1971年以来珠穆朗玛峰地区气候变化

Global climate change has profound influence on natural ecosystem and socioeconomic system and is a focus which governments, scientific societies as well as common people of various countries have paid much attention to. Observations indicate that there i…     

大渡河上游不同地带居民对环境退化的响应

Environmental degeneration in the Tibetan Plateau attracts worldwide attention, whereas case studies on how the residents understand and respond to environmental degeneration are scarce. Using a Participatory Rural Appraisal method, this paper investigates how the people in different regions in the upper Dadu River understand and respond to environmental degeneration, based on comparative field surveys in three villages, in which Danzamu village is chosen from villages in the valley region, Kerma village from mountainside region, Rico village from the mountain and plateau region. The results show that: (1) although awakened to environmental degeneration, the residents in different regions have different responses. As agricultural labors have been transferred to the secondary and tertiary industries, population pressure in Danzamu and Kerma villages is mitigated. Residents in Danzamu village actively respond to natural disasters and forest degradation, as their livelihoods never rely on forests and rangelands again. Whereas the residents in Kema village negatively respond to natural disasters, forest and meadow degradation and the ruin of wildlife resources, as their livelihoods still rely on stockbreeding. Labors in Rico village are hard to transfer to the secondary and tertiary industries, so they have to raise more livestock to make a living. Active measures are just taken to avoid livestock loss, not to avoid forest and meadow degradation and the ruin of wildlife resources. So the most fragile region is the mountain and plateau region and mountainside region, not the valley region. (2) Livelihood strategy is the key factor affecting the residents to respond to population pressure and environmental degeneration. So the framework of sustainable livelihood strategy should be used to explain and intervene in issues of population pressure and environmental degradation in ecotones. (3) Transferring agricultural labors to the secondary and tertiary industries were favorable to improving people’s livelihood. It is necessary to reduce the education fees to speed up the pace of labors transferring in the mountainside region. In the mountain and plateau region, preferable ways also include the development of towns, highways, education equipment and other establishments. Foundation: National Natural Science Foundation of China, No.40471009; No.30270256; National Basic Research Program of China, No.2002CB412500; No.2005CB422006; Knowledge Innovation Project of CAS, No.KZCX3-SW-339 Author: Yan Jianzhong, Ph.D., specialized in LUCC, global change and regional responses.     

西藏雅鲁藏布江中游河谷地区1830年耕地格局重建

通过收集、整理《铁虎清册》中记录的雅鲁藏布江中游河谷地区1830年的耕地税收数据,将其换算为现代耕地面积,在此基础上运用网格化模型重建出该区1 km×1 km空间分辨率的耕地格局。结果显示：① 从耕地数量分析,1830年研究区耕地面积约895 km²,其中政府占有耕地39%,贵族占有耕地31%,寺庙占有耕地29%。② 从耕地分布格局分析,研究区内耕地分布较少,只有27.4%的网格具有耕地分布,且呈分散分布状态,耕地主要分布在雅鲁藏布江干流及主要支流宽阔的河谷地区。③ 从垦殖程度分析,全区垦殖程度较低,其平均垦殖率仅有0.6%,其中垦殖率最高的地区是拉萨,平均垦殖率为6.3%;日喀则、江孜、乃东、琼结等地垦殖率均达到3%左右;工布地区和西部县区垦殖率均在1%以下,耕地垦殖率区域差异明显。     

科西河流域国际合作项目启动会召开

由澳大利亚国际开发署(Australian Agency for International Development, AusAID) 资助, 国际山地中心(ICIMOD) 主持的“科西河流域国际合作项目(Koshi Basin Programme - Phase I, KBP)”启动会和实施方案研讨会, 于2012年9 月3-5日在尼泊尔加德满都成功举行。     

青藏高原植物返青期变化及其对气候变化的响应

基于连续的植被指数（NDVI）、气温和降水数据,提取了1982—2009年青藏高原典型台站邻近区域的植物返青期以及0℃和5℃旬均温始期的时序数据,分析了其时空变化特征,探讨了青藏高原冬、春季的气温、降水变化对植物返青期的影响。结果表明：1) 青藏高原典型台站邻近区域植物返青期多年平均值在东西向和南北向上存在显著差异;1982—2009年间,青藏高原典型台站邻近区域植物返青期整体呈提前趋势。2) 青藏高原典型台站0℃和5℃旬均温始期整体呈提前趋势,5℃旬均温始期提前趋势更为显著。3) 青藏高原植物返青期随着冬、春季气温升高和降水增加而提前。与降水相比,返青期与气温的相关程度更高。冬季气温比春季气温对植物返青期的影响更大。     

全新世大暖期末期气候变化对甘青地区新石器文化的影响(英文)

The Holocene Megathermal is divided into early,middle and late periods,each having different impacts on the Neolithic cultures due to their different climate changing trends.This study is based on a comparative analysis of the environmental evolution information recorded in the Qinghai Lake,the western edge of the Loess Plateau and Zoige and the spatial distribution of Neolithic sites of the Gansu-Qinghai region.Results show that the early and middle periods towards warm and humid promoted the development o...     

近30年珠穆朗玛峰国家自然保护区冰川变化的遥感监测

利用1976、1988和2006年的3期陆地卫星遥感数据,采用面向对象的解译方法并结合专家知识分类规则自动提取珠穆朗玛峰国家自然保护区(以下简称珠峰保护区)3个时期的冰川信息,并利用遥感、地理信息系统和图谱的方法对冰川时空分布特征和变化及其原因与不确定性进行了分析。结果如下:(1)2006年珠峰保护区内冰川面积为2710.17±0.011km²,为研究区总面积的7.41%,主要分布在研究区南部海拔4700～6800m的高山区;(2)1976-2006年,珠峰保护区冰川持续退缩明显,总面积减少501.91±0.035km²,冰湖扩张迅速(净增加36.88±0.035km²);研究区南坡子流域冰川退缩率(16.79%)高于北坡子流域(14.40%);珠峰保护区冰川以退缩为主,退缩冰川主要分布于海拔4700～6400m,退缩区上限海拔为6600～6700m;(3)1976年以来,气温显著上升和降水减少是冰川退缩的关键因素。     

青藏高原植被覆盖对水热条件年内变化的响应及其空间特征

利用1982-2000年NOAA/AVHRR卫星的NDVI数据(时间分辨率旬,空间分辨率8 km×8 km),结合同时期的气温和降水资料,基于时滞互相关方法和GIS工具,分析了青藏高原植被覆盖对水、热条件年内变化的时滞响应及其空间特征。结果如下:①除高寒荒漠、森林外,青藏高原植被NDVI与同期旬均温和旬降水相关性均呈高度正相关。其中,中等覆盖度的植被受水、热影响表现更为强烈。②青藏高原植被NDVI对气温和降水有滞后效应,且滞后水平存在空间差异,高原北部(柴达木盆地、昆仑山北冀)和高原南部植被对降水、和温度的响应比较迟缓,而高原中、东部地区植被对温度和降水的响应比较敏感。③不同植被类型对水热条件的响应程度也存在差异,由高到低依次是草甸、草原、灌丛、高寒垫状植被、荒漠,最后是森林。     

植被覆盖状况影响中国地表气温变化的观测事实

利用NOAA/AVHRR归一化植被指数（NDVI）及观测气温与再分析地表气温的差值（Observation Minus Reanalysis, OMR）分析了植被覆盖状况对中国地表气温变化的影响.结果表明,地表气温OMR趋势值与NDVI在空间上呈现出显著的负相关关系,植被覆盖状况差（NDVI小于0.1）的区域地表升温较为显著,气温OMR趋势值超过0.2℃/10a,而植被覆盖度高（NDVI大于0.5）的区域气温OMR趋势值则变化不大,甚至出现降温.气温OMR趋势值对植被的季节变化还有着敏感的响应.不同区域植被覆盖状况的差异可能导致中国地表气温变化对全球变暖的响应不同,预测中国未来气候变化需要考虑植被覆盖状况及其动态变化的影响.