scholarly journals Climatic Anomalies and Glacial Dynamics in the Himalayan Region Northern Pakistan: A Spatio-Statistical Approach

2021 ◽  
Vol 53 (2) ◽  
Author(s):  
Zarka Mukhtar ◽  
Fazlul Haq ◽  
Syed Ali Asad Naqvi ◽  
Munazza Afreen

Glaciers are always climate-sensitive and affected by minor changes in temperature and other climatic elements. Past studies on the northern mountain ranges of Pakistan reveal changes in climatic patterns in and around these ranges. In this study, an attempt is made to explore and assess the temporal and spatial fluctuations occurring in the ice cover of the Himalayan Region of Pakistan as a result of changes in climatic pattern. Satellite imageries and meteorological data were used to explore the dynamics of both the ice cover and climatic elements. Remote Sensing and Geographical Information System were used to detect changes in snow cover both spatially and temporally. Various statistical techniques, mainly Mann Kendall Trend Test and Sen’s Slope Estimator, were used to analyze the temporal trend of climatic elements. Moreover, correlation and regression analysis were applied to establish the relationship between climate and ice cover. Analysis of the data reveals that the temporal trend in ice cover is not monotonic as there is glacial advancement in certain years while retreating in others. Moreover, it was found out that climatic elements such as temperature and precipitation have recorded changes during the past few decades.

2020 ◽  
Vol 11 (S1) ◽  
pp. 289-309 ◽  
Author(s):  
Hrachuhi Galstyan ◽  
Shamshad Khan ◽  
Hovik Sayadyan ◽  
Artur Sargsyan ◽  
Tatevik Safaryan

Abstract The primary goal of the study is to analyze the spatial-temporal trends and distribution of flood events in the context of climate change in Armenia. For that purpose, some meteorological parameters, physical-geographical factors and the flood events data were studied for the 1994–2019 period. The linear trends demonstrate an increasing tendency of air temperature and precipitation. Those trends expressed increased flood occurrences, especially for the 2000s, whereas the Mann–Kendall (MK) trend test reveals no significant change. The number of flood events reaches its maximum in 2011 with its peak in May. Out of 191 flood events, half of the occurrences are recorded in the flat areas and southern aspects of the mountains (22% of the country's territory). There is a certain clustering of flood events in the areas with up to 5° slopes (66% of flood events). The most flood vulnerable areas were analyzed and mapped via Geographical Information System (GIS). The GIS-based mapping shows the location of flood vulnerable areas in the central, northern parts of the country, and the coastal areas of Lake Sevan. Our methodological approach elaborates the localization of flood-prone sites. It can be used for the flood hazard assessment mapping and risk management.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 334
Author(s):  
Norbert Szymański ◽  
Sławomir Wilczyński

The present study identified the similarities and differences in the radial growth responses of 20 provenances of 51-year-old European larch (Larix decidua Mill.) trees from Poland to the climatic conditions at three provenance trials situated in the Polish lowlands (Siemianice), uplands (Bliżyn) and mountains (Krynica). A chronology of radial growth indices was developed for each of 60 European larch populations, which highlighted the interannual variations in the climate-mediated radial growth of their trees. With the aid of principal component, correlation and multiple regression analysis, supra-regional climatic elements were identified to which all the larch provenances reacted similarly at all three provenance trials. They increased the radial growth in years with a short, warm and precipitation-rich winter; a cool and humid summer and when high precipitation in late autumn of the previous year was noted. Moreover, other climatic elements were identified to which two groups of the larch provenances reacted differently at each provenance trial. In the lowland climate, the provenances reacted differently to temperature in November to December of the previous year and July and to precipitation in September. In the upland climate, the provenances differed in growth sensitivity to precipitation in October of the previous year and June–September. In the mountain climate, the provenances responded differently to temperature and precipitation in September of the previous year and to precipitation in February, June and September of the year of tree ring formation. The results imply that both climatic factors and origin (genotype), i.e., the genetic factor, mediate the climate–growth relationships of larch provenances.


2009 ◽  
Vol 50 (50) ◽  
pp. 126-134 ◽  
Author(s):  
Johanna Nemec ◽  
Philippe Huybrechts ◽  
Oleg Rybak ◽  
Johannes Oerlemans

AbstractWe have reconstructed the annual balance of Vadret da Morteratsch, Engadine, Switzerland, with a two-dimensional energy-balance model for the period 1865–2005. The model takes into account a parameterization of the surface energy fluxes, an albedo that decreases exponentially with snow depth as well as the shading effect of the surrounding mountains. The model was first calibrated with a 5 year record of annual balance measurements made at 20 different sites on the glacier between 2001 and 2006 using meteorological data from surrounding weather stations as input. To force the model for the period starting in 1865, we employed monthly temperature and precipitation records from nearby valley stations. The model reproduces the observed annual balance reasonably well, except for the lower part during the warmest years. Most crucial to the results is the altitudinal precipitation gradient, but this factor is hard to quantify from the limited precipitation data at high elevations. The simulation shows an almost continuous mass loss since 1865, with short interruptions around 1920, 1935 and 1980. A trend towards a more negative annual balance can be observed since the beginning of the 1980s. The simulated cumulative mass balance for the entire period 1865–2005 was found to be –46mw.e.


2017 ◽  
Vol 26 (2) ◽  
pp. 122 ◽  
Author(s):  
Kunpeng Yi ◽  
Yulong Bao ◽  
Jiquan Zhang

This study presents the spatial and temporal patterns of vegetation fires in China based on a combination of national fire records (1950–2010) and satellite fire data (2001–12). This analysis presents the first attempt to understand existing patterns of open fires and their consequences for the whole of China. We analysed inter- and intra-annual fire trends and variations in nine subregions of China as well as associated monthly meteorological data from 130 stations within a 50-year period. During the period 2001–12, an average area of 3.2 × 106 ha was consumed by fire per year in China. The Chinese fire season has two peaks occurring in the spring and autumn. The profiles of the burnt area for each subregion exhibit distinct seasonality. The majority of the vegetation fires occurred in the north-eastern and south-western provinces. We analysed quantitative relationships between climate (temperature and precipitation) and burnt area. The results indicate a synchronous relationship between precipitation variation and burnt area. The data in this paper reveal how climate and human activities interact to create China’s distinctive pyrogeography.


2007 ◽  
Vol 38 (1) ◽  
pp. 59-77 ◽  
Author(s):  
Pratap Singh ◽  
Umesh K. Haritashya ◽  
Naresh Kumar

In spite of the vital role of high altitude climatology in melting of snow and glaciers, retreat or advancement of glaciers, flash floods, erosion and sediment transport, etc., weather conditions are not much studied for the high altitude regions of Himalayas. In this study, a comprehensive meteorological analysis has been made for the Gangotri Meteorological Station (Bhagirathi Valley, Garhwal Himalayas) using data observed for four consecutive melt seasons (2000–2003) covering a period from May to October for each year. The collected meteorological data includes rainfall, temperature, wind speed and direction, relative humidity, sunshine hours and evaporation. The results and their distribution over the different melt seasons were compared with available meteorological records for Dokriani Meteorological Station (Dingad Valley, Garhwal Himalayas) and Pyramid Meteorological Station (Khumbu Valley, Nepal Himalayas). The magnitude and distribution of temperature were found to be similar for different Himalayan regions, while rainfall varied from region to region. The influence of the monsoon was meagre on the rainfall in these areas. July was recorded to be the warmest month for all the regions and, in general, August had the maximum rainfall. For all the stations, daytime up-valley wind speeds were 3 to 4 times stronger than the nighttime down-valley wind speeds. It was found that the Gangotri Glacier area experienced relatively low humidity and high evaporation rates as compared to other parts of the Himalayas. Such analysis reveals the broad meteorological characteristics of the high altitude areas of the Central Himalayan region.


2021 ◽  
Author(s):  
Simon C. Scherrer ◽  
Christoph Spirig ◽  
Martin Hirschi ◽  
Felix Maurer ◽  
Sven Kotlarski

<p>The Alpine region has recently experienced several dry summers with negative impacts on the economy, society and ecology. Here, soil water, evapotranspiration and meteorological data from several observational and model-based data sources is used to assess events, trends and drivers of summer drought in Switzerland in the period 1981‒2020. 2003 and 2018 are identified as the driest summers followed by somewhat weaker drought conditions in 2020, 2015 and 2011. We find clear evidence for an increasing summer drying in Switzerland. The observed climatic water balance (-39.2 mm/decade) and 0-1 m soil water from reanalysis (ERA5-Land: -4.7 mm/decade; ERA5: -7.2 mm/decade) show a clear tendency towards summer drying with decreasing trends in most months. Increasing evapotranspiration (potential evapotranspiration: +21.0 mm/decade; ERA5-Land actual evapotranspiration: +15.1 mm/decade) is identified as important driver which scales excellently (+4 to +7%/K) with the observed strong warming of about 2°C. An insignificant decrease in precipitation further enhanced the tendency towards drier conditions. Most simulations of the EURO-CORDEX regional climate model ensemble underestimate the changes in summer drying. They underestimate both, the observed recent summer warming and the small decrease in precipitation. The changes in temperature and precipitation are negatively correlated, i.e. simulations with stronger warming tend to show (weak) decreases in precipitation. However, most simulations and the reanalysis overestimate the correlation between temperature and precipitation and the precipitation-temperature scaling on the interannual time scale. Our results emphasize that the analysis of the regional summer drought evolution and its drivers remains challenging especially with regional climate model data but considerable uncertainties also exist in reanalysis data sets.</p>


2021 ◽  
Vol 13 (20) ◽  
pp. 4090
Author(s):  
Amit Kumar Batar ◽  
Hideaki Shibata ◽  
Teiji Watanabe

An estimation of where forest fragmentation is likely to occur is critically important for improving the integrity of the forest landscape. We prepare a forest fragmentation susceptibility map for the first time by developing an integrated model and identify its causative factors in the forest landscape. Our proposed model is based upon the synergistic use of the earth observation data, forest fragmentation approach, patch forests, causative factors, and the weight-of-evidence (WOE) method in a Geographical Information System (GIS) platform. We evaluate the applicability of the proposed model in the Indian Himalayan region, a region of rich biodiversity and environmental significance in the Indian subcontinent. To obtain a forest fragmentation susceptibility map, we used patch forests as past evidence of completely degraded forests. Subsequently, we used these patch forests in the WOE method to assign the standardized weight value to each class of causative factors tested by the Variance Inflation Factor (VIF) method. Finally, we prepare a forest fragmentation susceptibility map and classify it into five levels: very low, low, medium, high, and very high and test its validity using 30% randomly selected patch forests. Our study reveals that around 40% of the study area is highly susceptible to forest fragmentation. This study identifies that forest fragmentation is more likely to occur if proximity to built-up areas, roads, agricultural lands, and streams is low, whereas it is less likely to occur in higher altitude zones (more than 2000 m a.s.l.). Additionally, forest fragmentation will likely occur in areas mainly facing south, east, southwest, and southeast directions and on very gentle and gentle slopes (less than 25 degrees). This study identifies Himalayan moist temperate and pine forests as being likely to be most affected by forest fragmentation in the future. The results suggest that the study area would experience more forest fragmentation in the future, meaning loss of forest landscape integrity and rich biodiversity in the Indian Himalayan region. Our integrated model achieved a prediction accuracy of 88.7%, indicating good accuracy of the model. This study will be helpful to minimize forest fragmentation and improve the integrity of the forest landscape by implementing forest restoration and reforestation schemes.


Rangifer ◽  
2009 ◽  
Vol 27 (2) ◽  
pp. 107-119
Author(s):  
Henrik Lundqvist ◽  
Öje Danell

The 51 reindeer herding districts in Sweden vary in productivity and prerequisites for reindeer herding. In this study we characterize and group reindeer herding districts based on relevant factors affecting reindeer productivity, i.e. topography, vegetation, forage value, habitat fragmentation and reachability, as well as season lengths, snow fall, ice-crust probability, and insect harassment, totally quantified in 15 variables. The herding districts were grouped into seven main groups and three single outliers through cluster analyses. The largest group, consisting of 14 herding districts, was further divided into four subgroups. The range properties of herding districts and groups of districts were characterized through principal component analyses. By comparisons of the suggested grouping of herding districts with existing administrative divisions, these appeared not to coincide. A new division of herding districts into six administrative sets of districts was suggested in order to improve administrative planning and management of the reindeer herding industry. The results also give possibilities for projections of alterations caused by an upcoming global climate change. Large scale investigations using geographical information systems (GIS) and meteorological data would be helpful for administrative purposes, both nationally and internationally, as science-based decision tools in legislative, economical, ecological and structural assessments. Abstract in Swedish / Sammanfattning: Multivariat gruppering av svenska samebyar baserat på renbetesmarkernas grundförutsettningar Svenska renskötselområdet består av 51 samebyar som varierar i produktivitet och förutsättningar för renskötsel. Vi analyserade variationen mellan samebyar med avseende på 15 variabler som beskriver topografi, vegetation, betesvärde, fragmentering av betesmarker, klimat, skareförekomst och aktivitet av parasiterande insekter och vi föreslår en indelning av samebyar i tio grupper. Den största gruppen, som bestod av 14 samebyar, delades vidare in i 4 undergrupper. Klusteranalyser med 4 olika linkage-varianter användes till att gruppera samebyarna. Principalkomponentsanalys användes för att kartlägga undersökta variabler och de resulterande samebygruppernas karaktär. Samebygrupperna följde inte länsgränser och tre samebyar föll ut som enskilda grupper. Denna undersökning ger underlag för jämförelser mellan samebyar med beaktande av likheter och olikheter i fråga om produktivitet och funktionella särdrag istället för länsgränser och historik. Vi föreslår en ny administrativ indelning i sex områden som skulle kunna fungera som ett alternativt underlag för planering och beslut som rör produktionsaspekter i rennäringen. Resultaten ger också underlag för förutsägelser av förändringar i samebyars produktionsförutsättningar till följd av klimatförändringar.


2021 ◽  
Author(s):  
Christian Zeeden ◽  
Mathias Vinnepand ◽  
Kamila Ryzner ◽  
Christian Rolf ◽  
Christian Laag ◽  
...  

<p>Spatial patterns of precipitation and aridity across Europe are most likely to vary in response to changing temperature. Our knowledge about such responses is, however, still limited as most geoscientific studies provide point data rather than cover wider areas. Such an approach would require reliable proxies, which can be determined in high spatial resolution along with detailed knowledge about how these reflect climate. Classically, we derive (paleo-) precipitation and -temperature for terrestrial areas from climofunctions, which base on magnetic susceptibility (χ) and its frequency dependence (χ<sub>fd</sub>). These parameters reflect the quantity and modification state of magnetic minerals like magnetite, which are dependent on the combined influence of temperature and precipitation. Recently, also the maghemite contribution to the high-temperature dependent susceptibility (χ<sub>td</sub>) has been used to create climofunctions, which are mainly constrained to reconstruction of (palaeo-) precipitation. Yet, such relationships have mostly been reported from Asia.</p><p>In this study, we test if we can qualify and quantify (palaeo-) precipitation, temperature and aridity by room- and high-temperature rock magnetic and colorimetric data of recent topsoils in a narrow precipitation range between ~535 mm/a and 585 mm/a. The data are derived from geographically evenly distributed bulk-samples from the Backa Loess Plateau (Middle Danube Basin). Our results show that we can quantify precipitation by rock magnetic properties (χ, χ<sub>fd</sub>, as well as χ<sub>td</sub>), but colorimetric methods are more challenging to interpret. While we can also reconstruct aridity, temperature is difficult to determine in a meaningful way.</p><p>In this contribution, we show the results of statistical analysis performed on a multivariate rock magnetic and colorimetric dataset, and their relation to geographical differences in prevailing climatic regimes of the Middle Danube Basin. While care needs to be taken not to overfit the data (due to more colorimetric variables than spatial data points), we regard our multivariate approach at least as relevant as trying to fit individual magnetic or colorimetric proxies to climate variables.</p>


1993 ◽  
Vol 18 ◽  
pp. 107-112
Author(s):  
Tatsuhito Ito ◽  
Masaru Yamaoka ◽  
Hisayuki Ohura ◽  
Takashi Taniguchi ◽  
Gorow Wakahama

In Hokkaido we have often experienced hazardous accidents, such as tower collapses and conductor breakage, caused by wet-snow accretion on transmission lines, and over many years have developed countermeasures for wet-snow accretion. Recently we have been developing a system to forecast areas where snow accretion may occur. We used the southern part of Hokkaido, divided into 5 km × 5 km meshes, as a forecast area; our predictions were hourly, 3–24 hours in advance. A method of predicting meteorological data which forms an important part of the system predicts three elements which influence wet-snow accretion: air temperature, precipitation, and wind direction and speed. We used an interpolation for predicting temperature and precipitation and a one-level, mesoscale model for diagnosing surface winds for wind direction and speed. By applying the method to many examples of wet-snow accretion, we checked the prediction of weather elements.


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