黄土丘陵沟壑区坝地防洪保收有关技术研究

坝地土肥水足 ,抗旱能力强 ,是发展高产、优质、高效农业的理想境地 ,在黄土丘陵沟壑区发展潜力巨大。但是 ,该区雨热同步、暴雨洪水集中 ,6— 9月份坝地常常遭受洪涝灾害 ,如何作到防洪保收 ,有许多问题值得探讨。本文以我们承担完成的“黄河流域黄土高原地区近期水土保持淤地坝建设规划”项目为基础 ,通过试验研究、实地调查 ,认为坝地应以种植玉米、高粱等高秆作物为主 ,其防洪保收的关键时期为 7— 8月份 ;坝地作物的耐淹标准为淹水深度 <80 cm、淹水历时 <7天 ;进一步研究认为 ,坝地面积与控制面积的比值 ( A)反映了坝地承水面积与流域产水产流面积的比例关系 ,其大小决定了淹水深度、淹水历时 ,合理的 A值是实现防洪保收的前提条件。该研究成果为确定淤地坝工程建设规模、确定坝地利用阶段提供了科学依据。

Study on the Problems of Dam Land's Avoiding Flood and Ensuring Harvest in Loess Hilly Region

Dam land has abundant fertility, sufficient water, and powerful ability of fighting drought. It is a good circumstance to develop agriculture, and has great potentiallity of development in the hilly Loess region. But flood occurs frequently, and dam land often be waterlogging in this region. How to avoid flood and ensuring harvest, many problems must be studied. This paper takes the programmer of "construction planning of Dam land in Loess Plateau region" as foundation, obtains some conclusions by means of investigation and experiment. That is Dam land should be planted with maize and sorghum, and it's main period of avoiding flood and ensuring harvest is July to August; the waterlogged standard for Dam land's crop is that flood's depth is smaller than 0.7m and period is shorter than 7d, then maize and sorghum can grow normally. Furthermore, the proportion (A) of Dam land's area to it's controlling area reflects the relationship of accepting and producing water. The proportion (A) decides the drowning depth and period, It is the condition of avoiding flood and ensuring harvest. These conclusions can be taken as scientific base for dam land construction and utilization.