Estimation of the Carbon Sequestration Dynamics of Senegal’s Great Green Wall Based on Land Cover over the Past Three Decades

The severe drought observed in the Sahel during 1970s, 1980s and 1990s has deeply affected the population as well as the economies and the eco-systems of this climatic area. The GGW Initiative spearheaded by Africa Union in 2007 proposed to combat the land degradation and desertification by planting a wall of trees stretching from Dakar to Djibouti. A reforestation was then conducted in the Senegal’s GGW since 2006 as part as other areas in the Sahel. This paper aims to evaluate the carbon sequestration dynamics in the sites of the Senegal’s GGW over the last three decades. The method consists firstly of analyzing the evolution of land cover and land use dynamics based on ESA-CCI LC satellite data. There is an improvement of the surface areas of tree and shrub savanna of 11.40% (Tessekere), 8.25% (Syer) and 2.70% (Loughere-Thioly). The regreening of the different localities and a positive dynamic observed is explained by the return to normal rainfall and to reforestation actions, agroforestry practices, better management of natural resources undertaken. However, some non-reforested sites showed an opposite trend despite of the normal rainfall. Secondly, the results on land mapping are used as a proxy for the assessment of carbon stocks. The dynamic observed in vegetation cover since the beginning of the reforestation made it possible to sequester 5.8 million tons of carbon representing respectively 2.31% of African GGW. This gain in stored carbon is equivalent to 21.2 million tons of CO2 captured in the atmosphere. Through this study, it appears that carbon storage becomes significant 8 to 10 years after the start of reforestation. An urbanization without respect for the environmental factors could be a danger for the climate (case of Ballou).

Quantification of urban greenery using hemisphere-view panoramas with a green cover index

Urban greenery has positive impacts on the well-being of residents and provides vital ecosystem services.A quantitative evaluation of full-view green coverage at the human scale can guide green space planning and management.We developed a still camera to collect hemisphere-view panoramas(HVPs)to obtain in situ heterogeneous scenes and established a panoramic green cover index(PGCI)model to measure human-scale green coverage.A case study was conducted in Xicheng District,Beijing,to analyze the quantitative relationships of PGCI with the normalized difference vegetation index(NDVI)and land surface temperature(LST)in different land use scenarios.The results show that the HVP is a useful quantization tool:(1)the method adaptively distinguishes the green cover characteristics of the four functional areas,and the PGCI values are ranked as follows:recreational area(29.6)>residential area(19.0)>traffic area(15.9)>commercial area(12.5);(2)PGCI strongly explains NDVI and LST,and for each unit(1%)increase in PGCI,NDVI tends to increase by 0.007,and(3)LST tends to decrease by 0.21 degrees Celsius.This research provides government managers and urban planners with tools to evaluate green coverage in complex urban environments and assistance in optimizing human-scale greenery and microclimate.

Dataset of the mountain green cover index(SDG15.4.2)over the economic corridors of the Belt and Road Initiative for 2010-2019

Mountains are undergoing widespread changes caused by human activities and climate change.Given the importance of mountains,the protection and sustainable development of mountain ecosys-tems have been listed as the goals of the United Nations 2030 Sustainable Development Agenda.As one of the indicators,the Mountain Green Cover Index(MGCI)datasets can provide consis-tent and comparable status of green vegetation in mountainous areas,which can support the mapping of heterogeneous mountain ecosystem health and monitoring changes over time.The produc-tion of explicitly high-spatial-resolution MGCI datasets is therefore urgently needed to support the protection measures at subnational and multitemporal scales.In this paper,the MGCI datasets with 500-meter spatial resolutions,covering the economic corridors of the Belt and Road Initiative(BRI),were developed for 2010 to 2019 based on all available Landsat-8 data and the Google Earth Engine cloud computing platform.The validation of green vegeta-tion cover with the ground-truth samples indicated that the data-sets can achieve an overall accuracy of 94.06%,with well-detailed spatial and temporal variations.The archived datasets include the MGCI of each BRI economic corridor,matched to a geospatial layer denoting the economic corridor boundaries.The essential informa-tion of the datasets and their limitations,along with the production flow,were described in this paper.

Explaining farmers'reluctance to adopt green manure cover crops planting for sustainable agriculture in Northwest China

Green manure cover crops(GMCCs)planting has a potential for mitigating greenhouse gas emissions(GHG)in agroecosystems and provides important ecosystem services,thereby achieving the Sustainable Development Goals(SDGs)stipulated by the United Nations.However,the advantages of cultivating GMCCs on arable land are not widely recognized.For example,in the whole of China,the GMCCs planting area is less than 3.5%of total arable land.The aim of this study is to explore reasons for the low adoption rate of GMCCs planting.Using best–worst scaling(BWS)approach,farmers ranked their preferred conservation practices including three types of GMCC cropping systems.Taking Gansu Province in Northwest China as a case study,a survey with 276 farmers was conducted.The findings indicated that three factors are related to the low adoption rate of GMCCs:1)farmers preferred improving farmland irrigation facilities and substituting chemical fertilizers with organic rather than planting GMCCs;2)lack of awareness and understanding of government policy on GMCCs and limited access to training courses;3)financial support and subsidies from the government are insufficient.This study provides insights and strategic implications for policymakers on how to further promote GMCCs in the future.

Effects of V-pits covering layer position on the optoelectronic performance of InGaN green LEDs

The impact of the V-pits covering layer(VCL) position on the optoelectronic performance of InGaN-based green light-emitting diodes(LEDs) was investigated. It is found that earlier covering of V-pits will hinder the hole injection via the sidewall of V-pits, and then result in less quantum wells(QWs) participating in radioluminescence. The current-voltage characteristics show that the LEDs with earlier covering of V-pits have higher operating voltage at room temperature, and a more dramatic voltage rise with the reduction of temperature. Meanwhile, more manifested emission peaks for sidewall QWs and deeper QWs near to ntype layer was observed in the sample with earlier coveing of V-pits at cryogenic temperatures, for the reason that the holes being injected via V-pits sidewall have higher kinetic energy and could transport to deeper QWs.

Responses of vegetation cover to the Grain for Green Program and their driving forces in the He-Long region of the middle reaches of the Yellow River

The implementation of the Grain for Green Program is a great breakthrough in the history of China＇s ecological environment construction,which can control soil erosion effectively,increase land productivity and improve the ecological environment.To investigate the eco-environmental benefits brought by the Grain for Green Program,the spatiotemporal variations of vegetation cover in the growing season from 2000 to 2010 across the Hekou-Longmen （He-Long） region were analyzed by using remote sensing information,meteorological data and land use data.Moreover,the impacts of climate and human activities on vegetation change were evaluated objectively.Annual vegetation cover in the growing season increased very significantly.Increased vegetation cover occurred in 98.7％ of the region,of which the area for vegetation cover improved slightly constituted 79.8％ of the whole area.Vegetation moderately improved was mainly distributed in the south of the He-Long region,covering 9.6％ of the area,and the area for vegetation basically unchanged concentrated in the middle and upper reaches of the Wuding River.Precipitation was found to be an important natural factor influencing vegetation cover change.The area of vegetation cover showing a significantly positive correlation with precipitation occupied 22.14％ of the region.As driven by policies from the Grain for Green Program,forestland increased significantly and land use structure became more intensive.Human activities played a positive and effective role in the protection,restoration and improvement of vegetation in the places where vegetation cover was basically unchanged,even though precipitation declined greatly,and vegetation improved moderately with massive increases of forestland and grassland.

绿化覆盖率对城市绿地破碎度与地表温度的关系的影响

优化绿地空间配置(如破碎度)是改善城市热环境的有效途径。然而绿地破碎度对城市热环境的影响可能随绿化覆盖率的变化而变化,对改善城市热环境提出了巨大挑战,但相关研究十分缺乏。以长沙市为例,利用Landsat地表温度表征城市热环境,使用解译于高分2号遥感影像的城市绿地图在1 m像元尺度量化绿化覆盖率和绿地破碎度(用绿地边界密度表征)。以419个1 km格网为分析单元,应用分段线性回归揭示绿化覆盖率与绿地破碎度间的非线性关系,识别绿化覆盖率阈值并以此为标准将419个1 km格网划分为高绿化覆盖率区和低绿化覆盖率区。以1 km格网平均地表温度为因变量,绿化覆盖率、绿地破碎度、水体覆盖率和裸地覆盖率为自变量从研究区、高绿化覆盖率区和低覆盖率区3个方面建立多元线性回归模型阐明绿地破碎度对地表温度的影响。最后进行方差分解分析绿化覆盖率、绿地破碎度和其他土地覆盖率对地表温度的独立和联合影响。结果显示,1)绿地破碎度随绿化覆盖率的增加先增加后降低,阈值为44.9%。2)整个研究区,4个指标可解释69.1%的地表温度变异,地表温度随绿化覆盖率、水体覆盖率、裸地覆盖率和绿地破碎度的增加显著降低。3)低绿化覆盖率下绿地破碎度显著影响地表温度,高绿化覆盖率下绿地破碎度对地表温度呈不显著正影响。4)在研究区和不同绿化覆盖率区域,绿化覆盖率对地表温度的独立影响均高于绿地破碎度的独立影响。建议长沙城市绿地规划管理在提高绿化覆盖率的同时可提高低绿化覆盖率区域绿地破碎度以改善城市热环境。

Effects of Snow Cover on Alfalfa Overw intering and Turning Green

In order to investigate the effect of snow cover on alfalfa overwintering and turning green,6 different alfalfa varieties( including Longmu806,Gongnong No. 1,Aohan,Wega 7F,WL319 HQ,Caoyuan No. 3) were used as plant materials. There were 4 treatments in this study include snow-cover of 0,30%,70% and natural snow-cover( used as control). Nutrient content and antioxidant enzyme activity of root were measured before and after overwintering period. The rate of plant returning green and growth rate after greening were also measured after turning green. The result showed that the snow cover was the guarantee of alfalfa safely overwintering and turning green. The 54. 5-77. 9 cm snowfall was the optimum thickness of snow for safe overwintering. Alfalfa improved the overwintering ability by enhancing the root nutrients and antioxidant enzyme activity,and it was affected by snow cover. In addition total nitrogen and soluble sugar increased by 61% and 60% respectively,soluble protein reduced by8%,SOD and CAT reduced by 20% and 9% respectively than that before the overwintering under 70% of natural snow-cover. There were differences between overwintering ability of 6 different alfalfa varieties,in which Caoyuan No. 3 has more grass production and Wega 7F has stronger overwintering ability.

填闲作物还田方式对烟田土壤轻重组有机碳的影响

为了提高多年连作烟田的土壤肥力,改善土壤生态环境,在烤烟冬闲期种植油菜、冬牧70、光叶紫花苕等3种作物,同时以冬季空闲不种植任何作物为对照,采取2种方式(掩青和收割)进行处理,通过测定不同处理不同土层的土壤轻、重组有机碳含量、比例及储量,探讨填闲作物收割和掩青处理对烟田土壤轻重组有机碳的影响。结果表明,不同填闲作物和不同还田方式下土壤总有机碳、重组有机碳、轻组有机碳含量均随着土壤深度的增加而降低。与对照相比,填闲作物掩青处理能够显著增加土壤总有机碳、重组有机碳、轻组有机碳含量,尤其是冬牧70在20~40 cm土层增加比较显著,分别增加了22.3%、21.98%、27.78%;填闲作物收割处理会降低土壤轻组有机碳比例和土壤轻组有机碳储量,而掩青处理则会增加土壤轻组有机碳比例和轻组有机碳储量,其中冬牧70掩青在0~20 cm土层增加比较明显,分别增加了18.14%、40.03%。填闲作物掩青处理增加了烟田土壤的含水量和持水量、降低了土壤容重以及增加土壤轻重组有机碳储量。综合来看,冬牧70掩青处理效果最好,能显著增加土壤总有机碳和轻重组有机碳含量,油菜次之。

轮作及减氮对绿洲灌区农田温室气体排放及土壤酶活性的影响

基于2018年在武威绿洲农业试验站布设的田间定位试验,设春小麦-冬油菜-箭筈豌豆(WRV)、春小麦-冬小麦-箭筈豌豆(WWV)、春小麦-箭筈豌豆-春小麦-箭筈豌豆(WV)、春小麦连作(W)4种种植模式,减氮25%(270 kg·hm^(-2),N 1)、传统施氮(360 kg·hm^(-2),N 2)两个施氮水平,共8个处理,于2020—2021年测定并分析不同轮作模式结合减氮对农田CO 2、N 2O排放的影响及其与春小麦产量和土壤酶活性的关系,以期为当地农业绿色高效发展提供理论依据。结果表明:轮作结合减氮处理可显著降低温室气体排放,增加作物产量,以WRVN 1处理增产减排效果最佳,其CO 2、N 2O排放总量分别较WN 2处理降低了15.2%、28.0%,全球增温潜势(GWP)、温室气体排放强度(GHGI)分别降低15.7%和30.4%,作物产量增加16.7%。土壤脲酶和过氧化氢酶活性均表现为0~10 cm高于10~30 cm土层,轮作降低了小麦开花期土壤酶活性,以WRVN 1处理土壤酶活性最低;在N 1处理下土壤脲酶、过氧化氢酶活性较N 2处理分别降低20.1%~28.7%、8.3%~12.2%,且CO 2、N 2O排放速率与土壤脲酶、过氧化氢酶活性均呈显著正相关关系。综上,春小麦-冬油菜-箭筈豌豆轮作模式结合减氮25%可作为实现绿洲灌区农业增效减排的合理种植模式与施氮制度。

添加中药材对绿衣观音土曲品质影响及相关性分析

为探究中药材的加入对清香型白酒酒曲品质的影响,在绿衣观音土曲制备中加入不同添加量的10种中药材。对不同添加量中药材制备绿衣观音土曲的品质指标及存放时间进行分析,并探讨中药材添加量与绿衣观音土曲品质指标的相关性。结果表明,中药材添加量5.0%制作的土曲泡度较好,曲心红色,有少量黑心,药材味适宜。绿衣观音土曲存放时间1月质量较佳,其水分为4.56%、酸度为0.41 mmol/10 g、氨基酸态氮为0.27 g/kg、糖化率为31.2 g/100 g、发酵率为35.9%,乳酸菌、酵母和霉菌数量分别为163.5×10^(6)CFU/g、280.5×10^(6)CFU/g、2.0×10^(6)CFU/g,糖化酶、淀粉酶、酸性蛋白酶酶活分别为1217.7 U/m L、50.6 U/m L、44.0 U/m L。相关性分析表明,中药材添加量、水分、酸度和发酵率之间呈显著正相关(P<0.05),且这四个指标与淀粉酶活呈现显著负相关(P<0.05);霉菌数量与中药材添加量和水分呈显著负相关(P<0.05)。

青海省茫崖市马海地区钾矿绿色勘查措施

青海省实施大量的盐湖钻探施工项目,要求实施绿色勘查。本文以青海省茫崖市马海地区钾矿勘查9号孔为例,根据现场实际施工情况,结合矿区矿区自然生态概况,合理规划了生活区和施工区的平面布置,分析了造成环境扰动的主要因素有项目临时道路修筑、车辆行驶、项目驻地建设、钻探工程施工等方面,同时制定了对应的绿色勘查措施。可为提高地质钻探从业者的绿色施工的意识、形成绿色勘查习惯,以及其他单位在风成砂覆盖区开展地质钻探施工时提供了可复制、可参考的绿色勘查经验。

矿山水文地质环境勘查与治理方法研究

通过地质测绘测量、遥感解译和山地工程等综合手段,查明项目区内矿山地质环境现状和问题以及对周边环境的影响,并查明治理工程的地质条件,为工程设计和矿山复绿提供依据。收集相关资料,分析项目区域内地质环境,掌握水文地质条件和工程地质条件。通过无人机航测、地质调查,查明渣堆大小、形状,压占土地面积,环境破坏程度,评价其稳定性;确定治理工程地质参数和工程地质条件;调查工程施工的三通一平,临时占地和材料堆放场地。修建挡墙和排水设施后,消除矿山环境问题引发的地质灾害隐患,使矿山地质环境和生态环境得到恢复和改善,保障社会经济的可持续发展,社会效益显著。覆土绿化后,渣堆成为立体式绿地,抑制粉尘,净化空气,改善、修复生态环境,为周围群众营造良好的生活环境,环境效益显著。

生态防洪理念下的水污染治理建设分析

随着社会的快速发展,人类活动对水资源的压力不断增加,同时水资源的污染问题也日益严重。在这种情况下,生态防洪理念的出现为水污染治理提供了新的思路和方法。文章引入了生态防洪理念,结合流域内雨污分流管网建设及该黑臭水体整治的控源截污、内源治理、生态修复及清水补给措施,基本消除黑臭水体,利用生态防洪措施,形成空间层次丰富的植物群落,有效减免三棵松水流域洪涝灾害,为保护水资源和生态环境做出积极的贡献。

覆盖区矿产调查钻探查证技术方法研究

覆盖区矿产勘查是新一轮找矿突破战略行动的重要内容之一.采用更加绿色和有效的钻探技术,快速获取隐伏基岩信息与样品,是覆盖区找矿亟待总结和推广的工作.本研究基于绿色勘查理念,采用便携式浅层钻探装备与技术,以及空气反循环钻进工艺,在大兴安岭东南缘宝山浅覆盖区铜多金属矿勘查中开展钻探试验,实现了快速穿透覆盖层获取隐伏基岩信息、查证物探异常并采集地球化学样品的效果,同步结合孔内成像等技术,为填制覆盖区隐伏岩石地层单元分布范围和界线等提供了基础资料.试验结果表明,基于浅层绿色钻探技术,结合孔内成像,并为野外地球化学快速分析提供测试样品的多方法组合,可以有效解决浅覆盖区找矿难题,在矿产勘查过程中具有很好的推广价值.

节能减碳语境下的绿化屋顶在公路服务区建筑中的设计探索——以怒江美丽公路服务区建筑设计为例

研究了覆土式绿化屋顶在土壤隔热、植被遮阳、蒸腾散热、降低风压等方面的特点,以怒江美丽公路小沙坝服务区工程实际案例,分析了覆土式绿化屋顶对建筑节约采暖降温能耗、植物固碳、减少建筑碳排放的相关作用。

基于绿色建筑理念的地面材料防滑性能研究

随着绿色建筑行业的迅猛发展,建筑安全性逐渐受到了社会各界的广泛关注。其中,地面材料的防滑性能尤为关键,已成为评价场地与建筑安全性的核心指标。通过现场检测,对比分析了不同地面材料的防滑性能,旨在为不同要求的地面铺装材料设计提供切实可靠的参考依据。

无人机吊运模块化钻机技术研究与应用

根据推动绿色勘查工作、构建统筹生态环境保护与找矿突破的现代化装备体系的要求,本文针对南方地区典型的森林覆盖区地貌特征,探索了无人机吊运模块化钻机技术。分析了TF-500系列型重载无人直升机系统和ZY-800P型便携式全液压模块化钻机的性能及其选型适合性,并实际应用在湖南新化县月光冲矿区金矿详查项目钻机搬迁中。展示了该技术出色的环境适应性和应用实用性,利用无人机的飞行能力来实现对钻机设备的高效、精准吊装和运输,大幅缩短了搬运周期,减少了对生态的破坏,提高了作业的安全性和效率。

地铁车辆基地上盖开发中的垂直绿化设计研究

城市轨道交通车辆基地是地铁车辆的“4S店”,用地动辄几十公顷,占地面积大;在车辆基地上方进行上盖物业开发,可有效提高土地利用率,解决城市人口住房问题。但上盖开发体量大,割裂城市空间严重,在车辆基地盖板上下进行垂直绿化设计,不仅能够缓解给城市带来的冲击,还能够改善上盖开发品质,具有多重效益。从城市垂直绿化的意义出发,结合垂直绿化在车辆基地设计中的应用实例,重点阐述上盖开发垂直绿化设计中的要点,为打造空间丰富的上盖开发提出建议。

Forward Calculation of 2-D and 3-D Structures with a Cover by the Boundary Element Method while Using Electrical Methods

This paper develops the boundary element method, the authors employ two-layered earth Green 's functions as the weighting functions of residual and derive boundary integral equations. The forward problems of point sources on 2 - D and 3-D structures with an influencing cover are solved by this method. The results show that this method markedly improves the original boundary element method. The features of the improved method are greater numerical accuracy and much smaller systems of equations and thus considerable savings for the storage capacity of computers, allowing us to solve the above problems with only ordinary microcomputers. The results in this paper extend the scope of applying the boundary element method while using electrical methods for geophysical prospecting.