The impact of land use- and climate change on the managed eco-geomorphic balance in the Alps

Modification of the Earth’s surface i.e. land use change, is the main human activity for survival and is the key player in the management of natural resources, including water. Little attention has, however, been given to understand the role the territorial vegetation changes may play in strategic management of water resources. In the basin of Aswa northern Uganda, the changes in land use due to complex demographic and social economic factors is among the numerous challenges faced in management of the limited water resources in the area. The aim of the current study was to explore the opportunities land use changes in the basin may offer to water resources management, looking mainly at the expansion in future agriculture and afforestation as the critical land use change issues. The study was structured into four broad objectives: The first objective was to generate the reference land use dataset (1986 & 2001). The available techniques (the supervised and the unsupervised image classification) were explored using Landsat multi-spectral images. Through careful evaluation, the supervised image classification with the best classification accuracy of 81.48% was used to generate 1986 and 2001 land use maps. The second objectives of the study was to generate experimental land use scenarios required for testing the effect of spatial land use policies on hydrologic processes in the basin. The Multi-criteria-GIS methodology was developed and six experimental land use scenarios were generated using simple but consistence set of bio-physical and socio-economic parameters. The third objective was to customise the hydrologic process model SWAT that was used to simulate the hydrologic impact of the land use change scenarios. The calibration of the hydrologic model SWAT used monthly historical streamflow records from 1970 to 1974 recorded at the basin outlet. The model was manually calibrated using the Nash-Sutcliffe coefficient as objective function. The efficiency of the model during calibration was 0.46. Validation of the model using an independence monthly streamflow records from 1975 to 1978 was done and the model efficiency was 0.66, much better than in calibration period. The forth and last objective of the study was to simulate the hydrologic processes in the reference years and the hydrologic processes impacted by the land use change scenarios and to evaluate how this impact affects water resources management strategies. An independent validation of the model to identify the validity of extending the optimal parameters set in simulation of 2001 and land use change hydrologic processes was carried out by comparing the simulated actual evapotranspiration fraction with estimated actual evapotranspiration fraction obtained using surface energy balance method and the thermal MODIS images. Validation indicated acceptable model performance in simulating 2001 hydrologic processes, with a spatial correlation coefficient of 0.45. The application of the model in simulations of the hydrologic processes in the reference years noted that 2001 had more water yield than 1986 by 9.2 mm. The analysis of the impact of land use change in the reference years indicated an increase of 2.52 mm of water yield in the year 2001. Simulation of the hydrologic impact of the experimental land use indicated that Land use types, which in this study were restricted to plantation forest and generic agriculture, land use extent and location of the land use with respect to precipitation rate and amount, greatly influence the hydrologic process of the basin and the net water yield. It was noted that the water yield of the basin can be significantly decreased by over 15%, if more than 37% of the plantation forests are introduced in the wet zone. In the dry sub-basins however, afforestation of up to 42% had insignificant effect on water yield, which could therefore be exploited so as to offset the afforestation pressure in the wet sub-basin while at the same time enhancing the basin water yield. The effect of agricultural land use change on water yield was however less sensitive to climatic zones. 53% increase in agricultural land cover responded with an increase in water yield by about 27%.

علاوه بر تغییر‌اقلیم، تغییر‌کاربری‌اراضی به عنوان یک عامل جانبی اثرات مهمی بر سیلاب دارد. لذا پیش-بینی اثر این دو پارامتر بر وضعیت سیلاب دهه‌های آتی، راهگشای مقابله با این پدیده خواهد بود. هدف از مطالعه حاضر پیش‌بینی وضعیت هیدرولوژیکی حوزه آبخیز اسکندری در دهه آتی تحت اثر تغییر‌اقلیم و تغییر‌کاربری‌اراضی می‌باشد. جهت بررسی تغییرات اقلیمی دهه 2020، برونداد مدل HadCM3 تحت سناریوهای A2 و B1 توسط مدل LARS-WG ریزمقیاس گردید. پس از بررسی تغییرات کاربری-اراضی گذشته، دو سناریو جهت پیش‌بینی تغییرات آن در آینده طراحی شد. در انتها با تغییر هایتوگراف بارش و کاربری‌اراضی در مدلHEC-HMS که برای دوره گذشته کالیبره و اعتبارسنجی شده، اثر تغییر اقلیم و کاربری اراضی بر سیلاب منطقه مطالعاتی مورد بررسی قرار گرفته شد. نتایج نشان دهنده افزایش 2/7 تا 9/10 درصدی بارش متوسط سالانه دهه 2020 می‌باشد. افزایش توأمان دمای حداقل و حداکثر منطقه مطالعاتی در تمامی ماه‌ها موجب افزایش 82/0 تا 02/1 درجه سانتی‌گرادی دمای متوسط سالانه خواهد شد. افزایش دبی اوج و حجم سیلاب در ماه‌های مارس، اکتبر و فوریه و کاهش آن در ماه آوریل پیش بینی شده است. به طوری که در صورت تغییر‌کاربری‌اراضی همراه با تغییر‌اقلیم این افزایش شدیدتر خواهد بود.

Land use/land cover and climate change can significantly alter water cycle at local and regional scales. Xixian Watershed, an important agricultural area in the upper reach of the Huaihe River, has undergone a dramatic change of cultivation style, and consequently substantial land use change, during the past three decades. A marked increase in temperature was also observed. A significant monotonic increasing trend of annual temperature was observed, while annual rainfall did not change significantly. To better support decision making and policy analysis relevant to land management under climate change, it is important to separate and quantify the effect of each factor on water availability. We used the Soil and Water Assessment Tool (SWAT), a physically based distributed hydrologic model, to assess the impact of Land use and climate changes separately. The SWAT model was calibrated and validated for monthly streamflow. Nash-Sutcliff efficiency (NSE), percentage bias (PBIAS), and coefficient of determination (R 2) were 0.90, 6.3 %, and 0.91 for calibration period and 0.91, 6.9 %, and 0.911 for validation period, respectively. To assess the separate effect of land use and climate change, we simulated streamflow under four scenarios with different combinations of two-period climate data and land use maps. The joint effect of land use and climate change increased surface flow, evapotranspiration, and streamflow. Climate variability increased the surface water and stream-flow and decreased actual evapotranspiration; and land use change played a counteractive role. Climate variability played a dominant role in this watershed. The differentiated impacts of land-use/climate variabilities on hydrological processes revealed that the unapparent change in stream-flow is implicitly because the effects of climate variability on hydrological processes were offset by the effects of land use change.

چکیده در این مطالعه تأثیر تغییر کاربری اراضی از مرتع به زراعی بر برخی شاخص‌های میکروبیولوژیکی و بیوشیمیایی خاک در دو عمق 20-0 و 40-20 سانتیمتری در سه منطقه کنگاور، ده‌نو و سلطانیه مورد بررسی قرار گرفته است. بدین منظور از دو عمق خاک و در سه تکرار نمونه های مرکب خاک از هر سه منطقه که کاربری آن ها از مرتع به زراعی تغیـیر کرده است، تهیه و میزان تنفس میکروبی، تنفس برانگیخته، ضریب متابولیکی، کربن و نیتروژن توده زنده میکروبی و فعالیت آنزیم های اوره آز، فسفاتاز قلیایی، ساکاراز و آریل سولفاتاز تعیین گردید. نتایج نشان داد تغییر کاربری اراضی سبب کاهش تنفس میکروبی در منطقه کنگاور (64-36 درصد)، ده نو (60-45 درصد) و سلطانیه (34 درصد) گردید. تنفس برانگیخته نیز بر اثر تغییر کاربری در مناطق مورد مطالعه بین 13 الی 37 درصد کاهش یافت. همچنین کربن (60-30 درصد) و نیتروژن (56-18 درصد) توده زنده میکروبی و نسبت کربن به نیتروژن توده زنده میکروبی (17-9 درصد) در هر سه منطقه و در هر دو عمق کاهش یافتند. در حالی که شاخص‌های ضریب (کسر) متابولیکی (95-36 درصد)، درصد کربن (60-4 درصد) و نیتروژن (76-3 درصد) توده زنده میکروبی و درصد معدنی شدن کربن (43-9 درصد) در هر سه منطقه بر اثر تغییر کاربری افزایش پیدا کردند. بررسی فعالیت آنزیم‌ها نیز نشان داد فعالیت فسفاتاز قلیایی در هر سه منطقه و هر دو عمق بر اثر تغییر کاربری تغییر معنی‌دار نیافت. در منطقه سلطانیه تنها در عمق 20-0 سانتیمتری فعالیت اوره آز بر اثر تغییر کاربری به طور معنی‌دار کاهش (18 درصد) پیدا نمود و برای بقیه آنزیم‌ها تغییرات معنی‌دار نبود. تغییر کاربری در منطقه کنگاور فعالیت اوره آز، ساکاراز و آریل سولفاتاز را به طور معنی‌دار به ترتیب 20، 33 و 11 درصد کاهش داد، ولی در عمق 40-20 سانتیمتری تأثیر تغییر کاربری بر فعالیت این سه آنزیم معنی‌دار نشد و در منطقه ده نو فعالیت اوره آز و آریل سولفاتاز در هر دو عمق و ساکاراز تنها در عمق 20-0 سانتیمتری به طور معنی‌دار بر اثر تبدیل کاربری مرتع به زراعی کاهش یافت. به طور کلی می‌توان نتیجه گرفت که عملیات کشاورزی و به ویژه خاکورزی دراز مدت سبب افزایش دسترسی ریزجانداران خاک به اکسیژن شده و در نتیجه فعالیت های میکروبی و از جمله تنفس خاک افزایش می یابد که نهایتا منجر به تجزیه ذخیره مواد آلی و کاهش کیفیت خاک می گردد. واژه‌های کلیدی: فعالیت آنزیمی، کشت و کار، تغییر کاربری، تنفس میکروبی خاک، کیفیت خاک

Assessment of land use and climate change effects on land subsidence using a hydrological model and radar technique

Markov model was used to represent the land-use change data for several reasons.Firstly,land use change is not unidirectional in nature.A given parcel of land theoretically may change from one category of land-use to any other at any time.Markovian analysis uses matrices that represent all the multi-directional land-use changes between all the mutually exclusive land-use categories.Land use changes and scenarios in Lhasa district were analyzed in this paper using Markov model.The main conclusions are as follows: (1) Land use changes in Lhasa district during the last ten years were related to this period's integrated agricultural development project.In 10 years from 1990 to 2000,186.53 ha of cultivated land were converted into forest land,accounting for 54.857% of the total cultivated land area converting into the other land use categories;and 130.05 ha were converted into residential area,being 38.247%.The remaining limited area was converted into the other land use categories such as rangeland and water body. (2) The most extensive changes of land use from 1990 to 2000 in Lhasa district was rangeland conversion.Rangeland was converted into cultivated land,horticultural land,forestland,residential area and water body.Among them,2333.33 ha of forestland were converted from rangeland,or 94.093 %,the largest of all in area.These land use changes were related directly to the integrated development and construction project carried out in the central Tibetan Plateau in the mid 1990s.Because of the implementation of biological and engineering measures consisting of large scale of forestation and construction of field safeguarding forest,since the 1990s,remarkable effects in soil erosion control have been obtained through improving surface vegetation and land cover conditions. (3) Markov chain model prediction indicated that the general trends of land use changes,in Lhasa district in future were that cultivated land,rangeland,water body and unused land will decrease and forest,horticultural land and residential area will increase. (4) It should be pointed out that since there are many factors impacting land use changes,in particular in a short period of time,policies,regulations,important regional projects and human activities and other uncertain factors will affect regional land use changes,hence causing certain errors in prediction accuracy of land use changes in Lhasa district. (5) The simulated areas of land use changes in the future in Lhasa district by Markov mode are very close to the planning areas of land use changes of Tibet,therefore,land use change scenario based on the Markov model has an important value for making land use plan.

The key focus of this study is the use of future climate and land use data obtained from appropriate projection models to assess long-term annual streamflow changes in a basin located in northern Iran. Future climate projections were derived from the CanESM2 model under two Representative Concentration Pathways (RCP2.6 and RCP8.5), using the SDSM downscaling model for the mid- and end-21st century. The future land use map for the year 2050 was obtained from the Land Use Modeler (LCM). Streamflow under projected land use change (LUC) and climate change (CC) scenarios was simulated using the Soil and Water Assessment Tool (SWAT). The climate change evaluation indicates that precipitation will increase (up to 24%) in winter but decrease (up to -37%) in spring, summer, and autumn (except December). Additionally, temperature will rise in all months of the year. The effects of climate change on the Nekarood Basin are expected to increase streamflow in winter and decrease it in spring (except April), summer, and autumn (except December). The streamflow simulation results under the influence of land use change show that peak flow values will increase, while base flow will decrease. The combined effects of LUC and CC are projected to intensify future streamflow responses, with decreases of -2.9%, -8.3%, -8.1%, and − 9.2% in mid-century/RCP2.6, mid-century/RCP8.5, end-century/RCP2.6, and end-century/RCP8.5, respectively. A specific finding of this study is that the annual variations in streamflow are strongly influenced by climate in the basin.

There are major concerns about the impact of the large scale production of woody and grassy crops for energy production on the conversion of natural vegetation and on food security. The objective of this study is to evaluate the possibilities and limitations of avoiding these undesirable effects by increasing the productivity of crop and livestock production through investments in R&D in agriculture. An extended version of the Modular Applied GeNeral Equilibrium Tool (MAGNET) is used to model the R&D investments in agriculture to compensate the effects of 15 EJ to 100 EJ biomass supply from energy crop plantations. The costs of R&D investments in agriculture to avoid the expansion of land are estimated at 6 to 64 billion US$ for 15 to 100 EJ, respectively. Food security effects are less costly to compensate, i.e. food security improves when the land use change effects are compensated. The costs of R&D investments correspond to 0.4 to 0.6 $/GJ biomass from plantations. The costs of R&D investments are higher in industrialized countries compared to developing regions, because of the longer time lags between R&D investments and productivity increases in industrialized regions. The impact of R&D investments in agriculture to avoid land use change in 2030 results in positive effects in 2040 and 2050, i.e. agricultural land use decreases and food security improves compared to no bioenergy plantation scenario, because of the time lag of R&D investments. We conclude that investments in agriculture R&D are a potentially effective and low-cost strategy to avoid undesirable land use change effects of large scale use of biomass from energy crop plantations, but the time lag effect requires early planning and alignment in time of bioenergy policies with investments in R&D in agriculture.

The present study focuses on the economic, political/institutional, technological, cultural, demographic and environmental drivers of land use change. It aims to understand the factors influencing land use decisions at the household level, in particular the influence of migration. The study is guided by the hypothesis that international migration is driving land use change through the investment of remittances, funds sent back by migrants to their families in the country of origin. This research is based on a political ecology approach and the conceptual framework relies on three theoretical concepts. First, the concepts of proximate causes and driving forces were used to identify the factors behind changing land use. In addition, the concept of remittance landscapes, a concept developed in the framework of this study, which is defined as an emerging type of landscape driven by the investment of remittances, was used to evaluate the impact of remittances on land use in the study area. Fieldwork was conducted in the municipality of Autlán in the state of Jalisco in Mexico over a total period of 8 months between 2002 and 2004. Land use changes between 1990 and 2000 were quantified based on satellite image analysis. Underlying driving forces of these changes were examined based on land use change data collected by survey as well as data available from municipal, state and federal agencies. Land use changes observed in the study area between 1990 and 2000 include a slight increase of agricultural land (2%), of urban land cover (0.5%) and of pine-oak forest (0.7%). Over the same period, pasture increased by 18% while dry forest decreased by 10%. Rapid and extensive land use change is occurring on rainfed agricultural land, as maize cultivation is converted to the cultivation of agave azul used for the production of tequila. The first plantations of agave azul were established in 1996 and by 2002, agave azul was planted on 33% of all rainfed agricultural land of the municipality. 84% of owners of rainfed land included in the survey had changed land use from maize to agave during this time period. The dynamics of several proximate causes are driving this change: 1) Market prices for maize decreased by 46% between 1994 and 2004 while the costs for agricultural inputs continually increased so that the cultivation of rainfed maize was no longer economically profitable; 2) The variability of rainfall combined with a lack of irrigation water limits the choice of economically viable alternatives to agave azul; 3) In the large majority of cases, landowners rent out their land to tequila companies in reverse leasing arrangements for seven-year periods (the duration of one growing cycle of agave azul). During this time they do not have to work on their own fields and are free to find off-farm employment or to migrate to the US and; 4) Landowners continue to receive agricultural subsidies even though the land is rented out, as agave azul is one of the eligible crops. Overall, the main driving forces identified in the study area are economic (market prices), environmental (variability of rainfall, soil quality, topography), political/institutional (agricultural subsidies, land tenure) and demographic (labor availability). Technology and culture appear to be less important. Results of the present study confirm the hypothesis that global factors, especially international trade agreements such as NAFTA (North American Free Trade Agreement) increasingly influence land use change. However, they are not sufficient to function as a sole driver of land use change. Environmental factors are a critical determinant of whether a certain land use change will occur or not. The decisive aspect behind the observed land use changes are the multiple interactions between specific factors at different levels and not the predominance of one particular driving force functioning at a particular level. International migration is a significant livelihood strategy in the study area, especially for lower-income communities. On average, 50% of all households have or had at least one family member in the US as a migrant between 1980 and 2004, and remittances represent 45% of total household income. In general, the bulk of remittances income is used for subsistence needs and to repay debts. Nevertheless, on average, 30% of migrant households invest remittances in land, livestock, agricultural production and in house construction. All these investments lead to land use changes. The impact of remittances on land use changes is variable, and depends on the socio-economic, political and environmental context of the community and the individual situation of the migrant household. In low-income communities, remittances might be used to repair existing housing, while in higher-income communities, remittances are used to construct a new house, converting agricultural to urban land. With regard to changes in labor availability due to out-migration, the results are ambiguous. Migration can drive land use change by encouraging a shift to low-labor land use systems, but these land use changes that require less labor can also drive migration. The concept of remittance landscape developed by the researcher has proved useful for analysing the impact of remittances on land use changes. A combination of area-based and actor-based evaluation criteria are effective in order to describe quantitative as well as qualitative landscape transformations driven by the investment of remittances. Landscapes where the investment of remittances leads to a change of land use from subsistence to cash crop cultivation should be included as a potential type of remittance landscape, even though the basic type of the landscape (agricultural) remains unchanged. Accordingly, at least six different types of transformations into remittance landscapes are possible: a) forest to pasture, b) forest to agriculture, c) forest to urban, d) agriculture to pasture, e) agriculture to urban and f) change of agricultural system. In conclusion, the study area on which this research focused is not considered to contain any remittance landscapes because remittances are only partially driving the extensive land use changes occuring in the region.

We assessed the effects of historical (1931–1998) changes in both land use and climate on the water budget of a rapidly urbanizing watershed, Ipswich River basin (IRB), in northeastern Massachusetts. Water diversions and extremely low flow during summer are major issues in the IRB. Our study centers on a detailed analysis of diversions and a combined empirical/modeling treatment of evapotranspiration (ET) response to changes in climate and land use. A detailed accounting of diversions showed that net diversions increased due to increases in water withdrawals (primarily groundwater pumping) and export of sewage. Net diversions constitute a major component of runoff (20% of streamflow). Using a combination of empirical analysis and physically based modeling, we related an increase in precipitation (2.7 mm/yr) and changes in other climate variables to an increase in ET (1.7 mm/yr). Simulations with a physically based water‐balance model showed that the increase in ET could be attributed entirely to a change in climate, while the effect of land use change was negligible. The land use change effect was different from ET and runoff trends commonly associated with urbanization. We generalized these and other findings to predict future streamflow using climate change scenarios. Our study could serve as a framework for studying suburban watersheds, being the first study of a suburban watershed that addresses long‐term effects of changes in both land use and climate, and accounts for diversions and other unique aspects of suburban hydrology.

The main causes of habitat conversion, degradation, and fragmentation—all of which add to the loss in biodiversity—are human activities, such as urbanization and farmland reclamation. In order to inform scientific land management and biodiversity conservation strategies and, therefore, advance sustainable development, it is imperative to evaluate the effects of land-use changes on biodiversity, especially in areas with high biodiversity. Using data from five future land-use scenarios under various Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs), this study systematically assesses the characteristics of land-use and landscape pattern changes in southwest China by 2050. This study builds a comprehensive biodiversity index and forecasts trends in species richness and habitat quality using models like Fragstats and InVEST to evaluate the overall effects of future land-use changes on biodiversity. The research yielded the subsequent conclusions: (1) Grasslands and woods will continue to be the primary land uses in southwest China in the future. But the amount of grassland is expected to decrease by 11,521 to 102,832 km2, and the amounts of wasteland and urban area are expected to increase by 8130 to 16,293 km2 and 4028 to 19,677 km2, respectively. Furthermore, it is anticipated that metropolitan areas will see an increase in landscape fragmentation and shape complexity, whereas forests and wastelands will see a decrease in these aspects. (2) In southwest China, there is a synergistic relationship between species richness and habitat quality, and both are still at relatively high levels. In terms of species richness and habitat quality, the percentage of regions categorized as outstanding and good range from 71.63% to 74.33% and 70.13% to 75.83%, respectively. The environmental circumstances for species survival and habitat quality are expected to worsen in comparison to 2020, notwithstanding these high levels. Western Sichuan, southern Guizhou, and western Yunnan are home to most of the high-habitat-quality and species-richness areas, while the western plateau is home to the majority of the lower scoring areas. (3) The majority of areas (89.84% to 94.29%) are forecast to undergo little change in the spatial distribution of biodiversity in southwest China, and the general quality of the ecological environment is predicted to stay favorable. Except in the SSP1-RCP2.6 scenario, however, it is expected that the region with declining biodiversity will exceed those with increasing biodiversity. In comparison to 2020, there is a projected decline of 1.0562% to 5.2491% in the comprehensive biodiversity index. These results underscore the major obstacles to the conservation of biodiversity in the area, highlighting the need to fortify macro-level land-use management, put into practice efficient regional conservation plans, and incorporate traditional knowledge in order to save biodiversity.

Using a groundwater quality negotiation support system to change land-use management near a drinking-water abstraction in the Netherlands

This paper assesses the long-term combined effects of land use (LU) and climate changeon river hydrology and water scarcity of two rivers of the Western Ghats of India. The historical LU changes were studied for four decades (1988-2016) using the maximum likelihood algorithm and the long-term LU (2016-2075) was estimated using the Dyna-CLUE prediction model. Five General Circulation Models (GCMs) were utilized to assess the effects of climate change (CC) and the Soil and Water Assessment Tool (SWAT) model was used for hydrological modeling of the two river catchments. To characterize granular effects of LU and CC on regional hydrology, a scenario approach was adopted and three scenarios depicting near-future (2006-2040), mid-future (2041-2070), and far-future (2071-2100) based on climate were established. The present rate of LU change indicated a reduction in forest cover by 20% and an increase in urbanized areas by 9.5% between 1988 and 2016. It was estimated that forest cover in the catchments may be expected to halve compared to the present-day LU (55% in 2016 to 23% in 2075), along with large-scale conversion to agricultural lands (13.5% in 2016 to 49.5% in 2075). As a result of changes to LU and forecasted climate, it was found that rivers in the Western Ghats of India might face scarcity of fresh water in the next two decades until the year 2040. However, because of large-scale LU conversion toward the year 2050, streamflow in rivers might increase as high as 70.94% at certain times of the year. Although an increase in streamflow is perceived favorable, the streamflow changes during summer and winter may be expected to affect the cropping calendar and crop yield. The changes to streamflow were also linked to a 4.2% increase in ecologically sensitive wetlands of the Aghanashini river catchment.

تبدیل اراضی جنگلی و مرتع طبیعی به اراضی تحت کشت، وقتی که همراه با افزایش سریع جمعیت شروع شد، به عنوان یک دلیل جدی تخریب خاک مخصوصا در مناطق تپه ماهوری با توپوگرافی موج دار می‌باشد. این مطالعه به منظور بررسی اثر تغییر کاربری اراضی و موقعیت زمین نما بر تغییرات برخی خصوصیات خاک در منطقه مورد مطالعه انجام گرفت. در این منطقه از دو شیب تپه با کاربری مرتع و تحت کشت نمونه برداری انجام گرفت و در هر شیب تپه از چهار موقعیت شیب شامل: قله شیب، شانه شیب، شیب پشتی و پای شیب و در هر موقعیت از سه نقطه به صورت تصادفی و در عمق‌های 0-10،10-20 و 20-30 سانتی متری نمونه برداری صورت گرفت. نتایج نشان داد که میانگین ماده آلی در کاربری مرتع (1/2درصد) حدود 40 درصد بیشتر از میانگین ماده آلی در کاربری تحت کشت (2/1 درصد) به دست آمد که دارای تفاوت معنی دار بودند. به طور کلی ماده آلی، نیتروژن کل، پتاسیم قابل جذب، درصد رس و شن غالبا به طور معنی داری با تغییر کاربری مرتع به کشاورزی کاهش معنی دار نشان دادند. خصوصیاتی مانند آهک، چگالی ظاهری، اسیدیته و درصد سیلت با تغییر کاربری از مرتع به کشاورزی غالبا به طور معنی داری افزایش یافته اند. تغییر کاربری بر پذیرفتاری مغناطیسی اثر معنی دار داشته است و باعث کاهش معنی دار آن در کاربری تحت کشت به دلیل هدر رفت بیشتر رس و در نتیجه ذرات ریز مغناطیسی همراه آن شده است. تغییرات اکثر خصوصیات اندازه گیری شده خاک با تغییر موقعیت لند فرم نیز غالبا معنی دار شده است که می‌تواند به دلیل وجود فرسایش آبی شدید حاکم بر منطقه و وجود سازندهای حساس به فرسایش و مدریت نامناسب بشری باشد که باعث فرسایش خاک سطحی غنی از ماده آلی، عناصر غذایی و کانی‌های مغناطیسی از موقعیت‌های بالای شیب و رسوب آنها در موقعیت‌های پایین شیب باشد. در مجموع کشت و کار بر روی اراضی شیب دار باعث افزایش معنی دار فرسایش خاک و به دنبال آن هدر رفت بیشتر ذرات ریز خاک، ماده آلی، عناصر غذایی و کانی‌های ریز مغناطیسی می‌شود.

Vegetation dynamics is thought to be affected by climate and land use changes. However, how the effects vary after abrupt vegetation changes remains unclear. Based on the Mann-Kendall trend and abrupt change analysis, we monitored vegetation dynamics and its abrupt change in the Yangtze River delta during 1982–2016. With the correlation analysis, we revealed the relationship of vegetation dynamics with climate changes (temperature and precipitation) pixel-by-pixel and then with land use changes analysis we studied the effects of land use changes (unchanged or changed land use) on their relationship. Results showed that: (1) the Normalized Vegetation Index (NDVI) during growing season that is represented as GSN (growing season NDVI) showed an overall increasing trend and had an abrupt change in 2000. After then, the area percentages with decreasing GSN trend increased in cropland and built-up land, mainly located in the eastern, while those with increasing GSN trend increased in woodland and grassland, mainly located in the southern. Changed land use, except the land conversions from/to built-up land, is more favor for vegetation greening than unchanged land use (2) after abrupt change, the significant positive correlation between precipitation and GSN increased in all unchanged land use types, especially for woodland and grassland (natural land use) and changed land use except built-up land conversion. Meanwhile, the insignificant positive correlation between temperature and GSN increased in woodland, while decreased in the cropland and built-up land in the northwest (3) after abrupt change, precipitation became more important and favor, especially for natural land use. However, temperature became less important and favor for all land use types, especially for built-up land. This research indicates that abrupt change analysis will help to effectively monitor vegetation trend and to accurately assess the relationship of vegetation dynamics with climate and land use changes.