Land use and land cover (LULC) changes are dynamic and have been extensively studied; the change in LULC has become a crucial factor in decision making for planners and conservationists owing to its impact on natural ecosystems. Deriving accurate LULC data and analyzing their changes are important for assessing the energy balance, carbon balance, and hydrological cycle in a region. Therefore, we investigated the best classification method from the four methods and analyzed the change in LULC in the middle Yangtze River basin (MYRB) from 2001 to 2020 using the Google Earth Engine (GEE).
View Article and Find Full Text PDFWarmer temperatures significantly influence crop yields, which are a critical determinant of food supply and human well-being. In this study, a probabilistic approach based on bivariate copula models was used to investigate the dependence (described by joint distribution) between crop yield and growing season temperature (T) in the major producing provinces of China for three staple crops (i.e.
View Article and Find Full Text PDFAs an important component of terrestrial ecosystem, vegetation acts as a sensitive recorder of changes in hydroclimatic conditions. Long-term time series of remote sensing-based vegetation indices and their influencing environmental driving factors, such as human activities and climate change, have been widely discussed in the literature. Globally, however, little is known about the hydroclimatic processes controlling vegetation changes in mountainous regions, which are conceived as more sensitive to climate change than other landscapes.
View Article and Find Full Text PDFLand use and land cover (LULC) projections are critical for climate models to predict the impacts of LULC change on the Earth system. Different assumptions and policies influence LULC changes, which are a key factor in the decisions of planners and conservationists. Therefore, we predicted and analyzed LULC changes in future scenarios (SSP1-26, SSP2-45, SSP5-85) in the middle reaches of the Yangtze River basin (MYRB).
View Article and Find Full Text PDFQuantitatively, analyzing the driving mechanism of vegetation coverage change is of important significance for regional ecological environment evaluation and protection. Based on time series NDVI data and meteorological data of the Yellow River Basin (Inner Mongolia Section), the trend and significance of climate factors and vegetation coverage in the YRB (IMS) and four sub-regions (the Hetao Irrigation district, the Ten Tributaries region, the Hunhe river basin, and the Dahei river basin) from 2000 to 2018 were ascertained. We used geographic detectors to quantitatively analyze the effects of detection factors on vegetation coverage change.
View Article and Find Full Text PDFSci Total Environ
November 2019
Drought is an extremely widespread and common natural disaster that significantly impacts both the socio-economic activities of a community and the natural environment. A comprehensive and accurate understanding of hydrological drought is important for the drought prediction and risk management. In this study, a discussion of the characteristics of the historical and future hydrological drought in the Tarim River Basin (TRB) is presented.
View Article and Find Full Text PDFDroughts are extremely widespread natural disasters, which cause the most severe losses among natural disasters. The comprehensive drought risk in Northwest China (NWC) was evaluated based on the self-calibrating (SC) Palmer Drought Severity Index (PDSI) and copula method. The major conclusions are the following: (1) based on the rotated empirical orthogonal function (REOF), a significant consistency in the spatial distribution of the monthly averaged SC-PDSI was observed in NWC, especially in the subregions Inner Mongolia Plateau (IM), Hexi Corridor (HX), and Qiangtang Plateau (QT); (2) the largest frequency was obtained for slight drought and slight wet conditions, while extreme drought and extreme wet showed the lowest values; (3) with respect to the PDSI-th, the Clayton, Arch12, Arch12, Arch12, Arch12, and Frank played the major roles in the copula weight in the subregions IM, HX, Qinghai River Basin (QH), QT, North Xinjiang (NXJ), and South Xinjiang (SXJ), respectively.
View Article and Find Full Text PDFBased on the Moderate Resolution Imaging Spectroradiometer (MODIS) - Normalized Difference Vegetation Index (NDVI), the Vegetation Interfaces Processes (VIP) model simulated the spatio-temporal patterns of actual evapotranspiration (ET) and the water consumption of different ecosystems in the Aksu River Basin, Northwest China between 2000 and 2015. The results revealed that: (1) the applicability of the VIP model was confirmed, with good agreement (R=0.79, P<0.
View Article and Find Full Text PDFWith the threat of water shortages intensifying, the need to identify the terrestrial water storage (TWS) variation in the Tarim River Basin (TRB) becomes very significant for managing its water resource. Due to the lack of large-scale hydrological data, this study employed the Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) to monitor TWS variation in the TRB during the period of 2002-2015, cooperating with two statistical techniques, Principal Component Analysis (PCA) - Empirical Orthogonal Function (EOF) and Multiple Linear Regression (MLR). Results indicated that (1) the Tropical rainfall measuring mission (TRMM) data can be applied well in the TRB; (2) the EOF result showed that both the time series of TRMM precipitation and GRACE-derived TWS in the TRB between 2002 and 2015 were dominated by the annual signals, which were followed by the semiannual signals; (3) the linear trend for the spatially averaged GRACE-derived TWS changes exhibited an decrease of 1.
View Article and Find Full Text PDFEnviron Monit Assess
July 2015
Due to the rapid growth of the population and the development of economies in the Guanzhong district, central China, the river ecosystem is gradually deteriorating, which makes it important to assess the aquatic ecosystem health and take measures to restore the damaged ecosystem. An index of catchment ecosystem health has been developed to assist large-scale management of watersheds by providing an integrated measure of ecosystem health, including aquatic and terrestrial ecosystem. Most researches focus on aquatic ecosystem or terrestrial ecosystem, but little research integrates both of them to assess the catchment ecosystem health.
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