Evaluating Trends of Land Productivity Change and Their Causes in the Han River Basin, China: In Support of SDG Indicator 15.3.1

2021 ◽  
Vol 13 (24) ◽  
pp. 13664
Author(s):  
Yanxia Hu ◽  
Changqing Wang ◽  
Xingxiu Yu ◽  
Shengzhou Yin
Keyword(s):  
Spatial Heterogeneity ◽  
River Basin ◽  
Temporal Trends ◽  
Google Earth ◽  
Water Diversion ◽  
Productivity Change ◽  
Land Productivity ◽  
Population Count ◽  
Han River ◽  
Han River Basin

The Han River Basin is a main agricultural production area and a water source for the middle route of the South-to-North Water Diversion Project in China. Over the past 20 years, human exploitation and ecological construction have disturbed the sustainability of land productivity in the Han River Basin. Theil–Sen trend analysis, Mann–Kendall statistical test, and Hurst index methods were applied to examine spatial–temporal trends and sustainability characteristics of land net primary productivity (NPP) change in the Han River Basin from 2001 to 2019 using MOD17A3 NPP product, natural, and socio-economic data obtained from Google Earth Engine (GEE). The findings demonstrated that the interannual variation of land NPP exhibited a fluctuating upward trend, with a more pronounced growth rate from 2001 to 2010 than from 2011 to 2019. The spatial heterogeneity of land NPP was evident, with high values in the west and low values in the east. Of the basin area, 57.82% presented a significant increase in land NPP, while only 0.96% showed a significant decrease. In the future, land NPP in the Han River Basin will present sustained growth. The results were also compared with Trends.Earth’s calculations for the SDG 15.3.1 sub-indicator of land productivity. In addition, the spatial heterogeneity of factors influencing land NPP change was explored using a multiscale geographically weighted regression (MGWR) model. Precipitation and population count were the dominant factors in most regions. Besides, precipitation, population count, and human modification all exhibited inhibitory effects on the increase in land NPP except for elevation. The research can provide a scientific basis for tracking land degradation neutrality (LDN) progress and achieving sustainable socio-ecological development of the Han River Basin.

Characterization of the bacterioplankton community and the influencing factors in the upper reaches of the Han River basin

2021 ◽  
Author(s):  
He Sun ◽  
Baozhu Pan ◽  
Haoran He ◽  
Gengnan Zhao ◽  
Xiaoming Jiang ◽  
...  
Keyword(s):  
River Basin ◽  
High Throughput Sequencing ◽  
Source Region ◽  
Critical Role ◽  
Great Influence ◽  
Chemical Properties ◽  
Water Diversion ◽  
Bacterioplankton Community ◽  
Han River ◽  
Han River Basin

Abstract The upper reaches of the Han River are the source region of water for the Middle Route of China’s South-to-North Water Diversion Project, mainly for household, industrial, and irrigation purposes. Planktonic bacteria are more sensitive than macroorganisms to water physical and chemical properties and play a critical role in biogeochemical processes in river ecosystems. In November 2017 and April 2018, a systematic and methodical survey was carried out to evaluate the water quality and bacterial communities, on the mainstem of the Han River and its five main tributaries. In this study, high-throughput sequencing technology has been employed to investigate the bacterioplankton community composition. The results indicated that: 1) Diversity increased downstream, especially in the upper reaches of the Han River. 2) The relative abundance of Actinobacteria increased with the increase of river length, while that of Bacteroidetes decreased slightly. 3) Five tributaries were found to be importance sources of taxa to the Han River, however in both months a large proportion of OTUs (37.84% and 36.34%, respectively) had unknown sources. 4) Finally, redundancy analysis (RDA) and Bioenv analysis showed that environmental parameters (pH, TN, Cond, NH4+-N, DO, NO2−-N, Chl-a and T) had a great influence (p ≤ 0.05) on the bacterioplankton community. These research results are beneficial for the managing the ecological system, protecting the tributary biodiversity, and conserving the mainstem and tributaries of the Han River basin.

scholarly journals Analysis of the spatial-temporal change of the vegetation index in the upper reach of Han River Basin in 2000–2016

2018 ◽  
Vol 379 ◽  
pp. 287-292 ◽  
Author(s):  
Jinkai Luan ◽  
Dengfeng Liu ◽  
Lianpeng Zhang ◽  
Qiang Huang ◽  
Jiuliang Feng ◽  
...  
Keyword(s):  
River Basin ◽  
Vegetation Index ◽  
Temporal Change ◽  
Source Region ◽  
Remote Sensing Data ◽  
Area Ratio ◽  
Water Diversion ◽  
Han River ◽  
Increasing Trend ◽  
Han River Basin

Abstract. Han River is the water source region of the middle route of South-to-North Water Diversion in China and the ecological projects were implemented since many years ago. In order to monitor the change of vegetation in Han River and evaluate the effect of ecological projects, it is needed to reveal the spatial-temporal change of the vegetation in the upper reach of Han River quantitatively. The study is based on MODIS/Terra NDVI remote sensing data, and analyzes the spatial-temporal changes of the NDVI in August from 2000 to 2016 at pixel scale in the upper reach of Han River Basin. The results show that, the area with increasing NDVI between 0 and 0.005 per year accounts for 62.07 % of the area of upper reach of Han River Basin, and the area with changing rate between −0.005 and 0 per year accounts for 26.65 % of the research area. The area with significant decreasing trend only accounts for 2.76 %, while area significant increasing trend accounts for 13.47 %, and the area with increasing NDVI is much larger than the area with reducing NDVI. The vegetation index of each county is evaluated and found that, the areal proportion with significant decreasing trend in Hantai is the biggest, reaching 35.57 %. The areal proportion with significant increasing trend in Zhenba County, Ziyang County, Xunyang County, Zhashui County, Shangzhou District, Shanyang County and Yun County is larger than the others, and the areal proportions are more than 20 %. The largest areal proportion with significant increasing trend is in Shangzhou District and it reaches 31.11 %. On the whole, the area ratio in all districts and counties with increasing NDVI is much larger than the area ratio with decreasing NDVI.

scholarly journals Spatiotemporal Evolution of Landscape Ecological Risk Based on Geomorphological Regionalization during 1980–2017: A Case Study of Shaanxi Province, China

2020 ◽  
Vol 12 (3) ◽  
pp. 941
Author(s):  
Di Liu ◽  
Hai Chen ◽  
Hang Zhang ◽  
Tianwei Geng ◽  
Qinqin Shi
Keyword(s):  
River Basin ◽  
Ecological Risk ◽  
Land Surface ◽  
Risk Model ◽  
Shaanxi Province ◽  
Regional Differentiation ◽  
Ecological Risks ◽  
Han River ◽  
Han River Basin ◽  
Landscape Ecological

Land surface elements, such as land use, are in constant change and dynamically balanced, driving changes in global ecological processes and forming the regional differentiation of surface landscapes, which causes many ecological risks under multiple sources of stress. The landscape pattern index can quickly identify the disturbance caused by the vulnerability of the ecosystem itself, thus providing an effective method to support the spatial heterogeneity of landscape ecological risk. A landscape ecological risk model based on the degree of interference and fragility was constructed and spatiotemporal differentiation of risk between 1980 and 2017 in Shaanxi Province was analyzed. The spatiotemporal migration of risk was demonstrated from the perspective of geomorphological regionalization and risk gravity. Several conclusions were drawn: The risk of Shaanxi Province first increased and then decreased, at the same time, the spatial differentiation of landscape ecological risk was very significant. The ecological risk presented a significant positive correlation but the degree of autocorrelation decreased. The risk of the Qinba Mountains was low and the risk of the Guanzhong Plain and Han River basin was high. The risk of Loess Plateau and sandstorm transition zone decreased greatly and their risk gravities shifted to the southwest. The gravity of the Guanzhong Plain and Qinling Mountains had a northward trend, while the gravity of the Han River basin and Daba Mountains shifted to the southeast. In the analysis of typical regions, there were different relationships between morphological indicators and risk indexes under different geomorphological features. The appropriate engineering measures and landscape management for different geomorphological regionalization were suggested for effective reduction of ecological risks.

Spatial-Temporal Evolution of the Distribution Pattern of Neolithic Sites in Han River Basin, China

2018 ◽  
Vol 25 (1) ◽  
pp. 1-13
Author(s):  
Wenmin Qin ◽  
Lunche Wang ◽  
Aiwen Lin ◽  
Chao Yang ◽  
Hongji Zhu
Keyword(s):  
Distribution Pattern ◽  
River Basin ◽  
Temporal Evolution ◽  
Han River ◽  
Han River Basin

scholarly journals Optimal Rainfall Estimation by Considering Elevation in the Han River Basin, South Korea

2013 ◽  
Vol 52 (4) ◽  
pp. 802-818 ◽  
Author(s):  
Seong-Sim Yoon ◽  
Deg-Hyo Bae
Keyword(s):  
South Korea ◽  
River Basin ◽  
Flood Control ◽  
Rainfall Data ◽  
Spatiotemporal Variability ◽  
Radar Rainfall ◽  
Mountainous Regions ◽  
Han River ◽  
Orographic Rainfall ◽  
Han River Basin

AbstractMore than 70% of South Korea has mountainous terrain, which leads to significant spatiotemporal variability of rainfall. The country is exposed to the risk of flash floods owing to orographic rainfall. Rainfall observations are important in mountainous regions because flood control measures depend strongly on rainfall data. In particular, radar rainfall data are useful in these regions because of the limitations of rain gauges. However, radar rainfall data include errors despite the development of improved estimation techniques for their calculation. Further, the radar does not provide accurate data during heavy rainfall in mountainous areas. This study presents a radar rainfall adjustment method that considers the elevation in mountainous regions. Gauge rainfall and radar rainfall field data are modified by using standardized ordinary cokriging considering the elevation, and the conditional merging technique is used for combining the two types of data. For evaluating the proposed technique, the Han River basin was selected; a high correlation between rainfall and elevation can be seen in this basin. Further, the proposed technique was compared with the mean field bias and original conditional merging techniques. Comparison with kriged rainfall showed that the proposed method has a lesser tendency to oversmooth the rainfall distribution when compared with the other methods, and the optimal mean areal rainfall is very similar to the value obtained using gauges. It reveals that the proposed method can be applied to an area with significantly varying elevation, such as the Han River basin, to obtain radar rainfall data of high accuracy.

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