渭河流域水利水保措施减沙水代价分异特征与水沙调节模拟

 不同水利、水保措施减沙水代价研究,对于评价水利、水保措施减水、减沙效应和解决流域水沙问题,有着重要意义。通过对渭河流域梯田、造林、种草和坝地等坡面和沟道水土保持措施、洪水期和年均灌溉及水库等水利措施减流减沙比的比较,分析了渭河流域1970—1996年,不同措施减沙水代价的差异和区域分异特征,并根据不同假设,模拟了通过措施数量和区域调整,对渭河径流量的影响。研究表明,灌溉措施的减沙水代价最大,其次是种草、造林和梯田等坡面措施,水库和坝地的减沙水代价较小。措施减沙水代价,区域分异特征非常明显,除坝地外,各类措施的减沙水代价,均与洪期输沙模数呈显著负相关。模拟研究表明,在假定各区间水利措施不变,通过不同水保措施面积变化和不同区间水保措施调整,可以在减少泥沙量不变时,明显增加渭河径流量。

Characteristics and Regional Differences of Runoff Cost of Sediment Control of Conservation Measures and Their Simulation in Weihe River Basin

The runoff cost of sediment control of soil and water conservation measures and water resources engineering projects play an important role in integrated evaluation of influence of measures on runoff and sediment and resolving the sediment and water problems in Weihe River Basin. The soil and water conservation measures include terrace, reforestation, grass planting and dam land, and water resources engineering measures include irrigation with sediment flow and reservoir. By comparing the Ratio of detained Runoff and Sediment (R_rs) in different measures, the results showed that the runoff cost of sediment control of irrigation measures is the highest, that of terrace, reforestation, grass planting is less, and that of dam land and reservoir is relatively low. The regional differences of measures are clear, and the correlation between sediment flow modulus in flood period and the runoff costs of sediment control of all kinds of measures except dam land are evidently negative. The simulation showed that when the same amount of sediment are detained, the more runoff could occur in case of different measures change and regional distribution.