Valiantzas模型在广西参考作物蒸散发预测的适用性研究

Study on the Applicability of Valiantzas Model in the Prediction of Reference Evapotranspiration in Guangxi

关键词:  参考作物蒸散发  广西  喀斯特地貌  灌溉制度  Penman-Monteith模型

Key words:  Reference Evapotranspiration  Guangxi  karst landscape  irrigation schedule  Penman-Monteith model

摘要:

参考作物蒸散发(Reference Evapotranspiration，ET₀)的精确计算是灌溉制度设计、水资源分配及管理的基础。本研究基于广西喀斯特与非喀斯特地区10个典型气象站点5年半的逐日气温、风速、相对湿度和日照时数数据，系统评估了Valiantzas系列简化模型(对应于不同气象因子缺失情况)在广西的适用性，并以Kling-Gupta Efficiency系数(KGE)、Nash效率系数(NSE)、决定系数(R²)、均方根误差(RMSE)以及平均偏差(PBIAS)作为评价指标。结果表明：Valiantzas-M1模型与FAO-56 Penman-Monteith (FAO-56 P-M)模型所需气象因子相同,但精度较高，其NSE和RMSE分别为0.796-0.841和0.557-0.641 mm/d，便于实际应用，可替代FAO-56 P-M模型。缺失风速时，原始Valiantzas-M2模型误差较大，用广西地区平均风速对其进行修正的Valiantzas-M2-modify模型能够提高ET₀模拟精度，降低误差，NSE增加了16.6%-17.4%，RMSE降低了24.9%-27.4%。同时缺失太阳辐射和风速时，Valiantzas-M3模型在喀斯特和非喀斯特地区的RMSE值分别为0.991 mm/d和0.988 mm/d。同时缺失相对湿度和风速时，Makkink模型模拟ET₀效果优于Valiantzas-M5模型。本研究可为气象站点稀疏、岩溶干旱严重的广西农业水资源高效利用提供科学依据。

Abstract:

Accurate calculation of Reference Evapotranspiration (ET₀) is the basis of irrigation system design,water resources allocation and management.Based on the daily temperature,wind speed,relative humidity and sunshine duration data of 10 typical meteorological stations in karst and non-karst areas in Guangxi for 5 and a half years,the applicability of simplified Valiantzas models (corresponding to the absence of different meteorological factors) in Guangxi was systematically evaluated.Kling-Gupta Efficiency Coefficient (KGE),Nash-Sutcliffe Coefficient of Efficiency (NSE),Coefficient of determination (R²),Root Mean Square Error (RMSE) and Average Bias (PBIAS) were used as evaluation indexes.The results showed that Valiantzas-M1 model with the same meteorological factors as the FAO-56 Penman-Monteith (FAO-56 P-M) model has higher accuracy,and its NSE and RMSE were 0.796-0.841 and 0.557-0.641 mm/d,respectively.It was convenient for practical application and can replace the FAO-56 P-M model.When the wind speed was missing,the original Valiantzas-M2 model had a large error.The Valiantzas-M2-modify model modified by the average wind speed in Guangxi could improve the simulation accuracy of ET₀ and reduce the error.NSE increased by 16.6%-17.4%,RMSE decreased by 24.9%-27.4%.When solar radiation and wind speed were missing,the RMSE values of Valiantzas-M3 model in karst and non-karst areas were 0.991 mm/d and 0.988 mm/d,respectively.When the relative humidity and wind speed were missing at the same time,the Makkink model was better than the Valiantzas-M5 model in simulating ET₀.This study can provide a scientific basis for the efficient utilization of agricultural water resources in Guangxi with sparse meteorological stations and severe karst drought.