The Analysis of Ecological Water Requirement of the Overlapping Vegetation in the Otinday Sandy Area

In ecosystem health and economic development of our country's water resources has become a limiting factor , the accurate estimation of vegetation ecological water demand has important implications for the rational use of water resources , reduce Invalid soil moisture loss , increase water use efficiency . In this paper, the key projects of the National Natural Science Foundation of China , \- shrub and grass communities as the research object , and focuses on the overlap of vegetation ecological water demand relationship of the size and variety of factors . Overlapping natural vegetation growth period ecological water demand is composed of two parts , a part of the overlapping vegetation transpiration , which is used to maintain the overlapping vegetation life , so we call it life water demand . Another part is overlapping the lower part of the plant canopy soil evaporation , maintain overlapping vegetation habitats roots with water balance , we call it the habitat water demand . Overlapping vegetation non- growth period ecological water demand is frosty period , continued freezing period surface effectively free water evaporation , which maintain wintering habitat . The main contents of this paper consists of four parts : ( 1) determine the reference crop evapotranspiration rate of the study area in days for the calculation period ETo . (2) Based on 2005-2006 overlapping vegetation habitats meteorological factors and physiological factors Field test data , using the dual crop coefficient approach overlapping vegetation in two different hydrological years ecological water demand . (3) ecological water demand calculation results of the validation . (4) different hydrological years overlapping vegetation ecological water demand analysis, the quantitative relationship between environmental factors and physiological factors . Papers fixed by vegetation ecological water demand , the identification and analysis of the ecological water requirement to provide a theoretical basis for the adjustment of the internal structure of the restructuring of agriculture, forestry and animal husbandry and farming , to provide integrated decision-making for the rational utilization of water resources , improve the ecological environment .