نتایج جستجو برای: desertification intensity

تعداد نتایج: 182836  

2010
A Gad A Shalaby

Abstract Desertification is one of the fundamental problems that threaten many arid and semi-arid areas. The formulation of the United Nation Convention to Combat Desertification (UNCCD), adopted in Paris, 1994 and ratified in 1996, with the active participation of Egypt, gave emphasis on combating the major threats to sustainability of dry lands. Recently, different models were developed to fo...

Journal: :desert 2006
h. ahmadi a. a. norouzi m. r. ekhtesasi m. shafizadeh nasrabadi

the kind of land use and intensity of its change is considered as important desertification indices in different models. land use change is one of the main anthropogenic factors in the desertification. the current research was carried out around imam khomeini airport, with an area of 32000 km2, in order to evaluate mentioned area's land use changes effects during 1955-2003 on desertification. t...

Journal: :journal of rangeland science 2013
hamid toranjzar moslem poormoridi

several studies have been performed to evaluate the desertification in iran andother countries which led to present national and regional models. one of them is imdpamodel. this model was used as a case study in taraz nahid, saveh, iran. in this study, fivefactors including climate, soil, vegetation, irrigation, and socioeconomic ones wereevaluated. according to the region conditions for each c...

2011
M. GUO Y. LIU X. F. WANG H. TANI

Desertification is a serious threat to the sustainability of the environment and to human habitation. Kerqin sandy land is the largest sandy land in China, and is one of the most important origins of sandstorms in Northern China. Land desertification and frequent sandstorms in the spring strongly affect the growth of grassland vegetation and crops, and the effective of eco-environment in this r...

Introduction Nowdays desertification is a disaster in many countries , especially in developing countries. This problem includes natural factors and improper human activities. According to the expansion of desertification, providing the appropriate management methods will be reduced desertification intensity and its expansions. In this way, knowledge of processes of desertification and facto...

2018
Zhenming Zhang Yunchao Zhou Shijie Wang Xianfei Huang

In this paper, the spatial distribution of stony desertification characteristics and its influencing factors in Karst areas in different sampling scales are studied using a grid sampling method based on geographic information system (GIS) technology and geo-statistics, with the rock bareness rate obtained through sampling with 150m × 150m grids in the Houzhai River Basin being taken as the orig...

2018
Qingfu Liu Yanyun Zhao Xuefeng Zhang Alexander Buyantuev Jianming Niu Xiaojiang Wang

Degradation of semi-arid and arid ecosystems due to desertification is arguably one of the main obstacles for sustainability in those regions. In recent decades, the Mu Us Desert in China has experienced such ecological degradation making quantification of spatial patterns of desertification in this area an important research topic. We analyzed desertification dynamics for seven periods from 19...

Journal: Desert 2011
H. Ahmadi H.R. Abbasi M Jafari M.A. Zare chahouki

One of the characters in Iranian Model of Desertification Potential Assessment (IMDPA) is soil. Since soil is very important in the degradation of land, so some indices were determined for this character in order to evaluate desertification potential of arid, semi-arid and dry sub humid areas of Iran. The indices included soil texture, deep gravel percentage, soil depth, and EC. To calibrate th...

2008
Y. M. Yue K. L. Wang Z. C. Chen Y. Z. Yu

Karst rocky desertification is a special kind of land desertification developed under violent human impacts on the vulnerable ecogeo-environment in karst ecosystem. The process of karst rocky desertification results in simultaneous and complex variations of many interrelated soil, rock and vegetation biophysical parameters, rendering it difficult to develop simple and robust remote sensing mapp...

Journal: :Remote Sensing 2017
Qiang Guo Bihong Fu Pilong Shi Thomas Cudahy Jing Zhang Huan Xu

The Ordos Plateau, a typical semi-arid area in northern China, has experienced severe wind erosion events that have stripped the agriculturally important finer fraction of the topsoil and caused dust events that often impact the air quality in northern China and the surrounding regions. Both climate change and human activities have been considered key factors in the desertification process. Thi...

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