Jianzhong Yan

Prof. Jianzhong Yan

Southwest University

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 September 2016 in Sustainability
Verified
Journal Article
Open access
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Basanta PaudelBasanta Paudel
Basanta Paudel
JGJungang Gao
Jungang Gao
YZYili Zhang
Yili Zhang
XWXue Wu
Xue Wu
Shicheng LiShicheng Li
Shicheng Li
JYJianzhong Yan
Jianzhong Yan
In recent decades, human activities have significantly transformed land use and land cover (LULC) and the environment of the Central Himalayas region. LULC is a major component of environmental and climatic research. The aim of this study was to determine the changes in cropland status and its drivers in the Koshi River Basin (KRB) of the Central Himalayas region of Nepal between 1978 and 2010. The cropland status in 1978 was obtained from the Land Resources Mapping Project (LRMP) datasets. The cropland status in 1992 and 2010 was determined on the basis of satellite imagery, with an object-oriented classification method, together with field investigations. Advanced geographical tools were used for data processing and binary logistic regression models were used for the statistical analysis of potential driving factors of cropland change. A noticeable overall change in cropland area was found, with rapid increases from 1978 onward at differing rates and to different extents. The cropland area covered 7165 km2 in 1978. It peaked at 7867.49 km2 in 1992, and had reduced slightly (by 90 km2) to 7776.66 km2 by 2010. The change in cropland area was mainly related to four potential driving factors: topography (elevation, slope, and soil types), socioeconomics (population and foreign labor migration), climate (annual mean temperature and precipitation), and neighborhood factors (roads, rivers, and settlements). However, the effects of the different variables have occurred over various stages and at different rates. An understanding of long-term changes in cropland status in the KRB would be useful, and this could be extended to spatial reconstructions with the help of historical data, including cropland and climatic archives.

YZYihao Zhang
Yihao Zhang
JYJianzhong Yan
Jianzhong Yan
XCXian Cheng
Xian Cheng
XHXinjun He
Xinjun He
Wetland ecosystems play one of the most crucial roles in the world. Wetlands have the functions of ecological water storage, water supply, and climate regulation, which plays an indispensable role in global environmental security. The Pumqu River Basin (PRB) is located in an area with extremely vulnerable ecological environment, where climate change is obvious. Understanding wetland distribution, changes and causes in the PRB are of great importance to the rational management and protection of wetlands. Using the Landsat series satellite images, wetlands of this area in 2000, 2010, and 2018 were extracted. The results showed that (1) there were obvious regional differences in wetland types and their distribution patterns in the basin. Wetlands were mainly distributed in areas with slopes less than 12° and at elevations between 4000 m and 5500 m. (2) During the past 20 years, the wetland area in the basin decreased, and the changing trend of wetlands was different. Palustrine wetlands decreased tremendously, riverine and lacustrine wetlands first decreased and then increased, while floodplain wetlands first increased and then decreased. Palustrine wetlands were reclaimed to cultivated land, but the proportion of reclamation is small. (3) Climate dominated wetland changes in the PRB. The changes in riverine and lacustrine wetlands were mainly affected by the warm-season average temperature, the change in palustrine wetlands was mainly related to the annual precipitation and the warm-season average temperature, and the change in floodplain wetlands was related to the warm-season precipitation. To achieve sustainable development, the government plays a guiding role and actively formulates and implements wetland protection policies, such as restricting or prohibiting grazing on wetlands, which play an important role in wetland protection and restoration.

18 October 2022 in Journal of Rural Studies
Verified
Journal Article
Closed access
XHXinjun He
Xinjun He
JYJianzhong Yan
Jianzhong Yan
LYLiang Emlyn Yang
Liang Emlyn Yang
HZHong Zhou
Hong Zhou
YWYa Wu
Ya Wu
SWshihai wu
shihai wu

4 October 2011 in Journal of Geographical Sciences
Verified
Journal Article
Closed access
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JYJianzhong Yan
Jianzhong Yan
YWYingying Wu
Yingying Wu
YZYili Zhang
Yili Zhang

1 November 2017 in Mountain Research and Development
Verified
Journal Article
Open access
JYJianzhong Yan
Jianzhong Yan
HLHuilian Li
Huilian Li
Xiaobo HuaXiaobo Hua
Xiaobo Hua
KPKui Peng
Kui Peng
YZYili Zhang
Yili Zhang
The Sanjiangyuan region is a typical ecologically vulnerable region. Although environmental initiatives in the region have had positive results, criticism has arisen that one of these, the ecological migration policy, did not achieve the desired results regarding the transition to off-farm employment and livelihoods. This study examined key factors influencing the engagement of pastoralists in the Sanjiangyuan region in off-farm employment. Binary logit and probit models were adopted along with in-depth household surveys in the Sanjiangyuan region to support the quantitative and qualitative analyses. The results indicate that off-farm employment in the region is generally not significant (18.13% of the investigated households had members working in off-farm sectors), and that education and government subsidies have had significantly positive effects on engagement in off-farm employment, while the number of livestock and the distance between house and town have had significantly negative effects. These res...

4 February 2016 in Journal of Geographical Sciences
Verified
Journal Article
Open access
PDF file
JYJianzhong Yan
Jianzhong Yan
YZYili Zhang
Yili Zhang
Xiaobo HuaXiaobo Hua
Xiaobo Hua
LYLiang Yang
Liang Yang
Although there has been rapid rural-urban migration in rural China since the 1980s, the total grain production of China saw a continuous increase. As of today, the relationship between labor migration and grain output growth remains partial and contradictory. The main aim of this empirical study is to examine some specific measures adopted by peasants to deal with labor shortage and maintain grain output growth. Using tracking survey, participatory rural appraisal methods, and land plot investigation, we investigate 274 households and 1405 arable land plots in four villages in two stages in Jinchuan county, southwestern China. The results show that continuous emigration of labor from the four villages caused the abandonment of a small amount of land, decreased labor intensity, and reduced multiple cropping index, shifting from “corn-wheat” multiple cropping pattern to the “corn” cropping pattern, which means labor shortage in some households. At the same time, owing to surplus labor in the villages, the peasants utilize a series of means to offset the negative impacts of labor migration on grain output, such as cropland transfer, labor exchange in the busy seasons, and the substitution of capital and technology for labor. The econometric analysis also shows that labor migration boosts grain production. This study provides a reasonable explanation of grain output growth under rural-urban migration.