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1.
The Beautiful China Initiative(BCI)is a plan for the sustainable development of the Chinese nation as well as for China to fulfill the United Nations’2030 Agenda for Sustainable Development.The Chinese government’s“five-in-one”approach provides strategic arrangements for developing the BCI,and President Xi Jinping proposed a timetable and“road map”for the BCI at the National Conference on Ecological and Environmental Protection.Nevertheless,the theoretical basis,evaluation index system,evaluation criteria and effectiveness of the BCI are currently unclear.This paper begins by exploring the basic content of the BCI from narrow and broad perspectives.It regards the theory of human-nature harmonious coexistence and the five-in-one beauty theory as the core theoretical bases of the BCI and constructs a five-element BCI evaluation index system(ecological environment,green development,social harmony,system perfection and cultural heritage)and utilizes the assessment method of the United Nations’Human Development Index to assess scientifically the effectiveness of the BCI in 341 prefecture-level cities.The results show the average BCI index(the Chinese Academy of Sciences Beauty Index)score to be 0.28,which is quite low,while the average scores for the individual element indexes of the ecological environment index,green development index,social harmony index,system perfection index and cultural heritage index are 0.6,0.22,0.29,0.22 and 0.07,respectively.All of these are relatively low values,with relatively large discrepancies in regional development,indicating that progress in the BCI is generally slow and unbalanced.To realize the BCI’s timetable and roadmap to a high quality and high standard,it is suggested that a common system for evaluating the progress of the BCI is developed and promulgated so that dynamic monitoring and phased evaluations can take place;BCI technical assessment standards are compiled and published;BCI comprehensive zoning is undertaken;pilot projects adapted to local conditions are launched in BCI sample areas;and BCI results are incorporated into performance indicators at all levels of government. 相似文献
2.
Demand for food plays an important role in the adjustment of prices for agricultural products and for adjusting agricultural structure.By using the extended linear expenditure system(ELES),we analyzed the food consumption structure of rural residents in the Ganzhou district of Zhangye city,and determined the basic food-consumption demand,the marginal propensity of consumption,the income elasticities of demand,and the own-price and cross-price elasticities of local rural residents,all of which illustrate the influencing factors on food consumption of rural residents and for forecasting the food-consumption structure.Those analyses show the following:the rural residents’ expenditure on household basic food consumption reaches about 7,050.35 Yuan;the marginal propensities of consumption of fruits and vegetables are relatively high(0.062 and 0.106,respectively),followed by meat(0.044);the demands for various foods are increasing as income increases,with the largest income elasticity of demand corresponding to fruits(1.354) and the lowest to cereal(0.310);fruits and vegetables have relatively high own-price elasticities(respectively-0.879 and-0.442),with the cereal having the lowest one(-0.184).An increase in cereal prices would greatly affect demand for other products;with the rising size of rural households,the consumption for meat is decreasing whereas it is increasing for cereal.The improvement of household education levels will lead to the increase of fruit consumption(E = 0.297),which indicates that people will pay more attention to diet and nutrition structure with the improvement of education.Further,although the amount of cereal expenditure is continually growing,the share will be declining with the increase of household income in 2006-2012.For all these reasons,therefore,the government should encourage the cultivation of economic crops and guide the development of stockbreeding to ensure the stability of cereal output.In order to attain the balance between supply and demand,it is important to rationally a 相似文献
3.
Plant moisture content(PMC) is used as an indicator of forest flammability, which is assumed to be affected by climate drought. However, the fire-induced drought stress on PMC and its spatial and temporal variations are unclear. Based on a parallel monitoring experiment from 2014 to 2015, this study compared the PMCs and soil moisture contents(SMC) at five post-fire sites in central Yunnan Plateau, Southwest China. The number of years since last fire(YSF), season, topographic position, plant species and tissue type(leaf and branch) were selected as causal factors of the variations in PMC and SMC. A whole year parallel monitoring and sampling in the post-fire communities of 1, 2, 5, 11 and 30 YSF indicated that drought stress in surface soils was the strongest in spring within the first 5 years after burning, and the SMC was regulated by topography, with 64.6% variation in soil moisture accounted for by YSF(25.7%), slope position(22.1%) and season(10.8%). The temporal variations of PMC and SMC differed at both interannual and seasonal scales, but the patterns were consistent across topographic positions. PMC differed significantly between leaves and branches, and among three growth-forms. The mean PMC was lower in broad-leaved evergreen species and higher in conifer species. Season and soil temperature were the primary determinants of PMC, accounting for 19.1% and 8.3% of variation in PMC, respectively. This indicated phenology-related growth rather than drought stress in soil as the primary driver of seasonal changes in PMC. The significant variations of PMC among growth forms and species revealed that seasonal soil temperature change and dominant species in forest communities are useful indicators of fire risk assessment in this region. 相似文献
4.
基于垂直带谱的南北过渡带1:5万植被类型图遥感制图研究——以太白山为例 总被引：2，自引：1，他引：1
The compilation of 1:250,000 vegetation type map in the North-South transitional zone and 1:50,000 vegetation type maps in typical mountainous areas is one of the main tasks of Integrated Scientific Investigation of the North-South Transitional Zone of China.In the past,vegetation type maps were compiled by a large number of ground field surveys.Although the field survey method is accurate,it is not only time-consuming,but also only covers a small area due to the limitations of physical environment conditions.Remote sensing data can make up for the limitation of field survey because of its full coverage.However,there are still some difficulties and bottlenecks in the extraction of remote sensing information of vegetation types,especially in the automatic extraction.As an example of the compilation of 1:50,000 vegetation type map,this paper explores and studies the remote sensing extraction and mapping methods of vegetation type with medium and large scales based on mountain altitudinal belts of Taibai Mountain,using multi-temporal high resolution remote sensing data,ground survey data,previous vegetation type map and forest survey data.The results show that:1)mountain altitudinal belts can effectively support remote sensing classification and mapping of 1:50,000 vegetation type map in mountain areas.Terrain constraint factors with mountain altitudinal belt information can be generated by mountain altitudinal belts and 1:10,000 Digital Surface Model(DSM)data of Taibai Mountain.Combining the terrain constraint factors with multi-temporal and high-resolution remote sensing data,ground survey data and previous small-scale vegetation type map data,the vegetation types at all levels can be extracted effectively.2)The basic remote sensing interpretation and mapping process for typical mountains is interpretation of vegetation type-groups→interpretation of vegetation formation groups,formations and subformations→interpretation and classification of vegetation types&subtypes,which is a combination method of top-down method and bottom-up method,not the top-down or the bottom-up classification according to the level of mapping units.The results of this study provide a demonstration and scientific basis for the compilation of large and medium scale vegetation type maps. 相似文献
5.
Urban resilience is an emerging research topic of urban studies, and its essence is described by the ability of cities to resist, recover, and adapt to uncertain disturbances. This paper constructs a "Size-Density-Morphology" urban ecological resilience evaluation system, uses a coupling coordination degree model to measure the degree of coupling coordination between urbanization and ecological resilience in the Pearl River Delta from 2000 to 2015, and conducts an in-depth discussion on its spatiotemporal characteristics. The results show the following.(1) From 2000 to 2015, the urbanization level of cities in the study area generally increased while the level of ecological resilience declined. The coupling coordination degree between the two systems decreased from basic coordination to basic imbalance.(2) In terms of spatial distribution, the coupling coordination degree between urbanization and ecological resilience of cities presented a circular pattern that centered on the cities at the estuary of the Pearl River and increased toward the periphery.(3) Ecological resilience sub-systems played variable roles in the coupling coordination between urbanization and ecological resilience. Specifically, size resilience mainly played a reverse blocking role;the influence of morphology resilience was generally positive and continued to increase over time;the effect of density resilience was positive and continued to decline and further became negative after falling below zero. The main pathways for achieving coordinated and sustainable development of future urbanization and ecological resilience in the Pearl River Delta include: leading the coordinated development of regions with new urbanization, improving ecological resilience by strictly observing the three areas and three lines, adapting to ecological carrying capacity, and rationally arranging urban green spaces. 相似文献
6.
The Yangtze River Delta(YRD) is a region in China with a serious contradiction between economic growth and environmental pollution. Exploring the spatiotemporal effects and influencing factors of air pollution in the region is highly important for formulating policies to promote the high-quality development of urban industries. This study uses the spatial Durbin model(SDM) to analyze the local direct and spatial spillover effects of industrial transformation on air pollution and quantifies the contribution of each factor. From 2008 to 2018, there was a significant spatial agglomeration of industrial sulfur dioxide emissions(ISDE) in the YRD, and every 1% increase in ISDE led to a synchronous increase of 0.603% in the ISDE in adjacent cities. The industrial scale index(ISCI) and industrial structure index(ISTI), as the core factors of industrial transformation, significantly affect the emissions of sulfur dioxide in the YRD, and the elastic coefficients are 0.677 and-0.368, respectively. The order of the direct effect of the explanatory variables on local ISDE is ISCI>ISTI>foreign direct investment(FDI)>enterprise technological innovation(ETI)>environmental regulation(ER)> per capita GDP(PGDP). Similarly, the order of the spatial spillover effect of all variables on ISDE in adjacent cities is ISCI>PGDP>FDI>ETI>ISTI>ER, and the coefficients of the ISCI and ISTI are 1.531 and 0.113, respectively. This study contributes to the existing research that verifies the environmental Kuznets curve in the YRD, denies the pollution heaven hypothesis, indicates the Porter hypothesis, and provides empirical evidence for the formation mechanism of regional environmental pollution from a spatial spillover perspective. 相似文献
7.
Spatiotemporal evolution of urban carbon emission performance in China and prediction of future trends 总被引：1，自引：1，他引：0
Climate change resulting from CO_2 emissions has become an important global environmental issue in recent years.Improving carbon emission performance is one way to reduce carbon emissions.Although carbon emission performance has been discussed at the national and industrial levels,city-level studies are lacking due to the limited availability of statistics on energy consumption.In this study,based on city-level remote sensing data on carbon emissions in China from 1992–2013,we used the slacks-based measure of super-efficiency to evaluate urban carbon emission performance.The traditional Markov probability transfer matrix and spatial Markov probability transfer matrix were constructed to explore the spatiotemporal evolution of urban carbon emission performance in China for the first time and predict long-term trends in carbon emission performance.The results show that urban carbon emission performance in China steadily increased during the study period with some fluctuations.However,the overall level of carbon emission performance remains low,indicating great potential for improvements in energy conservation and emission reduction.The spatial pattern of urban carbon emission performance in China can be described as"high in the south and low in the north,"and significant differences in carbon emission performance were found between cities.The spatial Markov probabilistic transfer matrix results indicate that the transfer of carbon emission performance in Chinese cities is stable,resulting in a"club convergence"phenomenon.Furthermore,neighborhood backgrounds play an important role in the transfer between carbon emission performance types.Based on the prediction of long-term trends in carbon emission performance,carbon emission performance is expected to improve gradually over time.Therefore,China should continue to strengthen research and development aimed at improving urban carbon emission performance and achieving the national energy conservation and emission reduction goals.Meanwhile,neighboring cities with different neighborhood backgrounds should pursue cooperative economic strategies that balance economic growth,energy conservation,and emission reductions to realize low-carbon construction and sustainable development. 相似文献
8.
The Yangtze River Watershed in China is a climate change hotspot featuring strong spatial and temporal variability;hence, it poses a certain threat to social development. Identifying the characteristics of and regions vulnerable to climate change is significantly important for formulating adaptive countermeasures. However, with regard to the Yangtze River Watershed, there is currently a lack of research on these aspects from the perspective of natural and anthropogenic factors. To address this issue, in this study, based on the temperature and precipitation records from 717 meteorological stations, the RClim Dex and random forest models were used to assess the spatiotemporal characteristics of climate change and identify mainly the natural and anthropogenic factors influencing climate change hotspots in the Yangtze River Watershed for the period 1958-2017. The results indicated a significant increasing trend in temperature, a trend of wet and dry polarization in the annual precipitation, and that the number of temperature indices with significant variations was 2.8 times greater than that of precipitation indices. Significant differences were also noted in the responses of the climate change characteristics of the sub-basins to anthropogenic and natural factors;the delta plain of the Yangtze River estuary exhibited the most significant climate changes, where 88.89% of the extreme climate indices varied considerably. Furthermore, the characteristics that were similar among the identified hotpots, including human activities(higher Gross Domestic Product and construction land proportions) and natural factors(high altitudes and large proportions of grassland and water bodies), were positively correlated with the rapid climate warming. 相似文献
9.
Protected areas have a double mandate of both "protection" and "use." Naturebased tourism is considered an effective tool in terms of environmental conservation. Understanding the causes and consequences of a spatiotemporal succession of tourism construction is an important channel to explore the changes of tourism-environment interaction in the protected area. To analyze the spatio-temporal variations in tourism construction lands, we adopted Mt. Bogda as an example. We systematically quantified the interaction between these changes and environmental variables and explored the evolution process of tourism-environment interaction of the mountainous protected area in the northwest arid region. Our results revealed the following:(1) In the Bogda protected area, the proportion of tourism construction lands first appeared to be increasing, then decreasing dramatically, and finally growing slowly. The spatial expansion of tourism construction lands followed the "core-periphery" pattern, respectively showing shapely infilling, reasonable agglomeration, barycenter shift, and outlying growth from 1990 to 2018 as the stages of concentrating on the core.(2) The higher land-use intensity of tourism construction drove the changes of landscape fragmentation, diversity, stability, primitive, and nature degree in the protected area. The coupling coordination between tourism and the environment in the Bogda area decreased at first, and then slowly increased. Meanwhile, tourism did not cause irreversible damage to the natural environment, and the coupling coordination degree between tourism and the environment was still in the state of balanced development. It expressed the states of original balanced, development exceeds environment and barely balanced, and superiorly balanced. The historical evolution of tourism-environment interaction in Bogda reflects the pattern of periodic changes in China’s protected areas to a certain extent. 相似文献
10.
袁钰莹 《地理学报(英文版)》2019,29(3):449-464
With basic information from 8353 archaeological sites, this study describes a holistic spatial-temporal distribution pattern of archaeological sites of the prehistoric culture sequence from 9.5 ka BP (ka BP = thousands of years before 0 BP, where "0 BP" is defined as the year AD 1950) to 2.3 ka BP in the region that extends from the Yanshan Mountains to the Liaohe River Plain(i.e., the Yan-Liao region) in northern China. Based on spatial statistics analysis – including the spatial density of the sites and Geographic Information System nearest-neighbour analysis, combined with a review of environmental and climatic data – this paper analyses cultural evolution, the spatial-temporal features of the archaeological sites and human activities against the backdrop of climatic and environmental changes in this region. The results reveal that prehistoric cultural evolution in the Yan-Liao region is extensively influenced by climatic and environmental changes. The Xinglongwa, Zhaobaogou and Fuhe cultures, which primarily developed during a habitable period from 8.5 ka BP to 6.0 ka BP with strong summer monsoons, have similar maximum density values, spatial patterns and subsistence strategies dominated by hunting-gathering. Significant changes occurred in the Hongshan and Lower Xiajiadian cultures, with a significant increase in numbers and densities of sites and a slump in average nearest-neighbour ratio when the environment began to deteriorate starting in 6.0 ka BP. Additionally, with the onset of a weak summer monsoon and the predominance of primitive agriculture, sites of these two cultures present a different type of concentric circle-shaped pattern in space. As the environment continuously deteriorated with increasing aridity and the spread of steppe, more sites were distributed towards the south, and primitive agriculture was replaced by livestock husbandry in the Upper Xiajiadian culture. The most densely populated areas of the studied cultures are centralized within a limited area. The Laohahe River and Jiaolaihe River basins formed the core area in which most archaeological sites were distributed during the strong summer monsoon period and the first few thousand years of the weak summer monsoon period. 相似文献
11.
Dryness and wetness variations on different time scales in Shanghai were analyzed using the Standardized Precipitation Index (SPI) based on monthly precipitation data for 1873–2005. The SPI on scales of 3, 6, 12 and 24 months has been calculated. The SPI on 3, 6, 12 and 24 months present 4 wet periods prevailed during 1873–1885, 1904–1923, 1938–1960 and 1983–2005, and 3 dry episodes during 1886–1903, 1924–1937 and 1961–1982. Significant periods of higher wavelet power in the SPI-24 months occurred on the time scales of 2–7-year band in around 1880–1890, 1910–1950 and 1970–1990, and at 8–15-year band in 1920–1960 and 1965–2000 respectively. Periodicities in the SOI and ENSO indices are similar to those in SPI-24 months with little difference, namely, in the SPI-24 months, there are significant periods at the 2–7- and 8–15-year bands during 1930–1940. The periodicity components in individual SPI-24 months, SOI and ENSO indices are more complicated, showing the wetness and dryness variability in Shanghai is controlled by more than one physical factors. The research results indicate that the Shanghai area has experienced dryness and wetness variability on different time scales during the past 133 years. 相似文献
12.
Dryness and wetness variations on different time scales in Shanghai were analyzed using the Standardized Precipitation Index
(SPI) based on monthly precipitation data for 1873–2005. The SPI on scales of 3, 6, 12 and 24 months has been calculated.
The SPI on 3, 6, 12 and 24 months present 4 wet periods prevailed during 1873–1885, 1904–1923, 1938–1960 and 1983–2005, and
3 dry episodes during 1886–1903, 1924–1937 and 1961–1982. Significant periods of higher wavelet power in the SPI-24 months
occurred on the time scales of 2–7-year band in around 1880–1890, 1910–1950 and 1970–1990, and at 8–15-year band in 1920–1960
and 1965–2000 respectively. Periodicities in the SOI and ENSO indices are similar to those in SPI-24 months with little difference,
namely, in the SPI-24 months, there are significant periods at the 2–7- and 8–15-year bands during 1930–1940. The periodicity
components in individual SPI-24 months, SOI and ENSO indices are more complicated, showing the wetness and dryness variability
in Shanghai is controlled by more than one physical factors. The research results indicate that the Shanghai area has experienced
dryness and wetness variability on different time scales during the past 133 years.
Foundation: Frontier Project of Nanjing Institute of Geography and Limnology, CAS, No.CXNIGLAS200814; National Forestry Science and Technique
Foundation during the 11th Five-Year Plan Period, No.2006BAD03A1601; Project of Huaihe River Basin, No.HRM200708; National
Climate Center, China Meteorological Administration, No.CCSF2007-35
Author: Zhang Zengxin (1977–), Ph.D, specialized in climatic changes. 相似文献
13.
1960—2017年中国北方气候干湿变化及其与ENSO的关系 总被引：1，自引：0，他引：1
基于中国北方424个气象站实测数据,应用FAO Penman-Monteith模型计算潜在蒸散（Potential evapotranspiration,ET0）,使用降水和潜在蒸散数据计算得到标准化降水蒸散发指数（SPEI）,以此研究了1960—2017年中国北方干湿时空变化特征,分析了ENSO对北方气候干湿变化的影响。结果表明：中国北方干湿变化的线性趋势总体不显著,四季中春季和冬季变湿趋势明显。空间上,西北西部存在明显的变湿趋势,干旱化趋势主要发生在黄土高原、内蒙古东部和东北东部地区。全区各级干旱事件呈减少趋势,各级湿润事件呈增加趋势,其中以中等干旱的减少最为显著。西北西部中等干旱和极端干旱明显减少,东北北部和新疆部分地区极端湿润明显增加。全区四季3类干旱事件均表现为减少的趋势,3类湿润事件均表现为增加的趋势,西北西部四季3类干旱事件均呈减少趋势。ENSO对北方干湿的影响存在一定程度的滞后性。El Ni?o翌年气候湿润,La Nina翌年气候干旱。在年际和春季2个尺度上,SSTA与翌年SPEI存在显著的正相关关系。 相似文献
14.
提高干旱预测精度能为流域干旱应对及风险防范提供可靠数据支撑,构建比选合适的干旱模型是当前研究的热点。研究以4个时间尺度（3、6、9、12月）标准化降水指数（SPI）为表征指标,利用小波神经网络（WNN）、支持向量回归（SVR）、随机森林（RF）三种机器学习算法分别构建了海河北系干旱预测模型,利用Kendall、K-S、MAE三种检验方法判定模型表现及其稳定性。研究表明：（1） WNN、SVR模型呈现结果在不同时间尺度SPI存在差异,WNN最适合12个月尺度SPI干旱预测;SVR最适合6个月尺度SPI干旱预测。（2） 对3、12个月尺度SPI,RF预测性能最优（Kendall>0.898,MAE<0.05）;对6、9个月尺度SPI,SVR预测性能最优（Kendall>0.95,MAE<0.04）。（3） 模型预测性能稳定性存在区别,RF预测稳定性最高,其次为SVR。（4） 构建的三种模型表现异同主要是因为SVR转为凸优化问题解决了WNN易陷入局部最优解的不足,从而提高了模型预测性能,RF集成多样化回归树,降低了弱学习器的负面影响,提高了模型预测准确率及稳定性,同时,RF处理包含噪声的降水数据的能力更强。 相似文献
15.
16.
《自然地理学》2013,34(1):76-96
Regions based on seasonal precipitation variability for Hawaii are determined using a principal components analysis applied to 124 stations for the period 1971-2000. Nine regions are delineated and are consistent with known precipitation patterns; leeward and windward stations are in separate regions on all islands. Within each region, the relationship between precipitation and the El Niño-Southern Oscillation (ENSO) is examined using a correlation analysis with the Southern Oscillation Index (SOI), and the Niño 3.4 and Niño 1+2 indices. Precipitation is most frequently correlated with ENSO in the different regions using SOI and Niño 3.4. Using several nonparametric statistical tests, it is determined that while average precipitation received in Hawaii during El Niño events is significantly different from average precipitation (1971-2000) and from precipitation received during La Niña events, the relationship between precipitation and individual ENSO events within regions is rarely significant. Finally, during El Niño or La Niña events, average precipitation receipt across the regions co-varies during winter and summer under concurrent conditions and a one-season lag. Synoptic patterns are examined and indicate a deviation from average conditions during ENSO events that affects subsidence and precipitation patterns. 相似文献
17.
淮河流域洪涝特征初步研究 总被引：20，自引：3，他引：17
本文以《中国近五百年旱涝分布图集》为基础,采用一定的洪涝指标计算方法,建立了淮河流域近500年洪涝序列。在此基础上,从统计特征、时序特征和分形特征等方面讨论了淮河流域洪涝的基本特征。分析表明,淮河流域各等级洪涝具有较高的发生频次,且具有相对集中性特点和一定的持续发生机率;淮河流域洪涝具有不同长度的阶段性或周期性,存在约460年、150年和60-80年的周期及一些更小尺度的波动;淮河流域洪涝具有一定标度范围内的统计分形特征,时间分维值随洪涝强度的增加而降低,与洪涝周期呈反相关关系。时间分维是描述洪涝特征的一个较好的物理量,可能对揭示洪涝规律和进行有效预报具有重要作用。 相似文献
18.
选取1951~2013年韶关市分月降雨量数据,采用月降雨侵蚀力模型计算降雨侵蚀力,分析ENSO（厄尔尼诺-南方涛动）对韶关市降雨侵蚀力的影响。研究表明：① 韶关市降雨侵蚀力年际变化和年内变化较大,总体呈现波动上升趋势;② 降雨侵蚀力与赤道太平洋SST距平值呈现极显著相关,降雨侵蚀力随SST距平值增加呈现先增加后递减的趋势。ENSO冷暖事件发生时降雨侵蚀力较小,在其它土壤侵蚀因素不变的条件下,此时期的土壤侵蚀相对较轻;③ 降雨侵蚀力与SOI存在显著相关,降雨侵蚀力随着SOI增加而减小;④ 降雨侵蚀力与MEI呈现极显著的正相关关系。 相似文献
19.
宁夏降水变化及其与ENSO事件的关系 总被引：21，自引：7，他引：14
分析1959~2001年的月降水数据发现:20世纪60~80年代宁夏降水有较明显的干旱趋势,但90年代降水较80年代有所增加。功率谱分析表明,ENSO和宁夏降水具有一致的变化周期,即14年、3.75年、准2年和1.5年。宁夏降水对EL Nino事件达到最显著响应需要滞后2~4个月,而对LA Nina事件的响应比对EL Nina迅速,只需滞后1~2个月便达到最显著响应。ENSO对宁夏不同季节降水的影响差异很大。EL Nino发生4个月后,春、夏、秋三个季节降水都偏少,但冬季降水却是增加了。LA Nina发生1个月后,夏、秋、冬三个季节降水都偏多,但春季降水减少了。EL Nino事件发生期间,宁夏年降水偏少28 mm,占常年降水量的10%,而LA Nina发生期间,年降水偏多24 mm,占年降水量9%。 相似文献
20.
北京地区旱涝变化规律及其预测试验 总被引：6，自引：1，他引：5
本文提出用年旱涝指数来研究气候变化规律,具有一定的物理意义及代表性。对北京地区旱涝变化规律分析表明:有5年及22年周期变化规律。 在旱涝预测方面,本文还提出一种新的时间序列预测方法——周期模式法,它较之传统的方差分析方法具有较多的优越性。用它对北京地区年度旱涝趋势作预测试验。 相似文献