scholarly journals The Impact of Climate Change and Human Activity on Spatiotemporal Patterns of Multiple Cropping Index in South West China

2019 ◽  
Vol 11 (19) ◽  
pp. 5308 ◽  
Author(s):  
Chuangjuan Zhang ◽  
Hongming He ◽  
Ali Mokhtar
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Yunnan Province ◽  
Southwest China ◽  
Sichuan Province ◽  
Quantitative Relation ◽  
Eastern Region ◽  
Grain Production ◽  
Multiple Cropping ◽  
The Impact

Agricultural lands are very sensitive to climate and human activity changes, which result in variations in regional agricultural resources and decreased production of total grain output and increased difficulty in producing grain yields. Multiple cropping is one of the simplest ways to increase grain production. The research aims is to analyze the spatial and temporal variations in the multiple cropping index and study the factors that influence the multiple cropping index. Based on the maximum multiple cropping index (MCI) and a “heat-precipitation” quantitative relation model, we analyzed the theoretical potential multiple cropping index (PMCI) and the spatiotemporal changes in the potential increase in the multiple cropping index (PIMCI). Our results are as follows: The MCI was significantly higher in the eastern region than in the western region and higher in the central region than in the northern and southern regions; in Yunnan Province, it showed a fluctuating downwards trend; further, it exhibited sudden declines from 2004 to 2006 and from 2012 to 2014 in Guizhou, while it exhibited an increasing trend in Sichuan Province. The PMCIs were the highest in the eastern and southern regions, especially in eastern Sichuan Province, and the PIMCI was significantly higher in Yunnan Province than in Guizhou and Sichuan. Climate change, human activities, and terrain had significant influences on the MCI changes in southwest China, especially the temperature change, which was the key factor affecting the MCI changes. The dominant land use types in southwest China were forest (46%), grass (28%), and farmland (23%) during 1980–2015. Therefore, the adjustment of the planting structure in different terrain areas according to the temperature changes has become the main strategy to promote the sustainable development of cultivated land resources in the region, further, the results would help implement the plan to increase grain production capacity in southwest China.

scholarly journals Quantitative Evaluation of the Impact of Climate Change and Human Activity on Runoff Change in the Dongjiang River Basin, China

Water ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 571 ◽  
Author(s):  
Yuliang Zhou ◽  
Chengguang Lai ◽  
Zhaoli Wang ◽  
Xiaohong Chen ◽  
Zhaoyang Zeng ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Quantitative Evaluation ◽  
Human Activity ◽  
Impact Of Climate Change ◽  
Dongjiang River ◽  
Runoff Change ◽  
The Impact

scholarly journals How might climate change affect river flows across West Africa?

2021 ◽  
Vol 169 (3-4) ◽  
Author(s):  
Ponnambalam Rameshwaran ◽  
Victoria A. Bell ◽  
Helen N. Davies ◽  
Alison L. Kay
Keyword(s):  
Climate Change ◽  
West Africa ◽  
Regional Scale ◽  
Weather Data ◽  
Eastern Region ◽  
Water Shortages ◽  
River Flows ◽  
Considerable Uncertainty ◽  
Modelling Framework ◽  
The Impact

AbstractWest Africa and its semi-arid Sahelian region are one of the world’s most vulnerable regions to climate change with a history of extreme climate variability. There is still considerable uncertainty as to how projected climate change will affect precipitation at local and regional scales and the consequent impact on river flows and water resources across West Africa. Here, we aim to address this uncertainty by configuring a regional-scale hydrological model to West Africa. The model (hydrological modelling framework for West Africa—HMF-WA) simulates spatially consistent river flows on a 0.1° × 0.1° grid (approximately 10 km × 10 km) continuously across the whole domain and includes estimates of anthropogenic water use, wetland inundation, and local hydrological features such as endorheic regions. Regional-scale hydrological simulations driven by observed weather data are assessed against observed flows before undertaking an analysis of the impact of projected future climate scenarios from the CMIP5 on river flows up to the end of the twenty-first century. The results indicate that projected future changes in river flows are highly spatially variable across West Africa, particularly across the Sahelian region where the predicted changes are more pronounced. The study shows that median peak flows are projected to decrease by 23% in the west (e.g. Senegal) and increase by 80% in the eastern region (e.g. Chad) by the 2050s. The projected reductions in river flows in western Sahel lead to future droughts and water shortages more likely, while in the eastern Sahel, projected increases lead to future frequent floods.

Anthropogenic causes of landslides and their implications for monitoring

2021 ◽  
Author(s):  
Kaushik Ramanathan ◽  
Nirmala Vasudevan
Keyword(s):  
Climate Change ◽  
Natural Hazards ◽  
Human Activity ◽  
Global Climate ◽  
Extreme Weather Events ◽  
Anthropogenic Factors ◽  
Human Beings ◽  
Landslide Occurrence ◽  
Landslide Event ◽  
The Impact

<p>Are we justified in referring to all landslides as natural hazards? With the effects of climate change, landslide incidences are increasing all over the world, and many of them accompany floods and occur due to extreme weather events. It has been unequivocally established that humans are responsible for global climate change. Further, landslides also occur in deforested areas. Even if one were to discount the effects of deforestation on climate change and the subsequent occurrence of landslides, one cannot ignore the fact that deforestation leads to slope instabilities in multiple ways. It decreases the effective retaining strength of the slope materials and also exposes more slope material to weathering and consequent leaching. Thus, deforestation and climate change, caused directly or indirectly by human beings, have a significant bearing on landslide occurrence. Furthermore, several catastrophic landslides in recent times have occurred due to indiscriminate human activity, such as constructing dams and other structures on fragile slopes, blasting slopes for road construction without providing adequate toe support, excessive mining, constructing faulty retaining structures on unstable slope material, etc. Over the years, such human activity has resulted in landslides of all types and at various scales. Whether a landslide is natural, caused due to anthropogenic factors, or a combination of the two, the investigation approach and monitored parameters remain the same; we still need to identify the various causative factors and quantify their rates of change over time in the run up to the landslide event. However, we need a paradigm shift in our perspective and treatment of landslides. We need to accept that human activity is, or can be, responsible for landslide occurrence. With this change in perspective, we would monitor slopes with an increased awareness that human actions could negatively impact slope stability. This, in turn, would entail monitoring at every stage to ensure that no human activity adversely impacts the natural balance, thus paving the way for truly sustainable development. We would be doing great disservice to the investigation and monitoring of landslides by such preconceived notions as all landslides are natural hazards. It is high time that we accept our part in compounding the problem of landslide occurrences and come up with solutions to monitor the impact of human activity on the environment to prevent landslides.</p>

Human activity vs. climate change: Distinguishing dominant drivers on LAI dynamics in karst region of southwest China

2020 ◽  
pp. 144297
Author(s):  
Jian Peng ◽  
Hong Jiang ◽  
Qinghua Liu ◽  
Sophie M. Green ◽  
Timothy A. Quine ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Southwest China ◽  
Karst Region

Changes of grain production potential in farming–pastoral ecotone: a case study in West Jilin, China

2018 ◽  
Vol 156 (2) ◽  
pp. 151-161
Author(s):  
Fei Li ◽  
Shuwen Zhang ◽  
Yijing Zhang ◽  
Haijuan Yang ◽  
Jiuchun Yang
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Influential Factors ◽  
Zone Model ◽  
Grain Production ◽  
Production Potential ◽  
Period 2 ◽  
The Impact

AbstractGrain production potential is mainly influenced by agroclimate and land use. In the present study, substantial regional differences associated with the impact of climate change were found (i.e. the degree of climate-related impacts varied among regions). Currently, there is an urgent need for effective responses and adaptations to different agricultural districts and agricultural production modes. Therefore, the aim was to examine ecotones and explore trends and influential factors associated with grain production potential change. Using the Global Agro-ecological Zone model, the grain production potential of West Jilin, China under different conditions during various years were estimated, considering meteorological, soil, topographic, land use and other data. The results showed that total grain production potential (TGrPP) of West Jilin increased continuously from 1976 to 2013. The average annual increase in TGrPP was higher in period 1 (1976–2000) than period 2 (2000–2013). In period 1, grain production potential was influenced mainly by irrigation percentage changes, followed by land use change. The conversion of grassland to farmland was the most important land use change factor that was associated with increased grain production potential. Climate change affected grain production potential in period 1 negatively. In period 2, climate change had the largest impact and land use imparted the smallest effect on grain production potential. Finally, the decrease in irrigation percentage resulted in reduced grain production potential.

Streamflow change induced by climate change and vegetation recover in a karst region of southwest China

2021 ◽  
Author(s):  
Lianbin Cai ◽  
Xi Chen ◽  
Zhicai Zhang
Keyword(s):  
Climate Change ◽  
Carbonate Rock ◽  
Southwest China ◽  
Karst Area ◽  
Karst Region ◽  
Primary Role ◽  
Distributed Hydrological Model ◽  
Carbonate Area ◽  
The Impact ◽  
Impacts Of Climate Change

<p>In carbonate rock regions, the bedrock compositions strongly influence regolith properties that, in turn, might play the primary role in plant growth and hydrological processes. Since bedrock experiences uneven weathering processes due to different regolith materials in a karst area, how hydrological functions of bedrock layer and overlying vegetation rely on the bedrock weathering degree is seldom investigated. The objectives of this study are to quantify the impacts of climate change and reforestation on runoff in a watershed with two main bedrocks (dissolvable carbonate rock in karst area and detrital rock in non-karst area) in southwest China. The analyses are firstly executed by decomposion of the hydro-meteorological series into two series (T1, 1992-2003 and T2, 2004-2015), which have different hydro-meteorological responses due to reforestation. This study investigates the impacts of climate change and reforestation on runoff using two approaches: the sensitivity-based approach (Budyko hypothesis) is applied to estimate the overall watershed change in runoff attributed to human activities and climate change, and a distributed hydrological model based on simple soil water balance routing is used to estimate change in runoff and hydrographs in the two main bedrock areas. The results show that the hydrological modelling overestimates climate induced decrease of streamflow (88.6%), compared to estimated result by the Budyko formula (76.6%). The decrease of mean precipitation from T1 to T2 in the non-carbonate area is very close to the carbonate area, the proportion of the climate change induced decrease of streamflow in the non-carbonate area (86.3%) is less than the carbonate area (90.5%), indicating that the drier climate tendency takes a greater effect on decrease of streamflow in the carbonate area than the non-carbonate area. By contrast, there is a greater alteration of land cover/use in the non-carbonate area than the carbonate area. These findings will help develop a better understanding of the impact of climate change and reforestation on runoff in southwest China.</p>

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