نتایج جستجو برای: vegetation cover 0119

تعداد نتایج: 148663  

2016
Haixin Liu Anbing Zhang Tao Jiang Haitao Lv Xinxia Liu Hefeng Wang

This study proposes a modified vegetation-dependent temperature-vegetation dryness index (TVDI) model for analyzing regional drought disasters in the Beijing-Tianjin-Hebei Metropolitan Region (BTHMR) of China. First, MODIS monthly normalized difference vegetation index (NDVI), land surface temperature (LST) data and land use/cover data (Land cover type2) were pre-processed as a consistent big d...

2013
Jie Wang Hiroshi Ishidaira Wenchao Sun Shaowei Ning

Suspended sediment concentration of a river can provide very important perspective on erosion or soil loss of one river basin ecosystem. The changes of land use and land cover, such as deforestation or afforestation, affect sediment yield process of a catchment through changing the hydrological cycle of the area. A sediment rating curve can describe the average relation between discharge and su...

Journal: :Ecology 2008
James B Heffernan

Historically, desert drainages of the American southwest supported productive riverine wetlands (ciénegas). Region-wide erosion of ciénegas during the late 19th and early 20th century dramatically reduced the abundance of these ecosystems, but recent reestablishment of wetlands in Sycamore Creek, Arizona, USA, provides an opportunity to evaluate the mechanisms underlying wetland development. A ...

Journal: :Journal of the American Mosquito Control Association 1997
P A Turner W J Streever

Knowledge of oviposition sites selected by wetland mosquitoes could improve mosquito control and guide wetland rehabilitation practices to avoid creating or exacerbating a mosquito problem. Two studies that enumerated Aedes vigilax eggshells found in salt marsh soil on the western portion of Kooragang Island in New South Wales, Australia, allowed an evaluation of oviposition sites. In one study...

1997
Michael A. Patten

I conducted small-mammal trapping surveys on a desert scrub restoration site in Palm Springs, California, to document concomitant recovery of the rodent community. These surveys were conducted following quantitative vegetation sampling efforts that indicated that a predefined successful restoration criterion of 15% total shrub cover had been met throughout most of the area. But shrub cover, nat...

Journal: Desert 2010
a. malekian hamed Joneidi Jafari Hosein Azarnivand mohamad Zare Chahouki sh. nikoo

Abstract The objective of current research is to investigate distribution patterns of vegetation types and its relation with environmental factors in southern margin of Haj Aligholi Kavir of Damghan. Three vegetation types including Halecnemum strobilaceum, Sedlitzia rosmarinus and Artemisia sieberi were studied in marginal arid regions and uplands of the study area. Firstly, geographic locat...

Journal: Desert 2009
A. Tavili J. Farzadmehr M. Rostampour m.a Zare Chahouki

Abstract This paper presents a quantitative account of vegetation–environmental factor relationships in arid rangelands. Vegetation cover was recorded using Braun-Blanquet combined abundance-cover scale in each quadrat. Within each quadrat, one profile was dug and soil samples being taken at 0-20cm and 20-100cm depths. Under study physical-chemical characteristics included texture, lime, orga...

Journal: :Journal of environmental management 2012
Christopher M Gough Hunter L Elliott

Residential abandonment is on the rise in many urban areas, with unknown implications for ecosystem structure and function on land slated for partial or full restoration to native habitat. Partial decoupling of human and natural systems could reduce disturbance (e.g., trampling, recreational traffic) and modify vegetation structure in a way that alters soil carbon storage, an ecosystem function...

2011
THOMAS PANAGOPOULOS VERA FERREIRA JORGE JESUS

Soil erosion risk assessment at the watershed of Alqueva is urgently needed to conserve water resources and prevent the accelerated dam siltation. The variation of soil properties is one of the most important reasons for the spatial variability of vegetation cover and erosion. In order to achieve more and better management of rangelands around the largest reservoir of Europe, it is essential to...

2012
Kathryn Sheffield Elizabeth Morse-McNabb

This study aimed to develop a method for assessing changes in vegetation greenness and land cover over time at both landscape scales and for individual land parcels. It is hoped that an improved understanding of land cover history will increase understanding of soil condition, and linkages between soil health and productive capacity in Victorian agricultural landscapes. Gradual changes and diff...

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