我国东部呼伦贝尔草原地区是以露天开采为主的重要煤电基地,但是针对草原区露天煤矿开采对地下水系统影响及其水资源保护等问题研究较为不足。以呼伦贝尔草原宝日希勒露天矿区为研究对象,根据矿区煤炭资源开发与疏排水特征,将矿区露天...我国东部呼伦贝尔草原地区是以露天开采为主的重要煤电基地,但是针对草原区露天煤矿开采对地下水系统影响及其水资源保护等问题研究较为不足。以呼伦贝尔草原宝日希勒露天矿区为研究对象,根据矿区煤炭资源开发与疏排水特征,将矿区露天矿开采历史划分为初期、剧增期与稳定期3个阶段。应用地下水系统数值仿真技术,系统分析了露天矿区疏排水对地下水系统的影响规律。结果显示:第1阶段(初期),由于宝日希勒露天煤矿首采区疏排水影响(疏排水强度2.3×104 m 3/d),矿区范围内平均水位降深小于5 m;第2阶段(剧增期),宝日希勒露天矿西侧的东明露天矿相继开发,由于东明露天井田富水性好的松散含水层(渗透系数大于35 m/d)接受莫日格勒河地表水体补给充分,导致矿区疏排水强度增加至19.47×104 m 3/d,矿区范围内平均水位降深大于10 m;第3阶段(稳定期),宝日希勒露天矿首采区闭坑后2采区相继开采,矿区疏排水量趋于稳定(14.93×104 m 3/d),莫日格勒河地表水体渗漏补给松散层地下水强度约为11.02×104 m 3/d,约占东明露天矿疏排水量的80%,平均水位降深大于15 m。最后,根据矿区水文地质条件、帷幕减渗条件下地下水流场以及露天矿剥离开采条件下含水层涌水特征,构建了受强富水强补给露天矿在帷幕墙减渗条件下地下水系统仿真模型,评价了帷幕墙构建对疏排水的影响程度,模拟得出帷幕墙长度为4 km的条件下,疏排水量减少至6.65×104 m 3/d,降幅约为51.81%,总结提出帷幕墙阻水减渗方案是矿区针对强富水、强补给含水层地下水保护性开采与露天矿减少疏排水量的有效手段。展开更多
The transpiration rate and transpiration quantity＇of whole plants and foliages of Bromus innerrnis, Medicago sativa and Agropyron cristatum are measured by using improved quick and continuous weighting after being cu...The transpiration rate and transpiration quantity＇of whole plants and foliages of Bromus innerrnis, Medicago sativa and Agropyron cristatum are measured by using improved quick and continuous weighting after being cut off method （QCWC）. The results show that transpiration rate of branches and foliages of Agropyron cristatum is highest in 3 forages, Medicago sativa is second and Bromus innermis is lowest. From July to September, the average transpiration quantity of whole plants and foliages of 3 forages is highest in August, September is second and July is lowest.展开更多
The environmental factors that influence tree-grass abundances in tropical savanna and grasslands are not well understood,particularly for woodland-grassland mosaics in humid zones.We studied the effects of abiotic an...The environmental factors that influence tree-grass abundances in tropical savanna and grasslands are not well understood,particularly for woodland-grassland mosaics in humid zones.We studied the effects of abiotic and spatial variables on woody and herbaceous species distributions in a Terai ecosystem of northeastern India.We evaluated the importance of climatic and non-climatic factors that maintain variable tree-grass ratios across the landscape,and also accounted for spatial connectivity and dispersal.We measured species abundances of woody and herbaceous plant species in 134 plots with each 30 m×30 m in a 519 km^(2)protected Terai habitat,and derived several climatic and non-climatic environmental factors.We constructed variables based on different models of spatial connectivity among sites,to test their influence on species abundances.We then used redundancy analyses and variation partitioning to quantify the importance of environmental variables and spatial structure on variation in tree-grass abundances.We found that environmental variables including rainfall,fire,water stress,topography and soil nutrients had statistically significant effects on species abundance and tree-grass ratios.Spatial structure was significant,and the best spatial model was an inverse distance-weighted model with linkage extending to 23.5 km,indicating weak dispersal limitation.About 21%of the variation in species abundance was explained by the selected environmental and spatial factors.The results indicate that dynamic plant communities in which spatial-temporal variation in environmental factors may drive stochasticity in species distribution and abundance,thus dominantly influencing on the vegetation mosaic.展开更多
文摘我国东部呼伦贝尔草原地区是以露天开采为主的重要煤电基地,但是针对草原区露天煤矿开采对地下水系统影响及其水资源保护等问题研究较为不足。以呼伦贝尔草原宝日希勒露天矿区为研究对象,根据矿区煤炭资源开发与疏排水特征,将矿区露天矿开采历史划分为初期、剧增期与稳定期3个阶段。应用地下水系统数值仿真技术,系统分析了露天矿区疏排水对地下水系统的影响规律。结果显示:第1阶段(初期),由于宝日希勒露天煤矿首采区疏排水影响(疏排水强度2.3×104 m 3/d),矿区范围内平均水位降深小于5 m;第2阶段(剧增期),宝日希勒露天矿西侧的东明露天矿相继开发,由于东明露天井田富水性好的松散含水层(渗透系数大于35 m/d)接受莫日格勒河地表水体补给充分,导致矿区疏排水强度增加至19.47×104 m 3/d,矿区范围内平均水位降深大于10 m;第3阶段(稳定期),宝日希勒露天矿首采区闭坑后2采区相继开采,矿区疏排水量趋于稳定(14.93×104 m 3/d),莫日格勒河地表水体渗漏补给松散层地下水强度约为11.02×104 m 3/d,约占东明露天矿疏排水量的80%,平均水位降深大于15 m。最后,根据矿区水文地质条件、帷幕减渗条件下地下水流场以及露天矿剥离开采条件下含水层涌水特征,构建了受强富水强补给露天矿在帷幕墙减渗条件下地下水系统仿真模型,评价了帷幕墙构建对疏排水的影响程度,模拟得出帷幕墙长度为4 km的条件下,疏排水量减少至6.65×104 m 3/d,降幅约为51.81%,总结提出帷幕墙阻水减渗方案是矿区针对强富水、强补给含水层地下水保护性开采与露天矿减少疏排水量的有效手段。
基金Supported by "Eleventh Five-Year "National Scientific and Technological Support Projects(2006BAD25B09-8)"十一五"国家科技支撑计划项目(2006BAD25B09-8)
文摘The transpiration rate and transpiration quantity＇of whole plants and foliages of Bromus innerrnis, Medicago sativa and Agropyron cristatum are measured by using improved quick and continuous weighting after being cut off method （QCWC）. The results show that transpiration rate of branches and foliages of Agropyron cristatum is highest in 3 forages, Medicago sativa is second and Bromus innermis is lowest. From July to September, the average transpiration quantity of whole plants and foliages of 3 forages is highest in August, September is second and July is lowest.
基金We thank the UNESCO World Heritage Sites Program and the United States Fish and Wildlife Service Tiger Conservation Grant Program(F12AP00312)for financial support to carry out this work.
文摘The environmental factors that influence tree-grass abundances in tropical savanna and grasslands are not well understood,particularly for woodland-grassland mosaics in humid zones.We studied the effects of abiotic and spatial variables on woody and herbaceous species distributions in a Terai ecosystem of northeastern India.We evaluated the importance of climatic and non-climatic factors that maintain variable tree-grass ratios across the landscape,and also accounted for spatial connectivity and dispersal.We measured species abundances of woody and herbaceous plant species in 134 plots with each 30 m×30 m in a 519 km^(2)protected Terai habitat,and derived several climatic and non-climatic environmental factors.We constructed variables based on different models of spatial connectivity among sites,to test their influence on species abundances.We then used redundancy analyses and variation partitioning to quantify the importance of environmental variables and spatial structure on variation in tree-grass abundances.We found that environmental variables including rainfall,fire,water stress,topography and soil nutrients had statistically significant effects on species abundance and tree-grass ratios.Spatial structure was significant,and the best spatial model was an inverse distance-weighted model with linkage extending to 23.5 km,indicating weak dispersal limitation.About 21%of the variation in species abundance was explained by the selected environmental and spatial factors.The results indicate that dynamic plant communities in which spatial-temporal variation in environmental factors may drive stochasticity in species distribution and abundance,thus dominantly influencing on the vegetation mosaic.
