Evaluating the influences of urban expansion on multiple ecosystem services in drylands

Abstract

Context Effectively estimating the influences of urban expansion on multiple ecosystem services (ESs) is of great importance for improving urban planning in drylands. However, there are some shortcomings in the existing urban expansion models, which lead to great uncertainties in the assessment of the influences of urban expansion on multiple ESs. Objectives This study sought to effectively estimate the influences of urban expansion on multiple ESs in drylands. Methods We combined the land use scenario dynamics-urban model and ES models to estimate the influences of urban expansion on habitat quality, food production, water retention, air quality regulation, sand fixation, and aesthetics. Results The results showed that (1) our method can effectively evaluate the influences of urban expansion on multiple ESs in drylands, and the accuracy increased by more than 20% on average. (2) Under the impacts of future urban expansion, the annual average loss per unit area of habitat quality, food production, water retention, air quality regulation, sand fixation, and aesthetics will increase. (3) Future urban expansion will occupy more cropland and grassland, which will be the main reason for the intensified degradation of multiple ESs. Conclusions We suggest that the local government should focus on protecting key ecosystems, especially grasslands, from urban expansion to mitigate the potential influences on multiple ESs in drylands.

New Perspective to Evaluate the Carbon Offsetting by Urban Blue-Green Infrastructure: Direct Carbon Sequestration and Indirect Carbon Reduction

“…The low-to-low aggregation ratio of the carbon sequestration (13.3%) surpassed that of the water-saving carbon reduction (8.2%), implying that the carbon sequestration services were more adversely affected in the areas characterized by suburban sprawl than the stormwater retention services. This difference can be attributed to the fact that the urban expansion process led to vegetation degradation at the outskirts, and agricultural and grassland areas were primarily converted . This phenomenon suggests that the LCZ A on the suburban fringe (potential zone for urban expansion) may shift toward LCZ D under anthropogenic influences.…”

“…This difference can be attributed to the fact that the urban expansion process led to vegetation degradation at the outskirts, 65 and agricultural and grassland areas were primarily converted. 66 This phenomenon suggests that the LCZ A on the suburban fringe (potential zone for urban expansion) may shift toward LCZ D under anthropogenic influences. The average carbon sequestration rate of the LCZ D (0.47 kg•C/m 2 •yr) was much lower than that of the LCZ A (0.85 kg•C/m 2 •yr).…”

Study on Urban Expansion and Population Density Changes Based on the Inverse S-Shaped Function

“…There are three main categories of assessment methods for urban expansion: the first is the boundary assessment method, which defines the "city" based on administrative division data. This method can evaluate urban expansion over a long period but cannot distinguish between urban and rural areas within the "city" [50]. The second is the threshold method, which uses nighttime light data to build a threshold segmentation model, dividing urban and rural areas in remote sensing images, evaluating the urban extent, and calculating the expansion intensity.…”

Driving Mechanisms of Spatiotemporal Heterogeneity of Land Use Conflicts and Simulation under Multiple Scenarios in Dongting Lake Area

“…For the past several years, land use at the regional and global scales has undergone profound changes as a result of sustained development, the continuous expansion of built-up areas, and the successive emergence of ecological problems such as the occupation of wetland resources [6,7]. With the implementation of ecological protection, wetland ecological restoration, and other management methods, the regional LULC has shifted to a favorable situation [8,9]. However, problems such as land encroachment persist, which makes the contradiction between socioeconomic development and the ecological environment prominent.…”