--- a/artifacts/src/main/java/org/dive4elements/river/artifacts/sinfo/flowdepth/FlowDepthCalculation.java	Thu Feb 22 18:46:37 2018 +0100
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/sinfo/flowdepth/FlowDepthCalculation.java	Fri Feb 23 09:30:24 2018 +0100
@@ -154,8 +154,14 @@
         }
 
         BedQualityD50KmValueFinder bedMeasurementsFinder = null;
-        if (doCalcTkh)
+        if (doCalcTkh) {
             bedMeasurementsFinder = loadBedMeasurements(river, calcRange, sounding.getYear().intValue());
+            if (bedMeasurementsFinder == null) {
+                final String message = Resources.getMsg(this.context.getMeta(), "sinfo_calc_flow_depth.warning.missingSoilKind", null, label);
+                problems.addProblem(message);
+                doCalcTkh = false;
+            }
+        }
 
         final String bedHeightLabel = bedHeight.getDescription();
         final String wstLabel = wstKms.getName();
@@ -165,7 +171,13 @@
         DoubleRange qRange = null;
         if (doCalcTkh) {
             qInterpolator = DoubleUtil.getLinearInterpolator(((QKms) wstKms).allKms(), ((QKms) wstKms).allQs());
-            qRange = new DoubleRange( ((QKms) wstKms).allQs().min(), ((QKms) wstKms).allQs().max());
+            if (qInterpolator != null)
+                qRange = new DoubleRange( ((QKms) wstKms).allQs().min(), ((QKms) wstKms).allQs().max());
+            else {
+                final String message = Resources.getMsg(this.context.getMeta(), "sinfo_calc_flow_depth.warning.missingQ", null, label);
+                problems.addProblem(message);
+                doCalcTkh = false;
+            }
         }
         
         // FIXME: sort by station first, but in what direction?
@@ -180,13 +192,21 @@
         SoilKindKmValueFinder soilKindFinder = null;
         if (doCalcTkh) {
             soilKindFinder = new SoilKindKmValueFinder();
-            soilKindFinder.loadValues(river, calcRange);
+            if (!soilKindFinder.loadValues(river, calcRange)) {
+                doCalcTkh = false;
+                final String message = Resources.getMsg(this.context.getMeta(), "sinfo_calc_flow_depth.warning.missingSoilKind", null, label);
+                problems.addProblem(message);
+            }
         }
         
         FlowVelocityModelKmValueFinder flowVelocitiesFinder = null;
         if (doCalcTkh) {
             flowVelocitiesFinder = new FlowVelocityModelKmValueFinder();
-            flowVelocitiesFinder.loadValues(river, calcRange, qRange);
+            if (!flowVelocitiesFinder.loadValues(river, calcRange, qRange)) {
+                doCalcTkh = false;
+                final String message = Resources.getMsg(this.context.getMeta(), "sinfo_calc_flow_depth.warning.missingVelocity", null, label);
+                problems.addProblem(message);
+            }
         }
 
         for (final BedHeightValue bedHeightValue : sortedValues) {
@@ -219,11 +239,13 @@
                 else
                     discharge = Double.NaN;
 
-                // FIXME: calculate tkh
+                // Calculate tkh
                 double tkh = 0;
                 if (doCalcTkh) {
-                    double d50 = bedMeasurementsFinder.findD50(km);
-                    if (Double.isNaN(d50)) {
+                    double d50 = Double.NaN;
+                    try {
+                        d50 = bedMeasurementsFinder.findD50(km);
+                    } catch (Exception e) {
                         final String message = Resources.getMsg(this.context.getMeta(), "sinfo_calc_flow_depth.warning.missingD50", null, label);
                         problems.addProblem(km, message);
                         //FIXME: cumulate problems to one message?
@@ -231,6 +253,8 @@
                     if (!Double.isNaN(d50)) {
                         if (flowVelocitiesFinder.findKmQValues(km, discharge)) {
                             tkh = calculateTkh(wst - meanBedHeight, flowVelocitiesFinder.getFindVmainFound(), d50, flowVelocitiesFinder.getFindTauFound());
+                            if (!Double.isNaN(tkh) && (tkh < 0))
+                                tkh = 0;
                             /* log.debug(String.format("calculateTkh km %.3f q %.0f w %.2f mbh %.2f vm %.1f tau %.1f d50(mm) %.1f tkh(cm) %.1f",
                                 km, discharge, wst, meanBedHeight, flowVelocitiesFinder.getFindVmainFound(), flowVelocitiesFinder.getFindTauFound(), d50*1000, tkh)); */
                         }