基于信息融合的灌区水情预测方法研究

引入信息融合理论,通过在系统输入变量上叠加"干扰流量",基于对灌区用水模糊特征分析估计其不确定性,实现分散且孤立的实时监测数据之间的关联,使系统保持必要的信息冗余,进而实现灌区水情信息融合。该方法可用于建立具有跟踪和预测能力的灌区实时仿真系统,克服了信息融合理论用于非线性时变系统的诸多限制,扩展了信息融合理论在系统关系确定的民用领域的应用。     

土地利用及其变化对洮儿河流域中上游地区非点源污染的影响

为了评价老秃顶子自然保护区不同森林类型土壤水源涵养功能,对区内5种植被类型的土壤贮水能力与入渗特征进行了研究。结果表明,不同林型0—40cm土壤容重均值为0.76～1.71g/cm3,非毛管孔隙度均值为8.15%～22.07%,毛管孔隙度均值为27.60%～53.28%,灌木林、岳桦林、杂木林等天然次生林的土壤孔隙状况要好于落叶松人工林和红松人工林;不同林型0—40cm土壤的蓄水容量为1 429.8～2 834.3t/hm2,有效蓄容为325.9～882.7t/hm2,毛管持水量为1 103.8～2 131.0t/hm2,天然次生林土壤贮水能力相对较强;不同林型0—20cm土壤初渗率介于0.28～21.1mm/min之间,20—40cm土壤初渗率介于0.07～6.7mm/min之间,不同林型0—20cm土层稳渗率介于0.14～8.3mm/min之间,20—40cm土层稳渗率介于0.05～2.0mm/min之间,初渗率和稳渗率均表现为天然次生林高于人工林;土壤入渗速率与入渗时间存在良好的幂函数关系。     

基于分布式水文模型的嘉陵江流域氮磷非点源污染负荷预测

为研究在大尺度流域上以降雨径流为载体的非点源污染,以基于土地利用的分布式水文模型(SLURP Hydrological model)为基础,提出氮磷负荷预测模型及未来气象参数和土地利用分布图的构建方法.就嘉陵江流域土地利用、畜禽养殖和农业人口未来变化产生的总氮与总磷的月负荷量进行模拟和预测分析.结果表明,预测年降雨径流...     

河北北部二代粘虫发生的预测

根据丰南县1981～1990年粘虫田间发生的调查资料,经回报检验,10a 粘虫发生情况的回报准确率均为90%,明显高于经验预报,而且能在粘虫实际发生前1个月做出定量预报,具有较好的实用价值。     

试论农民代言人出现的背景及其对农民话语权回归的作用

介绍了在目前我国农民存在着制度缺陷型、能力欠缺型及信息断裂型话语缺失的背景下,一些非农精英人士自觉自愿承担起农民代言人的角色,为推动"三农"问题的解决发挥了巨大的作用。并提出农民代言人的终极使命应该是帮助农民完全掌握与其他阶层平等的话语权,实现从"代农民言"到"农民自己言"的转变。     

底层土对一年生苹果树生长发育的影响

一年生苹果树枝年生长量与表层根生长量相关显著，底层土肥沃疏松，植株生长中庸健壮，碳素积累水平高，底层土透气性良好而肥分低，粗根量大，底层土轻度盐碱，植株有最大生长量，但秋梢长，组织不充实，碳素积累少。     

不同年限的“丰产沟”对土壤微生物特性的影响

本文通过对使用不同年限“丰产沟”土壤微生物数量，种类分布等特性的分析研究．结果表明：“丰产沟”土壤随着使用年限的延长，微生物数量、类群将明显增加，对土壤微生物生态环境有良好影响。从而间接说明“丰产沟”对土壤改良，培肥地力将有明显效果，宜大力推广。     

漓江水资源环境问题的景观生态学思考

漓江风景区是驰名中外的国家级风景名胜区,每年接待国内外游客1 000多万人次,旅游收入达50亿元.但是,近年来随着工农业的快速发展,旅游开发力度的加大,人民生活水平的迅速提高,其生态环境问题日趋严重,主要表现在漓江汛期洪水泛滥、枯水期径流量变小、时间延长,由此引发河流自净能力降低,景区环境污染加重,水质变差,景区美景度和旅游承载力下降.漓江是漓江风景区的核心景观要素,漓江景区的很多生态环境问题均由漓江水资源环境问题引发.该文依据漓江水文观测资料,从景观生态学角度探讨解决其水资源环境问题的对策,为漓江风景区旅游可持续发展寻求新的有效途径.     

新世纪首都水源区发展战略研究报告

作为首都郊区的密云县 ,应该自觉找准本县在首都经济中的战略地位 ,找到一条持续快速健康发展的道路。新世纪首都水源区的发展战略应该是 :着眼首都未来发展对水源和环境的高标准要求 ,切实履行高质量保护水源和环境的特殊职责 ;走环境立县、引进强县、科教兴县和依法治县之路 ;努力建设清洁优美的自然环境、先进完善的设施环境、高效规范的体制环境和健康和谐的人文环境 ;构建以高新技术工业、绿色农业、生态旅游业和环保节能型建筑建材房地产业为支柱的首都水源区经济体系 ;突出县工业开发区、密云卫星城与中心镇建设、旅游西线开发和畜牧业产业化四个战略重点 ,促进经济持续快速健康发展 ,实现强县富民的目标。     

Response of hydrological drought to meteorological drought in the eastern Mediterranean Basin of Turkey

The hydrographic eastern Mediterranean Basin of Turkey is a drought sensitive area. The basin is an important agricultural area and it is necessary to determine the extent of extreme regional climatic changes as they occur in this basin. Pearson's correlation coefficient was used to show the correlation between standardized precipitation index(SPI) and standardized streamflow index(SSI) values on different time scales. Data from five meteorological stations and seven stream gauging stations in four sub-basins of the eastern Mediterranean Basin were analyzed over the period from 1967 to 2017. The correlation between SSI and SPI indicated that in response to meteorological drought, hydrological drought experiences a one-year delay then occurs in the following year. This is more evident at all stations from the mid-1990 s. The main factor causing hydrological drought is prolonged low precipitation or the presence of a particularly dry year. Results showed that over a long period(12 months), hydrological drought is longer and more severe in the upper part than the lower part of the sub-basins. According to SPI-12 values, an uninterrupted drought period is observed from 2002–2003 to 2008–2009. Results indicated that among the drought events, moderate drought is the most common on all timescales in all sub-basins during the past 51 years. Long-term dry periods with moderate and severe droughts are observed for up to 10 years or more since the late 1990 s, especially in the upper part of the sub-basins. As precipitation increases in late autumn and early winter, the stream flow also increases and thus the highest and most positive correlation values(0.26–0.54) are found in January. Correlation values(ranging between –0.11 and –0.01) are weaker and negative in summer and autumn due to low rainfall. This is more evident at all stations in September. The relation between hydrological and meteorological droughts is more evident, with the correlation values above 0.50 on longer timescales(12-and 24-months). The results presented in this study allow an understanding of the characteristics of drought events and are instructive for overcoming drought. This will facilitate the development of strategies for the appropriate management of water resources in the eastern Mediterranean Basin, which has a high agricultural potential.