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71.
南水北调对湖北丹江口水库区土地资源的影响 总被引:7,自引:1,他引:6
湖北省丹江口水库区是南水北调中线工程的水源区。随着调水工程的实施,库区土地资源将受到深远的影响。以丹江口水库及其四周海拔低于200m的区域为研究范围,选用90年代初获取的LandsatTM假彩色合成图像为主信息源,运用目视判读和地理信息系统(GIS)方法,对该区的土地资源利用现状进行了比例尺为25万分之一的遥感制图和计算机面积量算;在此基础上,对工程实施后本区土地资源的淹没损失、土地利用结构的变化进行了宏观分析,进而对区域土地资源的合理利用进行了初步探讨。 相似文献
72.
采用田间试验研究不同施肥处理对棕壤N2O排放量的影响。结果表明,N2O释放量随着耕层土壤硝态氮含量增加而上升。不同施肥处理对N2O排放量影响不同,低氮处理(N1)排放量(整个玉米生育期按185d计算)为1.18kg·hm-2,高氮处理(N2)为2.39kg·hm-2。随着施氮量的增加,反硝化作用加强,N2O排放量上升,以N2O形式损失加剧。相同施氮水平条件下,随着有机肥施入量的增加土壤N2O排放量上升,其中以高氮高有机肥处理(M2N2)N2O排放量最高,达到了7.05kg·hm-2,占所投入氮肥的2.34%。相同氮素供应水平条件下增施磷、钾肥,也会增加N2O排放量。整个玉米生育时期通过N2O排放损失的肥料占投入氮肥比例为0.99%~2.46%。 相似文献
73.
针对具体矿区的“点”型工程,结合AutoCAD技术,首次对矿区矸石场采前、施工期和工程运行期的生态修复措施进行全程研究,提出预防为主、全程修复、全程监管的理念,试图走出“先污染、后修复”的老路,以求达到绿化、美化、优化矿区生态环境,促进矿区人民生活质量和提高经济社会可持续发展的目的. 相似文献
74.
采用等体积浸渍法,制备了一系列含有相同含量活性组分(MoO3、CoO和NiO)不同USL沸石含量的加氢脱硫催化剂。通过X-射线衍射(XRD)、氮气吸附脱附、吡啶红外(Py-FTIR)和氨气程序升温脱附(NH3-TPD)等分析方法对样品进行了表征。结果表明:与Cat.0(参比剂,仅以γ-Al2O3为载体)相比,添加USL沸石催化剂所得加氢油的烯烃含量、芳烃含量和研究法辛烷值(RON)均增加;仅当催化剂载体中USL沸石加量在0~40m%之间变化时,加氢油的异构烷烃含量呈上升趋势;而当载体中USL沸石添加量在0~20m%之间变化时,催化剂的脱硫率有所升高。综合对比,当载体中USL沸石添加量约为40m%,催化剂具有最佳的综合性能指标,脱硫率达90%,RON损失仅为1.5左右。 相似文献
75.
ICCLP: An Inexact Chance-Constrained Linear Programming Model for Land-Use Management of Lake Areas in Urban Fringes 总被引:3,自引:1,他引:2
Lake areas in urban fringes are under increasing urbanization pressure. Consequently, the conflict between rapid urban development
and the maintenance of water bodies in such areas urgently needs to be addressed. An inexact chance-constrained linear programming
(ICCLP) model for optimal land-use management of lake areas in urban fringes was developed. The ICCLP model was based on land-use
suitability assessment and land evaluation. The maximum net economic benefit (NEB) was selected as the objective of land-use
allocation. The total environmental capacity (TEC) of water systems and the public financial investment (PFI) at different
probability levels were considered key constraints. Other constraints included in the model were land-use suitability, governmental
requirements on the ratios of various land-use types, and technical constraints. A case study implementing the system was
performed for the lake area of Hanyang at the urban fringe of Wuhan, central China, based on our previous study on land-use
suitability assessment. The Hanyang lake area is under significant urbanization pressure. A 15-year optimal model for land-use
allocation is proposed during 2006 to 2020 to better protect the water system and to gain the maximum benefits of development.
Sixteen constraints were set for the optimal model. The model results indicated that NEB was between $1.48 × 109 and $8.76 × 109 or between $3.98 × 109 and $16.7 × 109, depending on the different urban-expansion patterns and land demands. The changes in total developed area and the land-use
structure were analyzed under different probabilities (q
i
) of TEC. Changes in q
i
resulted in different urban expansion patterns and demands on land, which were the direct result of the constraints imposed
by TEC and PFI. The ICCLP model might help local authorities better understand and address complex land-use systems and develop
optimal land-use management strategies that better balance urban expansion and grassland conservation. 相似文献
76.
Yin Qian Wang Jinfeng Su Jianting Wei Zaihua 《Environmental science and pollution research international》2019,26(9):8895-8901
Environmental Science and Pollution Research - Few detailed, individual-focused studies have researched the added effect of temperature on cardiovascular disease (CVD), particularly in China.... 相似文献
78.
Qiuwen Chen Duan Chen Ruiguang Han Ruonan Li Jinfeng M Koen Blanckaert 《环境科学学报(英文版)》2012,24(11):1923-1928
For reservoir operation, maintaining a quasi-natural flow regime can benefit river ecosystems, but may sacrifice human interests. This study took the Qingshitan Reservoir in the Lijiang River as a case, and developed an optimization model to explore a trade-off solution between social-economic interests and nature flow maintenance on a monthly base. The objective function considered irrigation, cruise navigation and water supply aspects. An index of flow alteration degree was proposed to measure the difference between the regulated discharge and the natural flow. The index was then used as an additional constraint in the model besides the conventional constraints on reservoir safety. During model solving, different criteria were applied to the index, representing various degrees of alteration of the natural flow regime in the river. Through the model, a relationship between social-economic interests and flow alteration degree was established. Finally, a trade-off solution of the reservoir operation was defined that led to a favorable social-economic benefit at an acceptable alteration of the natural flow. 相似文献
79.
电镀废水中铜锌铬镍对农业环境的影响 总被引:2,自引:0,他引:2
廖金凤 《生态与农村环境学报》1999,(4)
电镀废水排入河涌会污染农业环境。以广东省南 海市平洲地区为例,农田灌溉水中Cu、Zn、Ni的含量超过允许限值1 ~14 倍,河涌底泥Cu、Zn、Cr、Ni超标12 ~37倍,土壤超标0.5 ~2.9倍,作物超标0.3 ~8 倍。进入河涌的Cu、Zn、Cr、Ni能较快沉积于底泥中。进入土壤的Cu、Zn、Cr、Ni主要累积在耕作层中。作物对Cu、Zn 的吸收能力远远高于对Cr、Ni的吸收能力,作物吸收系数是Zn > Cu > Ni> Cr 相似文献
80.