【摘要】：在陸地生態(tài)系統(tǒng)中,土壤、大氣和水分等要素通過(guò)植被來(lái)連接,熱量、水分及其分布格局決定著地球上各區(qū)域的植被類型,植被的變化往往會(huì)反映氣候的變化。研究水熱時(shí)空分布動(dòng)態(tài)變化及植被的相應(yīng)變化對(duì)揭示植被動(dòng)態(tài)變化與水熱條件的相關(guān)性,預(yù)測(cè)研究區(qū)的生態(tài)環(huán)境變化趨勢(shì)具有十分重要的意義。本文以烏珠穆沁草原作為研究區(qū)域,以2000-2013 MODIS植被產(chǎn)品和氣象數(shù)據(jù)為主要數(shù)據(jù)源,運(yùn)用時(shí)間序列分析法、趨勢(shì)分析法、相關(guān)分析法,結(jié)合GIS空間分析,定量分析了近15年烏珠穆沁草原水熱時(shí)空分布、ET及其植被覆蓋的變化特征,主要研究結(jié)果如下:1.從水熱年際變化來(lái)看,研究區(qū)降水以95.7mm/10a速率呈顯著增加趨勢(shì),氣溫呈以0.497℃/10a線性傾向率減少趨勢(shì),ET以線性傾向率為21.7mm/10a呈上升趨勢(shì),不及降水的增加速率;烏珠穆沁草原近15年氣候變化呈相對(duì)濕潤(rùn)化趨勢(shì)。2.2000-2013年,烏珠穆沁草原生長(zhǎng)季4月份降水、氣溫和蒸散量均呈下降趨勢(shì),5-9月份的降水和蒸散量呈增加趨勢(shì),5、6月份的氣溫有下降趨勢(shì)外,其他月份氣溫呈下降趨勢(shì),其中7月份氣溫下降趨勢(shì)最大。3.烏珠穆沁草原生長(zhǎng)季植被覆蓋度以0.05/10a速率呈增加趨勢(shì);其中,4月份植被覆蓋呈減少趨勢(shì),5-10月份的植被覆蓋有增加趨勢(shì)。4.植被長(zhǎng)勢(shì)主要受降水量的控制,降水量多的年份植被長(zhǎng)勢(shì)也好。3月份NDVI值隨氣溫升高而升高,3月份溫度高有助于植被的生長(zhǎng)發(fā)芽,對(duì)植被生長(zhǎng)尤為重要;其他時(shí)段氣溫對(duì)NDVI值負(fù)相關(guān),其中7月份植被生長(zhǎng)受氣溫的負(fù)相關(guān)性最明顯。4-6月植被生長(zhǎng)受當(dāng)月降水量的影響明顯,7、8月份NDVI值與6月份降水量呈顯著正相關(guān),表明植被生長(zhǎng)對(duì)降水變化具有一定滯后性,但8月份NDVI與當(dāng)月降水呈負(fù)相關(guān),是由于8月份植被長(zhǎng)勢(shì)達(dá)到最大值,過(guò)多降水可能導(dǎo)致澇災(zāi)而影響植被生長(zhǎng)。降水及溫度對(duì)植被NDVI的作用存在一個(gè)閾值,對(duì)植被的影響既有促進(jìn)作用也有減弱作用。
[Abstract]:In terrestrial ecosystem, the elements of soil, atmosphere and water are connected by vegetation. The distribution pattern of heat, water and water determines the vegetation types in every region of the earth, and the change of vegetation often reflects the change of climate. It is very important to study the temporal and spatial distribution of water and heat and the corresponding changes of vegetation in order to reveal the correlation between the dynamic changes of vegetation and the conditions of water and heat, and to predict the trend of ecological environment change in the study area. This paper takes Wuzhoumuqin grassland as the research area, taking the vegetation products and meteorological data of MODIS from 2000 to 2013 as the main data sources, using time series analysis, trend analysis, correlation analysis and GIS spatial analysis. The variation characteristics of et and its vegetation cover in Wudhumuqin grassland in recent 15 years were analyzed quantitatively. The main results are as follows: 1. From the point of view of the interannual variation of water and heat, the precipitation in the study area showed a significant increase trend at the rate of 95.7mm/10a, and the temperature showed a decreasing trend with the linear tendency rate of 0.497 鈩，

本文編號(hào)：2165996