Spatio-Temporal Analysis of Vegetation Dynamics as a Response to Climate Variability and Drought Patterns in the Semiarid Region, Eritrea

There is a growing concern over change in vegetation dynamics and drought patterns with the increasing climate variability and warming trends in Africa, particularly in the semiarid regions of East Africa. Here, several geospatial techniques and datasets were used to analyze the spatio-temporal vegetation dynamics in response to climate (precipitation and temperature) and drought in Eritrea from 2000 to 2017. A pixel-based trend analysis was performed, and a Pearson correlation coefficient was computed between vegetation indices and climate variables. In addition, vegetation condition index (VCI) and standard precipitation index (SPI) classifications were used to assess drought patterns in the country. The results demonstrated that there was a decreasing NDVI (Normalized Difference Vegetation Index) slope at both annual and seasonal time scales. In the study area, 57.1% of the pixels showed a decreasing annual NDVI trend, while the significance was higher in South-Western Eritrea. In most of the agro-ecological zones, the shrublands and croplands showed decreasing NDVI trends. About 87.16% of the study area had a positive correlation between growing season NDVI and precipitation (39.34%, p < 0.05). The Gash Barka region of the country showed the strongest and most significant correlations between NDVI and precipitation values. The specific drought assessments based on VCI and SPI summarized that Eritrea had been exposed to recurrent droughts of moderate to extreme conditions during the last 18 years. Based on the correlation analysis and drought patterns, this study confirms that low precipitation was mainly attributed to the slowly declining vegetation trends and increased drought conditions in the semi-arid region. Therefore, immediate action is needed to minimize the negative impact of climate variability and increasing aridity in vegetation and ecosystem services

Spatio-Temporal Analysis of Vegetation Dynamics as a Response to Climate Variability and Drought Patterns in the Semiarid Region, Eritrea

There is a growing concern over change in vegetation dynamics and drought patterns with the increasing climate variability and warming trends in Africa, particularly in the semiarid regions of East Africa. Here, several geospatial techniques and datasets were used to analyze the spatio-temporal vegetation dynamics in response to climate (precipitation and temperature) and drought in Eritrea from 2000 to 2017. A pixel-based trend analysis was performed, and a Pearson correlation coefficient was computed between vegetation indices and climate variables. In addition, vegetation condition index (VCI) and standard precipitation index (SPI) classifications were used to assess drought patterns in the country. The results demonstrated that there was a decreasing NDVI (Normalized Difference Vegetation Index) slope at both annual and seasonal time scales. In the study area, 57.1% of the pixels showed a decreasing annual NDVI trend, while the significance was higher in South-Western Eritrea. In most of the agro-ecological zones, the shrublands and croplands showed decreasing NDVI trends. About 87.16% of the study area had a positive correlation between growing season NDVI and precipitation (39.34%, p < 0.05). The Gash Barka region of the country showed the strongest and most significant correlations between NDVI and precipitation values. The specific drought assessments based on VCI and SPI summarized that Eritrea had been exposed to recurrent droughts of moderate to extreme conditions during the last 18 years. Based on the correlation analysis and drought patterns, this study confirms that low precipitation was mainly attributed to the slowly declining vegetation trends and increased drought conditions in the semi-arid region. Therefore, immediate action is needed to minimize the negative impact of climate variability and increasing aridity in vegetation and ecosystem services

Assessing Land Use Change and Its Impact on Ecosystem Services in Northern Thailand

Ecosystem services are highly vulnerable to a number of impacts due to the complex effects of human use of natural resources and subsequent land use change. Assessment of the impact of change in land use with respect to ecosystem services is necessary in order to implement appropriate land uses that enhance ecosystem services. This study analysed the impact of change in land use on ecosystem services using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model to map and quantify a set of ecosystem services, namely sediment retention, water yield, carbon stock, and habitat quality, in northern Thailand, which has experienced substantial policy induced land use change. The study also assessed the changes in land use from 1989 to 2013 and their impact on overall ecosystem services using GIS. Increased rubber plantation cultivation and built-up areas resulting in reduced forest cover were the major changes found in land use in the area. The results of the study show a general decrease in ecosystem services for the study period in the watershed, in particular, a negative impact on ecosystem services was observed in agricultural areas. The study findings on spatial and temporal distribution of ecosystem services can help guide the development of appropriate land use options to enhance ecosystem services

Simulating future land use and ecosystem services in Northern Thailand

<p>Enhancing ecosystem services is important as it provides foundation for the wellbeing of people. This paper presents the future land use simulation for enhancing ecosystem services using CLUMondo dynamic spatial model. The land use change was assessed from 1989 to 2013 in Wang Thong watershed of Northern Thailand using GIS and a set of ecosystem services was assessed using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model. Future land uses until 2030 were projected for three policy scenarios, namely business-as-usual, integrated land use development, and enhancing environmental services with different levels of emphasis on ecosystem services. In business-as-usual scenario, it was observed that ecosystem services will decline by 2030 from the base year of 2013, whereas in integrated land use development scenario, the ecosystem services will increase by 5% compared to base year due to anticipated effective protection of remaining forests in all existing and proposed protected areas of the study area. In enhancing environmental services scenario, the ecosystem services will increase by 15%. Such results can serve as useful information in policy formulation in developing land use options, which help enhance ecosystem services in future.</p

Adaptation to Climate Change by Rural Ethnic Communities of Northern Thailand

Northern Thailand has been experiencing the impact of climate change due to its fragile agro-ecosystem, inhabited by a resource-poor population. The study, conducted in a mountainous landscape of Doi Mae Salong area in Northern Thailand, explores the farmers’ perceptions of climate change, its impact on farming, and adaptation measures undertaken by the two ethnic communities in the area for coping with climate change impacts. The data were collected through a structured questionnaire survey of ninety farm households using the recall approach for the past twenty years. The findings suggest that the farmers have perceived the change in climate pattern of the study area, and its negative impact on farming. Farm households have been trying to cope with the impacts by adapting to alternate farming options and practices using traditional techniques. The impact was perceived to be higher in the community living at higher elevation compared to those at lower elevation. Although autonomous adaptation is occurring in the area, the vulnerability of farm households to the impact of climate change still exists in terms of the lack of knowledge and financial resources