Spatial-temporal dynamics of desert vegetation and its responses to climatic variations over the last three decades:a case study of Hexi region in Northwest China

Analysis of spatial-temporal variations of desert vegetation under the background of climate changes can provide references for ecological restoration in arid and semi-arid areas. In this study, we used the Global Inventory Modeling and Mapping Studies （GIMMS） NDVI data from 1982 to 2006 and Moderate Resolution Imaging Spectroradiometer （MODIS） NDVI data from 2000 to 2013 to reveal the dynamics of desert vegetation in Hexi region of Northwest China over the past three decades. We also used the annual temperature and precipitation data acquired from the Chinese meteorological stations to analyze the response of desert vegetation to climatic variations. The average value of NDVImax （the maximum NDVI during the growing season） for desert vegetation in Hexi region increased at the rate of 0.65x10-3/a （P〈0.05） from 1982 to 2013, and the significant increases of NDVImax mainly appeared in the typical desert vegetation areas. Vegetation was significantly improved in the lower reaches of Shule and Shiyang river basins, and the weighted mean center of desert vegetation mainly shifted toward the lower reaches of the two basins. Almost 95.32% of the total desert vegetation area showed positive correlation between NDVImax and annual precipitation, indicating that precipitation is the key factor for desert vegetation growth in the entire study area. Moreover, the areas with non-significant positive correlation between NDVImax and annual precipitation mainly located in the lower reaches of Shiyang and Shule river basins, this may be due to human activities. Only 7.64% of the desert vegetation showed significant positive correlation between NDVImax and annual precipitation in the Shule River Basin （an extremely arid area）, indicating that precipitation is not the most important factor for vegetation growth in this basin, and further studies are needed to investigate the mechanism for this phenomenon.

Comparisons between Movement Speed of Main Types of Dunes:A Case Study of Desert Areas in Hexi Region of Gansu Province

In desert areas in Hexi region,11 barchan dunes,6 chains of barchan dunes,6 pyramid dunes,6 parabolic dunes and 6 accumulated sand-belts were chosen to study their movement speed based on images obtained by Google Earth in various periods.The results show that among the dunes,the movement of the barchan dunes was the fastest,followed by the chains of barchan dunes,and only the tops of the pyramid dunes swayed,while the parabolic dunes and accumulated sand-belts hardly moved forward.The higher the barchan dunes(or the chains of barchan dunes) were,the slower the movement was.On the contrary,the higher the pyramid dunes were,the faster the swing was.There was a positive correlation between the movement speed of the barchan dunes and the average wind speed of sandstorms.

THOUGHTS ON CONSTRUCTING THE DEMONSTRATING AREAS OF THE ECOLOGICAL REBUILDING AND ECONOMIC SUSTAINABLE DEVELOPMENT IN HEXI REGION

Based on the field investigations, this paper analyzes systematically the achievements and problems of constructing the demonstrating areas of the ecological rebuilding and economic sustainable development in Hexi, Gansu Province, and then the thoughts on constructing the demonstrating areas are brought forward. It is considered that all kinds of ecological demonstrating areas should be merged in order to construct large scale characterized demonstrating areas which go beyond the district. In other words, in Hexi Region, Zhangye District should be constructed as the largest ecoagriculture demonstrating area of high technology; Wuwei District should be constructed as the largest ecological demonstrating area of agricultural comprehensive exploitation; JiuJia District, which is the shortened form of Jiuquan and Jiayuguan, should be constructed as the largest ecotourism demonstrating area; and Jinchang City should be constructed as the largest ecoindustry demonstrating area. At the same time, the constructing pattern should be selected according to the actual circumstances; science and technology should be applied to construct the demonstrating areas and accelerate the industrialization in the big market. Additionally, it is important to smooth the constructing system and implement the flexible and efficacious running mechanism, and it is suggested that the committee should be organized to administer the ecological demonstrating areas in Hexi Region.

Soil Properties and Characteristics of Soil Aggregate in Marginal Farmlands of Oasis in the Middle of Hexi Corridor Region, Northwest China

The composition and stability of soil aggregate are closely related to soil quality, soil erosion, and agricultural sustainability. In this study, 49 soil samples at the 0-10 cm surface layer were collected from four soil types （i.e., Ari-Sandic Primosols, Calci-Orthic Aridosols, Siltigi-Otrthic Anthrosols, and Ustic Cambosols） in the marginal farmland in the oasis of the middle Hexi Corridor region and was used to determine the characteristics of soil aggregates. The composition of dry- and wet- sieved aggregates and the physical and chemical properties （including soil particle distribution, soil organic carbon （SOC）, calcium carbonate （CaCO3）, and oxides of Fe^3＋ and Al^3＋） of the selected soils were analyzed. The results show that soil particle size distribution is dominated by fine sand fraction in most of soils except Ustic Cambosols. Soil organic carbon concentration is 5.88 ± 2.52 g kg^-1 on average, ranging from 4.75 g kg^-1 in Ari-Sandic Primosols to 10.51 g kg^-1 in Ustic Cambosols. The soils have high calcium carbonate （CaCO3） concentration, ranging from 84.7 to 164.8 g kg^-1, which is increased with soil fine particle and organic carbon content. The percentage of 〉0.25 mm dry aggregates ranges from 65.2% in Ari-Sandic Primosols to 94.6% in Ustic Cambosols, and large dry blocky aggregates （〉5 mm） is dominant in all soils. The mean weight diameter of dry aggregates （DMWD） ranges from 3.2 mm to 5.5 mm. The percentage of 〉0.25 mm water-stable aggregate is from 23.8% to 45.4%. The percentage of aggregate destruction （PAD） is from 52.4% to 66.8%, which shows a weak aggregate stability. Ari-Sandic Primosols has the highest PAD. The distribution and characteristics of soil aggregates are in favor of controlling soil wind erosion. However, the stability of aggregate of all soils is weak and soils are prone to disperse and harden after irrigation. The mass of macro-aggregates and DMWD are positively significantly correlated with the contents of soil clay and silt, soil organic carbon （SOC）, CaCO3, and oxides of Fe^3＋ and Al^3＋. Soil fine silt and clay, SOC and CaCO3 are important agents of aggregation in this region, and the effect of SOC and CaCO3 on aggregate stability is more significant than that of soil silt and clay. Converting cropland to alfalfa forage land can increase SOC concentration, and in turn, enhance the formation of aggregates and stability. For the marginal farmlands in this fragile ecological area, converting cropland to alfalfa grassland or performing crop-grass rotation is an effective and basic strategy to improve soil structure and quality, to mitigate soil wind erosion, and to enhance oasis agricultural sustainability.

Estimation Study of New Cancer Cases and Deaths in Wuwei, Hexi Corridor Region, China, 2018

Population-based cancer registration data were collected to estimate the cancer incidence and mortality in Wuwei, Hexi Corridor Region, China in 2018. We used the 2011-2013 data to predict the number of new cases and deaths in 2018 and the 2003-2013 data to analyze trends in cancer incidence and mortality. The goal is to enable cancer prevention and control directions. Our results indicated that stomach cancer is the most common cancer. For all cancers combined, the incidence and mortality rates showed significantly increasing trends（＋2.63% per year; P 〈 0.05 and ＋1.9% per year; P 〈 0.05）. This study revealed a significant cancer burden among the population of this area. Cancer screening and prevention should be performed after an epidemiological study of the cause of the cancer is completed.

气候变化和土地利用覆盖变化对河西地区植被净初级生产力的影响

河西地区不仅是我国重要的生态安全保护优先区,而且是丝绸之路经济带核心地段,开展该地区植被净初级生产力(NPP)评估及驱动力定量分析对于陆地生态系统与大气碳交换、气候变化与人类活动对植被综合作用等研究具有重要的理论价值和现实意义。基于MOD17A3产品数据、土地利用覆盖数据和气象数据,采用R-贡献率和偏相关分析方法,分析了2000—2020年河西地区植被NPP变化特征及土地利用覆被和气候变化对NPP的影响,结果表明:(1)河西地区耕地、水域和居民建筑用地面积整体呈增加趋势,而草地和未利用土地面积有所减少,且2010年后的土地利用覆盖变化(LUCC)整体动态度显著提高,其中,草地、耕地、建设用地和未利用地主导了土地利用类型的相互转换。(2)河西地区整体植被NPP呈增长趋势,2000—2010年和2010—2020年的变化斜率分别为0.86和1.29,且植被NPP具有明显的区域异质性,由东南向西北递减。(3)2000—2020年河西地区LUCC对植被NPP的影响逐渐增大,且气候变化对植被NPP的贡献率普遍高于LUCC,但二者对不同土地利用覆盖类型所起的作用不同,表现为耕地、林地和草地的植被NPP影响因子以气候变化为主导,未利用土地和居民建筑用地的植被NPP影响因子逐步以LUCC为主导。

河西走廊不同产区主栽酿酒葡萄品种品质特性

【目的】探究在甘肃河西地区张掖和武威2个产区种植的‘赤霞珠’‘梅鹿辄’‘马瑟兰’‘贵人香’4个酿酒葡萄品种的品质特征和差异,筛选出适合种植的优势品种和地区,为酿酒葡萄的推广利用提供理论依据。【方法】测定和分析4个酿酒葡萄品种的外观果实品质和品质指标(包括果粒质量、果皮质量、种子质量、果实纵横径、花青素与酚类化合物、可溶性固形物、总糖、总酸等),并采用主成分分析法对产区和品种的综合评价进行排序。【结果】发现2个产区的4个酿酒葡萄品种在成熟期的外观果实指标和品质指标存在显著差异。其中,‘贵人香’品种的果实纵、横径和质量最大,其次为‘赤霞珠’‘梅鹿辄’‘马瑟兰’。此外,总酚、单宁、黄酮和花青素的含量在果实不同部位中也存在差异,且各品种间的含量表现为‘赤霞珠’>‘贵人香’>‘梅鹿辄’>‘马瑟兰’,其中花色苷以‘赤霞珠’最高,‘贵人香’最低。总糖、还原糖和pH值则以‘梅鹿辄’最高,‘赤霞珠’最低,总酸以赤霞珠最高。综合分析显示,在张掖产区,‘赤霞珠’的品质表现最佳,适合持续种植。【结论】‘赤霞珠’具有深紫色、中等果粒大小、适中的糖酸比和丰富的酚类和可溶性固形物等品质特点。在张掖产区的综合品质最佳,适宜进一步发展种植。

河西地区2000—2020年植被生态需水量估算

植被生态需水量的准确估算不仅关乎水资源的合理开发与管理,而且为科学制定生态环境保护与修复政策提供基础支持.本研究探讨应用不同方法估算河西地区植被生态需水量的精度与适用性.通过收集河西地区11个通量观测站的植被耗水观测数据,对植被生态需水模型进行验证和标定,选取适合该地区的估算模型——植被覆盖度修正蒸散发法,结合野外观测数据和卫星遥感数据,对2000—2020年河西地区的植被生态需水量进行估算.结果显示,河西地区2000—2020年植被生态需水量为(173.86±6.10)×10^(8)m^(3),在空间上呈现出东南高、西北低的分布格局.随着植被覆盖度以每年0.002的速率显著增加,植被生态需水量呈现出以每年0.70×10^(8)m^(3)的速率显著增加的趋势.本研究为河西地区植被生态需水量的准确估算和深入分析提供科学依据,同时也为未来相关研究提供参考和借鉴.

河西地区水资源可持续利用研究

河西地区是甘肃省的关键农业生产区之一,随着人口增长、经济发展和气候变化,当地面临巨大的水资源压力。以水资源生态足迹法为手段,深入剖析河西地区水资源可持续利用现状。数据分析发现,2013—2022年,河西地区水资源可持续利用取得显著成果,农业用水效率和水资源利用效率明显提高。但是,水资源生态承载力不足,水资源供需关系不平衡,水资源压力指数波动大,仍面临较大的挑战。

汉晋时期河西走廊张掖地区的开发研究——以黑水国汉代墓葬为例

黑水国汉代墓葬出土的农具、动物骨骼、农作物遗存和人骨为人们了解河西走廊张掖地区汉晋时期生业经济和农业发展等问题提供了重要证据。通过动物骨骼、农作物遗存鉴定结果和人骨碳氮同位素检测结果,可以揭示汉晋时期黑水国人群的食物结构和生业模式特点。墓葬出土的农作物有粟、黍、稻,随葬动物有鸡、猪、绵羊、黄牛、狗、马,人骨骨胶原碳稳定同位素主要呈现C3和C4混合信号,部分呈现C3信号和C4信号,氮稳定同位素值相较牛羊等家养食草动物较高。综合研究说明汉晋时期河西走廊形成麦类、粟黍和豆类的混合农业模式,所以黑水国汉代先民摄取的粮食作物来源呈多样化。同时,河西走廊畜牧业发达,使当时人群摄取了大量的肉食资源,导致蛋白质摄入量较高。

甘肃河西地区抽水蓄能电站带动新能源经济规模研究

目前,抽水蓄能电站容量电价核定办法已通过两部制电价进一步完善,但缺少具体的电价实施细则,且尚未明确抽水蓄能电站配合新能源开发的价格分摊机制。为了解决抽水蓄能价格分摊机制和方式,以河西地区某抽水蓄能电站与新能源联合开发为切入点,采用“抽水蓄能电站+新能源电站”一体化开发方式,研究新能源不同弃电率、不同收益率情况下抽水蓄能电站带动的经济规模。结果表明:抽水蓄能与新能源联合开发的方式有利于抽水蓄能容量电价疏导,新能源规模为抽水蓄能规模的3~4倍时项目整体最为经济;河西地区新能源资源丰富,抽水蓄能供电甘肃电网的同时服务于新能源消纳,容量电价合理疏导方式为与当地新能源一体化开发,可优化资源配置、提升经济竞争力、共同获利,较为经济的抽水蓄能与新能源开发比例约为1∶3~1∶4。本研究可为新能源丰富地区后续核准、投运抽水蓄能电站的容量电费疏导途径提供思路,也为三北地区其他新能源基地配套抽水蓄能电站的合理规模提供参考。

略阳王氏与前凉政权

西汉时期从河西迁往陇右的休屠王后裔略阳王氏家族,在西晋末年至十六国初期开始崛起。王羌是史载与前凉发生关系最早的略阳王氏人物,他在反对后赵统治失败后逃奔到河西。后赵末年,石虎数次发兵进攻河西,王擢积极参与并充当急先锋。后赵灭亡,王擢依违于前凉和前秦政权之间,又与前燕和东晋政权取得联系。后王擢投奔张重华,因张祚猜忌而投降前秦苻健。前秦时期,王擢之子王统任凉州刺史,苻坚发兵河西,王统率州兵参与了前秦灭前凉之战。淝水之战后,前秦统治崩溃,北方地区大乱,王穆护送前凉末代世子张大豫逃至河西,与吕光争夺凉州控制权,后兵败被杀。

Environmental Conditions of Barchan Dune and Barchan Chain-A Case Study from the Hexi Desert Area of Gansu

[Objective] The paper was to discuss why the top of tall barchan dunes and barchan chains widespread in single prevailing wind area had not been leveled by wind erosion. [Method] Based on the preliminary survey of distribution status,the morphological characteristics and environmental conditions of barchan dunes and barchan chains in Hexi desert area of Gansu were investigated in details. The significance of difference between samples and significance of correlation between indicators were examined via variance test. [Result] Barchan dunes and barchan chains in Hexi desert area of Gansu distributed at the leeward direction of desert fringe,generally in patch distribution. The distribution area was gravelly beach or cohesive gravel beach,with broader dune slack; winds in distribution area of barchan dunes and barchan chains blew obviously from one direction,while winds at other directions were light or occasionally strong but with low frequency;the barchan dune in the desert fringe of Hexi desert area of Gansu was relatively tall,while barchan chain was even more taller and larger. Coincidence or separation of the dune peak and the sand ridge might be related to distribution frequency of dominant prevailing wind or wind at opposite direction and the observation seasons.[Conclusion]Studying top stability of barchan dune has an important academic value in revealing blowing sand movement rule at desert fringe,invasion of sand flow,and expansion of desert.

甘肃省河西地区锶矿泉水富集分布规律和水质特征分析

在甘肃河西地区采集水样点231个,锶含量为0.10-2.67 mg·L^(-1),最高值达2.67 mg·L^(-1),达到饮用天然矿泉水界限含量(锶含量≥0.40 mg·L^(-1))的水样点171个,占全部水点的74.0%。按各地貌单元统计,走廊平原区含锶矿泉水点占水点总数的比例最高,走廊平原区地下水中有利于锶的富集;从地下水类型分析,第四系地下水中含锶矿泉水点数量最多,其次为地表水体,基岩矿泉水点较少;从各类型水中锶含量达到矿泉水标准的比率分析,基岩地下水锶矿泉水达标率最高,其次为第四系地下水,地表水达标率较低。依据甘肃河西地区锶矿泉水富集分布规律和水文地质特征,结合地形地貌等要素,划分出走廊平原区第四系锶矿泉水富集区和山地锶矿泉水富集区2个大区,细分了13个小区。

甘肃河西地区社火文化的地域特色及发展困境探析--以武威凉州区社火为例

甘肃河西地区的社火文化既有边塞和军旅文化的特色,又有戏曲唱腔、秧歌小调、鼓乐演奏、人物服装等多种表演形式的特点,是一门综合多种职业角色、多种民族文化、多种宗教元素、多种表演形式的民俗文化。然而,伴随着农村经济社会的发展,河西地区社火文化资源却日益枯竭,演出技艺总体上呈现出明显的衰退趋势,其种类日益减少,社火文化内涵日趋弱化,面临发展困境。社火文化是我国民间民俗传统文化艺术中不可缺少的一部分,在当前全面实施乡村振兴战略的背景下,应加强对它的研究与保护。

基于土地综合整治的河西地区实用性村庄规划路径探索——以张掖市高家庄村为例

全域土地综合整治是实施乡村振兴战略和实现乡村高质量发展的重要抓手。以甘肃省全域土地综合整治试点张掖市高家庄村为例,探讨了村庄规划“六化”对高家庄村庄总体布局、产业发展、基础设施、公共服务设施、居民点建设、用地留白等具体规划编制路径的要求,明确了基于土地综合整治的河西地区实用性村庄规划路径选择,认为土地综合整治支持河西地区实用性村庄规划具有适宜性特征,而且基于土地综合整治的实用性村庄规划就应该将土地整治任务、指标和布局要求落实到具体村庄规划实施地块上去,要重点突出“种”“养”“住”的空间谋划和项目安排。另外,河西地区具有“天时、地利、人和”的土地综合整治全域推进优势。然而,在具体村庄规划编制及实施过程中,既要“求同”,也要“存异”。基于土地综合整治“好用、管用、有用”的实用性村庄规划,就需要既能够落实上位规划的战略意图又要体现村民主体的核心意愿,从而切实为河西地区乡村振兴提供强有力的多元支持。

灌水量、种植密度和行距对河西地区春玉米产量的影响

为确定河西地区膜下滴灌春玉米适宜的灌水量和配套栽培技术,2020年在中国农业大学石羊河流域农业与生态节水试验站开展大田试验,设置2个灌水量(W_(1),W_(2))、2个种植密度(D_(1),D_(2))和3种行距(L1,L2,L_(3)),共12个处理,3次重复.通过测定株高、叶面积指数(LAI)、干物质累积及分配等指标,研究灌水量、种植密度与行距对春玉米生长、产量和水肥利用效率的影响.结果表明,在相同灌水量下,处理D_(2)的株高和LAI显著高于D_(1),增加种植密度提高了玉米群体干物质积累量、产量及水分利用效率(WUE).处理W_(2)D_(2)L_(3)的干物质累积量和产量最高,分别为96.45和17.72 t/hm^(2);处理W_(1)D_(2)L_(3)的水分利用效率最大,为3.57 kg/m^(3).灌水量与种植密度两者交互作用对产量及其构成因素的影响具有统计学意义(P<0.05);灌水量、种植密度与和行距三者交互作用对收获指数的影响具有统计学意义(P<0.05),对作物耗水量(ET)和WUE的影响具有统计学意义(P<0.01).灌水量、种植密度与行距均对河西地区春玉米群体结构、耗水量、产量及水分利用效率存在一定的调控效应:由大到小为种植密度、行距和灌水量.综合分析,“80%ETc+10.0万株/hm^(2)+宽窄行”为河西地区膜下滴灌春玉米适宜的灌水和种植模式.

氮肥增效剂对春小麦产量和效益的影响

为验证氮肥增效剂在春小麦上的施用效果,以春小麦品种永良15号为指示品种,设添加不同用量的氮肥增效剂NBPT、DMPP,常规施肥和不施肥处理(对照)共5个处理,在河西灌区研究了减量施肥条件下添加肥料增效剂对春小麦生长性状、产量及经济效益的影响。结果表明,较传统施肥(N 232.5 kg/hm^(2)、P2O5241.5kg/hm^(2)、K2O 56.3 kg/hm^(2))减N 14.0%、P2O537.9%,添加脲酶抑制剂(NBPT)0.40 kg/hm^(2)、硝化抑制剂(DMPP)2.00kg/hm^(2)时春小麦主要性状表现较好,产量最高,为4693.3 kg/hm^(2),纯收益较传统施肥增加975.59元/hm^(2)。在河西灌区,春小麦在化肥减量并添加氮肥增效剂条件下能够实现节本增效,可在小麦生产中应用。

近20a河西地区绿洲效应时空变化特征及归因分析

绿洲效应在改善干旱区气候,支持绿洲系统自我维持和发展等方面发挥着极为重要的作用。本文以甘肃省河西地区为研究区,利用气象和遥感数据,选取绿洲效应强度指标,采用地理探测器模型,揭示近20 a绿洲效应时空变化特征,分析了绿洲效应强度影响因素。结果表明:(1)2000—2020年期间,研究区绿洲效应强度在春夏冬季均呈增大趋势,秋季呈减小趋势,白天与相应季节变化相似,但强度更大,最强为夏季,增加1.43℃;夜间春夏秋季变化与相应季节相似,但强度较低,2000年秋季和2010年冬季夜间出现微弱的绿洲暖岛效应;(2)强绿洲效应(“冷岛”)面积占比在夏季最大且变化较小,而绿洲“暖岛”效应面积占比冬季最大,呈逐年减小趋势;(3)夏季绿洲效应强度与绿洲的植被覆盖变化具有强负相关性,相关系数达-0.917。气候和地表因素是河西地区绿洲效应强度的主控因素,地表反照率的影响最弱,且因子间的交互作用不容忽视。

河西灌区酿酒葡萄水肥一体化栽培技术规程

酿酒葡萄是河西地区主要优势特色产业之一。为进一步完善酿酒葡萄水肥一体化技术体系,以节水控肥、提质增效为目标,基于多年定位试验基础,采用室内野外结合、实验分析与综合调查结合等研究方法,从适用范围、规范性引用文件、术语和定义、产地气候环境条件、水肥一体化系统组成与设备安装、栽培技术、肥水管理、设施维护等方面规范了河西酿酒葡萄水肥一体化高效栽培技术。