Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Doctorat → Chine → 2021 → Study on Evapotranspiration and Ecological Effects of Grassland under Different Utilization Patterns in Saihanwula,inner Mongolia

Nanjing University of Information Science & Technology (2021)

Study on Evapotranspiration and Ecological Effects of Grassland under Different Utilization Patterns in Saihanwula,inner Mongolia

张小华

Titre : Study on Evapotranspiration and Ecological Effects of Grassland under Different Utilization Patterns in Saihanwula,inner Mongolia

Auteur : 张小华

Grade : Doctoral Dissertation 2021

Université : Nanjing University of Information Science & Technology

Résumé partiel
Inner Mongolia grassland is located in the continental arid and semi-arid climate zone,which is with the feature of climate fluctuation,as well as fragile and severe.Therefore,the grassland ecosystem in the arid and semi-arid interlaced agro-pasturing areas is more prone to degradation.Precipitation is the main source of water supply in arid and semi-arid regions,and it is of great significance for vegetation restoration in this region.On the other side,evapotranspiration and runoff are the main water loss channels in arid and semi-arid regions.The vegetation restoration will inevitably increase water consumption and soil water loss.Therefore,it is very important to accurately estimate the evapotranspiration and rainwater resource utilization potential index in arid and semi-arid regions.In order to provide suggestions and theoretical support for regional vegetation allocation and grassland protection and rational utilization,this paper studied grassland evapotranspiration,rainwater resource utilization potential index and ecological effects under different conservation and utilization methods.In this study,the eddy correlation observation technique was used to collect observation data during grassland growth period.The changes of species composition,importance value,aboveground biomass,coverage and diversity under the three types of grassland conservation and utilization were analyzed.The ecological effect and its changing trend were evaluated.The SEBAL model was used to simulate ET and its change from 2000 to 2019,and analyze the spatio-temporal variation characteristics of ET.We calculated the RUP,studied the influences of grassland biomass,richness,abundance and coverage on ET under different utilization modes.The main results were as follows:1)Changes of evapotranspiration and meteorological factors in the growing season of grassland in the study area were observed.In our study,During the experimental observation period,evapotranspiration showed a downward trend from May to June,an upward trend from June to August and reached the peak,and continued to decline after August.The evapotranspiration in the growing season was 313.8 mm.The carbon source and sink effect of grassland fluctuated,and the volumetric water content of soil was consistent with the change of rainfall,and rainfall mostly concentrated in the later stage.2)The method of using water deficit to evaluate whether existing water resources can satisfy the sustainable development of ecosystem is also suitable for Chifeng area.Based on large-scale research,we found that the spatial distribution pattern of the actual ET of grassland was consistent with the potential of rainwater utilization in arid and semi-arid regions.

Mots clés : Arid and semi-arid region ;Meteorological factors ;Evapotranspiration;Rain water utilization potential indicator(RUP) ;Conservation and utilization methods ;

Présentation (CNKI)

Page publiée le 16 février 2022