Protected areas have had significant impacts on local communities primarily through the physical removal of people. In some instances, people continue to live within protected areas due to the inability of the state to evict them. The restrictions on livelihoods placed on people living inside protected areas lead to in situ displacement. We show how conservation enclosures in the Biligiri Rangaswamy Temple Tiger Reserve have produced a class of people that the state ‘lets die’ by banning customary practices such as fire use, hunting and harvesting of forest produce. Using longitudinal ethnographic, socio‐economic and ecological data, we demonstrate that conservation policy has alienated indigenous forest dwellers from their agricultural and forest‐land. The outcomes of conservation policy include dispossession through increased crop losses, reduced income from agriculture and forest produce, as well as a forest that is dominated by weeds due to fire suppression. The ban on hunting in particular has increased wildlife densities, which has enabled the state to accumulate revenues through the establishment of wildlife tourism facilities. All in all, centralized protected area governance has changed the relationships among people, forest and the state in a way that has produced adverse effects for both livelihoods and the ecosystem. 相似文献
Haryana plain is the drainage divide between the Ganga plain in the east and the Indus plain in the west. Being a part of the Himalayan foreland, its geomorphology, sedimentation processes, and tectonism are broadly controlled by the Himalayan tectonics. Soil and geomorphological mapping in Haryana plain bring out geomorphic features such as paleochannels, various active drainage patterns, and landforms such as old fluvial plains, floodplains, piedmonts, pediments, terminal fans, and eolian plains. Based on the degree of soil development, and Optical stimulated luminescence (OSL) ages, the soil-geomorphic units were grouped into six members (QIMS-I to VI) (Quaternary Indus Morphostratigraphic Sequence) of a morphostratigraphic sequence: QIMS-VI 9.86–5.38 Ka, QIMS-V 5.38–4.45 Ka, QIMS-IV 4.45–3.60 Ka, QIMS-III 3.60–2.91 Ka, QIMS-II <?2.91–1.52 Ka, and QIMS-I <?1.52 Ka. OSL chronology of different geomorphic features suggests six episodes of tectono-geomorphic evolution in the region since 10 Ka. Neotectonic features such as nine faults, two lineaments, and five fault-bounded tectonic blocks have been identified. Independent tilting and sagging of the blocks in response to neotectonics have resulted in modification of landforms, depositional processes, and hydro-geomorphology of the region. Major rivers like the Yamuna, the Ghaggar, and the Sutlej show different episodes of shifting of their courses. Lineament controlled few extinct channels have been recorded between 20 and 25 m depth below the surface in the ground-penetrating radar (GPR) profiles. These buried channels are aligned along the paleo-course of the Lost Saraswati River interpreted from the existing literature and hence are considered as the course of the lost river. Seven terminal fans have been formed on the downthrown blocks of the associated faults. The Markanda Terminal Fan, the first of such features described, is indeed a splay terminal fan and was formed by a splay distributary system of the Markanda River. Association of three terminal fans of different ages with the Karnal fault indicates the segment-wise development of the fault from west to east. Also, comparison with other such studies in the Ganga plain to further east suggests that the terminal fans formed by streams with distributary drainage pattern occur only in semiarid regions as in the present area and thus are indicators of semiarid climate/paleoclimate. Though the whole region is tectonically active, the region between the Rohtak fault and Hisar fault is most active at present signified by the concentration of earthquake epicenters. 相似文献
The Arabian Sea is characterized today by a well-developed and perennial oxygen minimum zone (OMZ) at mid-water depths. The Indian margin where the OMZ impinges provides sediment records ideal to study past changes in the OMZ intensity and its vertical extent in response to the changes of monsoon-driven primary productivity and intermediate water ventilation. Benthic foraminifera, depending upon their adaptation capabilities to variation in sea floor environment and microhabitat preferences, develop various functional morphologies that can be potentially used in paleoenvironmental reconstruction. In this study, we analysed benthic foraminiferal morphogroups in assemblage records of the last 30 ka in a sediment core collected from the lower OMZ of the Indian margin (off Goa). In total, nine morphogroups within two broadly classified epifaunal and infaunal microhabitat categories are identified. The abundance of morphogroups varies significantly during the late Glacial, Deglacial and Holocene. It appears that monsoon wind driven organic matter flux, and water column ventilation governing the OMZ intensity and sea-bottom oxygen condition, have profound influence on structuring the benthic foraminiferal morphogroups. We found a few morphogroups showing major changes in their abundances during the periods corresponding to the northern hemisphere climatic events. Benthic foraminifera with planoconvex tests are abundant during the cold Heinrich events, when the sea bottom was oxygenated due to a better ventilated, weak OMZ; whereas, those having tapered/cylindrical tests dominate during the last glacial maximum and the Holocene between 5 and 8 ka BP, when the OMZ was intensified and poorly ventilated, leading to oxygen-depleted benthic environment. Characteristically, increased abundance of taxa with milioline tests during the Heinrich 1 further suggests enhanced ventilation attributed probably to the influence of oxygen-rich Antarctic Intermediate Water (AAIW). 相似文献
In the present study, measurements of surface ozone (\(\hbox {O}_{3}\)) and its precursors (NO and \(\hbox {NO}_{2}\)) were carried out at a sub-urban site of Agra (\(27{^{\circ }}10'\hbox {N}\), \(78{^{\circ }}05'\hbox {E}\)), India during May 2012–May 2013. During the study period, average concentrations of \(\hbox {O}_{3}\), NO, and \(\hbox {NO}_{2}\) were \(39.6 \pm 25.3\), \(0.8 \pm 0.8\) and \(9.1 \pm 6.6 \, \hbox {ppb}\), respectively. \(\hbox {O}_{3}\) showed distinct seasonal variation in peak value of diurnal variation: summer \({>}\) post-monsoon \({>}\) winter \({>}\) monsoon. However, \(\hbox {NO}_{2}\) showed highest levels in winter and lowest in monsoon. The average positive rate of change of \(\hbox {O}_{3}\) (08:00–11:00 hr) was highest in April (16.3 ppb/hr) and lowest in August (1.1 ppb/hr), while average negative rate of change of \(\hbox {O}_{3}\) (17:00–19:00 hr) was highest in December (–13.2 ppb/hr) and lowest in July (–1.1 ppb/hr). An attempt was made to identify the \(\hbox {VOC--NO}_{\mathrm{x}}\) sensitivity of the site using \(\hbox {O}_{3}/\hbox {HNO}_{3}\) ratio as photochemical indicator. Most of the days this ratio was above the threshold value (12–16), which suggests \(\hbox {NO}_{\mathrm{x}}\) sensitivity of the site. The episodic event of ozone was characterized through meteorological parameters and precursors concentration. Fine particles (\(\hbox {PM}_{2.5}\)) cause loss of ozone through heterogeneous reactions on their surface and reduction in solar radiation. In the study, statistical analyses were used to estimate the amount of ozone loss. 相似文献
Debris flow has caused severe human casualties and economic losses in landslide-prone areas around the globe. A comprehensive understanding of the morphology and deposition mechanisms of debris flows is crucial to delineate the extent of a debris flow hazard. However, due to inherent complex field topography and varying compositions of the flowing debris, coupled with a lack of fundamental understanding about the factors controlling the geomaterial flow, interparticle interactions and its final settlement resulted in a limited understanding of the flow behaviour of the landslide debris. In this study, a physical model was set up in the laboratory to simulate and calibrate the debris flow using PFC, a distinct element modelling-based software. After calibration, a case study of the Varunavat landslide was taken to validate the developed numerical model. Following validation with an acceptable level of confidence, several models were generated to evaluate the effect of slope height, slope angle, slope profile, and grain size distribution of the dislodged geomaterial in the rheological properties of debris flow. Both qualitative and quantitative analysis of the landslide debris flow was performed. Finally, the utility of retaining wall and their effect on debris flow is also studied with different retaining wall positions along the slope surface.
It is important to identify and locate glacial lakes for assessing any potential hazard. This study presents a combination of semi-automatic method Double-Window Flexible Pace Search (DFPS) and edge detection technique to identify glacial lakes using Sentinel 2A satellite data. Initially, Normalized Difference Water Index (NDWI) has been used to identify water and non-water areas, while DFPS and Edge detection technique has been used to identify an optimum threshold value to distinguish between water and shadow areas. The optimal threshold from DFPS process is 0.21, while threshold value of gradient magnitude using edge detection process is 0.318. The number of glacial lakes identified using the above algorithm is in close agreement with previously published results on glacial lakes in Gangotri glacier using different techniques. Thus, a combination of DFPS and edge detection process has successfully segregated glacial lakes from other features present in Gangotri glacier. 相似文献