Drastic Changes In Land Use Research Articles

Impacts of land use and land cover change on the landscape pattern and ecosystem services in the Poyang Lake Basin, China

ContextDecades of intensifying human activities have led to drastic changes in land use and land cover (LULC) in the Poyang Lake Basin (PLB), resulting in significant changes in landscape pattern and ecosystem service value (ESV), thereby affecting regional sustainability.ObjectivesWe focused on understanding the impact of LULC changes on the landscape pattern and ESV of the PLB and used the Patch-generating Land Use Simulation model (PLUS) to predict LULC changes in 2050.MethodsWe evaluated landscape patterns using landscape metrics and calculated ESV using the ecosystem service equivalent factor method. The Pearson correlation coefficient was used to analyze the correlation between landscape patterns and ESV from 1990 to 2020. Then, we combined the PLUS model and the ecosystem service equivalent factor method to calculate the ESV under multiple scenarios from 2020 to 2050.ResultsFrom 1990 to 2020, the LULC of the PLB changed to varying degrees. The PLB has undergone a rapid process of landscape fragmentation, and the total ESV of the PLB has decreased. The total ESV was positively correlated with the CONTAG index and negatively correlated with the SHDI index. Between 2020 and 2050, the ESV of the PLB is projected to decrease under the NDS (nature development scenario) and EDS (economic development scenario) and increase under the EPS (ecological protection scenario).ConclusionsESV responded to changes in landscape pattern. We recommend that the PLB should increase patch connectivity. Additionally, future development in the PLB should prioritize ecological protection to prevent further declines in ESV.

An Index for Snowmelt-Induced Landslide Prediction for Zavoj Lake, Serbia

In February 1963, a huge landslide (ca. 1,950,000 m3) blocked the Visočica River and, thus, formed Zavoj Lake. The primary objective of this research was to investigate the importance of snowmelt in relation to landslide occurrence and to define the critical climatic conditions that may trigger massive winter landslides. We used monthly precipitation and average monthly maximum temperature data from meteorological and precipitation stations in the Visočica River basin (Dojkinci) and in the immediate proximity of Lake Zavoj (Pirot, Dimitrovgrad and Topli Do) as data inputs to the Snow-Melt Landslide (SML) index. It considers the summed monthly precipitation for previous months that continuously have an average maximum temperature below 0 °C. According to this method, the event at Zavoj Lake stands out among all other precipitation and snowmelt values for the past 72 years. After applying the SML index, all stations showed values of >300 mm for February 1963, which we consider as the threshold value for potential landslides appearance. In addition to meteorological data, we applied the SML index to data from the Coordinated Regional Downscaling Experiment (CORDEX) regional climate model outputs for the region from 2022 to 2100. As expected, climate change will have influenced the temperature values, especially during the winter. Conversely, the study area is experiencing drastic changes in land use caused by depopulation, leading to a reduced risk of winter landslides in the Visočica basin. We suggest that future climatic conditions in the area will make it more likely to experience extreme summer precipitation events, which might trigger large landslides. The SML method can be implemented for all landscapes that experience snowy winters, providing information in a timely manner so that local residents can react properly when the probability of landslide occurrence rises. The SML index, grounded in essential meteorological principles, provides a tailor-made, data-driven methodology applicable across varied geographical settings. Its utility extends to mitigating hydro-meteorological hazards on scales ranging from local to national scales, offering diverse and effective early warning solutions.

Impact of urban land use on mean and heavy rainfall during the Indian summer monsoon

Abstract. Northern India has undergone intense urbanization since the middle of the 20th century. The impact of such drastic land-use change on the regional weather and climate remains to be assessed. In this work, we study the impact of the modification of land use – from vegetation to urban – on the Indian summer monsoon rainfall as well as on other meteorological variables. We use the regional Meso-scale Non-Hydrostatic (Meso-NH) model coupled with an urban module (the Town Energy Balance model) to perform monthlong sensitivity simulations centered around Kolkata, the most urbanized area in northeastern India. Paired simulations, one with and another without urban settings, have been performed to identify the impacts related to urbanization through both thermodynamic and kinetic effects. We find that the perturbation induced by urban land use enhances the mean rainfall over the model domain, principally by intensifying the convective activity through thermodynamic perturbation, leading to a 14.4 % increase in the monthly mean rainfall. The urban area also induces a 15.0 % rainfall increase during two modeled periods of heavy precipitation caused by low-pressure systems. In addition, the modeling results demonstrate that the urban area not only generally acts as a rainfall enhancer, particularly during nighttime, but also induces the generation of a specific storm in one modeled case that would not have formed in the absence of the urban area. The initiation of this storm over the city was primarily due to the urban terrain's disturbance of the near-surface wind flow, leading to a surge in dynamically produced turbulent kinetic energy (TKE). The thermal production of TKE over the nighttime urban boundary layer, on the other hand, serves as a contributing factor to the storm formation.

Focusing on structural changes and future risks of ecosystems: An opportunity-cost based ecosystem service account for riparian ecosystems and its case study

The riparian is a buffer zone between the river and human society, and improper land development will increase the ecological vulnerability of the river basin. Different evaluation methods for the ecological impact of development behavior will produce different value perception results, which in turn will affect the judgment and choice of decision-makers and the public. Based on the construction of an opportunity-cost-based monetary valuation method in the SEEA-EA (System of Environmental Economic Accounting-Ecosystem Accounting), this study took the riparian under the influence of the Xiaolangdi Project of the Yellow River from 1990 to 2020 as the research object, and evaluated the impact of land development decisions on ecosystem services under the superimposed influence of major projects, policies and socio-economic changes. The results show that: (1) The inclusion of opportunity costs can reduce the distortion of ecological value caused by economic factors and supply–demand state. In the case study, the opportunity cost of each 5-year accounting period in 30 years reduced the total accounting value respectively by 196.76, 25.88, 80.57, 84.33, 27.96, and 577.48 million yuan. (2) Opportunity cost can effectively reflect the ecological profit and loss caused by land transformation between different ecosystem types caused by decision-making in different periods. From 2015 to 2020, the opportunity cost of ecosystems was high when the total ecological land in the riparian increased, which reflected the drastic changes in land use during the decision-making period. (3) Opportunity costs are included in the monetary account as part of the “stock reduction”, which directly reflects the risk of ecological land reduction and structural change caused by development behavior. This mixed account of physical and monetary stocks can reflect both physical changes in ecosystem services and ecological risks, thereby improving stakeholders’ scientific understanding of the fluctuations in the value of ecosystem services caused by riparian land use.

Spatial assessment of soil erosion by water using RUSLE model, remote sensing and GIS: a case study of Mellegue Watershed, Algeria-Tunisia.

Soil erosion is an important global phenomenon that can cause many impacts, like morphometry and hydrology alteration, land degradation and landslides. Moreover, soil loss has a significant effect on agricultural production by removing the most valuable and productive top soil's profile, leading to a reduction in yields, which requires a high production budget. The detrimental impact of soil erosion has reached alarming levels due to the exacerbation of global warming and drought, particularly in the arid climates prevalent in Tunisia and Algeria and other regions of North Africa. The influence of these environmental factors has been especially evident in the catchment of Mellegue, where profound vegetation loss and drastic changes in land use and cover, including the expansion of urban areas and altered agricultural practices, have played a significant role in accelerating water-induced soil loss between 2002 and 2018. The ramifications of these developments on the fragile ecosystems of the region cannot be overlooked. Accordingly, this study aimed to compare soil losses between 2002 and 2018 in the catchment of Mellegue, which is a large cross-border basin commonly shared by Tunisian-Algerian countries. The assessment and mapping of soil erosion risk were carried out by employing the Revised Universal Soil Loss Equation (RUSLE). This widely recognised equation provided valuable insights into the potential for erosion. Additionally, changes in land use and land cover during the same period were thoroughly analysed to identify any factors that may have contributed to the observed risk. By integrating these various elements, a comprehensive understanding of soil erosion dynamics was achieved, facilitating informed decision-making for effective land management and conservation efforts. It requires diverse factors that are integrated into the erosion process, such as topography, soil erodibility, rainfall erosivity, anti-erosion cultivation practice and vegetation cover. The computation of the various equation factors was applied in a GIS environment, using ArcGIS desktop 10.4. The results show that the catchment has undergone significant soil water erosion where it exhibits the appearance of approximately 14,000 new areas vulnerable to erosion by water in 2018 compared to 2002. Average erosion risk has also increased from 1.58 t/ha/year in 2002 to 1.78 in 2018, leading to an increase in total estimated soil loss of 54,000 t/ha in 2018 compared to around 25,500 t/ha in 2002. Maps of erosion risk show that highly eroded areas are more frequent downstream of the basin. These maps can be helpful for decision-makers to make better sustainable management plans and for land use preservation.

Spatiotemporal characteristics and the national variations of borderland use change in Laos within the geopolinomical context

Laos, the only landlocked country in Mainland Southeast Asia (MSEA), has established over 40 geopolinomical mechanisms with its neighboring countries (including China, Vietnam, Cambodia, Thailand, and Myanmar), leading to significant land-use change (LUC) in the border areas. However, the spatial characteristics and national differences of LUC in the border areas of Laos remain unknown. Through the use of land-use products from 1985 to 2020 and by employing GIS spatial analysis, the results indicate that (1) LUC along the Laos border has led to severe and extensive deforestation, primarily attributed to the rapid expansion of construction land and the consistent growth of cropland. (2) With strengthened border cooperation, differences between LUC in Laos and its neighboring countries have decreased since 1985. (3) Cropland and construction land on the Laos–China and Laos–Thailand borders show obvious bordering characteristics, with increasing land-use homogeneity in near-border areas. In contrast, the Laos–Vietnam, Laos–Cambodia, and Laos–Myanmar borders display the opposite trend. (4) Port areas (e.g., Boten–Mohan port) driven by geopolinomical relations have drastic LUC, but they have huge differences. This study provides a database for quantitative research on the interaction between geopolinomical relations and border LUC to promote border geography, including impact and response.

Construction of Low-Carbon Land Use and Management System in Coal Mining Areas

In 2021, the Chinese government set the national development goal of ‘carbon peak and carbon neutrality’. Defining the carbon cycle process of land use is the first step for the implementation of low-carbon land use in coal mining areas. In this study, the carbon income and expenditure of land use in coal mining areas were analyzed theoretically using normative analysis, and thus the corresponding conceptual model of the carbon budget was formed. Concretely, carbon emissions from the coal industry were mainly from two aspects, that is, soil carbon emissions caused by drastic changes in land use in the coal exploration and exploitation stage and greenhouse gas emissions in the coal collection stage. Moreover, carbon in the air is sequestered in the soil when exploration land and mining land were reclaimed into woodland and grassland. Meanwhile, to optimize the utilization of land resources and realize the land low-carbon pattern from the management perspective, the logic system of land low-carbon use management in coal mining areas was explored using normative analysis and literature review. Thus, a complete management system including the management objective, subject, object, means, and implementation guarantee mechanism was built in detail. This study provided ideas for carbon reduction in coal mining areas and laid a decision-making basis for regional low-carbon land use and sustainable development.

Urban rainfall-runoff flooding response for development activities in new urbanized areas based on a novel distributed coupled model

The development and construction activities of new urbanized areas lead to drastic changes in land use, resulting in severe flood disasters. The main purpose is to systematically reveal the response process to urban stormwater under different urban development degree (DD) and low-impact development (LID) implementation. A novel distributed hydrological and hydrodynamic coupled model (DHHCM), consisting of a sub-catchment-based hydrological method for plot areas and a grid-based hydrodynamic method for road areas was developed in this study. The Fengxi New Town, China was applied as the research object, a total of 11 combined events of DDs (0%, 20%, 40%, 60%, 80% and 100%) and LID deployment were simulated under five rainfall return periods (P = 2a, 5a, 30a,50a and 100a) to explore their impact on the flood process. The results indicated that the DD and the LID implementation have no obvious impact on road flood when P ≤ 5a. However, the road flood increases significantly with the increase of DD when P ≥ 30a. The peak discharge of the drainage system significantly increases with the increase in DD under different return periods, and the average peak discharge increases the most obviously (2.62 m3/s) under P = 30a. The implementation of LID measures has significantly improved the mitigation effect of surface inundation, drainage system discharge and runoff control, and its effect has increased with the DD increase. It is with great significance to accurately control the flood disaster evolution process in urban development activities, and provide data and technical support for quantifying the risks and losses in policy making.

Effect Of Land-Use Changes On Landscape Fragmentation: The Case Of Ramallah Area In Central Palestine

The urban sprawl of cities periphery is one of such changes that has led to drastic land-use changes, which resulted in landscape fragmentation. The objective of this study is to understand the process of landscape fragmentation because of urban expansion; identifying the most influential drivers that have changed the land-use. To achieve the objectives due to changes in land use, a study had conducted in Ramallah area of Palestine. The study utilized Fragstat software to quantify the landscape changes with regard to its pattern and structure through a number of indices, also using Geographic Information System tool to draw up different landscape parcels spatially with its characteristics. The spatial analysis carried out on the land-use change used the 1997 and 2017 aerial photos to quantify the landscape fragmentation, which included a variety of land-uses. Over 52% of the study area underwent noticeable urbanization process, resulting in appreciable landscape changes to the area, especially after 1993. The statistical analysis of the landscape fragmentation revealed significant changes in land-use during the period from 1997 to 2017; the green landscape has been fragmented at a large scale by increasing the number of landscape patches (from 71 to 148 patches). As a result, there was an obvious reduction in agricultural lands, such as olive groves and grassland. At the same time, the urban surface areas increased from 654 patches in 1997 to 2019 patches in 2017. These results indicate that the landscape has become more fragmented due to geopolitical and socio-economic drivers since mid-1995 after Oslo accord.

Spatial change in glomalin-related soil protein and its relationships with soil enzyme activities and microbial community structures during urbanization in Nanchang, China

Rapid urbanization brings about drastic changes in land use and soil quality. Glomalin-related soil protein (GRSP), a sensitive indicator of soil quality, is possibly secreted by arbuscular mycorrhizal fungi (AMF). Besides, soil microorganisms and enzymatic activities play an irreplaceable role in improving soil quality and regulating soil nutrient circulation. However, little data are available on the interactions between GRSP, microorganisms, and enzymatic activities during urbanization. Here, we selected a built-up area (505 km2) in Nanchang, China, and collected soil samples from 184 sites from different urbanized areas. Soil microorganisms, soil physicochemical properties, soil enzymatic activities, vegetation characteristics, and land-use configurations were used to decouple the variations in total GRSP (TG) and easily extractable GRSP (EEG) during urbanization. Results showed that TG and EEG contents significantly decreased by 16.2 % and 19.4 % from low to heavy urbanization areas, respectively. Moreover, N-acetylglucosamine glycosidase (NAG), acid phosphatase (AP), and leucine aminopeptidase (LAP) activities, and the biomass of gram-positive bacteria (G+) and actinomycetes were significantly larger in lightly urbanized than in heavily urbanized areas (p < 0.05). EEG and TG positively correlated with β-1,4-glucosidase (BG), NAG, LAP, AP, G+, gram-negative bacteria, actinomycetes, and total soil microbial biomass (p < 0.05). Variance partitioning analysis showed that soil enzymatic activities are pivotal in GRSP production. However, no direct evidence shows that AMF secrete GRSP. Furthermore, structural equation modeling found that urbanization could diminish soil enzymatic activities by reducing vegetation cover and increasing the proportion of impervious surface area, indirectly causing a decrease in GRSP content. In conclusion, urbanization could indirectly reduce GRSP content by affecting land-use configurations and soil enzymatic activities. In the future, we shall consider improving soil quality by increasing GRSP content during urbanization.

Comprehensive evaluation of the ecohydrological response of watersheds under changing environments

Human activities and climate change pose a continuous threat to the ecological stability of natural rivers in many ways. Understanding and analyzing changes in flow regimes from a multidimensional perspective is essential for water resources management. In this research, a comprehensive evaluation framework was developed to quantitatively assess the hydrological condition of the basin in four aspects: river flow regime, ecological water demand, multiple time scales, and drivers. The health status of the Yuanjiang River was assessed using a combination of Indicators of Hydrologic Alteration (IHA) and eco-flow metrics, and differences in different drivers at different time scales were quantified based on the Choudhury-Yang equation and the ABCD model. The results show that after the abrupt change of the Yuanjiang River in 2004, the runoff decreased by up to 72.97 mm, three of the five groups of IHA reached moderate alteration or above, and its ecological flow was in a tight state for a long time. In addition, the reduction of runoff by precipitation and potential evapotranspiration is not negligible (contribution 40.56%, 6.91%), and the drastic changes in land use and the construction and operation of cascade reservoirs highlight the human impact (contribution 52.53%). Anthropogenic contributions to runoff changes deepen in the order of spring, summer, fall, and winter (6%, 51%, 83%, 95%), and on a monthly scale, human activities were the dominant factor in runoff variability in nine months (61–98%), with climatic factors driving runoff increases of 0.24–6.07 mm only in March, June, September, November, and December.

Understanding relationships between landscape multifunctionality and land-use change across spatiotemporal characteristics: Implications for supporting landscape management decisions

Landscape elements are the basic units of the earth surface system, and their changes have a profound impact on the continuous supply of landscape functions. However, few studies address the spatiotemporal tradeoffs and synergies between landscape multifunctionality and land-use in complex urban agglomeration system. In the Wuhan metropolitan area, rapid socioeconomic development, urbanization, and industrialization process led to drastic changes in land use, generating a series of landscape function imbalance. Therefore, this study, based on multivariate data and detection model quantitatively mapped five landscape functions, explored the correlations between different land-use types and landscape functions, and explored their trade-offs and synergies. Our study showed that: for 2000–2015, residential support (RS) function increased by 13.95 people/km2, carbon sequestration (CS) and water conservation (WC) functions changed greatly, and their added values were 1226.72 gCm−2a−1, 284.51 mm, respectively, soil conservation (SC) function increased by 68.17 t hm−2, habitat maintain (HM) function decreased by 0.1. Most landscape functions showed trade-off relationships, while a few presented synergy relationships, and the spatial pattern of landscape functions had significant differences, and their distribution was uneven. The hotspots of landscape multifunctionality mainly concentrated in the Wuhan City and southeast region of the study area, and the proportions of III and IV hotspots were 36.87% and 9.56%, respectively. Furthermore, landscape functions and land-use types displayed obvious spatial non-stationary characteristics, and the bundles of similar landscape functions were significantly clustered in space, while the composition structure of landscape function was significantly different. There is an urgent need to optimize the development of surface resources and the implementation of precise policies can optimize the layout of landscape elements and improve the supply of landscape function in an orderly direction. The research results of this study can help us to provide scientific reference for landscape planning management and decision-making.

Latent Rural Depopulation in Latin American Open-Pit Mining Scenarios

The increasing expansion of open-pit mining and the drastic transformations of land use in Latin America have led to processes of rural depopulation among traditional inhabitants, causing unsustainability in rural life systems. In the context of profound, worldwide territorial and environmental transformations, it is necessary to anticipate change scenarios and identify territories prone to rural depopulation. The objective of this article is to determine rural depopulation propensities through an exploratory multivariate study of the demographic, social, economic, and environmental conditions of territories where open-pit mining projects are being installed. First, a theoretical model is created using the grounded theory method for the literature review. Subsequently, indicators are analyzed using quantitative methods and geographic information systems. The results show that latent rural depopulation tends to be generated in territories with socio-environmental vulnerability, where advanced mining extractivism makes them prone to future depopulation. Some factors possibly leading to decreased rural population include the reduction of water availability; deforestation and depeasantization, due to urban development; gentrification, due to real estate speculation in providing lodging and food services to the mining project; and drastic changes in land use.

Analysis and Prediction of Land Cover Changes using the Land Change Modeler (LCM): A Case Study of Candolim, Bardez-Goa, India

Earth is changing ever since it is born. Once entire earth was covered by molten material which later took the shape of the lithosphere. The primordial lithosphere had only land and water as land cover and later other land covers such as forests, grasslands, wetlands etc. took shape. With the humanization of the Earth, the landscape was used for development and conservation resulting in land use. Land is a fixed resource and every accessible piece of land has been utilized by man for his needs. The land use continues to change, today’s built-up area may have been agricultural land a decade ago or today’s plantation might have been forest. Detection of changes in the use of land will offer policymakers and planners to predict the future land cover and will help in the proper planning and management of towns and cities. Globally, the tour and travel industry has played an important role in bringing drastic changes in land use. Tourism leaves both constructive and destructive imprints on the environment. Of late, ‘beach tourism’ has fascinated a large number of travellers in the world. In Goa, tourism arrived immediately after its liberation in 1961 from the oppressive rule of the Portuguese with the appearance of 'Hippies' in Calangute, Anjuna, Vagator, Baga and Candolim villages of Bardez taluka. Tourism has played a vital role in the overall economic development of these villages and has led to change in the character of these villages. Hence, this study makes an in-depth analysis of the impact of tourism on the land use land cover in Candolim village of Bardez Taluka. The spatio-temporal analysis of land cover change is undertaken using Image Processing software Idrisi Selva 17.0 and ArcGIS 10.3. Landsat multitemporal satellite imageries of the year 2001 and 2021 and Google Earth data of the same period are used to define the current changes in the land use land cover patterns. ArcScene was used for 3D creation and modelling of Candolim village between the years 2001 and 2021. The study indicates that due to unplanned tourism growth, six land parcels such as the area under forestland, sandy beaches, barren land, agricultural land, plantations and shrub land have declined by 0.94, 2.33, 3.42, 1.52, 0.23 and 6.83 per cent respectively. Net change to Built-up land from different classes and cubic trend map of 2001 to 2021 depicts that shrub Land was more vulnerable to change into built-up land at a large scale.

Ecosystem health assessment based on AHP-DPSR model and impacts of climate change and human disturbances: A case study of Liaohe River Basin in Jilin Province, China

Rapid urban development, increasing urban population, and drastic land-use changes may cause deterioration of ecosystem health and pose a serious threat to sustainable development. In this study, the analytic hierarchy process-driving-pressure-state-response (AHP-DPSR) model was used to evaluate the ecosystem health of the Liaohe River Basin in Jilin Province, China. The DPSR model was used to select indicators, and 29 indicators were selected for the ecosystem health evaluation index system, including four aspects of driving, pressure, state, and response. At the same time, the weights of each index were determined using AHP, and the spatiotemporal change pattern of ecosystem health in the past 15 years was assessed. The results of the ecosystem health assessment in the study area were spatially spread using ArcGIS software. Finally, the influence of climate and human activities on ecosystem health status was explored. Spatial autocorrelation analysis of the ecosystem health structure was conducted to provide suggestions for the subsequent improvement of ecosystem health quality and sustainable development in the region. The results showed the following: (1) From 2005 to 2020, the health level of the ecosystem in the study area generally showed a trend of improvement. The percentages of ecosystem health in the study area, from high to low in 2020 were 26%, 24%, 31%, 12%, and 7%. (2) The regions with high spatial autocorrelation in 2020 were Gongzhuling City, Dongliao County, Xi'an District, and Longshan District. These areas can be prioritized for ecological management of the region. (3) The spatial and temporal variation in ecosystem health in the Liaohe River Basin of Jilin Province is significantly influenced by precipitation, temperature, and GDP in the region. The conclusions of this study can provide policy references and scientific guidance for the ecological environmental protection and sustainable development of the Liaohe River Basin in Jilin Province.

Geomatics and smart tools in Digital Land Resources Mapping and Sustainability of Coastal Agriculture, Egypt

The northwestern coast of Egypt is characterized by an international interest due to its history and magnificent environment. The area was known as being the bread basket during the Greek and Roman periods. Recently, drastic changes in land use resulting in destructing many of water harvesting tools, thus diminution of the agriculture importance. Restoration of the area and planning self-sufficient communities needs to develop a sustainable land resources database for these regions. Multi concept of remote sensing and the Geographic Information System (GIS) permit to store, merge, and manipulate the huge amounts of thematic maps and attribute data. Sentinel satellite image 2018 scenes, covering the study area at the Egyptian northwestern coast, were acquired. ENVI software was used for image processing. A number of 53 topographic maps at scale 1:50000 were used to input GIS thematic layers relevant to land resources, using Arc_GIS 10.2 system. Field investigation was carried out to represent different soil units and collect ground control points. Chemical and physical soil properties were determined to assist soil classification. Soil map was produced including dominant geographic units and soil association. MicroLEIS system was employed to define soil suitability classes to olives, peach, wheat, beans, and sunflower crops. An intelligent module will be added to analyze the digital maps, interact the given data with learning tool (layer) to provide the decision makers with suggested solution not only information. The results showed that the soils are generally characterized by the presence of Calcic, Petrogypsic and Salic horizons. The limiting factors found in the piedmont and coastal plains are salinity, soil depth and texture. These factors decrease the suitability classes to be between S2 and S5.It can be concluded that the digital mapping of land resources using Geographic Information System (GIS) and satellite data preserve in the investment spent in soil and other thematic mapping.

Effect of Land-Use Change on Runoff in Hyrcania

Population growth and human activities have resulted in drastic changes in land use in many areas of the world, including the Hyrcania region in northern Iran. Land-use changes affect the hydrological processes of water basins. This study evaluated the effect of land-use changes on runoff over 15 years in the Haraz River basin located in Hyrcania using remote sensing data and GIS analyses. The annual precipitation of the region is 66.5 cm. Two Landsat images were used to develop land-use maps for 1996 and 2011. Original image features, their principal components, and vegetation indices were used to classify the two Landsat images into different land-use categories. Runoff was predicted from precipitation, land use, and hydrological soil groups, using the SCS-CN model (the “curve number” approach). During the 15 years, 62.4% of the area remained unchanged and 37.6% had undergone a land-use change. The highest average runoffs were obtained for bare land (14.1–14.5 cm/year) and residential land (10.4–11.4 cm/year), and the lowest for dense forest (2.5–2.6 cm/year) and first-grade rangeland (2.8–3.1 cm/year). The volume of annual runoff increased by 9% during 1996–2011 due to land-use changes. Runoff was estimated at 9.4% of precipitation in 1996, and 9.6% of precipitation in 2011. Most of the increase was related to the increased area of bare land and decreased area of rangeland. The study indicated that combined use of the SCS-CN approach, remote sensing data, and GIS tools allow cost-effective runoff estimation, helping watershed management. The results on the effect of land-use change on runoff can be seen as a warning for land-use managers and policymakers, who should aim at stopping and reversing the current land-use trends of the Haraz River basin.

Trends and variability of drought in the extended part of Chhota Nagpur plateau (Singbhum Protocontinent), India applying SPI and SPEI indices

Drought is a hydrological extreme and it brings negative consequences over environment, society and livelihood. Globally, drought frequency and magnitude is being amplified due to natural as well as anthropogenic causes. This scientific research attempts to examine the drought severity, trend and consequences applying the SPI and SPEI indices in the extended part of Chhota Nagpur Plateau (India) considering last 25 years period along with 3, 6, 9, and 12 months time scale. Mann-Kendall test and future prediction have also been done to find out the trend of drought. The results show that the frequency and trend of meteorological and ground water drought are being amplified and the years 1999, 2003, 2010, 2015 and 2016 have been recorded as extreme drought. The research revealed that the principal causes of drought are slight change of precipitation, unscientific withdrawal of ground water, modification of cropping patterns and drastic landuse change. District statistical bureau report states that drought events eventually reduce the crop production in most of the blocks of Purulia and severe water crisis creates during post monsoonal months in this particular region. The future prediction result signifies that around 60% mild and 6% severe drought will be faced using SPI index while around 64% mild and 5% severe drought will be occurred considering SPEI index. This scientific study along with integrated watershed management strategies will definitely assist to the regional planners and administrators for sustainable water resource management particularly for semi-arid climatic region of India.

Linking Ecosystem Service and MSPA to Construct Landscape Ecological Network of the Huaiyang Section of the Grand Canal

Rapid urbanization and drastic land-use change have led to landscape fragmentation and ecological environment deterioration in the regions along the Grand Canal. Building an ecological network is an important means to improve the connectivity of habitat patches and carry out ecological protection and restoration of territorial space, which is of great significance to ensure regional biodiversity and ecological security. In this article, we took the Huaiyang Section of the Grand Canal (Huaiyang Canal) as the study area, used the ecosystem service assessment model, morphological spatial pattern analysis (MSPA), and the landscape connectivity evaluation method to identify ecological sources, then used the minimum cumulative resistance (MCR) model and the gravity model to extract and grade ecological corridors. Based on these, the ecological network was constructed by combining the identification method of ecological nodes and ecological breakpoints. The aim of this was to provide a reference for the ecological space optimization of Huaiyang Canal and even the entire Grand Canal, the formulation of an ecological protection plan, and the implementation of territorial space ecological restoration. The results showed that the spatial distribution of the water conservation service, soil conservation service, carbon sequestration service, and biodiversity conservation service were significantly different, and the level of ecosystem services showed a trend of continuous degradation from 1990 to 2018. There were 12 ecological source patches comprehensively identified by multiple methods, with a total area of 2007.06 km2. In terms of spatial distribution, large ecological source patches were mainly distributed in the central and western areas adjacent to the Grand Canal, while small ecological source patches were scattered in the eastern and southern border regions of the study area. The total length of ecological corridors was 373.84 km, of which the number of the primary ecological corridor, secondary ecological corridor, and tertiary ecological corridor were 9, 7, and 7, respectively, and the suitable width of the ecological corridor was 200–400 m. After optimization, the proposed ecological network was composed of 3 key ecological source patches, 9 important ecological source patches, 23 terrestrial corridors, 10 aquatic corridors, and 18 ecological nodes. Twenty-nine ecological breakpoints were key areas requiring ecological restoration. The overlap rate of the integrated ecosystem service change area and land-use change area was 99%, indicating that land-use change has a significant impact on regional ecosystem services. This study is of great significance for carrying out the ecological protection and restoration of the Huaiyang Canal and adjusting local land-use policies. It also provides a typical case demonstration for identifying an ecological network and formulating ecological restoration planning for other sections of the Grand Canal and cities along the canal.

Multi-Function Tradeoffs of Land System in Urbanized Areas—A Case Study of Xi’an, China

Multi-functional trade-offs and synergy research on land systems are hotspots in geography and land science research, and are of great significance for achieving sustainable development of land use and the effective allocation of land resources. Recently, the development of the western region and The Belt and Road Initiative have become key topics, bringing opportunities and challenges to Xi’an. The rapid development of cities is accompanied by drastic changes in land use, and the ecological problems in the Qinling Mountains are becoming increasingly severe. This study took Xi’an as a case study and quantitatively evaluated the spatial-temporal patterns and trade-offs of land system functions such as economic development (ED), grain production (GP), ecological service (ES), etc. on the scale of 1 km × 1 km by fusing the data on land use, topography, soil, climate, and social economy. The results showed that the ED function of the land system continued to rise between 1980 and 2015, the GP function first declined and then increased; however, the ES function continued to decline. The ED, GP and ES functions respectively present a spatial pattern of high-value agglomeration, high in the north and low in the south, and high in the south and low in the north. In general, the three land system functions were trade-offs between each other. In terms of spatial pattern, ED and ES functions showed trade-offs in the south and a synergy distribution in the north; ESs and GP function trade-off zone significantly larger than the synergy zone, the trade-off between the two was significant; while the trade-off and the synergy zone for GP and ED was relatively small, the trade-off zone was the main one. The significant trade-off between GP and ES functions of the land system is a serious problem in land use in Xi’an. Under the premise of limited arable land, it is the current feasible strategy to promote the high-quality development of agriculture to increase the cultivation rate and efficiency, and to strengthen the ecological protection of arable land. In addition, the continued decline of ES functions is also worthy of attention. It is necessary to focus on increasing the greening rate of the city and strengthening the ecological management of the northern foot of the Qinling Mountains.