森林生態(tài)系統(tǒng)碳循環(huán)模型參數(shù)優(yōu)化1)

陳晨　　　　　　　沃文偉　　　　　范文義

(東北林業(yè)大學(xué)，哈爾濱，150040)　　　　(黑龍江省水文水資源勘測(cè)局)　　　　(東北林業(yè)大學(xué))

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森林生態(tài)系統(tǒng)碳循環(huán)模型參數(shù)優(yōu)化1)

陳晨沃文偉范文義

(東北林業(yè)大學(xué)，哈爾濱，150040)(黑龍江省水文水資源勘測(cè)局)(東北林業(yè)大學(xué))

摘要以2011年帽兒山生態(tài)站通量塔觀測(cè)的二氧化碳通量(總初級(jí)生產(chǎn)力和顯熱通量)數(shù)據(jù)為基礎(chǔ)，使用集合卡爾曼濾波的順序同化技術(shù)，對(duì)北方生態(tài)系統(tǒng)生產(chǎn)力(BEPS)模型的關(guān)鍵參數(shù)進(jìn)行優(yōu)化。結(jié)果表明：參數(shù)在季節(jié)尺度上變化顯著，通常在展葉期迅速增大，夏季達(dá)到穩(wěn)定，秋季落葉期降低。根據(jù)優(yōu)化的參數(shù)，模型的總初級(jí)生產(chǎn)力、生態(tài)系統(tǒng)呼吸的模擬值精度顯著提高，精度分別達(dá)到91%、96%，比優(yōu)化之前的模擬值精度提高了8%和11%。說(shuō)明集合卡爾曼濾波的參數(shù)優(yōu)化可以明顯改善模型模擬碳水通量的能力。

關(guān)鍵詞BEPS模型；通量數(shù)據(jù)；集合卡爾曼濾波；數(shù)據(jù)同化；季節(jié)變化

分類(lèi)號(hào)S715.3

Optimization of Ecosystem Carbon Cycle Model Parameters//

Chen Chen

(Northeast Forestry University, Harbin 150040, P. R. China); Wo Wenwei(Hydrology and Water Resources Survey Bureau of Heilongjiang Province); Fan Wenyi(Northeast Forestry University)//

Journal of Northeast Forestry University，2016,44(5)：15-19.

With CO2flux observation data (gross primary productivity (GPP) and sensible heat flux (LE)) from Maoershan Ecosystem Station flux tower in 2011, we used sequential data assimilation and ensemble Kalman filter technique to optimize some of the key parameters of the Boreal Ecosystem Productivity Simulator (BEPS) model by taking into account the errors in inputs, parameters, and observations. We optimized the parameters by data assimilation including maximum photosynthetic carboxylation rate (Vcmax), and the slope of stomatal conductance and net photosynthetic rate (M). Parameters were optimized in daily steps. The parameters varied significantly at seasonal scales, was with usually rapid increase in leaf expansion period, and in summer would reach a steady and decline in senescence of leaves. According to optimized parameters, model simulated value of GPP and RE flux were significantly increased. GPP and RE simulated accuracy reached 91% and 96%, and the precision values of the simulated values before optimization were increased by 8% and 11%, respectively. Ensemble Kalman filter parameter optimization could significantly improve model capacity in simulating the carbon and water fluxes.

KeywordsBEPS model； Flux data； Ensemble Kalman filter； Data assimilation； Seasonal variability

森林生態(tài)系統(tǒng)是陸地生態(tài)系統(tǒng)的主體，在維持全球碳平衡、減緩全球氣候變化等方面起到重要的作用[1-2]，而生態(tài)系統(tǒng)和大氣之間的碳、水和能量交換對(duì)地球氣候影響顯著[3]。關(guān)于森林生態(tài)系統(tǒng)的碳水能量循環(huán)及其驅(qū)動(dòng)機(jī)制的研究已經(jīng)成為當(dāng)今全球氣候變化研究的重點(diǎn)問(wèn)題[4]。

陸地生態(tài)系統(tǒng)模型已經(jīng)廣泛應(yīng)用于模擬生態(tài)系統(tǒng)生產(chǎn)力、水分消耗以及溫室氣體的排放。由于生態(tài)過(guò)程的復(fù)雜性及其時(shí)空變異的特征，模型參數(shù)值通常存在空間和時(shí)間的異質(zhì)性，在應(yīng)用到大區(qū)域的時(shí)候，這些參數(shù)通常是不能直接測(cè)量的(如冠層級(jí)別的參數(shù))，但又顯著地影響模型模擬碳、水和能量通量的能力。……