Climate change and finger millet: Perception,trend and impact on yield in different ecological regions in Central Nepal

The views of local people on climate change along different ecological regions are relatively unexplored in Nepal. This study was conducted in 13 villages in central Nepal at different altitudes to document the views of small holder farmers and compare their perception with trends of climatic variables, finger millet yield, natural disasters, plant phenology(flowering and fruiting), status of forest and wild life, as well as the spread of diseases and pests. Analysis on the climatic data of stations for 36-41 years between 1975 and 2016 showed significant increases in the minimum temperature in lower tropical climatic region(500 m), upper tropical to subtropical climatic region(500-2000 m) and temperate climatic region(2000-3000 m) by 0.01, 0.026 and 0.054℃/year, respectively, and an increase of maximum temperature by 0.008, 0.018, and 0.019℃/year, respectively. Rainfall showed a strongly significant decreasing trend in all elevation regions. This result matches with the views of respondents except 38% respondent from temperate climatic region. People from the temperate climatic region also mentioned that current onset of snowfall is delayed but amount of snowfall remained the same. From the documented records, except events of wild fire, frequency of natural disasters events have increased in the recent years, which was in harmony with the views of local people. Multi-linear regression analysis showed that contribution of climatic variables on finger millet yield in lower tropical climatic region and upper tropical to subtropical regions was 23% and 57.3%, respectively, which was supported by increasing trend on average growing degree day(GDD) temperature at the rate of 0.01℃ in upper tropical to subtropical region and 0.007℃ in lower tropical climatic region yearly. Finger millet yield has been increasing at the rate of 7.39 and 36.9 kg/ha yearly in lower tropical climatic region and upper tropical to subtropical climatic region, respectively. This result provides deeper understanding of people's perception of causes and effects of climate change on diverse variables along different elevation and related magnitude which can contribute to policy making in Nepal.     

Predicting suitable habitat of an invasive weed Parthenium hysterophorus under future climate scenarios in Chitwan Annapurna Landscape,Nepal

Chitwan-Annapuma Landscape(CHAL)in central Nepal is known for its rich biodiversity and the landscape is expected to provide corridors for species range shift in response to climate change.Environmental assessments have identified biological invasions and other anthropogenic activities as major threats to the biodiversity in the CHAL.One of the rapidly spreading Invasive Alien Plant species(IAPs)in the CHAL is Parthenium hysterophorus L.,a neotropical invasive weed of global significance.This study aimed to investigate the current and future projected suitable habitat of P.hysterophorus in the CHAL using MaxEnt modelling in three"Representative Concentration Pathways"(RCPs 2.6,4.5 and 8.5)corresponding to different greenhouse gases emissiontrajectories for the year 2050 and 2070.A total of 288species occurrence points,six bioclimatic variablesmean diurnal range,isothermality,annual precipitation,precipitation of driest month,precipitation seasonality,precipitation of driest quarter and two topographic variables(aspect and slope)were selected for MaxEnt modelling.Potential range shift in terms of increase or decline in the suitable habitat areas under the projected scenarios were calculated.Slope and annual precipitation were the most important variables that explained the current distribution of P.hysterophorus.Twenty percent of the total area of CHAL was predicted to be suitable habitat for the growth of P.hysterophorus in the current climatic condition.Highest gain in the suitable habitat of this noxious weed was found under RCP 4.5 scenario in 2050 and 2070.whereas there will be a loss in thesuitable habitat under RCP 8.5 scenario in 2050 and2070.Out of four physiographic regions present in CHAL,three regions-Siwalik,Middle Mountain and High Mountain have suitable habitat for P.hysterophorus under current climatic condition.The mountainous region is likely to be affected more than the Siwalik region by further spread of P.fhysteropfhorus in the future under low(RCP 2.6)to medium(RCP 4.5)emission scenarios.The suitable habitat for this weed is likely to increase in the protected areas of mountain regions(Langtang National Park,Annapurna Conservation Area and Manaslu Conservation Area)in the future.The results have revealed a risk of spreading P.hysterophorus from present localities to non-invaded areas in the current and future climatic condition.Such risk needs to be considered by decision makers and resource managers while planning for effective management of this weed to reduce its ecological and economic impacts in the CHAL.     

Satellite stereo data for dem surfaces and derivatives

Various attributes can be derived from Digital Elevation Model (DEM), which are essential to analyze watershed physical characteristics. This paper discusses utility and accuracy of satellite DEM surfaces and their derivatives. Facilities available in various software packages were compared to generate DEM from satellite data and other sources. For test site at Chamba, Uttaranchal, DEMs produced from various algorithms were evaluated for accuracy of surface and its derivatives. Most of the algorithms have shown correlation coefficient of 0.99 and above but the desirable maximum error in spot height (1/5 of contour interval) is not achieved. Slope and aspect produced from various algorithms were comparable around 70-80%. Comparison of DEM surface and its derivatives were attempted for test sites at Shimla and Nahan using IRS-1C and SPOT PAN stereo pair, respectively. Model accuracy has shown that error in height is higher than planimetry. Surface derivatives from stereo DEM for Shimla and Nahan test sites have shown an overall accuracy of 56.5% and 59.2% for slope; 49.79% and 71.21% for aspect and 74.15% for topographic level slicing, respectively. Accuracy has improved when observed class value was lowered or put-up by one unit.     

Book reviews

VANCOUVER'S CHINATOWN: racial discourse in Canada 1875–1980 by K. J. Anderson. 16 × 24 cm, 323 pages. McGill‐Queen's University Press, Montreal, 1991. (ISBN 07735 0844 9) $C34.95 (hard).

GEOGRAPHIC INFORMATION SYSTEMS: developments and applications edited by L. Worrall. 15 × 23 cm, 251 pages. Belhaven, London, 1990. (ISBN 1 85293 140 X) £45.00 (hard).

SAVANNA ECOLOGY AND MANAGEMENT: Australian perspectives and intercontinental comparisons edited by P. A. Werner. 22 × 27 cm, xii and 221 pages. Blackwell Scientific, Oxford, 1991. (ISBN 0 632 03199 9) $A89.00 (soft).

GLOBAL CHANGE AND CHALLENGE: geography for the 1990s edited by R. J. Bennett and R. Estall. 14 × 22 cm, xii and 264 pages. Routledge, London, 1991. (ISBN 0 415 00143 9) $A29.95 (soft).

PLAINS OF PROMISE RIVERS OF DESTINY: water management and the development of Queensland 1824–1990 by J. M. Powell. 17 × 24 cm, xvii and 395 pages. Boolarong Publications, Brisbane, 1991. (ISBN 0 7242 4470 0) $A40.00 (hard).

A SHARED HARVEST: The Australian Wheat Industry, 1939–1989 by G. Whitwell and D. Sydenham. 17 × 25 cm, xi and 324 pages. Macmillan, Melbourne, 1991. (ISBN 0 7329 0584 2) $A29.95 (hard).

TAMING THE GREAT SOUTH LAND: a history of the conquest of nature in Australia by W. J. Lines. 16 × 23cm, xx and 337 pages. Allen & Unwin, Sydney, 1991. (ISBN 1 86373 017 6) $A34.95 (hard).

PLAINS OF PROMISE RIVERS OF DESTINY: water management and the development of Queensland 1824–1990 by J. M. Powell. 17 × 24 cm, xvii and 395 pages. Boolarong Publications, Brisbane, 1991. (ISBN 0 7242 4470 0) $A40.00 (hard).

THE HUMANITIES AND THE AUSTRALIAN ENVIRONMENT: Papers from the Australian Academy of the Humanities Symposium edited by D. J. Mulvaney. 24 × 17 cm, xiii and 123 pages. Australian Academy of the Humanities, Canberra, 1991. (ISBN 0 909897 22 0) $A18.50 posted (soft).

GROWTH (Vol. 167, Sage Library of Social Research) by H. Teune. 141 pages. Sage Publications, Newbury Park, CA, 1988. (ISBN 0 8039 3183 2) US$46.00 (hard); (ISBN 0 8039 3190 5) US$22.95 (soft).

BEYOND GROWTH: elements of sustainable development by U.E. Simonis. 151 pages. Edition Sigma Bohn, Berlin, 1990. (ISBN 3 924859 56 6) DM24.80 (soft).

BEYOND BEEF: the rise and fall of the cattle culture by J. Rifkin. 16 × 24 cm, xi and 353 pages. Viking O'Neil, Melbourne, 1992. (ISBN 0 670 84844 1) $35.00 (hard).

A QUESTION OF PLACE: exploring the practice of human geography by R.J. Johnston. 15 × 23 cm, ix and 280 pages. Blackwell, Oxford, 1991. (ISBN 0 631 18207 1) $39.95 (soft).

GEOGRAPHY IN SOCIETY edited by R. Gerber. 21 × 29 cm, 92 pages. Royal Geographical Society of Queensland, Brisbane, [1992]. (ISBN 0 949286 02 8) $8.00 (soft).     

Effect of reducing groundwater on the retardation of redox-sensitive radionuclides

Laboratory batch sorption experiments were used to investigate variations in the retardation behavior of redox-sensitive radionuclides. Water-rock compositions were designed to simulate subsurface conditions at the Nevada Test Site (NTS), where a suite of radionuclides were deposited as a result of underground nuclear testing. Experimental redox conditions were controlled by varying the oxygen content inside an enclosed glove box and by adding reductants into the testing solutions.     

Geostatistical modelling of the spatial life history of post-larval deepwater hake Merluccius paradoxus in the Benguela Current Large Marine Ecosystem

Optimal and sustainable management of fish resources cannot be ensured without a thorough understanding of the migration patterns and population (demographic stock) structure. Recent studies suggest that these aspects of the economically and ecologically important deepwater hake Merluccius paradoxus are not reflected in the current assessment and management practices for the Benguela Current Large Marine Ecosystem. In this study, we compiled data from multiple demersal trawl surveys from the entire distribution area and applied state-of-the-art geostatistical population modelling (GeoPop) to estimate growth rate, mortality, and spatial and temporal distribution patterns of M. paradoxus. The data and the model enabled us to follow temporal and spatial changes in the distribution and infer movements from the recruitment/nursery areas, through the juvenile phase and the adults’ migration to the spawning areas outside/upstream of the nursery areas. The results indicated one primary recruitment/nursery area on the west coast of South Africa and a secondary less-productive recruitment/nursery area on the south coast near Port Elizabeth. Juveniles initially migrated away from the main recruitment area, followed by natal homing by larger individuals. This pattern was highly consistent through the time-series of the study. This perception of a, primarily, panmictic population that performs transboundary migrations between Namibia and South Africa corresponds largely to the hypothesis and data plots given in recent studies. We recommend that fisheries assessment, advice and management take into consideration these aspects of the distribution and population (stock) structure of M. paradoxus.     

Hydrodynamic modelling and vulnerability analysis to assess flood risk in a dense Indian city using geospatial techniques

Natural Hazards - Urban flooding and waterlogging are causing menace in many cities around the world from the perspective of day-to-day functioning, health and hygiene, communication, and the...     

A method and a GUI based JAVA code for interactive gravity modeling of strike limited listric fault sources with arbitrary density-depth variations

A method coupled with a GUI based computer program, FRGMLSTRK, coded in JAVA, has been developed to interactively model the gravity anomalies of strike-limited listric fault sources where the detached hanging wall of the structure consists of several geologic formations that have different densities and thicknesses. The program is simple and user friendly in the sense that it allows interactive model construction and modification, the display of fault geometry, depth and the densities of various sub-surface formations, and real-time computation of the gravity anomalies arising from the model. The non-planar fault planes are analytically constructed by fitting a polynomial function of arbitrary but specific degree to a set of points selected on the fault plane by means of a few mouse clicks in the structure panel of the graphical layout. Further, input parameters pertaining to depths and densities of formations can be specified by means of mouse clicks in respective panels. Subsequent changes in these parameters can be realized by simple drag and drop mouse operations. The modeled gravity anomalies are automatically updated and displayed whenever changes are made to: (i) the geometry of the fault plane; (ii) depths of density interfaces; and (iii) densities of formations. These changes can be made either independently or in combination. In addition to displaying the results in graphical form, the code also generates the output in ASCII format. The applicability of the code is demonstrated with both a simple synthetic model and real-world gravity anomalies from the margin of the Chintalpudi sub-basin in India.     

大别北麓汤家坪花岗斑岩锆石LA-ICPMS U-Pb定年和岩石地球化学特征及其对岩石成因的制约

河南商城县汤家坪花岗斑岩产于大别造山带北麓,岩体位于早白垩世达权店花岗岩体的南缘。岩体斑晶含量占10%左右,主要由钾长石、斜长石和石英组成,基质主要由钾长石、斜长石、石英和少量黑云母组成,副矿物主要为磁铁矿、赤铁矿、锆石。花岗斑岩中锆石U-Pb年龄为121.6±4.6Ma,为早白垩世中晚期。汤家坪花岗斑岩含白云母,无角闪石,具高硅(SiO272%)、高碱(Na2O+K2O7.4%)的特征,铝饱和指数(ACNK)为0.99～1.18,轻稀土富集、重稀土亏损(La/Yb)N=10.9～44.5,明显亏损Eu(δEu=0.40～0.58)、Sr、Ba、Nb等。P2O5与SiO2含量呈正相关关系、Pb与SiO2含量呈负相关关系、Y、Th随Rb升高而降低,属弱过铝质高分异S型花岗岩。汤家坪花岗斑岩εHf(t)(-17.6～-10.4)和εNd(t)(-15.5～-13.7)值均显示出壳源特征,tDM2(Hf)和tDM2(Nd)分别为1843～2281Ma和2034～2178Ma,反映汤家坪花岗斑岩来源于古老地壳物质的重熔,中等的初始Sr同位素指示源岩中可能有部分低成熟度地壳物质加入。结合稀土元素特征,认为汤家坪花岗斑岩源岩来源较深,主要源于下地壳物质。