白于山区仁用杏基地建设探讨

根据杏属3个树种杏(鲜食杏)、仁用杏和西伯利亚杏在白于山区的树体生长量,根系分布,不完全花比例,花期不遇及花期遭遇霜冻时的坐果率和经济产值比较,认为仁用杏可作为该区的生态环境建设的搭配树种,不可列为基地建设树种。

白于山区仁用杏生长状况与评价

In Baiyushan hilly area, the roots system of almond-apricot mainly distributes vertically in the subsoil from 30 cm to 80 cm and horizontally distributes from 50 cm to 180 cm around the trunk. There are three growing peaks of the roots in a year and July-peak is the tallest one. From March to July is water losing period in subsoil of almond-apricot orchard, water losing is mainly from the aubsoil above 200 cm. There are three growing peaks for extending shoots and only one peak for fruit shoots in a vear. Fruit set percentage of almond-apricot is 15.61, of which short fruit branches are 22.62, long fruit branches are 8.56. Although there are differences in the growth of almond-apricot trees gown in slope lands with different elevation, aspects, and slopes, all trees grow well. Except frostbite harming, Baiyushan hilly area could be a better commodity production base of almond-apricot.

陕北白于山山区仁用杏引种观测与评价

Armeniaca vulgaris × A. sibirica is a new almond-apricot species of Armeniaca genus in Baiyushan mountainous area of northern Shaanxi that introduced from Zhuolu County, Hebei Province 12 years ago. After 11 years investigated and observed, the florescence of A. vulgaris × A. sibirica is the earliest and the shortest compared with A. vulgaris , A. vulgaris var . ansu and A.sibirica ; the number of non-harvest year caused by frost is the most; number of root is the least, and root distribution is lowest and narrowest; trunk diameter, height, and crown diameter are the least; almond is changed smaller and smaller with the tree age increased; production of stone is lower than A. vulgaris var . ansu and A.sibirica ; in small hilly region and medium mountain regionⅠ, production value is lower than A. vulgaris and higher than A. vulgaris var . ansu and A.sibirica ; in medium mountain regionⅡ, production value is lower than A. vulgaris var . ansu and A.sibirica ,very lower than A. vulgaris . A. vulgaris × A. sibirica shouldn’t be a dominating species in Baiyushan mountainous area.

特低渗透油藏见水特征及原因分析

大量低渗透油藏开发实践表明，油井见水情况与储层物性及裂缝性质有关。以BYS长4＋5油藏为例，从单井生产数据着手．通过井间注采对比、井间示踪剂测试和油水井连通关系分析，总结出4种含水变化类型及分布规律。从裂缝成因、构造应力场和沉积环境方面分析总结了不同见水特征的成因。

鄂尔多斯盆地白于山井网加密区延长组长4+5特低渗储层沉积特征和储层物性分析

以岩芯、薄片资料为基础,结合常规测井和成像测井等资料,综合分析鄂尔多斯盆地白于山井网加密区上三叠统延长组长4+5特低渗储层的沉积特征和储层特征,进而解剖储层砂体在纵向及平面的展布特征。结果表明,长4+5储层主要为一套中-细粒长石砂岩,发育平行层理和交错层理;储集空间以中小孔径的粒间孔为主,发育少量裂缝,储层物性较差。储层砂体在平面上呈较均匀的条带状展布,厚度在2~5 m之间;沉积亚相以三角洲前缘为主,发育水下分流主河道、水下分流浅河道、水下分流浅滩和水下分流间湾4种沉积微相。在纵向上,水下分流主河道及浅河道交替变化,在各小层有规律的展布。研究结果对进一步寻找白于山地区的油气富集区有一定的指示意义。

退耕还林(草)以来陕北白于山区植被覆盖与土壤侵蚀强度变化

为了研究白于山区土壤侵蚀特征,基于MODIS-NDVI和Landsat影像、DEM和土地利用数据,分析了白于山区2000-2018年植被盖度时空变化规律,并结合坡度和土地利用资料评估了退耕还林(草)工程以来的土壤侵蚀强度变化状况。结果表明:(1)白于山区植被覆盖呈显著增加趋势,年均NDVI增幅为0.065/10 a(p<0.01);(2)白于山区NDVI具有明显的空间分异性,高植被覆盖区主要集中在吴起县,低植被覆盖区主要集中在定边县西部和靖边县中部;受到地形因子的影响,NDVI分别在海拔1250~1400 m,坡度50°~56°范围内达到最大值,且阴坡植被覆盖大于阳坡;(3)白于山区植被盖度整体呈显著增加趋势,植被退化面积与恢复面积分别占研究区面积的3.18%,64.20%;(4)白于山区轻度侵蚀和中度侵蚀的面积减少,但强烈侵蚀、极强烈侵蚀和剧烈侵蚀的面积增加;(5)土壤侵蚀强度减弱的面积占总面积的51.30%,主要集中在吴起县,农耕地面积的减少是土壤侵蚀改善的主要原因。