Effects of changes in canopy interception on stream runoff response and recovery following clear-cutting of a Japanese coniferous forest in Fukuroyamasawa Experimental Watershed in Japan     

Tomoki Oda  Tomohiro Egusa  Nobuhito Ohte  Norifumi Hotta  Nobuaki Tanaka  Mark B. Green  Masakazu Suzuki 《水文研究》2021,35(5):e14177

Understanding changes in evapotranspiration during forest regrowth is essential to predict changes of stream runoff and recovery after forest cutting. Canopy interception (Ic) is an important component of evapotranspiration, however Ic changes and the impact on stream runoff during regrowth after cutting remains unclear due to limited observations. The objective of this study was to examine the effects of Ic changes on long-term stream runoff in a regrowth Japanese cedar and Japanese cypress forest following clear-cutting. This study was conducted in two 1-ha paired headwater catchments at Fukuroyamasawa Experimental Watershed in Japan. The catchments were 100% covered by Japanese coniferous plantation forest, one of which was 100% clear-cut in 1999 when the forest was 70 years old. In the treated catchment, annual runoff increased by 301 mm/year (14% of precipitation) the year following clear-cutting, and remained 185 mm/year (7.9% of precipitation) higher in the young regrowth forest for 12–14 years compared to the estimated runoff assuming no clear-cutting. The Ic change was −358 mm/year (17% of precipitation) after cutting and was −168 mm/year (6.7% of precipitation) in the 12–14 years old regrowth forest compared to the observed Ic during the pre-cutting period. Stream runoff increased in all seasons, and the Ic change was the main fraction of evapotranspiration change in all seasons throughout the observation period. These results suggest that the change in Ic accounted for most of the runoff response following forest cutting and the subsequent runoff recovery in this coniferous forest.  相似文献   

STRATEGY OF MAIZE′S CONCENTRATING TO ADVANTAGE AREAS IN JILIN PROVINCE     

JIANG Hui-ming  GU Li-li 《中国地理科学(英文版)》2003,(4)

WiththedevelopmentofagricultureandChina'sentryintoWTO,thesituationofsupplyanddemandinmaizemarkethaschangedgreatly.Facingtherelativesurplusofmaizeandtheformationofbuyer'smarket,weshouldfullydeveloprelativeadvantages,carryouttheunevenstrategyofsupportingthesuperior inmaizeproduction andcultivateadvantagedareasofmaize.Theabovestrategicmeasurescanrapidlyim-provetheinternationally competitiveabilityandpro-ductivityofmaizeinJilinProvince,getoutofthea-griculturalpredicamentandmaketheagriculturalde-…  相似文献   

STUDY ON GIS FOR YIELD ESTIMATION BY REMOTE SENSING IN JILIN MAIZE BELT     

Liu Xiangnan  Huang Fang  Zhou Zhanao 《中国地理科学(英文版)》1996,6(4):351-358

ＳＴＵＤＹ　ＯＮ　ＧＩＳ　ＦＯＲ　ＹＩＥＬＤ　ＥＳＴＩＭＡＴＩＯＮ　ＢＹ　ＲＥＭＯＴＥ　ＳＥＮＳＩＮＧ　ＩＮ　ＪＩＬＩＮ　ＭＡＩＺＥ　ＢＥＬＴＳＴＵＤＹＯＮＧＩＳＦＯＲＹＩＥＬＤＥＳＴＩＭＡＴＩＯＮＢＹＲＥＭＯＴＥＳＥＮＳＩＮＧＩＮＪＩＬＩＮＭＡＩＺ...  相似文献   

基于神经网络方法的芦苇叶面积指数遥感反演   总被引：2，自引：0，他引：2  

陈健  倪绍祥  李云梅 《国土资源遥感》2008,(2):62-67

提出了一种从TM图像上获取芦苇冠层叶面积指数的方法:首先对芦苇的生长背景进行分类;然后,对不同的背景光谱利用冠层反射率(FCR)模型计算得到查找表;最后,利用实测数据和查找表中的数据作为参数进行BP神经网络模型训练,从而得到芦苇冠层LAI。结果表明,人工神经网络方法有很强的非线性拟合能力,能够消除背景对反演结果的影响,有效提高LAI反演的精度。  相似文献   

Turbulence Statistics Inside and Over Forest: Influence on Footprint Prediction   总被引：2，自引：0，他引：2  

Ü. Rannik  T. Markkanen  J. Raittila  P. Hari  T. Vesala 《Boundary-Layer Meteorology》2003,109(2):163-189

Observations of wind statistics within and above a Scots pine forest are comparedwith those predicted from an analytical second-order closure model. The roughnesssublayer (RSL) effects, and the influence of stability on similarity functions, arestudied using observations. The commonly accepted forms of similarity functionsdescribe the influence of diabatic effects above the RSL well. According to earlierstudies they are expected also to apply within the RSL. As an exception, the averagewind speed normalised with friction velocity was found to be invariant with stabilityclose to the canopy top under unstable conditions. Lagrangian stochastic trajectorysimulations were used to evaluate the influence of canopy turbulence profiles onfootprint prediction. The main uncertainty was found to arise from parameterisationof the random forcing term in the Lagrangian velocity equation. The influence ofdiabatic conditions was studied, and it was found that thermal stability affectssignificantly the footprint function above the forest canopy, but significantuncertainty exists because of uncertainties in the formulation of stability functions.  相似文献   

用广角图象同时测量针叶树冠层叶角分布和叶面积指数的方法研究(英文)     

《遥感学报》1997,(Z1)

  相似文献   

冬小麦遥感冠层温度监测土壤含水量的试验研究   总被引：7，自引：0，他引：7       下载免费PDF全文

刘云  宇振荣  孙丹峰  Driessen P.M  刘云慧  王纯枝 《水科学进展》2004,15(3):352-356

在冬小麦主要生育期(2002年4月初到5月底),对不灌溉的冬小麦测定了冠层温度、地温、气温以及土壤含水量,计算了冠气温差且分析了冠层温度和冠气温差与不同土层厚度的土壤含水量相关关系。结果表明:14:00的冠层温度能较好地反映20cm土层的土壤含水量变化,但与其它各土层相关性有较大的波动性;14:00的冠气温差能较好地反映40cm以上土层的土壤含水量变化,二者的相关性很高,在20cm、40cm土层,两者相关系数R2分别为0.98866、0.99389,这为用区域遥感数据反演主要生育期冬小麦的冠气温差进而监测区域40cm土壤含水量提供了实验性的依据;拔节期和灌浆期,用14:00冠气温差来拟合各土壤层的土壤含水量有较高的精度,从而为用区域遥感数据监测区域土壤含水量提供了经验性的模型。  相似文献   

Damage Evaluation of Agro-meteorological Hazards in the Maize-Growing Region of Songliao Plain,China: Case Study of Lishu County of Jilin Province     

Zhang  Jiquan  Okada  Norio  Tatano  Hirokazu  Hayakawa  Seiji 《Natural Hazards》2004,31(1):209-232

Agro-meteorological hazards such as drought, waterlogging and cool summer occur with very high frequency and affect maize production and social-economic development in the maize-growing region of Songliao Plain, China. Moreover, both the frequency of these hazards and loss from them are considered to be increasing with global warming. The purpose of this paper is to quantitatively analyze the relationships between the fluctuation of maize yield and drought, waterlogging and cool summer, and to evaluate the consequences of these hazards in the maize-growing area of Songliao Plain, taking Lishu county as a case study area based on GIS (Geographic Information System). Crop yield-climate analysis and regression analysis were employed to analyze and quantify relationships between the fluctuation of maize yield and drought, waterlogging and cool summer, and to evaluate the consequences of these hazards. The parameters and model of damage evaluation were presented using weighted comprehensive analysis, and the degree of damage of drought, waterlogging and cool summer to maize production was comprehensively evaluated and regionalized. It is shown that from 1949 to 1990, the negative value years of the fluctuation of maize yield due to meteorological hazards accounted for 55% of seasons, of which 14% was caused by drought, 30% by waterlogging, 4% by cool summer and drought, 9% by cool summer and waterlogging, 13% by drought and waterlogging, 30% by drought, waterlogging and cool summer. Studies on the instability and spatial variation of the fluctuations in maize yield in Lishu county showed that the middle plains are stable areas to climatic influence, while southeastern hills and low mountains, the low lands of the plains along the East Liao River and the western plain are unstable areas in terms of areas in maize yield. The synthetic index of the degree of damage to maize of drought, waterlogging and cool summer showed a strong positive correlation with the ratio of the amount damaged to the normal yield of maize. This suggests that this index can be used to evaluate such damage. The degree of damage of drought, waterlogging and cool summer to maize in Lishu county shows the regional characteristics, which increase gradually from the center to the west and east, this being almost identical with the spatial distribution of the fluctuation of maize yield due to these hazards. This study can be expected to provide the basis for developing strategies to mitigate agro-meteorological hazards and reducing the losses from them, and adjust the medium and long-term distribution of agricultural activities so as to adapt to environmental changes.  相似文献   

川西亚高山三个森林群落的湿林冠蒸发速率     

杨万勤  王开运  肖玲 《山地学报》2004,22(5):598-605

于3个假说和林冠上方2m处的气象变量，采用Penman-Monteith组合模型估算了一个生长季节内川西亚高山林区分别以云杉(SF)、冷杉(FF)和白桦(BF)为优势树种的3个林分的湿林冠蒸发速率(Er)。研究结果表明，SF、FF和BF的湿林冠蒸发量(E)分别为44．51mm、88．51mm和57．8mm，分别占总降雨量的9．2％、16．6％和10．2％。与SF和BF相比，FF具有最高的月平均Er和蒸发比例。SF、FF和BF的平均Er分别为0．097mm／h(变化范围：0．028-0．487mm／h)、0．242mm／h(变化范围：0．068～0．711mm／h)和0．149mm／h(0．060～0．576mm／h)。最高和最低的月平均Er分别在6月(SF、FF和BF分别为0．120mm／h、0．317mm／h和0．169mm／h)和10月(SF、FF和BF分别为0．083mm／h、0．187mm／h和0．101mm／h)。8：00至16：00期间的平均点Er显著高于0：00至8：00以及16：00至0：00期间的平均Er。Er显著的日变化和月变化主要归因于林冠上方的太阳辐射、空气温度和相对湿度的变化。  相似文献   

Photosynthesis-transpiration coupling model at canopy scale in terrestrial ecosystem   总被引：1，自引：0，他引：1  

REN Chuanyou  YU Guirui  WANG Qiufeng  Guan Dexin 《中国科学D辑(英文版)》2005,48(Z1)

At the hypothesis of big leaf, an ecosystem photosynthesis-transpiration coupling cycle model was established by the scaled SMPT-SB model from single leaf to canopy, and model parameterization methods were discussed. Through simulating the canopy light distribution, canopy internal conductance to CO2 can be scaled from single leaf to canopy by integrating to canopy using the relationship between single internal conductance and photosynthetic photon flux density. Using the data observed by eddy covariance method from the Changbai Mountains site of ChinaFLUX, the application of the model at the canopy scale was examined. Under no water stress, the simulated net ecosystem photosynthesis rate fitted with the observed data very well, the slope and R2 of the line regression equation of the observed and simulated values were 0.7977 and 0.8892, respectively (n = 752), and average absolute error was 3.78 μmol CO2 m-2s-1; the slope, R2 and average absolute error of transpiration rate were 0.7314, 0.4355 and 1.60mmol H2O m-2 s-1, respectively (n = 752). The relationship between canopy photosynthesis,transpiration and external environmental conditions was discussed by treating the canopy as a whole and neglecting the comprehensive feedback mechanism within canopy, and it was noted that the precipitation course affected the transpiration rate simulation badly. Compared to the models based on eco-physiological processes, the SMPT-SB model was simple and easy to be used. And it can be used as a basic carbon and water coupling model of soil-plant-atmosphere continuum.  相似文献