基于MCI的中国干旱时空分布及灾情变化特征

利用中国825个气象站点1961—2015年逐日降水量、平均气温、最高气温、最低气温和平均风速等资料,根据2017年修订的国家标准《气象干旱等级》,计算得到各站点1961-2015年逐日气象干旱综合指数(meteorological drought composite index,MCI)。基于MCI指数系统分析了中国及东北、华北、西北东部、西南、长江中下游、华南6大区域中旱及以上干旱日数的时空分布及气候变化特征,并结合1951-2015年全国各省(区、市)农业干旱受灾面积和成灾面积,分析了我国不同地区干旱受灾情况以及灾情变化特征。结果表明:华北、黄淮、西北东部、东北西部、华南西部、西南大部以及内蒙古等地是我国干旱多发区,其中华北大部、黄淮东北部及陕西北部、甘肃河东大部、宁夏等地年干旱日数在60天以上,河北南部、宁夏大部、新疆北部和西部、云南中南部、海南南部等地最长连续干旱日数达210天以上;长江中下游、华南东部、西北中部、东北东部等地干旱日数相对较少。东北、华北干旱主要出现在春末和夏、秋季,西北地区东部主要发生在春末夏初,长江中下游地区主要出现在盛夏和秋季,华南地区的干旱主要出现在秋、冬季节,西南地区多出现在冬、春季节。1961—2015年,中国平均年干旱日数总体呈增加趋势,其中甘肃东南部、宁夏、陕西、山西南部、河南西部、湖北西北部、贵州中西部、云南中西部等地增加趋势明显,但西北中西部、东北中东部、江南大部、华南大部及青藏高原中西部、内蒙中西部等地年干旱日数呈减少趋势。1951—2015年,中国农作物因旱受灾和成灾面积总体呈增加趋势,但近年来有减少趋势。     

黔东南干旱的时空特征分析及其气候区划

利用黔东南1981—2012年16个县市的干旱受灾数据,通过主成分分析和旋转主成分分析方法对黔东南农业气象干旱进行分析。结果表明:黔东南农业气象干旱在空间上表现为较高的整体一致性,州中西部与其余地区,州南部与州北部具有反向变化的特征。32 a来,黔东南干旱总体呈加重趋势,其中2010—2011年发生了极端干旱事件,中西部与其余地区因干旱导致的受灾强度反向变化特征呈微弱下降的趋势,而南北反位相变化特征越发突出。黔东南农业气候干旱可以划分为3个明显的相关区域,分别为黔东南西北部、东北部以及中南部,州东北部及中南部总体而言干旱呈加重的趋势,而州西北部干旱呈缓解趋势,其中干旱年际变率最大的是中南部。     

中国干旱半干旱地区的冷季快速增温

利用中国713个观测站均一化的月平均温度资料,详细分析了近55年中国温度变化的季节性及区域特征,并进一步分析了中国干旱半干旱区冷季增温前后的大气环流特征。年际变化结果表明,中国的增温现象主要是从20世纪80年代中期开始,90年代快速增长,21世纪初增温变缓,其中干旱半干旱区的年均增温速率是湿润半湿润区的1.7倍。季节性特征为冷季增温速率是暖季的1.9倍,干旱半干旱区的冷季增温速率较大,都超过了0.3℃·(10a)-1,其中青藏高原、内蒙古中部、东北和华北增温尤其显著,湿润半湿润区的冷季增温相对较慢,其中中西部地区比东部沿海增温较慢。干旱半干旱区的冷季温度在1986年左右发生显著暖突变,突变前后的大气环流对比分析表明,极涡强度减弱、东亚大槽和欧洲浅槽变浅、极地冷高压和西伯利亚高压偏弱、气旋性异常环流和东部地区的异常东南气流都有利于干旱半干旱区冷季的快速增温。     

前期东部高温干旱 后期南方暴雨频繁

本月,上旬我国西部地区低温多雨,东部地区高温干旱;自中旬起,雨区向东推移,江淮及长江中下游等地连降暴雨;下旬北方也普降喜雨,旱情得以缓解。 月内共有两个台风生成。 天气概况 本月的降水量,江南和华南一般有200—300mm,山东西南部、河北南部、山西中部和南部、河南北部、关中、内蒙西部和西北地区西部一般不足50mm,其余大部地区月降水量50—200mm。与常年同期比较,东北地区东南部、嫩江平原、北京、天津、河北北部、山西北部、黄河中上游和长江中下游等地较常年同期偏多5成至3倍。内蒙西部、甘肃北部、新疆南部、山西中部、河南东部、浙江西部和四川盆地较常年同期偏少5成以上,其余地区接近常年同期(图1)。     

海安县优质弱筋小麦气候区划研究

本文利用海安县及周边6个基本台站(27个自动站)1990—2009年气象资料,通过对海安县农业气候资源和小麦生产气候条件的调查分析,在地理信息系统平台的支持下,采用样条函数法对气候因子和区划因子进行网格细化,运用综合评价法对海安县优质弱筋小麦种植实现基于小网格的气候适宜性区划,分为最佳种植区和适宜种植区,结果显示:海安中西部地区为优质弱筋小麦最佳种植区,东部沿海为适宜种植区。这为开发和利用海安县农业气候资源、高质高效生产种植弱筋小麦提供科学依据。     

海安县优质弱筋小麦气候区划研究

本文利用海安县及周边6个基本台站(27个自动站)1990—2009年气象资料,通过对海安县农业气候资源和小麦生产气候条件的调查分析,在地理信息系统平台的支持下,采用样条函数法对气候因子和区划因子进行网格细化,运用综合评价法对海安县优质弱筋小麦种植实现基于小网格的气候适宜性区划,分为最佳种植区和适宜种植区,结果显示:海安中西部地区为优质弱筋小麦最佳种植区,东部沿海为适宜种植区。这为开发和利用海安县农业气候资源、高质高效生产种植弱筋小麦提供科学依据。     

2004年春季我区气候影响评价

春季冷、暖空气交替明显，气温变幅较大．春末全区大部地区气温下降，局部地区气温出现历史同期最低值，部分地区为次低值。前期中西部及东部偏南地区降水偏少，东部偏北地区偏多；后期中西部大部地区降水偏多，特别是偏南地区雨量偏大，而东部大部地区偏少，旱情严重。全区霜冻、干旱灾害较往     

西南地区1971—2012年干旱变化特征分析

利用西南地区378个气象观测站1971—2012年逐月降水量和气温资料,计算标准化降水蒸散指数（SPEI）,分析西南地区干旱气候及气候变化特征,结果表明：1971—2012年西南地区干旱强度中部最高,西部次之,东部最低;干旱强度增强,中部地区干旱强度增强最为显著,东部地区干旱强度增强趋势明显强于西部地区;干旱面积明显增大,干旱面积比率线性趋势率为（47%）/10 a,2000年以后该地区干旱发生范围增大最为明显;干旱持续时间中西部长、东部短,随时间变化呈明显上升趋势,中部地区增长最明显,东部次之,而北部减少。总之1971—2012年西南地区干旱强度增强,干旱面积增大,持续时间增长,中部地区干旱化最为明显,其次为东部地区。     

河西走廊东部防御干旱的农业种植决策分析

河西走廊东部气候干旱,给农业生产带来许多困难,严重影响了农业经济的发展。为了趋利避害,减少损失,获得较大收益,本文对河西走廊东部干旱的农业气候特征、危害农怍物时段和发生机率作了一些分析,并提出防御干旱的农业种植决策。一、河西走廊东部干旱的农业气候特征河西走廊东部干旱气候的主要特征是降水稀少,分布不均。川区年平均降水量在110—210毫米左右,作物生长季(3—9     

哈密地区农作物生长季节主要气象灾害及防御对策

一、哈密地区的农业气候特点及作物布局哈密位于新疆东部,地处欧亚大陆腹地,属温带干旱气候.由于天山山脉横贯东西,构成地区南北气候差异明显.天山北部的巴里坤广大山间盆地,属中温带干旱区,四季不分明,只有冷暖季节之分,暖季气候温凉;无霜期较短,降水比南部平原偏多,光照较充足;种植以春小麦为主,豌豆、油菜、马铃薯为辅的喜凉性作物,一年一熟,是哈密粮食生产的主要基地.南部盆     

新疆气候对地表水资源影响的区域差异性初探

利用单相关、典型相关及逐步回归方法, 分析了新疆气候对地表水资源影响的区域差异性, 得到以下几点新认识:(1) 新疆气候对地表水资源时空变化的影响, 以北疆为最大, 东疆最小, 南疆居中。(2) 揭示了北疆、东疆、南疆气候场对其地表水资源场空间分布特征的主要影响形式。(3) 发现在北疆及东疆, 水文年降水是决定其地表水资源场时空分布特征的主导气候因子, 5~9月平均温度是辅助气候因子, 它通过影响蒸发对地表水资源起减少作用, 但在东疆5~9月平均温度对其地表水资源的影响要比北疆大些。南疆5~9月平均温度是决定其地表水资源场时空分布特征的主导气候因子, 高山区前2年的水文年降水为辅助气候因子, 它通过冰川融水的形式对当年的地表水资源起增加作用。     

Temporal change of climate zones in China in the context of climate warming

In China, ten climate types were classified using the K-means cluster analysis based on monthly temperature and precipitation data from 753 national meteorological stations for the period 1966–2005. However, 11 mountain climate stations, which are located in southeast China, were classified as one type due to their distinct climate characteristic that differentiated them from other stations. This type could not represent the climate characteristic of this region because all climate stations in this type were located at high-elevation mountains. Thus, it was eliminated when defining climate zones based on climate types. Therefore, nine climate zones were defined in China. Moreover, the temporal change of climate zones was detected in 20-year intervals (1966–1985 and 1986–2005). Although 48 stations changed their climate zones between these two periods, the whole pattern of all climate zones remained stable in these two periods. However, the boundaries between some climate zones changed slightly due to inconsistent variation of regional temperature and precipitation. The most obvious change was the eastern movement of the boundary between an arid temperate zone and a sub-humid temperate zone. There was also a northern shift of the boundary between a tropic zone and a southern subtropic zone. All these changes were probably connected with the climate change in recent 40 years.     

甘肃省干旱气候变化及其对西部大开发的影响

利用历史文献及有器测以来的甘肃省气象,水文.卫星遥感资料,对全省历史气候背景作了分析,特别是对近70年气候变化和2000年干旱气候特征进行了系统研究.在此基础上提出了干旱气候变化对西部大开发的影响,重点讨论了对甘肃农业、水资源的影响,进而指出需要思考的问题及相应的对策.     

Fluctuations of the Semi-Arid Zone in China, and Consequences for Society

Herein, we calculate an aridity index, D, based on annual precipitation, P, and measured evaporation, PET, from φ20 evaporation pans: D = P/PET. The data were collected between 1951 and 1999 at 295 meteorological stations operated by the Chinese Meteorological Administration. On the basis of the index, three climatic regions are recognized in China: an arid zone in which D ≤ 0.20, a semi-arid zone with 0.20 < D ≤ 0.50, and a humid zone in which D > 0.50. Temporal fluctuations of the climate boundaries are substantial, and differ significantly regionally, and have the shifting features in the same direction in some areas and in opposite directions in others over the past 50 years. The semiarid zone lies along the border of the monsoon, and is thus highly susceptible to environmental change in China. In the period from the late 1960s to the early 1970s, the climate became drier in most parts of the regions of northern China. Moreover, the drought has an increasing trend. The fluctuations of climatic boundaries and the alternation from drier to wetter climate have substantial inter-decadal features. The main factors affecting the fluctuations in climate boundaries are the East Asian summer monsoon, the Indian Monsoon, the plateau monsoon in Tibetan Plateau, the westerly circulation, and the West Pacific Subtropical High. The different types of circulation and the strength of these circulations result in regional and temporal differences in aridity. Inter-decadal variations of the dry- and wet climate boundary fluctuations and of the arid and humid climate result from the inter-decadal changes of East Asian summer monsoon, Indian Monsoon, plateau monsoon, westerly circulation, and West Pacific Subtropical High. The anomalous general atmospheric circulation in the Northern Hemisphere during the late 1960s to the early 1970s is the cause of the remarkable change in arid and humid climate in China. Major natural disasters produced by arid and humid change are drought and flood disasters. They cause enormous economic losses to agriculture and industry. Furthermore, the loss has a substantial increasing trend. More than 110 cities are in severe water-deficiency conditions because of shortage of water resource in China. Drought has been a limiting factor of economic and social development in China.     

中国生态脆弱区高温热浪和干旱历史变化特征分析北大核心CSCD

高温热浪和干旱是影响陆地生态系统最主要的极端天气气候事件。已有关于中国高温热浪和干旱历史变化的定量研究主要针对全国范围、地理分区或单一区域,对于我国生态脆弱区相关极端事件的历史变化特征尚不清楚。本文利用中国CN05.1格点化观测数据集中的日最高气温观测资料和全球逐月标准化降水蒸发指数格点数据,分析了中国典型生态脆弱区1980~2014年发生的高温热浪和干旱的时空变化特征。结果表明:1980~2014年中国生态脆弱区的年高温日数和热浪次数整体呈增加趋势,两者变化趋势的空间分布类似。在空间分布上,高温热浪显著增加的区域主要位于北方生态脆弱区的中部和西部以及南方生态脆弱区的东部。其中,高温热浪增长显著的面积比率在西南岩溶山地石漠化脆弱区最高,在南方农牧脆弱区最低。区域平均来看,除南方农牧脆弱区较少发生高温热浪外,各脆弱区高温日数和热浪次数均呈现增加趋势,且除北方农牧林草区外,其余脆弱区增加趋势显著。北方生态脆弱区高温和热浪的发生频率和年际变化在20世纪90年代中期起均迅速增加。此外,中国生态脆弱区东部多呈现变干趋势且中等和极端干旱发生月数增多,其余地区则多变湿且极端干旱发生月数减少;区域平均来看,除西南岩溶山地石漠化脆弱区区域平均的干旱发生月数呈现显著增加趋势以外,其他区域的干湿和干旱发生月数的变化趋势小且不显著。     

Climate change and human activities: a case study in Xinjiang, China

We examined both long-term climate variability and anthropogenic contributions to current climate change for Xinjiang province of northwest China. Xinjiang encompasses several mountain ranges and inter-mountain basins and is comprised of a northern semiarid region and a more arid southern region. Climate over the last three centuries was reconstructed from tree rings and temperature series were calculated for the past 50 years using weather station data. Three major conclusions from these analyses are: (1) Although temperature varied considerably in Xinjiang over the last 200 years, it was non-directional until the last 50 years when a substantial warming trend occurred; (2) The semiarid North Xinjiang was representative of the northern hemisphere climate, while the more arid South Xinjiang resembled the southern hemisphere climate, meanwhile, (3) The entire Xinjiang province captured the global-scale climate signal. We also compared human contributions to global change between North and South Xinjiang, including land cover/land use, population, and greenhouse gas production. For both regions, urban areas acted as heat islands; and large areas of grassland and forest were converted to barren land, especially in North Xinjiang. Additionally, North Xinjiang also showed larger increase in population and greenhouse gas emissions mainly associated with animal production than those in South Xinjiang. Although Xinjiang province is a geographically coupled mountain–basin system, the two regions have distinct climate patterns and anthropogenic activities related to land cover conversion and greenhouse gas production.     

Regionalization-based spatiotemporal variations of precipitation regimes across China

Daily precipitation data from 595 stations are analyzed based on regionalization to investigate changing properties of precipitation regimes across the entire China. The results indicate that the northwestern China is characterized by increasing monthly precipitation. The abrupt increase of precipitation is after early 1980s and early 1990s in the western arid zone and Qinghai-Tibet plateau, respectively. Other climate zones are dominated by decreasing precipitation regimes in autumn and increasing precipitation regimes in winter, and it is particularly true in the southwestern, southern and central China, showing seasonal shifts of precipitation changes. Besides, weak precipitation regimes are decreasing and strong precipitation regimes are increasing, and it is particularly the case in the southwestern, southern and central China, implying intensifying hydrological cycle reflected by precipitation changes in these regions. This study steps further into different hydrological responses within different regions of China to climate changes and will be relevant in regional management of agriculture development and water resources.     

Predicting climate change effects on agriculture from ecological niche modeling: who profits, who loses?

The susceptibility of agriculture to changing environmental conditions is arguably the most dangerous short-term consequence of climate change, and predictions on the geography of changes will be useful for implementing mitigation strategies. Ecological niche modeling (ENM) is a technique used to relate presence records of species to environmental variables. By extrapolation, ENM maps the suitability of a landscape for the species in question. Recently, ENM was successfully applied to predict the geographic distribution of agriculture. Using climate and soil conditions as predictor variables, agricultural suitability was mapped across the Old World. Here, I present analogous ENM-based maps of the suitability for agriculture under climate change scenarios for the year 2050. Deviations of predicted scenarios from a current conditions model were analyzed by (1) comparing relative average change across regions, and (2) by relating country-wide changes to the data indicative of the wealth of nations. The findings indicate that different regions vary considerably in whether they win or lose in agricultural suitability, even if average change across the entire study region is small. A positive relationship between the wealth of nations and change in agriculture conditions was found, but variability around this trend was high. Parts of Africa, Europe and southern and eastern Asia were predicted to be particularly negatively affected, while north-eastern Europe, among other regions, can expect more favorable conditions for agriculture. The results are presented as an independent “second opinion” to previously published, more complex forecasts on agricultural productivity and food supply variability due to climatic change, which were based on fitting environmental variables to yield statistics.     

中国不同气候区的高温危险性分析

高温危险性评价是高温灾害风险评价的重要组成部分和基础工作。基于过去60年(1961—2020年)的日最高温度数据,选择高温日数、最高温度、高温强度三个指标,逐站点使用核密度函数估算三个高温指标的概率密度函数,计算了四个重现期(即五年一遇、十年一遇、二十年一遇和五十年一遇)下的三个指标的取值,进而通过K-means非监督聚类得到各指标下的高温危险性等级分布图,然后将各指标叠加,对我国不同气候区的综合高温危险性进行了评估。研究表明：(1)从高温日数来看,发生高温可能性最大的地区位于我国西北干旱(半干旱)区和华中、华南地区的交界部分;(2)从最高温度来看,发生高温可能性最大的区域是西北干旱(半干旱)区和华北地区,华中地区的最高温度在不同重现期下的增强最显著;(3)从高温强度来看,发生高温可能性最大的区域是西北干旱(半干旱)区,西南地区和青藏高原地区内不同区域的高温强度差异较大,需局部防范高温灾害;(4)随着重现期年限的增长,不同高温指标值均明显增长,高值区域面积逐渐增加。全国高温综合高危险性等级地区主要位于西北干旱(半干旱)地区、华北地区南部、华中地区、华南地区和西南地区北部,其余气候区少量...     

The potential effects of climate change on ecosystem processes and cattle production on U.S. rangelands

In spite of the uncertainties of potential climate change, a scientific consensus is emerging that increasing concentrations of atmospheric CO₂ could alter global temperatures and precipitation patterns. Changes in global climate as predicted by General Circulation Models (GCM) could therefore, have profound implications for global agriculture. The objective of this study was to assess the impacts of potential climate change on livestock and grassland production in the major producing regions of the United States. Simulation sites were selected for the study on the basis of the region's economic dependence on rangeland livestock production. Five thirty-year simulations were conducted on each site using the Simulation of Production and Utilization of Rangelands model and Colorado Beef Cattle Production Model. Climate change files were obtained by combining historic weather data from each site with predicted output from three GCM's. Results from nominal runs were compared with the three climate change scenarios and a doubled CO₂ run. The magnitude and direction of ecosystem response to climate change varied among the GCM's and by geographic region. Simulations demonstrated that changes in temperature and precipitation patterns caused an increase in above-ground net primary production for most sites. Increased decomposition rates were recorded for northern regions. Similarly, animal production in northern regions increased, implying an increase in economic survivability. However, because decreases in animal production indicators were recorded for the southern regions, economic survivability in southern regions is less certain.