scholarly journals Temporal and Spatial Characteristics of Precipitation and Temperature in Punjab, Pakistan

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1916 ◽  
Author(s):  
Nawaz ◽  
Li ◽  
Chen ◽  
Guo ◽  
Wang ◽  
...  
Keyword(s):  
Climate Change ◽  
Climatic Variability ◽  
Regional Scale ◽  
Elevation Gradient ◽  
High Elevation ◽  
Maximum Temperature ◽  
Moderate Increase ◽  
Study Region ◽  
Lower Elevation ◽  
Precipitation And Temperature

Identifying the changes in precipitation and temperature at a regional scale is of great importance for the quantification of climate change. This research investigates the changes in precipitation and surface air temperature indices in the seven irrigation zones of Punjab Province during the last 50 years; this province is a very important region in Pakistan in terms of agriculture and irrigated farming. The reliability of the data was examined using double mass curve and autocorrelation analysis. The magnitude and significance of the precipitation and temperature were visualized by various statistical methods. The stations’ trends were spatially distributed to better understand climatic variability across the elevation gradient of the study region. The results showed a significant warming trend in annual Tmin (minimum temperature) and Tmean (mean temperature) in different irrigation zones. However, Tmax (maximum temperature) had insignificant variations except in the high elevation Thal zone. Moreover, the rate of Tmin increased faster than that of Tmax, resulting in a reduction in the diurnal temperature range (DTR). On a seasonal scale, warming was more pronounced during spring, followed by that in winter and autumn. However, the summer season exhibited insignificant negative trends in most of the zones and gauges, except in the higher-altitude Thal zone. Overall, Bahawalpur and Faisalabad are the zones most vulnerable to warming annually and in the spring, respectively. Furthermore, the elevation-dependent trend (EDT) indicated larger increments in Tmax for higher-elevation (above 500 m a.s.l.) stations, compared to the lower-elevation ones, on both annual and seasonal scales. In contrast, the Tmin showed opposite trends at higher- and lower-elevation stations, while a moderate increase was witnessed in Tmean trends from lower to higher altitude over the study region. An increasing trend in DTR was observed at higher elevation, while a decreasing trend was noticed at the lower-elevation stations. The analysis of precipitation data indicated wide variability over the entire region during the study period. Most previous studies reported no change or a decreasing trend in precipitation in this region. Conversely, our findings indicated the cumulative increase in annual and autumn precipitation amounts at zonal and regional level. However, EDT analysis identified the decrease in precipitation amounts at higher elevation (above 1000 m a.s.l.) and increase at the lower-elevation stations. Overall, our findings revealed unprecedented evidence of regional climate change from the perspectives of seasonal warming and variations in precipitation and temperature extremes (Tmax and Tmin) particularly at higher-elevation sites, resulting in a variability of the DTR, which could have a significant influence on water resources and on the phenology of vegetation and crops at zonal and station level in Punjab.

scholarly journals Strong controls of daily minimum temperature on the autumn photosynthetic phenology of subtropical vegetation in China

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Peixin Ren ◽  
Zelin Liu ◽  
Xiaolu Zhou ◽  
Changhui Peng ◽  
Jingfeng Xiao ◽  
...  
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Time Lag ◽  
Evergreen Forest ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Study Region ◽  
Cumulative Precipitation

Abstract Background Vegetation phenology research has largely focused on temperate deciduous forests, thus limiting our understanding of the response of evergreen vegetation to climate change in tropical and subtropical regions. Results Using satellite solar-induced chlorophyll fluorescence (SIF) and MODIS enhanced vegetation index (EVI) data, we applied two methods to evaluate temporal and spatial patterns of the end of the growing season (EGS) in subtropical vegetation in China, and analyze the dependence of EGS on preseason maximum and minimum temperatures as well as cumulative precipitation. Our results indicated that the averaged EGS derived from the SIF and EVI based on the two methods (dynamic threshold method and derivative method) was later than that derived from gross primary productivity (GPP) based on the eddy covariance technique, and the time-lag for EGSsif and EGSevi was approximately 2 weeks and 4 weeks, respectively. We found that EGS was positively correlated with preseason minimum temperature and cumulative precipitation (accounting for more than 73% and 62% of the study areas, respectively), but negatively correlated with preseason maximum temperature (accounting for more than 59% of the study areas). In addition, EGS was more sensitive to the changes in the preseason minimum temperature than to other climatic factors, and an increase in the preseason minimum temperature significantly delayed the EGS in evergreen forests, shrub and grassland. Conclusions Our results indicated that the SIF outperformed traditional vegetation indices in capturing the autumn photosynthetic phenology of evergreen forest in the subtropical region of China. We found that minimum temperature plays a significant role in determining autumn photosynthetic phenology in the study region. These findings contribute to improving our understanding of the response of the EGS to climate change in subtropical vegetation of China, and provide a new perspective for accurately evaluating the role played by evergreen vegetation in the regional carbon budget.

scholarly journals The Fingerprint of Climate Change and Urbanization in South Korea

Atmosphere ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 273 ◽  
Author(s):  
Won-Ho Nam ◽  
Guillermo Baigorria ◽  
Eun-Mi Hong ◽  
Taegon Kim ◽  
Yong-Sang Choi ◽  
...  
Keyword(s):  
Climate Change ◽  
South Korea ◽  
Urban Areas ◽  
Temporal Trends ◽  
Weather Data ◽  
Maximum Temperature ◽  
Island Effect ◽  
Temperature Trends ◽  
Agricultural Areas ◽  
Precipitation And Temperature

Understanding long-term changes in precipitation and temperature patterns is important in the detection and characterization of climate change, as is understanding the implications of climate change when performing impact assessments. This study uses a statistically robust methodology to quantify long-, medium- and short-term changes for evaluating the degree to which climate change and urbanization have caused temporal changes in precipitation and temperature in South Korea. We sought to identify a fingerprint of changes in precipitation and temperature based on statistically significant differences at multiple-timescales. This study evaluates historical weather data during a 40-year period (1973–2012) and from 54 weather stations. Our results demonstrate that between 1993–2012, minimum and maximum temperature trends in the vicinity of urban and agricultural areas are significantly different from the two previous decades (1973–1992). The results for precipitation amounts show significant differences in urban areas. These results indicate that the climate in urbanized areas has been affected by both the heat island effect and global warming-caused climate change. The increase in the number of rainfall events in agricultural areas is highly significant, although the temporal trends for precipitation amounts showed no significant differences. Overall, the impacts of climate change and urbanization in South Korea have not been continuous over time and have been expressed locally and regionally in terms of precipitation and temperature changes.

scholarly journals Assessing runoff sensitivities to precipitation and temperature changes under global climate-change scenarios

2018 ◽  
Vol 50 (1) ◽  
pp. 24-42 ◽  
Author(s):  
Lei Chen ◽  
Jianxia Chang ◽  
Yimin Wang ◽  
Yuelu Zhu
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Yellow River ◽  
Control Variable ◽  
Maximum Temperature ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Temperature Changes ◽  
Runoff Change ◽  
Precipitation And Temperature

Abstract An accurate grasp of the influence of precipitation and temperature changes on the variation in both the magnitude and temporal patterns of runoff is crucial to the prevention of floods and droughts. However, there is a general lack of understanding of the ways in which runoff sensitivities to precipitation and temperature changes are associated with the CMIP5 scenarios. This paper investigates the hydrological response to future climate change under CMIP5 RCP scenarios by using the Variable Infiltration Capacity (VIC) model and then quantitatively assesses runoff sensitivities to precipitation and temperature changes under different scenarios by using a set of simulations with the control variable method. The source region of the Yellow River (SRYR) is an ideal area to study this problem. The results demonstrated that the precipitation effect was the dominant element influencing runoff change (the degree of influence approaching 23%), followed by maximum temperature (approaching 12%). The weakest element was minimum temperature (approaching 3%), despite the fact that the increases in minimum temperature were higher than the increases in maximum temperature. The results also indicated that the degree of runoff sensitivity to precipitation and temperature changes was subject to changing external climatic conditions.

scholarly journals Dendrochronological Assessment of Whitebark Pine Response to Past Climate Change: Implications for a Threatened Species in Grand Teton National Park

2014 ◽  
Vol 37 ◽  
pp. 58-64
Author(s):  
Kendra McLauchlan ◽  
Kyleen Kelly
Keyword(s):  
Climate Change ◽  
National Park ◽  
Fire History ◽  
Multiple Stressors ◽  
Fire Suppression ◽  
Climatic Variability ◽  
High Elevation ◽  
Whitebark Pine ◽  
Grand Teton National Park ◽  
Pine Trees

One of the keystone tree species in subalpine forests of the western United States – whitebark pine (Pinus albicaulis, hereafter whitebark pine) – is experiencing a significant mortality event (Millar et al. 2012). Whitebark pine occupies a relatively restricted range in the high-elevation ecosystems in the northern Rockies and its future is uncertain. The current decline of whitebark pine populations has been attributed to pine beetle infestations, blister rust infections, anthropogenic fire suppression, and climate change (Millar et al. 2012). Despite the knowledge that whitebark pine is severely threatened by multiple stressors, little is known about the historic capacity of this species to handle these stressors. More specifically, it is unknown how whitebark pine has dealt with past climatic variability, particularly variation in the type of precipitation (rain vs. snow) available for soil moisture, and how differences in quantity of precipitation have influenced the establishment and growth of modern stands. We propose to study the past responses of whitebark pine to paleoclimatic conditions, which would be useful to park ecologists in developing new conservation and regeneration plans to prevent the extinction of this already severely threatened high-elevation resource. The purpose of this study is to determine in great temporal and spatial detail the demographics of the current stand of whitebark pine trees in the watershed surrounding an unnamed, high-altitude pond (known informally as Whitebark Pine Moraine Pond) located approximately 3.06 miles NW of Jenny Lake in Grand Teton National Park (GTNP). The main objectives of this study were: 1.) To obtain the precise GPS locations of the current stand of whitebark pine trees in the watershed to generate a GIS map detailing their locations. 2.) To obtain increment cores of a subset of the trees in the watershed to estimate age and date of establishment for the current stand of whitebark pines, with particular attention to fire history. 3.) To analyze ring widths from core samples to identify climatic indicators that may influence the regeneration and survival of whitebark pine.

Expected impacts of climate change on tree ferns distribution and diversity patterns in subtropical Atlantic Forest

2020 ◽  
Author(s):  
André Luís de Gasper ◽  
Guilherme Salgado Grittz ◽  
Carlos Henrique Russi ◽  
Carlos Eduardo Schwartz ◽  
Arthur Vinicius Rodrigues
Keyword(s):  
Climate Change ◽  
Atlantic Forest ◽  
Regional Scale ◽  
Distribution Area ◽  
Study Region ◽  
Β Diversity ◽  
Forest Sites ◽  
Tree Ferns ◽  
Α Diversity ◽  
Climatic Scenarios

ABSTRACTTree ferns are common elements in the Atlantic Forest domain, sometimes reaching more than half of total dominance at forest sites. Just as most groups, climate change might impact the distribution and diversity of tree ferns. To investigate the extent of these impacts in the subtropical Atlantic Rainforest, we measured the changes in species distribution, α- and β-diversity between current climate and future climatic scenarios for 2050. Most tree ferns species tend to lose their distribution area. Hence, species richness tends to decrease in the future, especially in the Rainforest sites. In general, β-diversity tend to not change on the regional scale, but some sites can change its relative singularity in composition. Our results show that climate change can impact distribution and α-diversity of tree ferns, but with no trend to cause homogenization in the tree ferns of the study area. Protected Areas (PAs) in our study region manage to withhold more α-diversity than areas without PAs — the same applies to β-diversity. Our study offers a new light into the effects of climate change in tree ferns by integrating the evaluation of its impacts on distribution, α- and β-diversity in all study areas and inside PAs.

scholarly journals Impact of Climate Change on the Streamflow Modulated by Changes in Precipitation and Temperature in the North Latitude Watershed of Nepal

Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 117
Author(s):  
Manisha Maharjan ◽  
Anil Aryal ◽  
Rocky Talchabhadel ◽  
Bhesh Raj Thapa
Keyword(s):  
Climate Change ◽  
Temperature Distribution ◽  
Assessment Tool ◽  
Rate Of Change ◽  
Maximum Temperature ◽  
Water Yield ◽  
Impact Of Climate Change ◽  
Northern Latitudes ◽  
The Impact ◽  
Precipitation And Temperature

It is unambiguous that climate change alters the intensity and frequency of precipitation and temperature distribution at the global and local levels. The rate of change in temperature in the northern latitudes is higher than the worldwide average. The annual distribution of precipitation over the Himalayas in the northern latitudes shows substantial spatial and temporal heterogeneity. Precipitation and temperature are the major driving factors that impact the streamflow and water availability in the basin, illustrating the importance of research on the impact of climate change on streamflow by varying the precipitation and temperature in the Thuli Bheri River Basin (TBRB). Multiple climate models were used to project and evaluate the precipitation and temperature distribution changes in temporal and spatial domains. To analyze the potential impact of climate change on the streamflow in the basin, the Soil and Water Assessment Tool (SWAT) hydrological model was used. The climate projection was carried out in three future time windows. The result shows that the precipitation fluctuates between approximately +12% and +50%, the maximum temperature varies between −7% and +7%, and the minimum temperature rises from +0.7% to +5% in intermediate- and high-emission scenarios. In contrast, the streamflow in the basin varies from −40% to +85%. Thus, there is a significant trend in the temperature increase and precipitation reduction in the basin. Further, the relationship between precipitation and temperature with streamflow shows a substantial dependency between them. The variability in precipitation and streamflow is successfully represented by the water yield in the basin, which plays an important role in the sustainability of the water-related projects in the basin and downstream to it. This also helps quantify the amount of water available for hydropower generation, agricultural production, and the water ecosystem in the TBRB.

scholarly journals Treeline dynamics with climate change at the central Nepal Himalaya

2014 ◽  
Vol 10 (4) ◽  
pp. 1277-1290 ◽  
Author(s):  
N. P. Gaire ◽  
M. Koirala ◽  
D. R. Bhuju ◽  
H. P. Borgaonkar
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Plant Density ◽  
Elevation Gradient ◽  
Age Distribution ◽  
Maximum Temperature ◽  
High Mountain ◽  
Nepal Himalaya ◽  
Central Nepal ◽  
The Impact

Abstract. Treeline shifting in tandem with climate change has widely been reported from various parts of the world. In Nepal, several impacts of climate change on the physical environment have been observed, but study on the biological impacts is lacking. This dendrochronological study was carried out at the treeline in the high mountain slope of Kalchuman Lake (3750–4003 m a.s.l.) area of Manaslu Conservation Area in the central Nepal Himalaya to explore the impact of climate change on the treeline dynamic. Two belt transect plots (size: 20 m wide, > 250 m long) were laid which included treeline as well as tree species limit. Ecological mapping of all individuals of dominant trees Abies spectabilis and Betula utilis was done and their tree cores were collected. Stand character and age distribution revealed an occurrence of more matured B. utilis (max. age 198 years) compared to A. spectabilis (max. age 160 years). A. spectabilis contained an overwhelmingly high population (89%) of younger plants (< 50 years) indicating its high recruitment rate. Population age structure along the elevation gradient revealed an upward shifting of A. spectabilis at the rate of 2.61 m year-1 since AD 1850. The upper distribution limit of B. utilis was found to be stagnant in the past few decades. An increment in plant density as well as upward shifting in the studied treeline ecotones was observed. The temporal growth of A. spectabilis was correlated negatively with the monthly mean and minimum temperature of June to September of the current and previous year. The regeneration of A. spectabilis, on the other hand, was positively correlated with August precipitation and monthly maximum temperature of the month of the current year. The growth and regeneration of A. spectabilis was more sensitive to maximum and minimum temperature rather than average temperature. The growth of the B. utilis was mainly limited by moisture stress during the pre-monsoon season. As these two species presented species-specific responses to climate change with differential pattern in regeneration condition, much wider differences are anticipated in their population status as climate continues to change throughout the century.

scholarly journals Niche expansion leads to small-scale adaptive divergence along an elevation gradient in a medium-sized passerine bird

2008 ◽  
Vol 275 (1647) ◽  
pp. 2155-2164 ◽  
Author(s):  
John E McCormack ◽  
Thomas B Smith
Keyword(s):  
Gene Flow ◽  
Regional Scale ◽  
Elevation Gradient ◽  
Passerine Bird ◽  
High Elevation ◽  
Adaptive Divergence ◽  
Small Scale ◽  
Niche Expansion ◽  
Aphelocoma Ultramarina ◽  
Pine Cones

Niche expansion can lead to adaptive differentiation and speciation, but there are few examples from contemporary niche expansions about how this process is initiated. We assess the consequences of a niche expansion by Mexican jays ( Aphelocoma ultramarina ) along an elevation gradient. We predicted that jays at high elevation would have straighter bills adapted to feeding on pine cones, whereas jays at low elevation would have hooked bills adapted to feeding on acorns. We measured morphological and genetic variation of 95 adult jays and found significant differences in hook length between elevations in accordance with predictions, a pattern corroborated by analysis at the regional scale. Genetic results from microsatellite and mtDNA variation support phenotypic differentiation in the presence of gene flow coupled with weak, but detectable genetic differentiation between high- and low-elevation populations. These results demonstrate that niche expansion can lead to adaptive divergence despite gene flow between parapatric populations along an elevation gradient, providing information on a key precursor to ecological speciation.

scholarly journals Effect of Land Use and Climate Change on Runoff in the Dongjiang Basin of South China

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Yanhu He ◽  
Kairong Lin ◽  
Xiaohong Chen
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
Land Use Change ◽  
Urban Areas ◽  
Regional Scale ◽  
Moderate Increase ◽  
Great Decrease ◽  
Runoff Change ◽  
Social And Economic Development

Variability and availability of water resources under changing environment in a regional scale have been hot topics in recent years, due to the vulnerability of water resources associated with social and economic development. In this paper, four subbasins in the Dongjiang basin with a significant land use change were selected as case study. Runoffs of the four subbasins were simulated using the SCS monthly model to identify the quantitative impacts of land use and climate change. The results showed that (1), in the Dongjiang basin, temperature increased significantly, evaporation and sunlight decreased strongly, while precipitation showed a nonsignificant increase; (2) since the 1980s, land uses in the Dongjiang basin have experienced a significant change with a prominent increase in urban areas, a moderate increase in farmlands, and a great decrease in forest areas; (3) the SCS monthly model performed well in the four subbasins giving that the more significant land use change in each subbasin, the more runoff change correspondingly; (4) overall, runoff change was contributed half and half by climate change and human activities, respectively, in all the subbasins, in which about 20%~30% change was contributed by land use change.

scholarly journals Impact of climate change on the blue water footprint of agriculture on a regional scale

2018 ◽  
Vol 19 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Huiping Huang ◽  
Yuping Han ◽  
Dongdong Jia
Keyword(s):  
Climate Change ◽  
Temporal Change ◽  
Water Footprint ◽  
Regional Scale ◽  
Maximum Temperature ◽  
Agricultural Water ◽  
Climate Change Projections ◽  
Change Models ◽  
Average Value

Abstract In the case study of Tangshan city, Hebei Province, China, this paper analyzes the temporal change of the blue agricultural water footprint (WF) during 1991–2016 and discusses the applicability of different climate change models during 2017–2050. Results show effective rainfall, wind speed and maximum temperature are leading factors influencing the blue agricultural WF. Relative error analysis indicates that the HadGEM2-ES model is the most applicable for climate change projections in the period of 2017–2050. Agricultural blue WF is about 1.8 billion m3 in RCP2.6, RCP4.5 and RCP8.5 emission scenarios, which is almost equal to the average value during 1991–2016.

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