Chaohe River basin in 2005, the three allocation plans of food grain security plan, eco-priority plan, and comprehensive plan are established, as soil and water conservation measures. Impacts of the three allocation plans for soil and water conservation on annual runoff of the Chaohe River are simulated and analyzed based on the water reduction norm of level terraces and forestlands under different precipitation schedules. Results show that if all the soil erosion areas are converted to artificial woodland, the impact to annual runoff reduction is greater, with the reductions in wet year, normal year, and dry year being 8. 27%, 8. 28%, and 11. l3% of the annual average runoff, respectively. Adopting comprehensive allocation plan may affect annual runoff greatly and the reductions in wet year, normal year, and dry year are 11. 42%, 8. 38%, and 13. 21% of the annual average runoff, respectively. The impact of grain security allocation plan on annual runoff reduction is littler and the reductions are 7.59%, 6.03%, and 9. 11% of the mean annual runoff during wet year, normal year, and dry year, respectively.