砂姜黑土区多目标农田排水系统优化布置研究

砂姜黑土区受其土质以及降雨特点的影响,涝渍与干旱灾害交替出现,以往单一的排水系统设计标准难以满足除涝抗旱以及环境保护等多重目标。本文利用田间水文模型-DRAINMOD,以淮北平原砂姜黑土区为例,模拟分析了不同排水系统布置方案对提高作物产量以及减少农田排水对环境的不利影响等因素。结果表明,在综合考虑作物产量、经济效益、环境保护以及节约耕地等多重目标下,研究区农田排水系统宜采用暗管浅密布置的方案,推荐排水暗管布置间距在18~30m之间,埋深以不超过1.2m为宜;仅在农沟一级采用暗管代替排水明沟可节约耕地10%以上。本研究成果可为当地排水系统改建、新建工程提供科学依据。

Optimization of agricultural drainage system design with multiple objectives in a vertisol soil district of China based on DRAINMOD simulations

Owing to the unevenly distributed rainfall, water logging and drought hazards happen concurrently almost every year in the poorly drained vertisol soil district in the Huaibei Plain of China. The existing drainage system was designed for single objective of water logging control, which neglected equal needs of drought prevention and water quality protection. With the aid of the field hydrology model-DRAINMOD, this paper presents a simulation study of drainage system design considering multiple objectives including maximizing crop yields, minimizing subsurface drainage, and land saving etc. The results show that the optimized subsurface drainage system layout for the study area is placing the drain pipes at depths no deeper than 1.2m and spacing between 18 to 30m. The analysis also shows that replacing the existing open drainage ditches at field level may save land area of more than 10% in the study area.