基于生态需水约束下辽河平原水稻布局调整

文章根据下辽河平原多年的水文、气象及工、农业等资料,采用旱涝指数与正负距平、彭曼—蒙斯特公式、最小月平均径流量、恢复地下水位年需水量等方法计算,着重对下辽河平原用水结构的变化特征、水田用水时空的变化特征及生态需水的时空变化特征进行研究,同时提出对下辽河平原水稻布局进行合理的调整。结果表明:下辽河平原用水结构以水田用水为主,在平水年与干旱年水田用水挤占生态环境用水最为明显,特别是在干旱年,生态环境用水仅为0.66亿m3,辽阳市、锦州市等生态环境用水为0,无法满足生态需水;下辽河平原生态需水的变化特征为干旱年的生态需水量大于平水年,在不同水文年型中下辽河平原生态需水的恢复量变化特征为干旱年中生态需水的恢复量大于平水年;对该区水稻生产布局做出合理的调整,在平水年水田需削减9.15万hm2/a,干旱年水田需削减10.623万hm2/a,锦州市水田削减量占本市水稻种植面积的比例最大。该研究结果对防止生态环境问题恶化、优化下辽河平原农业种植结构、水资源的可持续发展提供了参考。

RICE LAYOUT ADJUSTMENT BASED ON ECOLOGICAL WATERRESTRICTION IN THE LOWER REACH OF THE LIAOHE RIVER PLAIN

The lower reach of the Liaohe River Plain is an important industrial and agricultural production base and the center of economic development in Liaoning province. Rice planting area accounts for about 78 percent of total area of the province. However, 65 % of the water supply comes from groundwater resources, of which 36 percent of water was used for rice cultivation. Meanwhile, along with the development of industry, agricultural production and living water consumption, the lower reach of the Liaohe River Plain has become serious water shortage area due to the prominent contradiction between water supply and demand. So it needs to correctly evaluate the social, economic and environment demands on water resources. Based on the statistical data of hydrology, meteorology, industry, and agriculture,this paper analyzed the spatial and temporal features of the water utilization structure, calculated the paddy water and the ecological water demand in the lower reach of the Liaohe River Plain of Liaoning province, using the methods of the flood and drought index, the positive and negative anomaly, equation of Penman-Monteith, minimum monthly mean runoff, etc., and made reasonable adjustments in rice layout. The main results were as follows: 1) water use for paddy was dominant, especially in the drought year, the water use for ecological environment was only 0.66×108m3, which was 0 in Liaoyang and Jinzhou.Water resources cannot meet the ecological water requirement.2)The ecological water demand in dry year was more than that in median water year. In different hydrological model years, the water amount of ecological water restoration in the drought year was greater than that in the normal year. 3) rice production layout in this area should be adjusted, the paddy field area need to cut 91.5×103hm2/a in the normal years, and 106.23×103hm2/a in the drought years.The reduction of paddy field in Liaoyang city accounted for the largest proportion of rice planting area.4) The results of this study provided a reference to prevent deterioration of the ecological environment, optimize agricultural planting structure, and sustainably develop water resources in the lower reach of the Liaohe River Plain.