摘要
本文从分析沙漠化的物理机制入手,将生态建设政策对沙漠化的作用以政策指数(PIX)来表示,并将其分解为空间广度(PSS)和时间强度(PEF)两个变量,PIX=(PSS+PEF)/2。以宁夏盐池县退耕还林和草地禁牧两种政策为例,在政策实施区分别选取40个样本点,提取沙漠化变化、植被指数变化、政策指数等数据。计算表明:退耕还林和草地禁牧政策与沙漠化变化相关系数分别为-0.664和-0.746,两种政策都对沙漠化面积的减少起到了显著的作用。政策广度和政策强度都与沙漠化的逆转显著相关,说明构建的政策指数可以更准确地反映政策因素对沙漠化的作用。政策因素对沙漠化作用的定量分析,对沙漠化治理政策的绩效评价以及新制度的设计,都有重要意义。
This paper starts with the physical mechanism of sandy desertification,and policy index(PIX)is used to represent the impact that ecological construction policy has on sandy desertification.This index is divided into two variables:spatial scope(PSS)and time intensity(PEF),PIX=(PSS+PEF)/2.This paper sets Grain-to-Green Program and Prohibiting Grazing carried out in Yanchi County,Ningxia Province as an example,and selects 40sample points in policy implementation area to extract the data of sandy desertification area'change,NDVI(Normalized Difference Vegetation Index)and policy index et al.Calculation shows that,coefficient of correlation of Grain-to-Green Program,Prohibiting Grazing and change of sandy desertification area are-0.664 and-0.746,which means both policies play a significant role in desertification area reduction.PSS and PEF are significantly associated with sandy desertification,which shows that policy index can more accurately reflect the effect of factors on sandy desertification.Quantitative analysis of policy factors'effect on desertification is of significance on evaluating the performance of desertification management policy and design of new.
出处
《中国沙漠》
CSCD
北大核心
2014年第3期893-900,共8页
Journal of Desert Research
基金
国家自然科学基金项目(41071353)资助
关键词
沙漠化
生态建设政策
定量分析
sandy desertification
ecology construction policy
quantitative analysis
