Recent climate trends on the northern slopes of the Tianshan Mountains, Xinjiang, China

In arid regions, mountains fulfill important ecological and economic functions for the surrounding lowlands. In the scenario of global warming, mountain ecosystems change rapidly, especially in the arid region of northwestern China. This paper provides an assessment of the changes in temperature and precipitation in the historical records of climate on the northern slopes of the eastern Tianshan Mountains. A Mann-Kendall nonparametric trend and Sen＇s tests are employed to analyze the interannual changes and innerannual variability in temperature and precipitatiofi in the regions of low to high altitude. The present study finds that the largest increases in annual temperature are observed at stations in the low altitude regions. The significant increasing trends in temperature tend to occur mainly in late winter and early spring at stations from middle to high altitude, but in summer and autumn at stations of low altitudes. The increasing trends in annual precipitation are found from the middle to high altitude areas, but decreasing trends are found in the low altitude areas. The significant increasing trends in precipitation occur mostly in winter and earlier spring at stations from the middle to high altitudes, while the increasing and decreasing trend coexists at stations of low altitude with most of the significant trend changes occurring in March, June and August.     

施肥及刈割对干旱地区紫花苜蓿产量和品质的影响

在黄土高原中部干旱区采用随机区组试验,研究3个施氮水平(0、51.75、103.5 kg·hm^-2)和3个磷水平(0、126、252 kg·hm^-2)下不同刈割次数(3、4次)对“甘农3号”紫花苜蓿种植当年和第2年产量、株高、再生速度及品质的影响,并对紫花苜蓿生长两年中各指标进行比较.结果表明:干旱地区“甘农3号”紫花苜蓿在具备灌溉条件下,种植当年施肥可显著提高产量、株高和再生速度,且4次刈割下显著高于3次刈割;施肥也能增加紫花苜蓿粗蛋白含量,降低中性洗涤纤维和酸性洗涤纤维含量,4次刈割下品质更好;高氮低磷处理(N 103.5 kg·hm^-2+P₂O₅ 126 kg·hm^-2)下效果最好,单施氮肥较单施磷肥效果好.同时,第2年紫花苜蓿产量显著高于第1年,第1年增幅较第2年明显,说明在试验地区,“甘农3号”紫花苜蓿种植当年施肥更有效,第2年施肥仍有益;在灌溉和配施N103.5 kg·hm^-2+P₂O₅ 126 kg·hm^-2条件下,种植当年即可实现4次刈割.     

极端干旱地区绿洲小气候特征及其生态意义

1 Introduction Microclimate is one of the most important environmental factors for plant growth and development. Different plant communities create different microclimatic environments and different microclimatic environments support different biotic comm…     

西北干旱地区的水分评价问题

指出了用水文统计法确定的“水资源总量”难以将西北干旱地区与我国东部地区水资源作出合理的比较分析.只有考虑了土壤水这一重要水资源分量才能予以改进,因为两地的土壤水在水文统计中有不同的含义.在干旱地区,土壤水主要来自灌溉水,即“水资源总量”的一部分;而在华北等地,它主要来自降水,未能统计在“水资源总量”中.     

利用遥感技术进行干旱半干旱区找水的方法和实践

随着遥感技术和地面物探技术的发展和深入应用,产生了一种现代的综合勘探方法。本文介绍了在内蒙古锡林浩特市胜利煤田露天矿区供水水文地质普查中运用综合水文地质勘察方法的情况、遥感方案的选择、技术思路,以及利用遥感方法进行区域水文地质调绘所取得的成果,对遥感水文地质的发展提出了作者的看法。     

论气候在西非萨赫勒地带荒漠化中的作用：兼谈近期人类活动的影响

西非萨赫勒地带是世界上最严重的荒漠化地区。本文论述了气候在其荒漠化中的作用这一理论问题。文中提出，不能简单化和绝对化对看待这个问题。气候在该地带荒漠化中的作用具有复杂性，既有直接作用，又有间接作用；既能单独起作用，又能与人类过度经济活动因素结合在一起发挥巨大的作用。     

半干旱—干旱地区以钙积层为采样介质的隐伏金矿地球化学勘查

在隐伏金矿的地球化学勘查中,常用的采样介质包括岩石、水系沉积物、土壤、植物和地气等.近几十年,澳大利亚在半干旱—干旱地区以钙积层作为隐伏金矿床地球化学勘查的采样介质,并取得了成功.本文对以钙积层作为隐伏金矿地球化学勘查采样介质的理论和勘查进展进行总结,其勘查理论基础是土壤剖面中金-钙高度相关性,其成因机理较合理地解释为...