Abstract:To identify the groundwater flow system in the North China Plain, the chemical and stable isotopes of the groundwater and surface water were analysed along the Chaobai River and Yongding River basin. According to the field survey, the study area in the North China Plain was classified hydrogeologically into three parts: mountain, piedmont alluvial fan and lowland areas.The change of electrical conductance and pH values coincided with groundwater flow from mountain to lowland areas. The following groundwater types are recognized: Ca-HCO 3 and Ca-Mg-HCO 3 in mountain areas, Ca-Mg-HCO 3 and Na-K-HCO 3 in piedmont alluvial fan areas, and HCO 3 -Na in lowland areas.The stable isotope distribution of groundwater in the study area also has a good corresponding relation with other chemical characteristics. Stable isotope signatures reveal a major recharge from precipitation and surface water in the mountain areas. Chemical and stable isotope analysis data suggest that mountain and piedmont alluvial fan areas were the major recharge zones and the lowland areas belong to the main discharge zone. Precipitation and surface water were the major sources for groundwater in the North China Plain. Stable isotopic enrichment of groundwater near the dam area in front of the piedmont alluvial fan areas shows that the dam water infiltrated to the ground after evaporation.As a result, from the stable isotope analysis, isotope value of groundwater tends to deplete from sea level (horizontal ground surface) to both top of the mountain and the bottom of the lowland areas in symmetrically. This suggests that groundwater in the study area is controlled by the altitude effect. Shallow groundwater in the study area belongs to the local flow system and deep groundwater part of the regional flow system.

Land-use change and lack of conservation in Bogowonto Watershed area have caused land degradation due to erosion and landslides. The rate of land degradation can be measured through the morphological characteristics of the soil and landscape. This study aimed to identify the relationship between the morphological characteristics of the soil and the rate of land degradation in Bogowonto Watershed area. The research framework initiated from the interpretation of thematic maps, surveys and field observations, and verification using land degradation assessment software. Sample points were determined using a stratified random sampling method. In general, land degradation is affected by slope, limited soil development, suboptimal conservation measures, and land-use change. Particularly, land degradation is affected by the type of landscape and the morphological characteristics of the soil. Volcanic hilly landscapes show a degradation rate of fine to very fine, characterized by thick soil depth (>60 cm), generous root distribution, loamy textured soil, fine soil particle size (Ø <0.002 mm), and good soil structure. The distribution of easily weathered volcanic ash causes volcanic hills to have thick and fertile soil characteristics. Quaternary-tertiary volcanic transition landscapes show a degradation rate of damaged to heavily damaged, characterized by thin soil depth (<60 cm), limited rooting, dominant coarse fraction (Ø 2-0.05 mm), and contact with fields lithological discontinuity. The data obtained provide information on the morphological characteristics of the soil and land degradation in Bogowonto Watershed area. The results of the study can also be used as a formulation for the conservation of Bogowonto Watershed area.

No abstract

Activities of Old Lawu volcano in the past resulted in various soil development in the south side of the volcano, especially in the area of the east side of Wonogiri and west side of Ponorogo, that located in the Java island. This area is also famous as herbal crops producer for raw materials of traditional herbal medicine industry. The purpose of this research is to identify the process of exposure of the parent materials in the Old Lawu volcanic environment, the development of the soil parent materials, and the mineralogy variation.  Four Sites with different geological formation were observed, and each Site was selected for soil profile identification on the process of weathering of rocks.  All layers of each profile were then sampled and then sand fraction of the fine earth particle was determined for the mineral type using X-ray diffraction (XRD).  The results showed that materials of the Old Lawu volcanic activity that was of quaternary period had sized material of gravel, sand, silt, and clay. These materials were then exposed and undergone the process of weathering, transportation, and sedimentation according to the landform at that period. The development of soil as geoheritage in this region was influenced by the material size, landform, and settling process. There are four typologies of the environment on the soil development at the present study, there are: (1) Soil that developed in the inter-fluvial basins is characterized by thick soil and a clear horizon differentiation process as a feature of maturity stage of soil development. (2) Soil developed on the slope of hill area is characterized by shallow in solum and it is in early-stage soil development. (3) Soil developed on the volcanic materials that were transported and sedimented in the river environment is characterized by the thick soil above the layered fine size parent material with a variety of color. (4) Soil developed on the tertiary breccia showed early soil development.

One of the indicators of land productivity assessment is soil fertility. The causes of infertile soil have been widely reported. This study aimed to evaluate soil fertility using the Soil Fertility Capability Classification (SFCC) approach and to determine the relationship between soil morphological and physiochemical properties and soil fertility. The research was conducted in North Galela Sub-district, North Halmahera Regency. The research framework began with the interpretation of thematic maps, surveys, field observations, and the making of soil fertility evaluation maps. Soil sampling was carried out based on the stratified random sampling method and supported by laboratory measurements according to USDA international standards. The research result showed that the research area had 14 soil fertility statuses. The fertility classes having the most significant limiting factor were loamy texture (Ø&lt;0.002 mm), rock surface, gravel subsoil, moderate salinity (0.2-0.4 mS cm^-1), low exchangeable K (&lt;20 cmol₍₊₎ kg^-1), and sloping slope (8%) with Lithic Haprendolls type and loamy texture (Ø&lt;0.002 mm), subsoil &gt;15% rock outcrop, moderate salinity (0.2-0,4 mS cm^-1), Na saturation &gt;15%, and a rather steep slope (14%) with Lithic Eutrudepts type. Both of these classes have a top layer texture, and the bottom layer contains clay &lt;35%, with limiting factors of hard layer inhibiting root to a depth of 50 cm, extremely low nutrient reserve, low electrical conductivity (EC) and high Na. The limiting factors found in North Galela Sub-district were hard root-restricting layer, exchangeable K, electrical conductivity, Na saturation, slope, and gravel.