Effects of land use/cover change on land surface energy partitioning and climate in Northeast China

Yang

2023

Preprint

In order to explore the spatio-temporal evolution law of surface heat flux during the urbanization process in new mountainous development city, the spatio-temporal evolution law of heat balance process of different land use types and heat flux process before, during and after urbanization in Yuelai New City were analyzed by satellite remote sensing image data and SEBAL model, the effect of land use/vegetation cover on surface heat flux was also discussed. The results include (1) the net radiation flux and difference of various land use types in Yuelai New City reached the maximum in July and the minimum in January, vegetation coverage was one of the factors affected sensible heat flux of different land use types. The order of latent heat flux was woodland > farmland > bare land > residential land, and the order of soil heat flux was bare land > residential land > woodland > farmland. (2)The urbanization process increased the area of low net radiation value in Yuelai New City, and sensible heat flux showed an increasing trend and accounted for the largest proportion in the energy output. The low value area of latent heat flux gradually expanded to the north and south. Soil heat flux and sensible heat flux were higher in the area with low latent heat flux. The distribution rules of soil heat flux and sensible heat were basically consistent, and both showed an increasing trend. (3)The correlation between soil heat flux and land use area was the best among the energy output factors. Fractional vegetation cover(FVC) had a greater impact on heat fluxes than land use area. Residential combined land was most closely related to FVC, and latent heat flux was most affected by FVC.

Section: Introductionmentioning

confidence: 99%

Spatio-temporal evolution of surface heat flux during new urbanization in mountainous region: A case study of Yuelai New City

Yang

2023

Preprint

“…In recent years, land use and land cover in developing countries, especially China, have changed rapidly, thereby posing serious challenges to natural and human environments [16][17][18][19][20]. Although many studies have investigated the impact of LULCC on regional climate change [21,22], more research is needed about the specific effects in China and comparisons with other areas in the world [23]. Various models, including the InVEST model and ALARO model, have been utilized in numerous studies analyzing the influence of LULCC on regional climate and hydrological changes in China to examine parameters such as water yield and purification, soil retention, and land surface albedo [24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Land-Use-Change-Induced Cooling and Precipitation Reduction in China: Insights from CMIP6 Models

Tian,

Jian,

et al. 2023

Sustainability

In the 21st century, the effect of land use/land cover change (LULCC) on climate has become an area of active research. To explore the effects of LULCC on temperature and precipitation in China, we used outputs from the BCC-CSM2-MR, CESM2, IPSL-CM6A-LR, and UKESM1 models, which participated in the Land Use Model Intercomparison Project (LUMIP) of the Coupled Model Intercomparison Project Phase 6 (CMIP6). Based on these models, we identified temporal variations in precipitation and near-surface air temperature (hereinafter temperature) with and without historical land use changes and their relation with LULCC in China during 1850–2014. We then determined the significant changing period (1972–2012) and revealed the relation between the spatial distribution of historical change in vegetation cover types, precipitation, and temperature. The results showed that annual historical precipitation decreased faster (132.23 mm/(1000 a) faster), while annual historical temperature increased slower (2.70 °C/(1000 a) slower) than that without LULCC during 1850–2014. LULCC not only influenced surface properties to change local precipitation and temperature distributions and mean values, but also affected other components through atmospheric circulations due to typical monsoon characteristics in China. The relative contribution of grassland change to precipitation variation was the largest, while relatively, cropland change contributed the most to temperature variation. Our study innovatively used new model outputs from LUMIP to analyze the impacts of LULCC on precipitation and temperature, which can help to guide and improve future land use management and predictions of precipitation and temperature.

“…Land cover is known as the observed biophysical coverage of the ground surface, such as vegetation, bare soil, rock and built-up features on the Earth's surface [6], while land use is routinely derived from land cover and is related to local actions in the surrounding environment [7,8]. Land use/land cover (LULC) and related dynamics have been prioritized by the Global Land Project [9] as they essentially affect the biosphere, hydrosphere, atmosphere and lithosphere [10]. Reliable LULC dynamic maps can provide insight into human and ecosystem interactions [11,12] in an ever-changing world.…”

Section: Introductionmentioning

confidence: 99%

Deep Insight on Land Use/Land Cover Geospatial Assessment through Internet-Based Validation Tool in Upper Karkheh River Basin (KRB), South-West Iran

Mallah

Gorji

Balali

et al. 2023

Land

Recently, the demand for high-quality land use/land cover (LULC) information for near-real-time crop type mapping, in particular for multi-relief landscapes, has increased. While the LULC classes are inherently imbalanced, the statistics generally overestimate the majority classes and underestimate the minority ones. Therefore, the aim of this study was to assess the classes of the 10 m European Satellite Agency (ESA) WorldCover 2020 land use/land cover product with the support of the Google Earth Engine (GEE) in the Honam sub-basin, west Iran, using the LACOVAL (validation tool for regional-scale land cover and land cover change) online platform. The effect of imbalanced ground truth has also been explored. Four sampling schemes were employed on a total of 720 collected ground truth points over approximately 14,100 ha. The grassland and cropland totally canopied 94% of the study area, while barren land, shrubland, trees and built-up covered the rest. The results of the validation accuracy showed that the equalized sampling scheme was more realistically successful than the others in terms of roughly the same overall accuracy (91.6%), mean user’s accuracy (91.6%), mean producers’ accuracy (91.9%), mean partial portmanteau (91.9%) and kappa (0.9). The product was statistically improved to 93.5% ± 0.04 by the assembling approach and segmented with the help of supplementary datasets and visual interpretation. The findings confirmed that, in mapping LULC, data of classes should be balanced before accuracy assessment. It is concluded that the product is a reliable dataset for environmental modeling at the regional scale but needs some modifications for bare land and grassland classes in mountainous semi-arid regions of the globe.