基于组合熵权RSR法的董志塬沟谷发育评价

doi:10.13866/j.azr.2023.03.14

Abstract

Abstract:

As a typical erosion geomorphic unit in the loess areas, gullies continuously erode loess surface under the action of internal and external forces, rainfall, and other factors. There are significant differences in the degree of development of gullies and valleys. Evaluating the development pattern of gullies and valleys can enhance the understanding of their organized, systematic formation and evolution. In addition, comprehensive quantitative indexes can facilitate the understanding of the longitudinal, lateral, and horizontal characteristics of gullies and valleys from multiple perspectives, which can help in the accurate and effective implementation of gully consolidation and loess protection projects, and reduce the constraints on development caused by this fragile geological environment. Evaluating the development of loess valleys is also crucial for exploring the intrinsic mechanism of valley formation, soil erosion, and guiding the ecological restoration of loess areas. In this study, ten quantitative indicators of gully development were selected based on the horizontal spatial, climatic, and point-line characteristics of the gullies, and used to establish an indexed evaluation model of the developmental stages of Dongzhi Loess Plateau gullies based on the efficient multi-factor comprehensive indexing evaluation capacity of the combined entropy-weight rank-sum ratio (RSR) method. Results showed that: (1) The highest weight of 16.08% could be attributed to the normalized vegetation index (NDVI) based on the entropy weighting method, followed by gully density (15.621%), both of which are important indicators for predicting the degree of gully development. (2) The combined entropy weighting RSR method could classify the 82 gullies of Dongzhi Loess Plateau into juvenile, youth, prime, and old age categories, with the percentage of gully area under the prime and old age categories accounting for 88.48% and 88.48%, respectively, while the eastern and northern parts of Dongzhi Loess Plateau exhibited more developed features and strong erosion on the loess surface. (3) The degree of gully development was highly correlated with the underlying palaeomorphology, tectonic geology, and loess thickness. (4) A significant model variance consistency test at P<0.001, with a linear regression R² fit of 0.986 was observed, which indicated a good performance of the model.

Key words: loess, quantitative index system, combined entropy-weighted RSR method, graded evaluation of gully development, Dongzhi Loess Plateau

CUI Shuai, XU Qiang, YUAN Shuang, PU Chuanhao, CHEN Wanlin, JI Xu. Evaluation of Dongzhi Loess Plateau Gully development based on combined entropy weight Rank-Sum Ratio method[J].Arid Zone Research, 2023, 40(3): 481-491.

Figures/Tables 14

Fig. 1

Tab. 1

Positive indicators for gully development evaluation"

指标名称	计算公式	解释	指标意义
边界维数	$D = 2 l n N - C l n M$	M为沟谷面积；N为沟谷沿线周长；C为沟谷周长	反映水平方向上沟谷空间展布的复杂程度和沟谷的发育程度。指标值越大，说明局部沟谷与整体沟谷网络的相似程度越高,沟谷形态结构越复杂,发育程度越高。
沟谷密度	$D l = ∑ i = 1 n l i A$	$D l$ 为沟谷密度； $l i$ 为流域内各条沟谷的长度；A为流域面积	反映沟头前进及沟谷侵蚀发育程度的重要指标。指标值越大，说明沟头前进程度越大，即沟谷生长延伸程度越大，发育程度越高。
地表切割深度	$G i$ = $H m e a n - H m i n$	$G i$ 为地表切割深度； $H m e a n$ 为地面某点一定邻域范围内的平均高程； $H m i n$ 为该点同一邻域范围内的最低高程	直观反映了沟谷下切发育程度和地表被侵蚀切割的程度。指标值越大，地表侵蚀切割越剧烈,沟谷下切发育程度越高。
平均坡度	$s l o p e = a r c t a n f x 2 + f y 2 × 180 π$	$f x$ 为x方向的高程变化率； $f y$ 为y方向的高程变化率	在一定程度上反映沟谷地貌的发育程度。沟谷发育初期,沟谷发育以下切为主，指标值逐渐增大，随着沟谷发育程度的增加,沟谷在深切的同时也在横向展宽，指标值反而有所下降。
月平均降雨	$R i = R A 12$	$R i$ 为月平均降雨； $R A$ 为年总降雨	气候影响因素之一，降雨的多少一定程度上影响水流侵蚀的剧烈程度。

Tab. 1

Tab. 2

Negative indicators for gully development evaluation"

指标名称	计算公式	解释	指标意义
主沟支沟比	$R = L 0 L$	R为主沟支沟比； $L 0$ 为主沟谷长度； $L$ 为沟谷总长度	从沟谷长度的角度反映沟谷系统中支沟的发育程度。指标值越小，沟谷系统中支沟发育越明显，说明沟谷系统整体发育程度越高。
土地利用程度综合指标	$L a = 100 × ∑ j = 1 n A i × C i$	$L a$ 为土地利用程度综合指数；A_i为第i级的土地利用程度分级指数；C_i为第i级土地利用程度分级面积百分比	是针对一个具体年份内所有土地利用类型整体反映的土地利用集约化程度。通过对土地利用程度的分级,量化人类活动对于土地系统的影响程度,定量地描述该地区土地利用的综合水平和变化趋势，是衡量指定区域内土地利用情况的一个重要指标。
主沟纵比降	$J = H s - H 0 l$	$J$ 为主沟道纵比降, $H s$ 为主沟道出水口点的高程； $H 0$ 为主沟道沟头点的高程； $l$ 为主沟道长度	反映沟谷整体侵蚀势能,是描述沟谷在垂直方向上侵蚀发育程度的重要指标。指标值越小，说明沟谷的侵蚀能量越低，沟谷越趋近于稳定的宽谷，发育程度越高。
归一化植被指数	$N D V I = N I R - R N I R + R$	NIR为近红外波段的反射值；R为红光波段的反射值	反映土地覆盖植被状况的一种遥感指标，定义为近红外通道与可见光通道反射率之差与之和的商。
圆度率	$e i = 4 π S i C i$	$e i$ 为圆度率； $S i$ 为沟谷面积； $C i$ 为沟沿线长度	反应水平方向上沟谷接近圆的程度，其值越接近1，则越接近圆，其发育程度越低。

Tab. 2

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Tab. 3

Fig. 6

Tab. 4

Tab. 5

Fig. 7

Fig. 8

Fig. 9

References 39

[1]	熊礼阳, 汤国安. 黄土高原沟谷地貌发育演化研究进展与展望[J]. 地球信息科学学报, 2020, 22(4): 816-826. doi: 10.12082/dqxxkx.2020.190519
	[Xiong Liyang, Tang Guo’an. Research progresses and prospects of gully landform formation and evolution in the Loess Plateau of China[J]. Journal of Geo-information Science, 2020, 22(4): 816-826.] doi: 10.12082/dqxxkx.2020.190519
[2]	罗来兴. 划分晋西、陕北、陇东黄土区域沟间地与沟谷的地貌类型[J]. 地理学报, 1956, 22(3): 201-222. doi: 10.11821/xb195603002
	[Luo Laixing. A tentative classification of landforms in the Loess Plateau[J]. Acta Geographica Sinica, 1956, 22(3): 201-222.] doi: 10.11821/xb195603002
[3]	黄秉维. 编制黄河中游流域土壤侵蚀分区图的经验教训[J]. 科学通报, 1955, 6(12): 15-21, 14.
	[Huang Bingwei. Lessons learned from the preparation of soil erosion zoning maps in the middle reaches of the Yellow River basin[J]. Chinese Science Bulletin, 1955, 6(12): 15-21, 14.]
[4]	袁宝印, 巴特尔, 崔久旭, 等. 黄土区沟谷发育与气候变化的关系(以洛川黄土塬区为例)[J]. 地理学报, 1987, 42(4): 328-337. doi: 10.11821/xb198704005
	[Yuan Baoyin, Bartel, Cui Jiuxu, et al. The relationship between gully development and climatic changes in the Loess Yuan Region: Examples from Luochuan, Shanxi Province[J]. Acta Geographica Sinica, 1987, 42(4): 328-337.] doi: 10.11821/xb198704005
[5]	胡刚, 伍永秋. 发生沟蚀(切沟)的地貌临界研究综述[J]. 山地学报, 2005, 23(5): 55-60.
	[Hu Gang, Wu Yongqiu. Progress in the study of geomorphic threshold theory in channel (gully) Erosion[J]. Mountain Research, 2005, 23(5): 55-60.]
[6]	邓成龙, 袁宝印. 末次间冰期以来黄河中游黄土高原沟谷侵蚀-堆积过程初探[J]. 地理学报, 2001, 56(1): 92-98. doi: 10.11821/xb200101011
	[Deng Chenglong, Yuan Baoyin. Processes of gully erosion and accumulation in the central Loess Plateau of China since the last interglacial[J]. Acta Geographica Sinica, 2001, 56(1): 92-98.] doi: 10.11821/xb200101011
[7]	黄骁力. 基于DEM的黄土沟谷地貌演化空代时研究[D]. 南京: 南京师范大学, 2019.
	[Huang Xiaoli. Space-for-time Substitution and Gully Evolution in the Chinese Loess Plateau[D]. Nanjing: Nanjing Normal University, 2019.]
[8]	王崔林. 黄土董志塬沟谷侵蚀发育空间分异特征及其综合治理模式研究[D]. 成都: 成都理工大学, 2020.
	[Wang Cuilin. Study on the Gully Spatial Differentiation Characteristics and Comprehensive Control Mode of Dongzhiyuan Area in the Loess Plateau[D]. Chengdu: Chengdu University of Technology, 2020.]
[9]	周毅, 王泽涛, 杨锋. 基于DEM的黄土沟谷横剖面形态特征研究——以宜君、延安、绥德为例[J]. 地理科学, 2020, 40(3): 455-465. doi: 10.13249/j.cnki.sgs.2020.03.014
	[Zhou Yi, Wang Zetao, Yang Feng. Morphological characteristics of gully cross-section in the Loess Region based DEM: Taking Yijun, Yan’an and Suide as cases[J]. Scientia Geographica Sinica, 2020, 40(3): 455-465.] doi: 10.13249/j.cnki.sgs.2020.03.014
[10]	李晨瑞. 基于地形特征要素的黄土沟谷发育及区域差异性研究[D]. 南京: 南京师范大学, 2018.
	[Li Chenrui. Studies on Gully Development and Regional Difference in Loess Plateau Based on Topographic Feature Elements[D]. Nanjing: Nanjing Normal University, 2018.]
[11]	景可. 黄土高原沟谷侵蚀研究[J]. 地理科学, 1986, 6(4): 340-347.
	[Jing Ke. A study on erosion on the Loess Plateau[J]. Scientia Geographica Sinica, 1986, 6(4): 340-347.]
[12]	何雨, 贾铁飞, 李容全. 黄土丘陵区沟谷发育及其稳定性评价[J]. 干旱区地理, 1999, 22(2): 64-70.
	[He Yu, Jia Tiefei, Li Rongquan. Development of gullies and evaluation on their stability in Loess Hill Region[J]. Arid Land Geography, 1999, 22(2): 64-70.]
[13]	陈传康. 陇东东南部黄土地形类型及其发育规律[J]. 地理学报, 1956, 22(3): 223-231. doi: 10.11821/xb195603003
	[Chen Chuankang. Topographic types of loess in southeastern Longdong and their development pattern[J]. Acta Geographica Sinica, 1956, 22(3): 223-231.] doi: 10.11821/xb195603003
[14]	严宝文, 王涛, 马耀光. 黄土高原水蚀沟谷发育阶段研究[J]. 人民黄河, 2004, 26(6): 16-18.
	[Yan Baowen, Wang Tao, Ma Yaoguang. Study on the development stages of water erosion gullies in Loess Plateau[J]. Yellow River, 2004, 26(6): 16-18.]
[15]	袁爽, 许强, 赵宽耀, 等. 基于统计学的陇东地区沟谷分布及演化研究[J]. 水土保持通报, 2020, 40(5): 172-180.
	[Yuan Shuang, Xu Qiang, Zhao Kuanyao, et al. Gully distribution and evolution in East Gansu Province based on statistics[J]. Bulletin of Soil and Water Conservation, 2020, 40(5): 172-180.]
[16]	Li C, Li F, Dai Z, et al. Spatial variation of gully development in the loess plateau of China based on the morphological perspective[J]. Earth Science Informatics, 2020, 13(4): 1103-1117. doi: 10.1007/s12145-020-00491-4
[17]	Wang R, Sun H, Yang J, et al. Quantitative evaluation of gully erosion using multitemporal UAV data in the southern black soil region of Northeast China: A case study[J]. Remote Sensing, 2022, 14(6): 1479. doi: 10.3390/rs14061479
[18]	Wang T, He F, Zhang A, et al. A quantitative study of gully erosion based on object-oriented analysis techniques: A case study in Beiyanzikou catchment of Qixia, Shandong, China[J]. The Scientific World Journal, 2014, 15(2): 1-11.
[19]	Thwaites R N, Brooks A P, Pietsch T J, et al. What type of gully is that? The need for a classification of gullies[J]. Earth Surface Processes and Landforms, 2022, 47(1): 109-128. doi: 10.1002/esp.v47.1
[20]	Liu D, Liang X, Chen H, et al. A quantitative assessment of comprehensive ecological risk for a loess erosion gully: A case study of Dujiashi Gully, Northern Shaanxi Province, China[J]. Sustainability, 2018, 10(9): 3239. doi: 10.3390/su10093239
[21]	孙利娟, 邢小军, 周德群. 熵值赋权法的改进[J]. 统计与决策, 2010, 26(21): 153-154.
	[Sun Lijuan, Xing Xiaojun, Zhou Dequn. Improvement of entropy assignment method[J]. Statistics & Decision, 2010, 26(21): 153-154.]
[22]	刘晓华, 许启发. 方差分析与虚拟变量回归模型的比较研究[J]. 统计与决策, 2012, 28(7): 34-38.
	[Liu Xiaohua, Xu Qifa. A comparative study of analysis of variance and dummy variable regression models[J]. Statistics & Decision, 2012, 28(7): 34-38.]
[23]	杜家菊, 陈志伟. 使用SPSS线性回归实现通径分析的方法[J]. 生物学通报, 2010, 45(2): 4-6.
	[Du Jiaju, Chen Zhiwei. A method for implementing throughput analysis using SPSS linear regression[J]. Bulletin of Biology, 2010, 45(2): 4-6.]
[24]	刘畅, 周毅, 雷雪. 陕北黄土高原水蚀沟谷多维度侵蚀特征量化研究[J]. 地理科学进展, 2022, 41(4): 707-717. doi: 10.18306/dlkxjz.2022.04.014
	[Liu Chang, Zhou Yi, Lei Xue. Quantitative analysis of multi-dimensional erosion characterstics of waterworn gullies on the Loess Plateau of Northern Shaanxi[J]. Progress in Geography, 2022, 41(4): 707-717.] doi: 10.18306/dlkxjz.2022.04.014
[25]	赵卫东, 周文怡, 马雷, 等. 基于势能信息熵的黄土小流域沟谷网络演化特征研究[J]. 地理与地理信息科学, 2021, 37(6): 1-6.
	[Zhao Weidong, Zhou Wenyi, Ma Lei, et al. Study on evolution characteristic of valley network in small loess watershed based on potential energy information entropy[J]. Geography and Geo-Information Science, 2021, 37(6): 1-6.]
[26]	刘洋, 李春阳. 植被因子对水土流失的影响[J]. 世界科技研究与发展, 2005, 27(5): 95-99.
	[Liu Yang, Li Chunyang. The impact of plant factor on water and soil erosion[J]. World Sci-Tech R & D, 2005, 27(5): 95-99.]
[27]	杜峰, 程积民. 植被与水土流失[J]. 四川草原, 1999, 20(2): 7-12.
	[Du Feng, Cheng Jimin. Loss of water, erosion of soil and vegetation[J]. Journal of Grassland and Forage Science, 1999, 20(2): 7-12.]
[28]	解明曙. 林木根系固坡土力学机制研究[J]. 水土保持学报, 1990, 4(3): 7-14, 50.
	[Xie Mingshu. A study on the soil mechanical role of tree roots in the stability of slopes[J]. Journal of Soil and Water Conservation, 1990, 4(3): 7-14, 50.]
[29]	Jiao J, Zou H, Jia Y, et al. Research progress on the effects of soil erosion on vegetation[J]. Acta Ecologica Sinica, 2009, 29(2): 85-91. doi: 10.1016/j.chnaes.2009.05.001
[30]	杨丹, 王晓峰. 黄土高原气候和人类活动对植被NPP变化的影响[J]. 干旱区研究, 2022, 39(2): 584-593.
	[Yang Dan, Wang Xiaofeng. Contribution of climatic change and human activities to changes in net primary productivity in the Loess Plateau[J]. Arid Zone Research, 2022, 39(2): 584-593.]
[31]	Renison D, Hensen I, Cingolani A M. Anthropogenic soil degradation affects seed viability in Polylepis australis mountain forests of central Argentina[J]. Forest Ecology and Management, 2004, 196(2-3): 327-333. doi: 10.1016/j.foreco.2004.03.025
[32]	Zhou Z C, Shangguan Z P, Zhao D. Modeling vegetation coverage and soil erosion in the Loess Plateau Area of China[J]. Ecological Modelling, 2006, 198(1-2): 263-268. doi: 10.1016/j.ecolmodel.2006.04.019
[33]	Zhao J, Vanmaercke M, Chen L, et al. Vegetation cover and topography rather than human disturbance control gully density and sediment production on the Chinese Loess Plateau[J]. Geomorphology, 2016, 274: 92-105. doi: 10.1016/j.geomorph.2016.09.022
[34]	田剑, 汤国安, 周毅, 等. 黄土高原沟谷密度空间分异特征研究[J]. 地理科学, 2013, 33(5): 622-628. doi: 10.13249/j.cnki.sgs.2013.05.622
	[Tian Jian, Tang Guo’an, Zhou Yi, et al. Spatial variation of gully density in the Loess Plateau[J]. Scientia Geographica Sinica, 2013, 33(5): 622-628.] doi: 10.13249/j.cnki.sgs.2013.05.622
[35]	姚文波. 历史时期董志塬地貌演变过程及其成因[D]. 西安: 陕西师范大学, 2009.
	[Yao Wenbo. The Evolution Process of Dongzhi Loess Plateau Landform and Its Causes During the Historical Period[D]. Xi’an: Shaanxi Normal University, 2009.]
[36]	熊礼阳. 基于DEM的黄土地貌继承性研究[D]. 南京: 南京师范大学, 2015.
	[Xiong Liyang. DEM based Research on the Loess Landform Inheritance in the Loess Plateau of China[D]. Nanjing: Nanjing Normal University, 2015.]
[37]	袁爽, 许强, 赵宽耀, 等. 陇东地区残塬分布规律及影响因素分析[J]. 人民长江, 2019, 50(8): 63-69, 108.
	[Yuan Shuang, Xu Qiang, Zhao Kuanyao, et al. Analysis on distribution law and influencing factors of residual tableland in east Gansu Province[J]. Yangtze River, 2019, 50(8): 63-69, 108.]
[38]	Shahab H, Emami H, Haghnia G H. Effects of gully erosion on soil quality indices in northwestern Iran[J]. Journal of Agricultural Science and Technology, 2018, 20(6): 1317-1329.
[39]	姜琳, 王清晨, 王香增, 等. 鄂尔多斯盆地东南部中生界地层节理发育特征与古应力场[J]. 岩石学报, 2013, 29(5): 1774-1790.
	[Jiang Lin, Wang Qingchen, Wang Xiangzeng, et al. Joint development and paleostress field in Mesozoic strata of the southeastern Ordos Basin.[J]. Acta Petrologica Sinica, 2013, 29(5): 1774-1790.]

发育阶段	百分位临界值	Probit	秩和比临界值（拟合值）	频数	面积/km²	面积占比
幼年期	<6.681	<3.5	<0.3106	5	10.04	0.63%
青年期	6.681~50	3.5~5	0.3106~0.4692	36	177.61	10.89%
壮年期	50~93.319	5~6.5	0.4692~0.6277	35	799.58	49.06%
老年期	>93.319	>6.5	>0.6277	6	642.44	39.42%

	非标准化系数		标准化系数	t	P	VIF	R²	调整R²	F
	B	标准误	Beta
常数	-0.059	0.007	-	-8.173	0.001	-	0.986	0.986	5567.72
Probit	0.106	0.001	0.993	74.617	0.001	1	0.986	0.986	5567.72

Evaluation of Dongzhi Loess Plateau Gully development based on combined entropy weight Rank-Sum Ratio method

RichHTML

PDF (PC)

Like

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 14

References 39

Related Articles 15

Metrics

Comments

Recommended 0

[1]	ZHAO Yuqi, WEI Tianxing. Changes in vegetation cover and influencing factors in typical counties of the Loess Plateau from 1990 to 2020 [J]. Arid Zone Research, 2024, 41(1): 147-156.
[2]	SONG Jiajia, LI Gangtie, GUO Jingjie, GU Zhonghou, LIU Kun, LI Zhilong, KANG Xia. Population structure and dynamic analysis of natural Juniperus rigida in a loess hilly area [J]. Arid Zone Research, 2023, 40(8): 1304-1311.
[3]	WANG Siqi, ZHANG Jianjun, ZHANG Yanqin, ZHAO Jiongchang, HU Yawei, LI Yang, TANG Peng, WEI Zhaoyang. Understory plant community diversity of Robinia pseudoacacia plantation with different densities in the loess plateau of western Shanxi Province [J]. Arid Zone Research, 2023, 40(7): 1141-1151.
[4]	LYU Jinxin, LIANG Kang, LIU Changming, ZHANG Yihui, LIU Lu. Spatial differentiation mechanism of land cover and related changes in water-carbon variables in Wuding River Basin [J]. Arid Zone Research, 2023, 40(4): 563-572.
[5]	HE Junqi,BAI Hanwei,XU Yiwei,NI Lili. Main nutrient characteristics and influencing factors of farmland soil in the Loess Plateau of the Shaanxi Province [J]. Arid Zone Research, 2023, 40(12): 1907-1917.
[6]	PEI Hongze, ZHAO Yachao, ZHANG Tinglong. Analysis of spatial and temporal patterns and drivers of local regional NEP in the Loess Plateau from 2000 to 2020 [J]. Arid Zone Research, 2023, 40(11): 1833-1844.
[7]	XIAO Xu, ZHENG Cheng, DING Chengqin, FAN Chenzhe, BAI Yuejiang, LIN Longchao, YAN Ting, GAO Yu, SHI Haijing. Comparative analysis of the temperatures and rainfall in loess hilly regions using the ANUSPLIN model [J]. Arid Zone Research, 2023, 40(10): 1575-1582.
[8]	LIU Huanhuan, CHEN Yin, LIU Yue, GANG Chengcheng. Simulation of spatial pattern and future trends of grassland net primary productivity in the Loess Plateau based on random forest model [J]. Arid Zone Research, 2023, 40(1): 123-131.
[9]	AN Bin,XIAO Weiwei,ZHU Ni,LIU Yufeng. Temporal and spatial variations of precipitation concentration degree and precipitation concentration period on the Loess Plateau from 1960 to 2019 [J]. Arid Zone Research, 2022, 39(5): 1333-1344.
[10]	LONG Zhi,SUN Yingqi,LANG Lixia,CHEN Xingpeng,ZHANG Zilong,PANG Jiaxing. Spatiotemporal patterns and characteristics of carbon emissions in the Loess Plateau: A case study of Qingcheng County [J]. Arid Zone Research, 2022, 39(5): 1631-1641.
[11]	SU Yuanyi,FENG Zhaohong,ZHANG Yang,LEI Na,ZHANG Tingyu. Runoff and sediment yield and relationship between water and sediment of sand covered slope of loess hilly region [J]. Arid Zone Research, 2022, 39(4): 1166-1173.
[12]	FENG Qiang,ZHAO Wenwu,DUAN Baoling. Relationship between trade-off intensity of ecosystem services and matching degree of supply and demand: A case study in Shanxi Province [J]. Arid Zone Research, 2022, 39(4): 1222-1233.
[13]	JING Mingbo,WANG Jincheng,ZHANG Wei,ZHOU Lihui,ZHANG Shaopeng. Comparison of phytoremediation effects of Medicago sativa and Coreopsis basalis on crude-oil-contaminated soil in eastern Gansu Province [J]. Arid Zone Research, 2022, 39(3): 853-862.
[14]	YAO Hongjia,WANG Baorong,AN Shaoshan,YANG E’nv,HUANG Yimei. Variation in soil extracellular enzyme activities stoichiometry during biological soil crust formation in the Loess Plateau [J]. Arid Zone Research, 2022, 39(2): 456-468.
[15]	DU Mengyin,YUAN Jianyu,LI Guang,YAN Lijuan,LIU Xingyu,QI Xiaoping,PANG Ye. Effects of protective measures on N₂O emission from farmland soil in a semi-arid area of the Loess Plateau [J]. Arid Zone Research, 2022, 39(2): 493-501.