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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A influência da decomposição da vegetação na qualidade da agua de reservatórios / The influence of the decomposition of vegetation on the quality of water of reservoirs

Mucci, José Luiz Negrão 06 August 1993 (has links)
O presente trabalho estuda, em escala de laboratório, a influência da decomposição de diferentes estruturas da vegetação terrestre, na qualidade física, química e biológica da água de reservatórios nos quais a vegetação foi \"afogada\". Foram testadas tanto estruturas íntegras, como amostras calcinadas. Do ponto de vista físico e químico foram avaliados: Cor, Turbidez, Condutividade, pH, Oxigênio Dissolvido, Demanda Bioquímica de Oxigênio, Nitrogênio Total e Fósforo Total. A comunidade biológica que se desenvolveu em cada caso, foi avaliada por meio do exame qualitativo do fitoplâncton (algas) e de zooplâncton (protozoários). Em ambos os casos, a maior degradação da qualidade da água foi verificada com as amostras onde havia Eucalyptus sp e Paspalum sp, que provocaram alterações consideráveis nas concentrações dos parâmetros físicos e químicos, inclusive com depleção total do Oxigênio Dissolvido. A comunidade biológica nestas amostras foi sempre característica de ambientes onde predominam os processos de oxidação de matéria orgânica. / This paper studies, in a laboratory test using samples of water from Guarapiranga reservoir (S.P), the influence of the decomposition of different parts of the submerged terrestrial vegetation, on the physico-chemical and biological quality of water of reservoirs. Parts of vegetation were submerged in a fixed volume of water, which was daily analyzed for: Color, Turbidity, Conductivity, pH, Dissolved Oxygen, Biochemical Oxygen Demand and Total Nitrogen and Phosphorous. The biological changes were evaluated through the qualitative analysis of the phytoplankton (algae) and protozooans (zooplankton) community. The effect of the decomposition of ashes was also evaluated, by sUbmerging the same amount of burned vegetation. The results show that in both cases, the strongest changes in water quality (including the total consumption of the Dissolved oxygen, in a short time) were verifyed in the experiments with samples B (Eucalyptus sp) and C (Paspalum sp).
2

A influência da decomposição da vegetação na qualidade da agua de reservatórios / The influence of the decomposition of vegetation on the quality of water of reservoirs

José Luiz Negrão Mucci 06 August 1993 (has links)
O presente trabalho estuda, em escala de laboratório, a influência da decomposição de diferentes estruturas da vegetação terrestre, na qualidade física, química e biológica da água de reservatórios nos quais a vegetação foi \"afogada\". Foram testadas tanto estruturas íntegras, como amostras calcinadas. Do ponto de vista físico e químico foram avaliados: Cor, Turbidez, Condutividade, pH, Oxigênio Dissolvido, Demanda Bioquímica de Oxigênio, Nitrogênio Total e Fósforo Total. A comunidade biológica que se desenvolveu em cada caso, foi avaliada por meio do exame qualitativo do fitoplâncton (algas) e de zooplâncton (protozoários). Em ambos os casos, a maior degradação da qualidade da água foi verificada com as amostras onde havia Eucalyptus sp e Paspalum sp, que provocaram alterações consideráveis nas concentrações dos parâmetros físicos e químicos, inclusive com depleção total do Oxigênio Dissolvido. A comunidade biológica nestas amostras foi sempre característica de ambientes onde predominam os processos de oxidação de matéria orgânica. / This paper studies, in a laboratory test using samples of water from Guarapiranga reservoir (S.P), the influence of the decomposition of different parts of the submerged terrestrial vegetation, on the physico-chemical and biological quality of water of reservoirs. Parts of vegetation were submerged in a fixed volume of water, which was daily analyzed for: Color, Turbidity, Conductivity, pH, Dissolved Oxygen, Biochemical Oxygen Demand and Total Nitrogen and Phosphorous. The biological changes were evaluated through the qualitative analysis of the phytoplankton (algae) and protozooans (zooplankton) community. The effect of the decomposition of ashes was also evaluated, by sUbmerging the same amount of burned vegetation. The results show that in both cases, the strongest changes in water quality (including the total consumption of the Dissolved oxygen, in a short time) were verifyed in the experiments with samples B (Eucalyptus sp) and C (Paspalum sp).
3

Soil properties in relation to topographic aspects, vegetation communities and land use in the south-eastern highlands of Ethiopia /

Yimer, Fantaw, January 2007 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.
4

MAPPING VEGETATION STATUS AT LAKE NAKURU NATIONAL PARK AND SURROUNDS, KENYA

Kaloki, McNichol Kitavi 23 June 2017 (has links)
No description available.
5

Energetická bilance povrchu krajiny v lesně-zemědělském povodí / Energy balance of landscape surface in forested and agricultural catchment

SCHNEEDÖRFLER, Marek January 2018 (has links)
This diploma thesis deals with the statistical evaluation of the energy balance of landscape surface and its other chosen specifications via remote sensing and ground meteorological features. The thesis also includes the mapping of the landscape cover and its influence on the microclimate in the given area. The Novohradské Mountains, specifically the catchment of Bedřichovsky creek became the model area for this type of research. As each group of Land Cover (forest, permanent of grass cover, arable land, buildings) appears right in the catchment of Bedřichovský potok, it is suitable to evaluate the energy balance right in there.
6

以全波形光達之波形資料輔助製作植被覆蓋區數值高程模型 / DEM Generation with Full-Waveform LiDAR Data in Vegetation Area

廖思睿, Liao, Sui Jui Unknown Date (has links)
在植被覆蓋的山區中,由於空載雷射掃描可穿透植被間縫隙的特性,有較高機會收集到植被下的地面資訊,因此適合作為製作植被覆蓋地區數值高程模型的資料來源,而在過濾過程中,一般僅利用點雲間的三維位置關係進行幾何過濾,而全波形空載雷射掃描可另外提供點位的波形寬、振幅值、散射截面積以及散射截面積數等波形資料,本研究將透過波形資料分析進行點雲過濾。 首先經最低點採樣後,本研究利用貝氏定理自動分析並計算得到地面點的波形資料的特徵區間範圍,採用振幅值、散射截面積以及散射截面積係數得到的特徵區間範圍開始第一階段的波形資料過濾,完成後再以第二階段的一般幾何過濾濾除剩餘之非地面點,最後的成果將與航測以及只採用幾何過濾時的成果比較。 由研究成果中顯示,不同的植被覆蓋間的單一回波波形資料的差異較明顯,最後回波類似。同一植被覆蓋下的單一回波及最後回波反應不同。而在成果的比較中,本實驗的成果與不採用波形資料輔助的成果大致相同本研究的成果在部分植被覆蓋的區域成果稍差,但透過波形過濾,可將幾何過濾所需計算的點雲數減少許多,可以增進整理過濾的效率。本研究的成果與航測相比時,在植被覆蓋區域較航測成果貼近實際的地面起伏,數值高程模型成果較為正確。 / In mountain areas covered with vegetation, discrete airborne laser scanning is an appropriate technique to produce DEMs for its laser signal is able to reach the ground beneath the vegetation. Once the scanned data was derived, point cloud filtering was performed based on the geometry relationship between the points at the processing stage. With the development of the advanced full-waveform laser scanning system, the additional waveform data has been proved useful for improving the performance of point cloud filtering. This research therefore focused on using the waveform data to extract DEM over vegetation covered area. The amplitude, backscatter cross-section and backscatter cross-section coefficient were the waveform parameters used to do the filtering. After initial waveform analysis was accomplished, an automated method to determine threshold range of each parameter representing ground points was proposed. By applying the thresholds, the original point cloud was filtered. Geometric filtering method was then used to eliminate the remained non-ground points. As a result, the DEM over the target vegetated area was derived. With the comparison against photogrammetric DEM and DEM derived from traditional filtering method, it was demonstrated that the quality of the resultant DEM was improved.

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