Influence Of Land Cover Change Research Articles

The Effect of Land Cover Change on Soil Erosion in Awach Kibuon Sub-basin, Kenya

Land cover change is a significant driver of soil erosion. While soil erosion is a natural process, human activities can significantly alter the landscape, making soil more vulnerable to erosion. This erosion reduces a watershed's capacity to sustain vital natural resources and ecosystem services. This study investigated the impact of these changes on soil erosion within four hydrological units (Awach Kibuon, Awach Owade, Awach Kasipul, and Awach Kabondo) of the Awach Kibuon sub-basin between 2018 and 2023. The specific objective of the study was to quantify the effect of land cover change on soil erosion rate and determine how specific land cover types affect soil erosion in the study area. This study employed a quasi-longitudinal design to assess the influence of land cover changes on soil erosion. Sentinel-2 NDVI satellite imagery provided land cover data. The land cover maps, soil data, rainfall data and the Digital Elevation Model were used in the Revised Universal Soil Loss Equation Model within a GIS environment to estimate soil erosion rates. The study revealed a consistent decline in vegetation cover across all hydrological units, as indicated by a decrease in NDVI. The mean NDVI decreased by 12.88%, 10.92%, 4.78%, and 11.92% in Awach Kibuon, Awach Owade, Awach Kasipul and Awach Kabondo respectively. Conversely, the mean soil erosion rate increased by 23.9% in Awach Kibuon, 17.85% in Awach Owade, 24.43% in Awach Kasipul, and 20.54% in Awach Kabondo. Sediment yield increased by 33% in Awach Kibuon, 18% in Awach Owade, 17% in Awach Kasipul, and 23% in Awach Kabondo. These findings suggest a direct relationship between reduced vegetation and elevated soil erosion. The relationship between land cover and erosion varies depending on the density of vegetation. Areas with dense vegetation cover have an inverse relationship, highlighting the protective role of vegetation cover. However, the study also observed that very dense vegetation areas which were also found in high-sloped areas experienced high soil erosion rates. The erosion rate increases even in areas that have experienced an increase in vegetation cover. This is because these areas are also found in high-sloped areas. The slope factor superseded the ability of vegetation cover to protect against soil loss. In conclusion, the change in land cover has significantly increased soil erosion in the Awach Kibuon Sub-basin, however, the slope factor also accelerated soil loss in the basin. Therefore, a holistic approach that combines promoting vegetation cover with land management techniques like terracing and drainage channels is crucial for mitigating soil degradation and water sedimentation in sub-basin.

The Impact of Land Cover Change on Surface Water Temperature of Small Lakes in Eastern Ontario from 1985 to 2020

Land Cover Change (LCC) has been shown to significantly impact the magnitude and trend of Land Surface Temperature (LST). However, the influence of LCC near waterbodies outside of an urban environment remain less understood. Waterbodies serve as local climate moderators where nearby LCC has the potential to decrease their cooling ability. Altered water surface temperatures can lead to altered species migration and distribution in aquatic species depending on a given species thermal boundary. In this study, using remotely sensed land cover and surface temperature data, we investigate the role that LCC around small lakes (500 m) plays on the surface water temperature change of nine small lakes in the Cataraqui Region Conservation Authority’s watershed, located in Eastern Ontario, from 1985 to 2020. The Continuous Change Detection Classification (CCDC) algorithm was used alongside the Statistical Mono-Window (SMW) algorithm to calculate LCC and LST, respectively. Results indicated a strong positive relationship (R2 = 0.81) between overall LCC and lake surface water temperature (LSWT) trends, where LSWT trends in all inland small lakes investigated were found to be positive. The land cover class sparse vegetation had a strong positive correlation with water temperature, whereas dense vegetation displayed a strong negative correlation. This 35-year study contributes to the broader understanding of the impact that LCC has on the surface water temperature trends of inland lakes.

The Influence of Land Cover Change Towards Connectivity Networks of Forest Ecosystem in Tesso Nilo National Park

Tesso Nilo National Park is one of the protected areas designated as KPA by the Decree of the Minister of Forestry No.225/Menhut-II/2004 dated July 19, 2004 covering an area of ​​38,576 ha, then expanded again through the Decree of the Minister of Forestry No.663/Menhut/2009 dated 19 October 2009 with an area of ​​± 83,068 ha. The Tesso Nilo National Park area is experiencing the dynamics of land cover changes, namely the conversion of forest land which causes the forest area to become increasingly narrow in this area. With the reduction in forest area in this area, it causes a decrease in ecosystem network connectivity due to forest fragmentation that occurs, so that forests are separated and further apart. This study aims to analyze changes in land cover in the Tesso Nilo National Park area to find out information on changes in habitat ecosystems in the last 20 years. the observations were made using satellite images in 1999, 2010 and 2019. so that it can be seen the effect of forest fragmentation on ecosystems in the Tesso Nilo National Park area. From the results of the analysis, it was found that the area of ​​forest cover in the Tesso Nilo National Park decreased from 1999 to 2019 and caused changes in the connectivity network of forest ecosystems, which was found in the study, the weakest connectivity separated forest fragments as far as 17394.47 meters due to forest cover fragmentation.

Impact of Land Cover Changes on the Wetland Ecosystem Water Environment Using Soft Computing Methods

Economic growth is accelerating in the entire world due to new inventions and advancements in the field of science and technology. The technology is progressing at a rapid pace and resulting in the infrastructure and technical progression of each nation. The utilization rate of land in the world has also increased substantially where the cultivated land is used for the development of industries and buildings. This land occupancy is alarming for the environment, and it is impacting the ecosystem of the earth in many adverse ways. In this study, the impact of land cover changes on the wetland ecosystem water environment has been studied in depth using soft computing techniques. The water environment data of the wetland ecosystem are obtained from real-world scenario and are mined using a particle swarm K-means clustering approach based on chaos search. The water environment assessment approach is used to analyze the influence of land cover changes on the water environment of the wetland ecosystem. The findings of this research work reveal that the cultivated land in the wetland is steadily decreasing, and the fertile forestland is steadily decreasing in the early stages and gradually increasing in the latter stages. The wetland water quality is gradually degrading over the period of time. The outcomes of the study demonstrate that a nonpoint source of pollution produced by land-use changes is the most important factor, which is affecting water quality. The analytical results’ accuracy is as high as 0.98 when compared to the real-world circumstances.

Influence of land cover change on spatio-temporal distribution of urban heat island —a case in Wuhan main urban area

In this study, the relationship between land cover (LC) characteristics and urban heat island (UHI) intensity in the main urban area of Wuhan City are investigated. The effects of LC change on green space and land surface temperature (LST) was investigated, along with the relationship among LST, LC, and normalised differential vegetation index (NDVI). The land was divided into five categories, namely, built-up area, agricultural land, water, forest, and bare land. LST was determined using the infrared band image from the same period. The area of built-up areas accounted for only 32.81% in 2007, and it increased to 46.01% in 2020, while agricultural land decreased by 12.14%, which is the primary reason for the increase in built-up areas. The average LST in the study area increased from 25.92℃ to 31.71℃, and the range of LST moved forward to high-temperature range. The high-temperature areas (>32℃) expanded from point distribution to plane distribution and its expansion direction was consistent with the urbanisation direction. The water and forest have the strongest mitigation capacity for UHI and should be protected. Urban managers should avoid the increase of bare land due to the degradation of agricultural land and forest because the increase in LST caused by this type of LC change is obvious. LST was negatively correlated with NDVI, indicating that fewer vegetation resulted in higher LST.

Land use and land cover change influence on soil organic carbon content for a pastoral area: use of geographical information system

Data on land use and cover change and soil organic carbon (SOC) in rangelands are essential. This is because rangelands ecosystems are fragile, and poor land-use practices can significantly threaten their sustainability by depleting SOC and increasing atmospheric carbon dioxide. This study investigated soil organic carbon variations as influenced by land use/land cover changes in the unprotected area of the Sanga agropastoral ecosystem, southwestern Uganda. Landsat images provided data for land use and cover for 1987 and 2020. Soil organic carbon contents were investigated in farmland (FL), grassland (GL), woodland (WL), and bare land (BL) as control at 0-15 cm and 15-30 cm depths. Soil samples were analyzed for organic carbon and bulk density using the colorimetric and core ring methods, respectively. Total soil organic carbon content was significantly high in grassland (31.55 Mg C ha-1), p=0.005, and woodland (27.89 Mg C ha-1), p=0.028 compared to bare land (16.17 Mg C ha-1). Additionally, total soil organic carbon concentration in grassland (2.10%) was higher than SOC concentration in farmland (1.39%) p=0.001 and bare land (1.00%), p<0.001, respectively. Similarly, woodlands soil organic carbon concentration (1.98%) was higher than soil organic concentrations in bare lands, p=0.003 and farmlands, p=0.028. Bulk density was significantly different at lower horizons, with farmland having a higher bulk density than other land use types, p=0.013. Roots and litter inputs in woodlands and grasslands contributed to higher organic carbon than farmland and eroded/bare lands. Cultivation also increased the soil bulk density. This study concludes that land use and the land cover change affected soil organic carbon sequestration and bulk density. Therefore, farmers need to increase farm management practices to avoid an increase in bulk density. Further study to compare the effects of grazing intensity on SOC and modeling future SOC content in the study area is recommended.

Understanding the influence of land cover change and landscape pattern change on evapotranspiration variations in Gwayi catchment of Zimbabwe

Understanding dynamics in hydrological processes helps to improve water resource management. Climate and land cover changes influence ecohydrological processes. This study sought to assess the influence of climate, land cover and landscape structure dynamics on actual evapotranspiration (ETa). To achieve this, the catchment parameter (w) was parameterised and the relationship between ETa and selected landscape metrics was determined. The ratio of precipitation to potential evapotranspiration was < 1 and the w was < 2, suggesting that land cover changes were more influential to ETa changes than climate variations. Given the low w (1< w < 2), we conclude that the catchment had a low water retention capacity and was sensitive to land cover changes. There was a negative correlation between landscape fragmentation and ETa, indicating that unregulated landscape fragmentation could be adversely impacting catchment water balance. Therefore, promoting initiatives that improve land cover consolidation could enhance water retention capacity.

The influence of land cover changes on landscape hydric potential and river flows: Upper Vistula, Western Carpathians

This paper presents an approach for mitigating water-related problems, that relates the retention of precipitation and use of ecosystems, as a tool for improving the quality, quantity and availability of water resources throughout the region. One approach is the determination of the landscape’s hydric potential (LHP). Land cover changes can influence ecosystems in different ways depending on crucial factors that depend on water resources. Thus-far, many studies describe the influence of land cover changes on individual features of catchments and hydrological regime, but few have made an attempt to analysis how changes in land cover can holistically influence processes in catchments. In this context the innovative aspect of this work presents the consequence of land cover changes on water retention expressed by LHP — a general descriptor that is linked with many composite influence factors on water retention. A study was carried out on 33 catchments located in central Europe. Results show increased forest cover having a positive trend in the context of LHP. Conversely, increased urban and industrial areas negatively impact LHP. The presented analysis reveals that a few land cover changes had direct and clearly positive effects on LHP. The LHP had decreased in 21 catchments and increased in 12 catchments. Decreased LHP was generally observed in catchments located on the left side of the Vistula basin where there are more advantageous conditions for agriculture, rising industry and urban areas. The study showed that during the analyzed period, obtained changes of LHP values did not strongly affect hydrological regimes in studied catchments. Our results show that LHP is a very good and useful descriptor that includes many characteristics of catchment and could be used for river catchment management purposes. The landscape’s hydric potential can be used in any catchment in the world.

Modeling watershed carbon dynamics as affected by land cover change and soil erosion

Process-based ecosystem carbon cycle models typically incorporate vegetation growth, vegetation mortality, and soil respiration as well as the biotic and environmental drivers that influence these variables. However, few spatially explicit process models can efficiently incorporate the influence of land cover change and carbon lateral movement at regional scales or high spatial resolution. This study uses the Land Use and Carbon Scenario Simulator (LUCAS) to demonstrate the development of a fast ecosystem model that not only considers the basic carbon cycle but also incorporates the impact of land cover change, soil erosion, and soil deposition. As input to the LUCAS modeling framework, we used the integrated biosphere simulator (IBIS) to simulate a non-spatial reference carbon cycling scenario without considering land cover change for the Nisqually River watershed in the northwestern United States. We then used the Land Change Monitoring, Assessment, and Projection (LCMAP) remotely sensed 30-m sequential land cover data to generate annual land change history for the Nisqually River area from 1985 to 2017 and used the Unit Stream Powered Erosion and Deposition model (USPED) to estimate annual soil carbon lateral movement. Finally, we combined the annual carbon outputs from IBIS, the land change history from LCMAP, and the soil erosion and deposition from USPED within the LUCAS simulation framework. Results showed that from 1985 to 2017, along with the dynamic land cover changes, total ecosystem biomass carbon increased from 11.4 to 18.6 TgC, mainly due to forest growth. Total ecosystem soil carbon declined from 31.7 to 29.7 TgC, but the overall loss in soil carbon was not uniform across land cover types. Forestland (forest sector) and grassland lost carbon, while wetland, developed land and agricultural land gained carbon. Forest, grassland, and developed land lost 0.0553 TgC during the study period (1.73 Gg of C per year; 1 Gg = 0.001 Tg) from erosion, while wetland gained 0.0071 TgC (0.22 Gg C per year) from deposition. Agricultural land was neutral in terms of soil erosion.

Characterizing the spatiotemporal response of runoff to impervious surface dynamics across three highly urbanized cities in southern China from 2000 to 2017

Urbanization affects the regional hydrological cycle, but quantitative assessment of the hydrological regime in regions of high urbanization remains unexplored. This study investigates the response of runoff to impervious surface area (ISA) dynamics across three highly urbanized cities in southern China. The Soil Conservation Service Curve Number hydrologic model is modified by coupling the 1-km high-resolution calibrated precipitation data and 250-m-resolution percentages of remotely sensed land cover. Results demonstrate that runoff metrics increase noticeably during 2000–2017 at the city scale, with larger (smaller) magnitudes observed for high-flow (low-flow) runoff metrics. Runoff trend variations are more pronounced during high-flow seasons and are remarkable over land surfaces. Analyses of linear regression and generalized additive models indicate that ISA changes account for 23–27% of the total variance of increased runoff. The ascending trend of runoff is not affected substantially by the slight decrease in ISA during 2014–2017, which is attributed to the combined influence of land cover changes and climate. At the subwatershed scale, changes in ISA explain 17% of runoff variations. The runoff regime is more (less) responsive at the high (low) ISA percentage, and one threshold indicative of substantial modification to runoff is detected in the ISA percentage. Overall, runoff responses identified in the spatiotemporal analysis underscore the importance of monitoring and assessing the hydrological regime in southern China as urbanization progresses.

The Influence of Land Cover Changes on Landscape Hydric Potential and River Flows: Upper Vistula, Western Carpathians

The Influence of Land Cover Changes on Landscape Hydric Potential and River Flows: Upper Vistula, Western Carpathians

Modeling the Influence of Eucalypt Plantation on Wildfire Occurrence in the Brazilian Savanna Biome

In the last decades, eucalypt plantations are expanding across the Brazilian savanna, one of the most frequently burned ecosystems in the world. Wildfires are one of the main threats to forest plantations, causing economic and environmental loss. Modeling wildfire occurrence provides a better understanding of the processes that drive fire activity. Furthermore, the use of spatially explicit models may promote more effective management strategies and support fire prevention policies. In this work, we assessed wildfire occurrence combining Random Forest (RF) algorithms and cluster analysis to predict and detect changes in the spatial pattern of ignition probability over time. The model was trained using several explanatory drivers related to fire ignition: accessibility, proximity to agricultural lands or human activities, among others. Specifically, we introduced the progression of eucalypt plantations on a two-year basis to capture the influence of land cover changes over fire likelihood consistently. Fire occurrences in the period 2010–2016 were retrieved from the Brazilian Institute of Space Research (INPE) database. In terms of the AUC (area under the Receiver Operating Characteristic curve), the model denoted fairly good predictive accuracy (AUC ≈ 0.72). Results suggested that fire occurrence was mainly linked to proximity agricultural and to urban interfaces. Eucalypt plantation contributed to increased wildfire likelihood and denoted fairly high importance as an explanatory variable (17% increase of Mean Square Error [MSE]). Nevertheless, agriculture and urban interfaces proved to be the main drivers, contributing to decreasing the RF’s MSE in 42% and 38%, respectively. Furthermore, eucalypt plantations expansion is progressing over clusters of high wildfire likelihood, thus increasing the exposure to wildfire events for young eucalypt plantations and nearby areas. Protective measures should be focus on in the mapped Hot Spot zones in order to mitigate the exposure to fire events and to contribute for an efficient initial suppression rather than costly firefighting.

Water Tower Ecosystems under the Influence of Land Cover Change and Population Growth: Focus on Mau Water Tower in Kenya

Land cover and population is key in considering sustainable management of the environment. An assessment focusing on the two may aid planning for sustainable management of the ecosystems. This is particularly vital for the water tower ecosystems which are extremely vulnerable. This paper provides a scientific assessment on the extent of land cover change in Mau Water Tower Ecosystem from 1986 to 2015 using satellite images. It analyzes the implications of observed population dynamics and forecasts the extent of land cover change in this resource. The results indicate a sharp increase in the area covered by grassland with a drastic decline in forest cover. Cropland showed marked fluctuations during the entire period. The change in forest cover had a very strong significant negative relationship with the rapid population increase. Forecast on land cover change, based on a “Business as Usual” (BAU) scenario, indicated further decline in forest cover and an increase in the area covered by grassland. The results of the study suggest that land cover change and population growth within the water towers are closely interlinked and cause significant effects on these ecosystems. These findings lay the foundation for a review of conservation and agricultural policies in order to enhance sustainable management of Mau Water Tower.

Expanding Rubber Plantations in Southern China: Evidence for Hydrological Impacts

While there is increasing evidence concerning the detrimental effects of expanding rubber plantations on biodiversity and local water balances, their implications on regional hydrology remain uncertain. We studied a mesoscale watershed (100 km2) in the Xishuangbanna prefecture, Yunnan Province, China. The influence of land-cover change on streamflow recorded since 1992 was isolated from that of rainfall variability using cross-simulation matrices produced with the monthly lumped conceptual water balance model GR2M. Our results indicate a statistically significant reduction in wet and dry season streamflow from 1992 to 2002, followed by an insignificant increase until 2006. Analysis of satellite images from 1992, 2002, 2007, and 2010 shows a gradual increase in the areal percentage of rubber tree plantations at the watershed scale. However, there were marked heterogeneities in land conversions (between forest, farmland, grassland, and rubber tree plantations), and in their distribution across elevations and slopes, among the studied periods. Possible effects of this heterogeneity on hydrological processes, controlled mainly by infiltration and evapotranspiration, are discussed in light of the hydrological changes observed over the study period. We suggest pathways to improve the eco-hydrological functionalities of rubber tree plantations, particularly those enhancing dry-season base flow, and recommend how to monitor them.

Influence of Land Cover Changes and Climatic Variability on Discharge Regime of Njoro River Catchment in Kenya

This study analyzed influence of land cover changes and climatic variability from 1973 to 2000 on discharge regime of Njoro River Catchment in Kenya. Analysis focused on hydro-meteorological data of 1977-1984 (Period I) and 1992-2000 (Period II), which are the periods found with available data and Landsat imageries for the same periods. Results show a downward trend of annual discharge that corresponded to increased deforestation. Forest area decreased by 25% while open fields combined with grasslands increased by 58% between the two periods. Discharge in Period I was 36% (0.23 m3/s or 82 mm/a) higher than Period II whereas increase of annual temperature (0.75℃) between the two periods was significant (P 3.98) in rainy years compared to dry years, and 2) mean discharge in Period II was different (P 4.77). Influence of climatic variability alone accounted for 25% (0.06 m3/s) on reduction of discharge while human activity mainly deforestation accounted for 75% (0.17 m3/s) on reduction of discharge in Period II. This implies that land cover changes were largely responsible for decrease in discharge and therefore, intervention measures of restoring forest cover are recommended for Njoro River Catchment.

Distinct Influences of Land Cover and Land Management on Seasonal Climate.

Anthropogenic land use and land cover change is primarily represented in climate model simulations through prescribed transitions from natural vegetation to cropland or pasture. However, recent studies have demonstrated that land management practices, especially irrigation, have distinct climate impacts. Here we disentangle the seasonal climate impacts of land cover change and irrigation across areas of high agricultural intensity using climate simulations with three different land surface scenarios: (1) natural vegetation cover/no irrigation, (2) year 2000 crop cover/no irrigation, and (3) year 2000 crop cover and irrigation rates. We find that irrigation substantially amplifies land cover‐induced climate impacts but has opposing effects across certain regions. Irrigation mostly causes surface cooling, which substantially amplifies land cover change‐induced cooling in most regions except over Central, West, and South Asia, where it reverses land cover change‐induced warming. Despite increases in net surface radiation in some regions, this cooling is associated with enhancement of latent relative to sensible heat fluxes by irrigation. Similarly, irrigation substantially enhances the wetting influence of land cover change over several regions including West Asia and the Mediterranean. The most notable contrasting impacts of these forcings on precipitation occur over South Asia, where irrigation offsets the wetting influence of land cover during the monsoon season. Differential changes in regional circulations and moist static energy induced by these forcings contribute to their precipitation impacts and are associated with differential changes in surface and tropospheric temperature gradients and moisture availability. These results emphasize the importance of including irrigation forcing to evaluate the combined impacts of land surface changes for attributing historical climatic changes and managing future impacts.

The influence of land-cover changes on the variability of saturated hydraulic conductivity in tropical peatlands

Understanding the movement of water through peat is essential for effective conservation and management strategies for peatlands. Saturated hydraulic conductivity, Ks, describes water movement through the peat profile. However, the spatial variability of Ks in tropical peatlands and the effects of land conversion on peat characteristics are poorly understood. Utilizing the slug test method, we estimated hydraulic conductivity in tropical peatlands in West Kalimantan, Indonesia, at three depths (0.75, 3.5, and 5.5 m) across four different land-cover types (undrained forests, recently burned forests, early seral communities, and oil palm (Elaeis guineensis Jacq.) plantations). We found strong spatial autocorrelation among measurements collected at our 19 study sites and evaluated the relationship between hydraulic conductivity and land-cover types, peat properties, and depth of measurement with a hierarchical linear model. Hydraulic conductivity varied greatly (c. 0.001–13.9 m d−1). The best approximating model for estimating Ks contained depth, forest cover, a depth and forest cover interaction, and the von Post degree of decomposition (Ks ~ depth + forest + depth × forest + von Post). Parameter estimates indicated that Ks was greater in forested than non-forested sites and decreased with increasing depth and decomposition stage. There was no evidence that Ks differed among the non-forested sites or was related to other physical and chemical peat properties. Our results suggest that Ks should be measured directly in tropical peatlands rather than estimated as a function of peat properties. Additionally, the strong spatial dependence suggests that similar research designs should examine the sample data for spatial dependence and, if necessary, incorporate hierarchical models.

Variations in the susceptibility to landslides, as a consequence of land cover changes: A look to the past, and another towards the future

Land cover is one of the most important conditioning factors in landslide susceptibility analysis. Usually it is considered as a static factor, but it has proven to be dynamic, with changes occurring even in few decades. In this work the influence of land cover changes on landslide susceptibility are analyzed for the past and for future scenarios. For the application, an area representative of the hilly-low mountain sectors of the Italian Southern Apennines was chosen (Rivo basin, in Molise Region). With this purpose landslide inventories and land cover maps were produced for the years 1954, 1981 and 2007. Two alternative future scenarios were created for 2050, one which follows the past trend (2050-trend), and another one more extreme, foreseeing a decrease of forested and cultivated areas (2050-alternative). The landslide susceptibility analysis was performed using the Spatial Multi-Criteria Evaluation method for different time steps, investigating changes to susceptibility over time.The results show that environmental dynamics, such as land cover change, affect slope stability in time. In fact there is a decrease of susceptibility in the past and in the future 2050-trend scenario. This is due to the increase of forest or cultivated areas, that is probably determined by a better land management, water and soil control respect to other land cover types such as shrubland, pasture or bareland. Conversely the results revealed by the alternative scenario (2050-alternative), show how the decrease in forest and cultivated areas leads to an increase in landslide susceptibility. This can be related to the assumed worst climatic condition leading to a minor agricultural activity and lower extension of forested areas, possibly associated also to the effects of forest fires. The results suggest that conscious landscape management might contribute to determine a significant reduction in landslide susceptibility.

Apple orchard phenology response to desiccation and temperature changes in Urmia Lake region

Agricultural production activities, such as those for various fruits and cereals, play a significant role in the local economy and food security of the Urmia Lake region. In particular, this region has thousands of hectares of apple orchards, which have an important socioeconomic impact on the life of people. Climate and land cover changes over the past several decades threaten the apple orchards phenology (AOP). Recent studies have emphasized the effect of temperature on plant phenology; however, they have overlooked the influence of land cover changes, such as Lake Desiccation, on plant phenology. Meanwhile, how climate change and Lake Desiccation will affect the AOP is still not very well understood. Therefore, in this study, we used the Enhanced Vegetation Index (EVI) extracted from remote sensing images acquired by the MODIS sensor spanning from 2003 to 2014, in order to extract the AOP events. Furthermore, we used a random forest regression (RFR) for analyzing the relationship between temperature changes/Lake Desiccation and AOP. The results revealed that EVI is a very useful tool for estimating the AOP with a mean root-mean-square error of 6.25 days. Moreover, there is a linear trend toward the early start of season in this region. The end of season (EOS) and the growing season length have also increased in the areas closer to the lake until 2008. This seems that the delayed EOS in the area closest to Urmia Lake has been associated with the lake microclimate since 2008.

Modeling and analysis of the potential impacts on regional climate due to vegetation degradation over arid and semi-arid regions of China

The regional climate effects of vegetation change in arid and semi-arid regions of China, which has experienced serious grassland degradation, are investigated in this study using the Weather Research and Forecasting (WRF) regional climate model. Two long-term simulation experiments (from January 1, 1980 to March 1, 2010), one with the land cover derived from the original United States Geological Survey’s (USGS) data (denoted as CTL) and the other (denoted as SEN) with a modification of the former one by vegetation degradation in arid and semi-arid regions of China, are undertaken to investigate the influence of land cover change on regional climate over arid and semi-arid regions of China. The possible mechanisms of how land cover change affects the regional climate in arid and semi-arid regions of China are also examined. The simulation results indicate that when compared with the observation datasets, the WRF model simulates the spatial pattern of observed temperature and precipitation quite well. After vegetation degradation over the arid and semi-arid regions of China, the net radiation and evaporation are reduced mainly within the degraded areas in summer, consistent with the reduction in precipitation and the increase in 2-m air temperature (T2 m).