基于PCA和GRA-TOPSIS相耦合的灌区用水效率评价模型构建与应用

【目的】对灌区用水效率进行科学合理的综合评价,为灌区改造建设提供决策依据。【方法】从灌区用水水平、工程状况、管理水平和灌溉技术水平等方面建立了评价指标体系,在此基础上,构建了PCA和GRA-TOPSIS相耦合综合评价模型,以内蒙古引黄灌区5个大型灌区为例进行验证。【结果】PCA和GRA-TOPSIS相耦合法与GRA-TOPSIS法对各评价灌区的综合评价排序完全一致、与FMA法对各评价灌区的综合评价排序位次基本一致,表明评价结果合理;3种评价方法所得评价值的极差分别为0.501、0.448、0.500,变异系数分别为0.699、0.450、0.921,PCA和GRA-TOPSIS相耦合法所得评价值的变异系数比其他2种方法大,更有利于直观地区分各灌区的灌溉用水效率水平,更适宜用于灌区灌溉用水效率等级划分;PCA与GRA-TOPSIS相耦合法所得各评价灌区综合评价值符合灌区实际,评价结果可靠。【结论】PCA与GRA-TOPSIS相耦合评价法适宜于灌区用水效率的综合评价。

考虑回归水重复利用的灌区用水评价指标

为了正确评价灌区用水效率及用水效益,构建了考虑回归水重复利用的灌区用水效率及效益指标。利用地表水-地下水耦合模型、SWAP模型和线性模型对柳园口灌区的水量和作物产量进行了分布式模拟,在此基础上,对柳园口灌区不同用水模式以及田间不同节水灌溉模式下的灌区用水效率及效益指标进行了计算,分析不同节水措施对灌区用水效率及效益指标的影响规律。结果表明,井渠结合调控模式和田间节水灌溉模式对柳园口灌区不同区域用水效率及效益的影响效果不同,但均能提高灌区总体的用水效率及效益。

Effects of Alternative Partial Root-zone Irrigation and Nitrogen Fertilizer on Plukenetia volubilis Seedlings

This study was aimed to investigate the effects of alternative partial rootzone irrigation and nitrogen fertilizer on the potted seedlings of Plukenetia volubilis.A total of 7 treatments were designed with three factors, i.e., irrigation amount, irrigation mode and nitrogen fertilizer. The growth, photosynthesis and water use efficiency were analyzed. The results showed that compared with those under full irrigation, the biomass and water consumption under alternative partial root-zone irrigation were reduced by 5% and 75%, respectively, and the water use efficiency was increased by 60%. Under severe drought conditions, the root cap ratio in the nitrogen fertilizer treatment group was increased by 30%; the leaf area index, photosynthetic rate and biomass under alternative partial root-zone irrigation were reduced by 38%, 9% and 18%, respectively. It indicates that under severe drought conditions, alternative partial root-zone irrigation is not suitable to be matched with application of nitrogen fertilizer. In short, under moderate drought conditions, alternative partial root-zone irrigation could reduce transpiration and improve water use efficiency, and it is an effective water-saving irrigation technology for the plantation of P.volubilis plants.

Effect of Drip Irrigation Intervals and Some Antitranspirants on the Water Status, Growth and Yield of Potato （Solanum tuberosum L,）

In order to reduce the quantity of water applied by irrigation, increase the water use efficiency and determine the appropriate period for irrigation potato crop, a field experiment was implemented at vegetables field, Department of Plant Production, Agriculture Technical College, Mosul, Iraq, during spring season of 2014. This study involved four irrigation intervals （3, 4, 5 and 6 d） under drip irrigation system, with spraying by five antitranspirant substances （control, kaolin 5 g/L, MgCO3 3 g/L, liquid paraffin 2% and Nu-film 17 1%）, which subjected in a factorial experiment within split plot system in a randomized complete block design with three replications. The results showed that increasing irrigation intervals from 3 d to 6 d decreased the total water content of the leaves from 83.59% to 81.81%, the rate of relative transpiration from 0.174% to 0.162%, stomata area from 1.620 lam2/stomata to 0.921 ~m2/stomata, plant yield from 542.22 g to 425.80 g, total yield of tubers from 25.808 tons/ha to 20.253 tons/ha and marketable yield of tubers from 24.471 tons/ha to 18.822 tons/ha, whereas caused an increase in the leaf water deficit from 19.19% to 23.86% and water use efficiency from 8.63 kg/m3 to 13.32 kg/m3. Spraying potato plants with liquid paraffin 2% led to the highest total water content 83.37%, stomata area 1.466 ~tm2/stomata, the lowest relative transpiration 0.152%, the lowest leaf water deficit 20.33%, the highest plant yield 509.22 g, total yield 24.236 tons/ha, marketable yield 22.770 tons/ha and water use efficiency I 1.83 kg/m3. On the other hand, the interaction treatments between irrigation intervals and antitranspirants resulted in a significant effect in many studied parameters.