摘要
为提出一种合理有效的南方多水源灌区灌溉用水量模拟统计方法,该文针对南方多水源灌区水循环及灌溉取水特点对SWAT模型进行改进,尤其添加了多水源自动灌溉模块用于模拟作物不同水源类型的灌水量,并统计推求灌区灌溉用水量。以浙江省浦江县通济桥水库灌区为例,应用改进SWAT构建灌区水循环模型,利用灌区出口实测月径流数据及4条干渠渠首监测的灌水量数据校正及验证模型,其中月径流在验证期的Nash-Suttclife效率系数为0.89,干渠灌溉用水量模拟值与观测值相对误差的绝对值最大不超过20%,表明改进SWAT模型具有良好的模拟效果。利用所建模型模拟分析通济桥水库灌区长系列灌溉用水量,结果显示灌区灌溉用水量呈现丰水年小、干旱年大的变化规律;除监测的骨干水源通济桥水库及浦阳江取水以外,灌溉用水量的41.40%来源于灌区内部的河道、塘堰及小型水库,说明只监测干渠渠首灌水量无法统计整个灌区灌溉用水量;随着灌区节水改造投入,灌区灌溉水利用系数提高,其灌溉用水量减少。基于改进SWAT模型进行多水源灌区灌溉用水量模拟为灌区灌溉用水量统计分析提供了一种有效的方法。
The statistics of irrigation water consumption in irrigation districts are of great significance to implement the most stringent water resources management system. On account of the impossibility of complete measurement, it is quite difficult to accurately calculate the irrigation water consumption in multi-source water irrigation districts in the south of China. Therefore, a precise and effective way is needed to estimate irrigation water consumption in multi-source water irrigation districts. In this study, the Soil and Water Assessment Tool（SWAT） was modified according to the characteristics of hydrologic cycle and irrigation operation in the multi-source water irrigation district in the south of China for accurately estimating irrigation water consumption. The water balance modules of paddy field were modified in SWAT model, in addition, a canal seepage loss calculation was added to SWAT model. Specifically, a multi-source water auto-irrigation module was added as one of the components of SWAT model to estimate the irrigation water consumptions from different types of water sources. Furthermore, the modified SWAT model with a digital elevation model（DEM）, a soil map, a land cover map and multi-year meteorological data, was applied to build a distributed hydrological model of Tongjiqiao Reservoir Irrigation District（TID） in Zhejiang Province. Moreover, the observed monthly runoff was used to calibrate（1995-2007） and validate（2008-2015） the simulated runoff via SWAT Calibration and Uncertainty Programs（SWATCUP）, and the observed irrigation water consumptions of 4 main irrigation canals in 2017 were used to calibrate the simulated irrigation water consumptions. The results showed that the simulated monthly runoff matched well with the observed values in calibration and validation periods, the absolute relative errors（RE） were less than 12%, the coefficients of determination（R2） were greater than or equal to 0.88, and the Nash–Sutcliffe efficiency coefficients（NS） were greater than or equal to 0.85 in both periods; in addition, the maximum of the absolute relative errors between simulated irrigation water consumptions and the observed values of 4 main irrigation canals was less than 20%, indicated that the modified SWAT model has a good performance in the multi-source water irrigation districts. Additionally, the irrigation water consumptions in different hydrological years in TID, multi-year averages of simulated irrigation water consumptions and water supply proportions of different types of water source were simulated and calculated based on the modified SWAT model, in addition, the effect of water saving reform on irrigation water consumption was also analyzed. And the results indicated that the irrigation water consumption is small in wet year and large in dry year. Moreover, in addition to the key water sources（namely the Tongjiqiao Reservoir and the Puyang River）, 41.40% of the irrigation water consumption came from the rivers inside sub-basins, ponds and small-sized reservoirs, indicating that the amounts of water monitored at the head of canals fetching water from the key water sources did not represent the irrigation water consumption in irrigation districts. Beyond that, with the development of water saving reform in irrigation district, the irrigation water use efficiency increased so that the irrigation water consumption decreased. Consequently, the modified SWAT model can be used to simulate and analyze the irrigation water consumption in multi-source water irrigation districts accurately and reasonably, and the simulation of irrigation water consumption in multi-source water irrigation districts based on the modified SWAT model is an effective and rational method for calculation and analysis of irrigation water consumption in irrigation districts in the south of China, which satisfied the requirements of the total amount of water statistics and the most stringent water resources management system.
作者
崔远来
吴迪
王士武
温进化
王贺龙
Cui Yuanlai;Wu Di;Wang Shiwu;Wen Jinhua;Wang Helong(State Key Laboratory of Water Resources and Hydropower Science,Wuhan University,Wuhan 430072,China;Zhejiang Institute of Hydraulics ＆ Estuary,Hangzhou 310020,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2018年第14期94-100,共7页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金(51579184)
浙江省水利科技计划项目(RC1712)
关键词
灌溉
模型
水库
多水源灌区
改进SWAT
不同水源类型
irrigation
models
reservoirs
multi-source water irrigation district
modified SWAT
different types of water sources
