广西近50年来气温、降水气候变化

采用广西1958～2005年的气温、降水资料，运用统计方法，分析了全区近50a来的年平均气温、最高气温、最低气温、四季平均气温和年、汛期降水量的分布特点及变化趋势。结果显示，近50a来，广西年及春、秋两季平均气温和最低气温呈明显偏高趋势，年最高气温、夏、冬两季平均气温及年降水、汛期降水变化较平稳。     

The Spatial Variation of LURR and Seismic Tendency in Western United States

INTRODUCTIONThe Load-Unload Response Ratio(LURR)is a new promising method for medium-termearthquake prediction put forward by Yin,X.C.(Yin,1987;Yin,and Yin,1991;Yin,et al.,1994;2000).In recent years,by this method,a lot of strong earthquakes have been suc…     

华北地区未来强震概率统计分析

应用泊松模型的极值分布对华北地区的地震活动趋势进行估计和分析，结果表明，2008年前华北地区发生6级以上地震的危险性较大；2005年地震活动短期内可能还会持续目前较弱的态势，但未来1～2年内华北地区地震活动很有可能明显增强。     

黄河流域分区天然径流量趋势性与持续性特征

水资源具有趋势性和持续性特征。利用Kendall秩次相关和Hurst指数分别分析了黄河流域15个分区1951-1998年天然径流量的趋势性和持续性特征，结果显示：黄河流域15个分区天然径流量的趋势性和持续性各不相同；对黄河流域而言，年径流量与汛期径流量都通过了显著性检验，且呈下降趋势，并具有一定的持续性。     

基于多时相卫星图像的稀土矿开发变化检测

利用研究区1999年ETM+和2005年SPOT图像对稀土矿区进行遥感变化检测。引入散点控制回归方法对图像进行辐射归一化处理,选用分类后对比检测法生成类别变化转移矩阵,确定了矿区面积增加的来源和新增矿区的分布范围,达到了预期效果。     

Deforestation-induced costs on the drinking water supplies of the Mumbai metropolitan,India

The success of incorporating natural capital into resource- and land-use decisions hinges on the ability to quantify the ecosystem services, forecast the returns to the investments, convert these values into effective policy and finance mechanisms, and the presence of well-functioning institutions and infrastructure. However, ecosystem production functions i.e., the relationship between regulatory functions of the ecosystem and the economic activity it protects or supports are often poorly understood. Even with respect to Forest Watershed Services – a service that is widely recognized and even institutionalized through market based mechanisms in some parts of the world – the biophysical relationships between forests and services such as stream flow stabilization, water quality and water quantity are undefined, particularly for the tropics. For this reason, this study through time series data and multivariate analysis characterizes the relationships between Forest Cover (all lands with tree cover of a canopy density of 10% and above when projected vertically on the horizontal ground with minimum areal extent of 1 ha), water quality and cost of water treatment in the Western Ghats of peninsular India. In particular, the recursive relationship between the economic and environmental components is estimated by tracing the effects through the two-stage model. Annual value of impacts (increased ‘treatment cost’, increased ‘water losses due to backwash and desludging’, and changes in ‘water yield’) induced by loss of Forest Cover is estimated as 64.96 Indian rupee/m³ treated water/ha/year ($1.32/m³ treated water/ha/year). At an annual rate of change in the forest cover by −0.0088% (average annual rate of change in the forest cover between the years 1994–2007) the deforestation induced costs translate to 3.73 million Indian rupee/year ($0.075 million/year) according to the 2010–2011 prices for the Panjrapur treatment plant of the Municipal Corporation of Greater Mumbai. Thus, if deforestation is avoided the Municipal Corporation can save significant amount towards recurring costs of water treatment and to some extent mitigate the costs for the development of a new source.     

1992—2012杭州湾海域生物多样性的变化趋势及原因分析

本文依据浙江省舟山海洋生态环境监测站(1992—2012年)20年的杭州湾生态环境质量监测数据,对杭州湾海洋生物多样性的现状及发展趋势进行了分析,并结合环境因子对生物多样性的变化原因进行了探讨。结果表明:杭州湾海域生物生存环境较为恶劣,生物多样性较低,生物群落结构简单,种类较少。20年间,杭州湾海域生物多样性的变化可大体分为2个阶段,第一阶段是20世纪90年代初至2000年,杭州湾生物群落的各项指标普遍呈现下降的趋势;第二阶段是2000年后至今,由于各项生态环境保护措施加强,杭州湾生物群落得到一定程度的恢复。相关性分析表明,DIN、DIP、COD和富营养化对杭州湾海域生物多样性产生了显著的影响。20年来杭州湾海域生物多样性的变化主要受人类活动的影响,污水排放导致的富营养化对生物多样性的丧失也有很大影响,滩涂围垦等沿海开发使海洋生物栖息地片段化,单调化,加速了生物多样性的降低。     

Recent changes in ground surface thermal regimes in the context of air temperature warming over the Heihe River Basin, China

Changes in ground surface thermal regimes play a vital role in surface and subsurface hydrology, ecosystem diversity and productivity, and global thermal, water and carbon budgets as well as climate change. Estimating spring, summer, autumn and winter air temperatures and mean annual air temperature（MAAT） from 1960 through 2008 over the Heihe River Basin reveals a statistically significant trend of 0.31 °C/decade, 0.28 °C/decade, 0.37 °C/decade, 0.50 °C/decade, and 0.37 °C /decade, respectively. The averaged time series of mean annual ground surface temperature（MAGST） and maximum annual ground surface temperature（MaxAGST） for 1972–2006 over the basin indicates a statistically significant trend of 0.58 °C/decade and 1.27 °C/decade, respectively. The minimum annual ground surface temperature（MinAGST） in the same period remains unchanged as a whole. Estimating surface freezing/thawing index as well as the ratio of freezing index to thawing index（RFT） in the period between 1959 and 2006 over the basin indicates a statistically significant trend of-42.5 °C-day/decade, 85.4 °C-day/decade and-0.018/decade, respectively.     

On quantifying post-classification subpixel landcover changes

The post-classifications change matrix is well defined for hard classifications. However, for soft classifications, where partial membership of pixels to landcover classes is allowed, there is no single definition for such a matrix. In this paper, we argue that a natural definition of the post-classification change matrix for subpixel classifications can be done in terms of a constrained optimization problem, according to which the change matrix should allow an optimal prediction of the subpixel landcover fractions at the latest date from those of the earliest date. We first show that the traditional change matrix for crisp classification corresponds to the optimal solution of the unconstrained problem. Then, the formulation is generalized for subpixel classifications by incorporating certain constraints pertaining to desirable properties of a change matrix, thus resulting in a constrained least square (CLS) change matrix. In addition, based on intuitive criteria, a generalized product (GPROD) was parameterized in terms of an exponent parameter and used to derive another change matrix. It was shown that when the exponent parameter of the GPROD operator tends to infinity, one of the most commonly used methods for map comparison from subpixel fractions, namely the MINPROD composite operator, results. The three matrices (CLS, GPROD and MINPROD) were tested on both simulated and real subpixel changes derived from QuickBird and Landsat TM images. Results indicated that, for small exponent values (0–0.5), the GPROD matrix yielded the lowest errors of estimated landcover changes, whereas the MINPROD generally yielded the highest errors for the same estimations.     

乌鲁木齐市寒潮气候特征分析

摘要：利用1961-2014年乌鲁木齐市4个气象站资料,分析了近53a乌鲁木齐市的寒潮气候特征。结果表明：乌鲁木齐市单站寒潮特征地域差异较大,寒潮频次由南部山区向北部平原逐渐减少;平均初寒潮日由南向北逐渐推迟,终寒潮日则相反;城区春季寒潮最多,山区为秋季、谷地和平原则冬季最多;强寒潮及特强寒潮出现比例城区最大。乌鲁木齐市区域寒潮平均每年4.0次,出现在当年9月至次年5月,其中4月最多,区域强寒潮和特强寒潮春季发生频次最多。近53a来区域寒潮以0.3次/10a的速率递减,并在1976年发生了由多向少的突变,寒潮变化与气温、风速之间具有较好的相关性。