青藏公路与铁路沿途1981年～2001年植被覆盖变化

在青藏公路与铁路沿途区域,利用1981年至2001年的8km分辨率PathfinderNOAA/NDVI数据,基于每个象元变化的年植被峰值计算进行了像元水平的线性趋势分析,并运用地理信息系统(GIS)软件研究了区域植被覆盖的空间分布和动态变化特征.主要结论:①在研究区内,反映植被覆盖的NDVI值在空间上呈现出两端高中间低的态势,依次是农作区和森林区＞高寒草甸＞高寒草原＞荒漠草原;②20年间,研究区植被覆盖程度变化总体趋于稳定,覆盖程度呈减少趋势的区域明显高于增加的区域,植被覆盖程度增减因区域而异;植被覆盖程度增加和显著减少地区主要分布在农作区和高寒草甸区,轻微减少地区主要分布在高寒草原和荒漠草原区;③植被覆盖变化程度在拉萨河谷地、湟水谷地和黄河流域等人类活动比较频繁的区域增减趋势比较明显;而在可可西里地区等人类活动比较少的区域变化轻微.

东营凹陷北部陡坡带砂砾岩体性油气藏形成机理及分布规律研究

The north steep slope zone of Dongying Depression has great potential in oil resource and as the usage of 3-d seismic data in the last decade, the exploration of oil and gas has get into the stage of sandy glavel body lithological oil-gas pool exploration. In this thesis, writer take the north steep slope zone of Dongying Depression as target area and take Sha-III and Sha-[V Menber as purpose stratum, study on sequence stratigraphy, depositional system, reservoir description, emphasesing on analyzing of forming of lithological oil-gas pool, especially the dynamics principle of oil and gas preliminary movement from the source rock to the reservoir form lithological oil-gas pools. The aim of this work is to give some quantitatively explanation for the mechanism of lithological oil-gas pool forming, and set up the theory of pool form with characteristic terrestrial faulted basin. There are main conclusions and views as follow. 1. Applying with principle of sequence stratigrapgy, according to the depositional cycles of Dongying Depression, the sequence stratigraphical partition of Tertiary was finished, stressing on dismembering Sha-III and Sha-IV Menber as 5system tracts. 2. The structure of Dongying Depression especially of the north steep slope zone has accomplished, including the analyzing the structural cortroling to depositional condition of the north steep slope zone of Dongying Depression, discussed relationship between the structure of the north steep slope zone and the pool-forming. 3. The horizontal and vertical exchanges of ancient climates and ancient physiognomy of the all stratum units and studies on characteristic of depositional system distribution have been finished, found that there are five depositional systems in the north steep slope zone of Dongying Depression as fluvial, delta (tan-delta), sub-water fluvial fan lacustrine, gravitive flow, and seven formations of sandy glavel body, and forecasting of all kinds of sandy glavel body has been made. 4. Seismic stratigraphy and log stratigraphy have been made, described and forecasted all kinds of reservoir of objective stratum by means of physical geography method, setup a series means of sandy glavel body description suit to target area. 5. The pool-forming system has been studied, analyzing all the elements in petroleum sub-system of Sha-III and Sha-IV Menber of Dongying Depression with view of source controlling, estimated the petroleum system applying source rock potential index combining with distribution ofreservior. 6.Through studying types of pool, the controlling factors of pool-forming of sandy glavel body were discussed by deposition stages, formation types, structure ect. as a conclusion that the characteristics of pool forming in the north steep slope zone of Dongying Depression are, the controlling factor of the pools is mainly lithology, petrophysics of oil sands vary greatly, with a large heterogeneity, all kind of reservoir with different formation has different pool-forming conditions, and as a result, formed various pools of sandy glavel body along the steep slope with regular combination, distribution and constituted the multiple petroleum accumulative pattern. 7. It's the first time to cauculate and estimate the fluid pressure in source rock of Dongying Depression, set up the stratum fluid pressure in Dongying Depression, and firstly use equivalent charging pressure and reservoir forming index to quantitatively evaluate the pool-forming condition of lithological pool.8. Above all studies, follow up the scent of the exploration combined with practice a lot of explorative targets were found, and got geat economic and social benefit.